CHAPTER 8

CHAPTER 8 PLANT SAFETY AND LAYOUT

8.1

Introduction

Process safety study is an important factor in designing the industrial plant to avoid major accidents. By ensuring the risk and hazards of chemical processes, accidents can be reduced to acceptable level. It has to be done to ensure process and operation in safe condition throughout the life of a plant. Furthermore, it ensures the safety of the work powers, public and environment. Industrial safety deals with the area of safety engineering and public health that are concerned with protecting the workers’ workers ’ health, through control of the work environment to reduce hazards. In Malaysia, The Occupational Safety and Health Act, (OSHA) 1994 is is a tool which which provided provided a new legal and and administrative administrative as a driving force to promote, encourage and stimulate the high quality standards of health and safety at work place. Both parties such as employers and employees must give their support and co-operate to obey the law and does not misuse safety in order to increasing the promotion of safety awareness and effective safety organization and performance in companies. companies. There are a few objectives that must be achieved in designing designing a safe plant and layout of the industry. T he objectives that need to be achieved are listed below: 1) To bring along the human, political political and financial financial costs of having having accidents in the plant to the minimum level. The proper start-up and shut down procedures of the plant must be prepared. prepared. 2) To educate people and employees employees in the plant on how to work safely according to Hazard and Operating (HAZOP) studies. 3) To expose the plant layout and the emergency response plan (ERP).

8.2

Plant Start-up & Shut-down Procedure and Standard Operating

Procedure (SOP) Basically, the plant has a procedure in doing a start-up the plant and shutting it down. But, there also need a heavy concern about the safety when doing that. During start-

8-1

up and normal operating phase of the new facility, procedures should be in placed to maintain the integrity of process equipment, equipment, where hazardous materials are involved. involved. The probability for a successful start-up is greatly enhances t hrough operator training and process design that anticipates start-up problems before they actually occurred. In contrast, shut-down procedure is important on occasion for the maintenance, emergency situations and to do an adjustment in product inventories. During the shut-down phase, deviations outside of any normal operating range can also be expected. The operating personnel and plant designer have to make sure that the operating problem problem is not occurred during during plant shut-down. shut-down. A successful shut-down shut-down of operating facility may results a smooth shut-down procedure in the plant. If a shutdown procedure is not well implemented, then it will give drawbacks to the plant. The objectives in prepared the start-up and shut-down procedures for this production plant which are listed below: 1) To make sure sure that there is is a good practice during during start-up of the plant. 2) To ensure a good practice practice provided provided while shutting shutting down down the plant. 3) To synthesize the knowledge about the standard operating procedures (SOP) of all equipment that used in the production plant. 4) To provide the proper checklist of each of the SOP of of the equipment and checklists for start-up and shut down procedures for the production plant.

8.3

Plant Start-Up and Shut-Down Procedure

Plant start-up and shut-down is two important elements in operating a plant. This is due to the present of risk and hazards during these two stages. The procedure of the plant start-up must be safe, easily and flexible enough to be carried out in several ways.

8.3.1

Plant Start-Up

In commissioning a new chemical plant, there are huge effort in research, evaluations and finally the construction. The good start-up of the plant will lead towards a smooth plant operation throughout it plant’s life. The following start-up procedure that should be followed are:

8-2

up and normal operating phase of the new facility, procedures should be in placed to maintain the integrity of process equipment, equipment, where hazardous materials are involved. involved. The probability for a successful start-up is greatly enhances t hrough operator training and process design that anticipates start-up problems before they actually occurred. In contrast, shut-down procedure is important on occasion for the maintenance, emergency situations and to do an adjustment in product inventories. During the shut-down phase, deviations outside of any normal operating range can also be expected. The operating personnel and plant designer have to make sure that the operating problem problem is not occurred during during plant shut-down. shut-down. A successful shut-down shut-down of operating facility may results a smooth shut-down procedure in the plant. If a shutdown procedure is not well implemented, then it will give drawbacks to the plant. The objectives in prepared the start-up and shut-down procedures for this production plant which are listed below: 1) To make sure sure that there is is a good practice during during start-up of the plant. 2) To ensure a good practice practice provided provided while shutting shutting down down the plant. 3) To synthesize the knowledge about the standard operating procedures (SOP) of all equipment that used in the production plant. 4) To provide the proper checklist of each of the SOP of of the equipment and checklists for start-up and shut down procedures for the production plant.

8.3

Plant Start-Up and Shut-Down Procedure

Plant start-up and shut-down is two important elements in operating a plant. This is due to the present of risk and hazards during these two stages. The procedure of the plant start-up must be safe, easily and flexible enough to be carried out in several ways.

8.3.1

Plant Start-Up

In commissioning a new chemical plant, there are huge effort in research, evaluations and finally the construction. The good start-up of the plant will lead towards a smooth plant operation throughout it plant’s life. The following start-up procedure that should be followed are:

8-2

1) Final inspection inspection of the unit unit operations should should be made made for conformance conformance to the the requirement. 2) Turnaround work list is checked again, whether everything has been completed and the associated lines have been correctly resembled. 3) All the heat exchangers that were open up to maintenance, must have undergone the hydrostatically hydrostatically test after it has been assembled. 4) The instrument control control loops loops are checked from from the transmission transmission from the plant plant signal to control system and also the alarm system circuits to make sure that it has been correctly located. 5) All the level gauges glasses are confirmed clear and operator can easily record its reading. r eading. 6) All the flanges are made sure to have have good joints, joints, with good gasket, in order order to prevent leakage. 7) All the control valves are checked to determine its operability. operability. 8) The operability operability of pumps pumps is is checked. checked. 9) The operating manual and and P&ID are updated updated with with the latest condition condition of the plant. 10) All the utilities, power supply, steam supply and cooling water supply checked. 11) The onsite fire protection equipment such as extinguishers, water hoses, nozzles and steam hoses are in place and ready for immediate use. 12) The condition of drains is check to make sure that it is unplugged and water is drained out from the equipment. 13) The supply of reactants, catalysts and chemicals are adequate. 14) Air Air freeing and tightness testing are carried out. 15) Gas blanketing for certain equipment.

8.3.2

Plant Shut-Down

Plant shutdown is the process of stopping the production no matter the duration, it will resulting decreased in revenue. Shut down can be defined as scheduled down period for a plant for schedule maintenance maintenance for an extended period of time. t ime. Shutdown provide unique opportunities to a maintenance department not normally available during standard operation or even during short shutdown periods. There are three type of shut down which are: 1) Normal Shut-down

8-3

This is temporary shutdown for a short duration of time usually for repair and maintenance. After the maintenance, the plant must be started as soon as possible to reduce loss in production. A plant shutdown always has a negative financial impact. This negative impact is due to both loss of production revenue and major cash outlay for the plant turnaround and shutdown expenses. The positive impact f rom turnaround are increase in equipment and reliability and reduction in the risk of unscheduled outages or catastrophic failure.

2) Annual Shut-down During the plant annual shutdown, all the main equipment and instruments are to be prepared and serviced. The modification is also to be done in order to improve the performance of the plant. All manholes are opened for vessels and tank. All bearing must be changed and instruments are calibrated to maintain the accuracy.

3) Emergency Shut-down Emergency shutdown usually happen when there is accident happen in the plant operation or tripped by interlock system due to danger resulting automatic shutdown. General emergency shutdown process as below:

i)

Inform and confirm with the authorized person, manager or supervisor and also all person at site for shutdown preparation.

ii)

The rate of production will slowly down to minimum capacity

iii)

Digital cellular screen shows the shutdown target on its screen and the system will automatically shut down the plant by sequence.

iv)

Make sure there is no flow of any material in the system.

v)

After all the equipment stopped, the area that having problem will be inspected.

The following shut-down procedure that should be followed are: 1) The turnaround work work list is prepared prepared includes repairing, repairing, cleaning, cleaning, inspection inspection and modification of all items. 2) The detailed plan of the shutdown and turnaround schedule should be prepared, probably by-hour schedule. 3) Control system of equipment equipment must be checked, before shutting down the plant. 8-4

4) The fire-fighting fire-fighting equipment equipment is is located located correctly. correctly. 5) The personal protective equipment is is available available for immediate immediate use. 6) All special precaution that that is specified specified for the shutdown shutdown is taken care. 7) All items that are needed during shutdown are prepared includes blinds, hoses, etc. 8) Advanced preparation work prior to the shutdown of the equipment are to be carried out, to avoid any delay in mechanical work during the actual shutdown, for example the erection of scaffolding.

8.4

Standard Operating Procedure (SOP) for Main Equipment

Standard Operating Procedure (SOP) providing the step by step instruction and enable the operation to be performed in consistent manner. The documents involved in SOP serves as the source of instruction which allows employees to act precisely based on the certain conditions. SOP enables the instructions provided can be understand easily based on its step by step instructions which describe both technical and fundamental programmatic operational elements.

8.4.1

Plug Flow Reactor, R-101

The standard operating procedures (SOP) for performing start-up and shut-down of reactor unit are as f ollows: Start-up procedure: procedure: 1) Ensuring the correct correct catalyst type, catalyst levels levels and support beds are are in place. 2) Starting the heating or cooling jacket system: Since the reactions are exothermic, the heat of reaction must be removed from the reactor. 3) Adding the correct correct quantities of reactants, reactants, or starting the feed flows flows to the reactor. 4) Setting pressure pressure controller controller to the specified specified reactor reactor pressure. pressure. 5) Controlling flows, pressure pressure and temperature temperature during during the reaction reaction cycle. Shut-down procedure: 1) Shutting off of the reactant reactant feeds to stop stop reactions and and heat generation generation by closing the inlet valve.

8-5

2) Shutting off heating or cooling to the reactor. 3) Cooling and flushing products from the reactor by re-circulating one of the feeds. 4) When the reactor has been flushed and cooled, all feed and product flows are stopped and the maintenance can come in action.

8.4.2

Heat Exchanger, E-102

The standard operating procedures (SOP) for performing start-up and shut-down of heat exchanger unit are as follows: Start-up procedure: 1) Open the vent connections. 2) Slowly start circulates the cold medium side. 3) Make sure that the entire cold side of the exchanger is completely flooded before closing its vents. 4) The hot medium gradually introduced, until all passages are filled with fluid. 5) Close the hot side vents and slowly bring the equipment up to its operating temperature. Shut-down procedure: 1) Stop supply of hot fluid into the heat exchanger by close the valve. Allow air to enter and drain the process fluid. 2) The valve of cold medium is also close. Open the cold side vent and drain the valves to remove the cooling fluid.

8.4.3

Absorption Column, T-102

The standard operating procedures (SOP) for performing start-up and shut-down of absorption column unit are as follows: Start-up procedure: 1) Ensure the inlet is closed to prevent the feed flow into the column. 2) Make sure the outlet and inlet connections including pressure gauge connection are properly installed in order to prevent the leakage of feed or product desires.

8-6

3) Ensure the relief valve connection can work properly before the column is switched on for emergency backup. 4) Turn on the feed pumps if necessary and the pump settings need to be adjusted on the computer. 5) Wait the pressure and the temperature of the column become stabilized before running the separation process. Shut-down procedure: 1) Set the collection tank for the discharged valve to closed and set the feed of the pump output to zero. 2) Turn off the pressure gauge and remove the connection from the flash vessel 3) Remove the unwanted liquid or gas into the waste container to ensure properly disposed the potentially hazardous liquid or gas.

8.4.4

Distillation Column, T-103

The standard operating procedures (SOP) for performing start-up and shut-down of distillation column unit are as follows: Start-up procedure: 1) Turn the switch box indicator to Distillation Control setting. 2) Switch the column power source lever to the “on” position. Turn the Reboiler Heater Control knob clockwise. This prevents over heating of t he reboiler. 3) Turn on the cold water supply (CWS) valve until the computer stops telling the user to increase the volume of the CWS valve. 4) Adjust the Reflux Control to the desired setting. 5) Assure all computer settings are as desired. 6) Allow the tray temperatures to reach a steady-state value. 7) Turn on the feed and reboiler pumps as applicable. The pump settings can be adjusted on the computer. Shut-down procedure: 1) Turn the Reboiler Heater Control knob to zero. 2) Turn off the pumps (feed and reboiler). 3) Turn off the CWS valve when the temperature of the distillate is below the boiling point of the light component of the mixture. 4) Press the stop button. 8-7

5) Shut off the computer, by selecting the “Shut -down” option from the special menu.

8.5

Hazard and operability (HAZOP) study for equipment

Hazard and operability (HAZOP) study is one of the most tedious, forms of hazard analysis. It identifies potentially complex hazards in a system. HAZOP examines a combination of every part of the system and analyse the collected data to located potentially hazardous areas. HAZOP study is a procedural tools designed to identify the safety and operability deficiencies in the design of a treatment facility. Basically, HAZOP concentrate on identifying both hazards as well as operability problems. Although hazard identification is the main focus, operability problems should be identified to the extent that they have the potential to lead to process hazards, result in an environmental violation or have a negative impact on profitability. Once a potential cause has been identified in the HAZOP study, the HAZOP study team will identify the potential consequences.

If the cause is feasible, and the

consequences severe enough, a member of the study team may have to investigate the potential means of eliminating or reducing the problem. The objectives of HAZOP study are: 1) To identify design information not currently available to the team. 2) To familiarize the study team with the design information available. 3) To identify areas of the design that may possess a significant hazard potential. 4) To provide a mechanism for feedback to the client of the study team’s detailed comments. 5) To identify and study features of the design that influences the probability of a hazardous incident occurring. 6) To ensure that a systematic study is made of the areas of significant hazard potential.

8-8

8.5.1

HAZOP Procedure

A HAZOP study takes a description of plant and subjects the description to a critical examination. The structure of the search is provided by the use of simple word models to create potential deviations at each point in the plant. Then, it will be decided whether the search deviation can be applicable or not. Actions for prevention and mitigation of the consequences will be provided. The HAZOP team focuses on specific portions of the process called “nodes”. Generally these are identified from the P&ID of the process before the study begins. A process parameter is identified, say flow, and an intention is created for the node under consideration. Then a series of guidewords is combined with the parameter “flow” to create deviations. The team then focuses on listing all the credible causes of deviation beginning with the cause that can result in the worst possible consequence the team can think of at the time. Once the causes are recorded the team lists the consequences, safeguards and any recommendations deemed appropriate. The process is repeated for the next deviation and so on until completion of the node. The team moves on to the next node and repeats the process. HAZOP

procedure

use

the

following

steps

to

complete

an

analysis

(HAZOP Guidelines, 2011): 1) Begin with detailed flow sheet. Break the flow sheet into a number of process units. Thus, the reactor area might be one unit, and the distillation column is another unit. Therefore, select each unit f or study. 2) Choose a study node such as reactor, column and operating instruction. 3) Describe the design intent of the study node. 4) Pick process parameter such as flow, level, temperature, pressure and concentration. 5) Use the guide words as tabulated in Table below. 6) If the deviation is applicable, determine possible causes and note any protective systems. 7) Evaluate the consequences of the deviation if applicable. 8) Recommend action by stating what, whom when involve in the action. 9) Record all information. 10) Repeat steps 5 through 9 until all applicable guide words have been applied to the chosen parameter.

8-9

11) Repeat steps 4 through 10 until all applicable process parameters have been considered for the given study node. 12) Repeat steps 2 through 11 until all study nodes have been considered for the given section and proceed to the next section on the flow sheet. The normal guide words that have been used in HAZOP analysis are explain in Table below.

Table 8.1: HAZOP guide words for analysis (HAZOP Guidelines, 2011) Guide

Meaning

Explanation

Words

Example of Deviation

NO or NOT

The complete

No part of the

or NONE

negation

intensions is achieved

of these

but nothing else

intension

happens

MORE/HIGH

Quantitative

These refer to

More flow, more

or

increases

quantities and

temperature, high

LESS/LOW

and decreases

properties such as flow

pressure or less

rates and temperatures,

flow, less

as well as activities like

temperature, less

‘HEAT’ and ‘REACT’

pressure

A quantitative

All the design and

Extra unplanned

increase

operating intentions are

process operation

AS WELL AS

No flow in pipe

achieved together with some additional activity PART OF

REVERSE

A quantitative

Only some of the

Reduced strength,

decrease

intentions are achieved,

missing

some are not

component

The logical

This is mostly

Back flow or back

opposite of

applicable to activities,

pressure heat

the intention

for example reverse flow or chemical reaction

8-10

OTHER

Complete

No part of the original

Wrong material

THAN

substitution

intention is achieved.

charging, start-up,

Something quite

shutdown

different happens.

As shown in the Figure below, HAZOP analysis have been developed for each main equipment in this plant which involve plug flow reactor (R-101), heat exchanger (E102), distillation column (T-103) and absorption column (T-102). All analysis information are tabulated as below. In addition, the P&ID after HAZOP also have been developed and shown after the tabulated analysis.

8-11

Study node 4

Study node 3

Study node 1

Study node 2

Figure 8.1: Study node before HAZOP based on overall plant

8-12

Study Node 1: Plug flow reactor, R-101 Table 8.2: HAZOP analysis on plug flow reactor, R-101 Process

Guide Word

Possible Causes

Possible Consequences

Actions Required

Parameter Flow

No



Control valve fails to operate

/

fails



No reaction occur

to

Install air-to-open valve for inlet stream

supply at set point 





Blockage in pumps

Install flow controller to control the set point

and piping system High



Flow controller fails to



operate 

Low




Low



Regular maintenance

reactor



Install flow alarm high

Uncontrolled output

Not



operate

Temperature

Rupture pipes inside the

achieved

desired

output



Fracture pipelines



Jacket failure





Low flow rate of hot oil



(FAH) 

Install relief valve



Regular maintenance

Install



flow

alarm

low

(FAL) Reaction rate drop

Not

feed

output 8-13

achieve

desired



Regular maintenance on the jacket

Study Node 1: Plug flow reactor, R-101 Table 8.2: HAZOP analysis on plug flow reactor, R-101 Process

Guide Word

Possible Causes


Actions Required

Parameter Flow

No



Control valve fails to operate

/

fails



No reaction occur

to

Install air-to-open valve for inlet stream

supply at set point 





Blockage in pumps


and piping system High






operate 

Low




Low



Regular maintenance

reactor



Install flow alarm high

Uncontrolled output

Not



operate

Temperature

Rupture pipes inside the

achieved

desired

output



Fracture pipelines



Jacket failure





Low flow rate of hot oil



(FAH) 




Regular maintenance

Install



flow

alarm

low

(FAL) Reaction rate drop

Not

feed

achieve




desired

output 8-13



Install temperature alarm low (TAL)

High



Jacket failure



Runaway reaction



Uncontrolled hot oil



Damage the catalyst

feed flow



Not

achieved

desired






Install flow controller on the hot oil feed

output 

Install temperature alarm high (TAH)

Pressure

Low



Leakage of pipeline



Temperature drop



Shut-down process



Failure of compressor



Reversible flow occur



Install pressure alarm low

Not



achieve

(PAL)

desired

reaction



Regular maintenance on the pipeline

High



Blockage of pipeline



Rupture the vessel



Shut-down process



Failure



Temperature increase



Install pressure alarm high

of pressure

indicator

(PAH) 




8-14





High



Jacket failure



Runaway reaction



Uncontrolled hot oil



Damage the catalyst

feed flow



Not

achieved

desired






Install flow controller on the hot oil feed

output 

Install temperature alarm high (TAH)

Pressure

Low



Leakage of pipeline



Temperature drop



Shut-down process



Failure of compressor






Install pressure alarm low

Not



achieve

(PAL)

desired

reaction




High






Rupture the vessel



Shut-down process



Failure



Temperature increase




of pressure

indicator

(PAH) 




8-14

Figure 8.2: P&ID after HAZOP for reactor, R-101

8-15


Figure 8.2: P&ID after HAZOP for reactor, R-101

8-15

Study Node 2: Heat Exchanger, E-102 Table 8.3: HAZOP analysis on heat exchanger, E-101 Process

Guide Word

Possible Causes


Actions Required

Parameter Flow

No



Control valve fails to



operate 

Increase in temperature



and pressure

Rupture pipeline



A desired temperature

control the set point 

cannot be achieved

High






Affect further process




operate Amount



coolant



increase

Low












Fracture pipelines



A desired temperature cannot be achieved



8-16


Install flow alarm high (FAH)



and pressure 


cannot be achieved

operate 



and pressure of

Install flow controller to


Install



(FAL)

flow

alarm

low

Study Node 2: Heat Exchanger, E-102 Table 8.3: HAZOP analysis on heat exchanger, E-101 Process

Guide Word

Possible Causes


Actions Required

Parameter Flow

No






operate 




and pressure

Rupture pipeline



control the set point




cannot be achieved

High










operate Amount

coolant



increase

Low
















Install



cannot be achieved 

Install flow alarm high (FAH)

and pressure

Fracture pipelines




operate 



cannot be achieved



and pressure of



Install flow controller to

flow

alarm

low

(FAL)


8-16

Reverse



Cooling stream pump



Unable to control the temperature



of



Inspection done regularly



Install one way flow valve

outlet

High pressure in flow out



Cooling process is not

at the cooling stream pipe

effective Temperature

Low

Temperature



controller

not



Temperature increases



Shut down the process



Affect another process






No

change

in

temperature at the



High








Pressure increase



Failure

to

other






Install temperature alarm

The temperature of

high (TAH)

hot fluid is extremely



Explosion could occur

high



Increase in temperature of process fluid

Pressure

Low



Leakage of tube



Temperature drop




8-17



Install pressure alarm low (PAL)

Reverse



Cooling stream pump



Unable to control the temperature



of






Install one way flow valve

outlet

High pressure in flow out



Cooling process is not

at the cooling stream pipe

effective Temperature

Low

Temperature



controller

not



Temperature increases






Affect another process






No

change

in

temperature at the



High








Pressure increase



Failure

to

other






Install temperature alarm

The temperature of

high (TAH)

hot fluid is extremely



Explosion could occur

high



Increase in temperature of process fluid

Pressure

Low



Leakage of tube



Temperature drop







8-17

High



Fouling on tube

Reduce



heat

transfer



coefficient and efficiency of heat exchanger

Install pressure alarm high (PAH)



Hot Flow Out

Process Liquid In

Process Liquid Out Sensor

Heat Exchanger TT

Final Control Element Hot Flow In

Pressure Transmitter

S-6

S-1

PT

FT

FC

Flow Transmitter Pressure Indicator

PI

PAL

Temperature Controller

Flow Controller

TC

Pressure Alarm Low

Figure 8.3: P&ID after HAZOP for heat exchanger, E-102

8-18

Temperature Transmitter

High



Fouling on tube

Reduce



heat

transfer



coefficient and efficiency of heat exchanger




Hot Flow Out

Process Liquid In

Process Liquid Out Sensor

Heat Exchanger TT

Final Control Element

Temperature Transmitter

Hot Flow In

Pressure Transmitter

S-6

S-1

PT

FT

FC

Flow Transmitter Pressure Indicator

PI

PAL

Temperature Controller

Flow Controller

TC

Pressure Alarm Low

Figure 8.3: P&ID after HAZOP for heat exchanger, E-102

8-18

Study Node 3: Distillation Column, T-103 Table 8.4: HAZOP analysis on distillation column, T-103 Process

Guide Word

Possible Causes


Actions Required

Parameter Flow

No



Control valve (V-17)



fails to operate 

Decrease of level inside the column

Rupture inlet pipeline






Column overheat



Desired separation is not



operate



Blockage

at

outlet



pipeline





Pump fails to operate Blockage

Outflow

Pressure column

occur



Install level indicator



Regular maintenance on

at

inlet

inside

the

increase

and

Install



flow

and

level

indicator 




Reflux drum increase






The desired separation cannot be achieved

is

the pipeline

might ruptured

pipeline 

can


inside the column



Low

Flooding


achieved High



greater

than inflow

8-19

Install



flow

indicator

and

level

Study Node 3: Distillation Column, T-103 Table 8.4: HAZOP analysis on distillation column, T-103 Process

Guide Word

Possible Causes


Actions Required

Parameter Flow

No



Control valve (V-17)



fails to operate 


Rupture inlet pipeline






Column overheat






operate



Blockage

at

outlet



pipeline





can

occur

Pressure column


at

inlet







inside

the

increase

and

is

flow

and

level

indicator 




Reflux drum increase







Outflow

Install



might ruptured

pipeline 


inside the column



Low

Flooding


achieved High



Install



flow

and

level

indicator

greater

than inflow

8-19

Reverse



Pump at reboiler fails



to operate



High

Low

pressure

at

occur






Increase pressure inside



Shut down process



Install

the column

Temperature



controller

can

inside the column

bottom flow Temperature

Flooding



is

not

functioning

Ineffective

separation

process 

temperature

indicator


High



Inlet flow extremely



increase 

Pressure

inside

the

column increase

Flow controller is not



functioning

Ineffective






Install

separation

temperature

indicator

process 


Pressure

Low



Leakage of pipeline



Compressor / Pump



fails to operate

Temperature inside the



column drop 


Reversible flow inside



the column can occur


when outlet pressure is low High






increase

Flooding

can

occur



inside the column if liquid

(PAH) 

8-20


Install flow controller

Reverse



Pump at reboiler fails



to operate



High

Low

can

occur







Shut down process



Install

inside the column

pressure

at



bottom flow Temperature

Flooding

the column

Temperature



controller



is

not

functioning

Ineffective

separation

process 

temperature

indicator


High






increase 

Pressure

inside

the

column increase




functioning

Ineffective






Install

separation

temperature

indicator

process 


Pressure

Low



Leakage of pipeline



Compressor / Pump



fails to operate




column drop 













increase

Flooding

can

occur








pressure is high than



Shut down process

vapour pressure









Install

8-20

Blockage

of



outlet

stream 

Level

Low





Mechanical damage

vapour inlet



Column may rupture

Outflow greater than



Pump failure

Over

compressed





Blockage

of

inlet

Pressure

inside

the

column may increase

stream

level

alarm

low

(LAL)

and affect the separation process

High



Inflow

greater

than



outflow Blockage



Flooding

inside

column may occur of

outlet

stream

8-21

the






Install level alarm high (LAH)

Blockage

of



outlet

stream 

Level

Low



Shut down process

vapour pressure









Install

Mechanical damage

vapour inlet



Column may rupture




Pump failure

compressed





Over






Blockage

of

inlet

Pressure

inside

the

column may increase

stream

level

alarm

low

(LAL)


High



Inflow

greater

than



outflow Blockage



Flooding

inside

the

column may occur of

outlet

stream

8-21

Figure 8.4: P&ID after HAZOP for distillation column, T-103

8-22







Figure 8.4: P&ID after HAZOP for distillation column, T-103

8-22

Study Node 4: Absorption Column (T-102) Table 8.5: HAZOP analysis on absorption column, T-102 Process

Guide Word

Possible Causes


Actions Required

Parameter Flow

No






operate 


Rupture pipeline






Column overheat






operate



Blockage

at

outlet



pipeline






Outflow

Pressure column

at



inlet

pipeline 

can

occur








inside the column



Low

Flooding


achieved High



the pipeline

inside

the

increase

and

Install



than inflow

8-23

level

might ruptured




The desired separation




cannot be achieved Install

greater

and

indicator



is

flow

flow

indicator

and

level

Study Node 4: Absorption Column (T-102) Table 8.5: HAZOP analysis on absorption column, T-102 Process

Guide Word

Possible Causes


Actions Required

Parameter Flow

No






operate 


Rupture pipeline






Column overheat






operate



Blockage

at

outlet



pipeline





can

occur

Pressure column


at










inside the column



Low

Flooding


achieved High



the pipeline

inside

the

increase

and

Install






The desired separation




cannot be achieved

inlet

Install

is

level

indicator



Outflow

and

might ruptured

pipeline 

flow

flow

and

level

indicator

greater

than inflow

8-23

Reverse



High

pressure

at



bottom flow 

Low

Blockage at bottom

occur









Shut down process



Install

the column

Temperature



controller

can

inside the column

stream Temperature

Flooding



is

not

functioning

Ineffective

separation

process 

temperature

indicator


High






increase 

Pressure

inside

the

column increase




functioning

Ineffective






Install

separation

temperature

indicator

process 


Pressure

Low



Leakage of pipeline



Compressor / Pump



fails to operate




column drop 













increase

Flooding

can

occur




(PAH) 

8-24



Reverse



High

pressure

at



bottom flow 

Low

can

occur







Shut down process



Install

inside the column

Blockage at bottom



stream Temperature

Flooding

the column

Temperature



controller



is

not

functioning

Ineffective

separation

process 

temperature

indicator


High






increase 

Pressure

inside

the

column increase




functioning

Ineffective






Install

separation

temperature

indicator

process 


Pressure

Low



Leakage of pipeline



Compressor / Pump



fails to operate




column drop 













increase

Flooding

can

occur











Shut down process

vapour pressure









Install

8-24

Blockage

of



outlet

stream 

Level

Low





Mechanical damage

vapour inlet



Column may rupture




Pump failure

Over

compressed





Blockage

of

inlet

Pressure

inside

the

column may increase

stream

level

alarm

low

(LAL)


High



Inflow

greater

than



outflow Blockage



Flooding

inside

column may occur of

outlet

stream

8-25

the







Blockage

of



outlet

stream 

Level

Low



Shut down process

vapour pressure









Install

Mechanical damage

vapour inlet



Column may rupture




Pump failure

compressed





Over






Blockage

of

inlet

Pressure

inside

the

column may increase

stream

level

alarm

low

(LAL)


High



Inflow

greater

than



outflow Blockage



Flooding

inside

the

column may occur of

outlet

stream

8-25

Figure 8.5: P&ID after HAZOP for absorption column, T-102

8-26







Figure 8.5: P&ID after HAZOP for absorption column, T-102

8-26

Study Node 5: Sequencing Batch Reactor (SBR) Tank Table 8.6: HAZOP analysis on SBR tank Process

Guide Word

Possible Causes


Actions Required

Parameter Flow

No






operate

High

Decrease of level inside



the tank



Rupture pipeline



Pump fails to operate



High flow from the




No reaction occur






inlet stream

Flooding

can

occur

Install



inside the tank 

Pressure inside the tank

flow

and

level

indicator 





increase Low






at

Outflow



is

Tank takes longer time to fill than normal

inlet

stream 



Affect retention time of

Install



the process

greater

flow

and

level

indicator

than inflow Other Than



Mixer fails to operate



Air diffuser fails to



operate 8-27

Desired reaction may not occur



Regular maintenance

Study Node 5: Sequencing Batch Reactor (SBR) Tank Table 8.6: HAZOP analysis on SBR tank Process

Guide Word

Possible Causes


Actions Required

Parameter Flow

No






operate

High

Decrease of level inside



the tank



Rupture pipeline



Pump fails to operate



High flow from the




No reaction occur






inlet stream

Flooding

can

occur

Install



inside the tank 

flow

and

level

indicator

Pressure inside the tank







increase Low






at



to fill than normal

inlet

stream



Outflow

is



Tank takes longer time

Affect retention time of

Install



the process

greater

flow

and

level

indicator

than inflow Other Than



Mixer fails to operate



Air diffuser fails to



Desired reaction may not



Regular maintenance

of




the



Install

occur

operate 8-27

Temperature

High



High

temperature

Rapid



from upstream unit

evaporation

contents

during

process 

indicator

Increased

vapour

concentration

around

the

tank

temperature

possibly

to

hazard level 

Affect the lifetime of the biological agent

Pressure

High



High

pressure

of

upstream unit



Mechanical damage



Install pressure indicator



Tank may rupture



Shut down process



Affect the lifetime of the



Install level controller




biological agent Level

Low



Blockage

of

inlet

stream



Pump failure



Pressure inside the tank may increase and affect the process

High

Decant



phase

not



efficient 

Flooding inside the tank may occur

Blockage

of

sedimentation

at

outlet stream

8-28

Temperature

High



High

temperature

Rapid



from upstream unit

evaporation

contents

during

of




the



Install

process 

indicator

Increased

vapour

concentration

around

the

tank

temperature

possibly

to

hazard level 

Affect the lifetime of the biological agent

Pressure

High



High

pressure

of

upstream unit



Mechanical damage



Install pressure indicator



Tank may rupture



Shut down process



Affect the lifetime of the







biological agent Level

Low



Blockage

of

inlet

stream



Pump failure



Pressure inside the tank may increase and affect the process

High

Decant



phase

not



efficient 

Flooding inside the tank may occur

Blockage

of

sedimentation

at

outlet stream

8-28

Figure 8.6: P&ID after HAZOP for SBR Tank

8-29

Figure 8.6: P&ID after HAZOP for SBR Tank

8-29

On a long-term basis, operational feedback should confirm that the assessment and control steps are adequately addressing the risk question. If this is not the case, it may be necessary to review all assumptions. Feedback should correspond to ensuring that assumptions made about the level of residual risks are still valid. Residual risks are risks that are expected to remain after risk control strategies have been exercised. It is also important to note that new risks may arise from risk control practices. Sometimes risks that were not originally identified or may have been filtered out during the initial risk assessment can become aggravating factors due to the implementation of risk control measures (Risk Management Training Guides, HAZOP). In order to make sure HAZOP is more efficient, the HAZOP team must be assembled by equipment. The advantages of HAZOP team are more problems can be identified and solved productively. Normally, HAZOP team is come from individuals with their own expertise in equipment processes.

8.6 Hazard Identification, Risk Assessment and Risk Control (HIRARC) HIRARC is a compound word which is made up of three consecutive activities running one after the other. The activities consist of hazard identification, risk

On a long-term basis, operational feedback should confirm that the assessment and control steps are adequately addressing the risk question. If this is not the case, it may be necessary to review all assumptions. Feedback should correspond to ensuring that assumptions made about the level of residual risks are still valid. Residual risks are risks that are expected to remain after risk control strategies have been exercised. It is also important to note that new risks may arise from risk control practices. Sometimes risks that were not originally identified or may have been filtered out during the initial risk assessment can become aggravating factors due to the implementation of risk control measures (Risk Management Training Guides, HAZOP). In order to make sure HAZOP is more efficient, the HAZOP team must be assembled by equipment. The advantages of HAZOP team are more problems can be identified and solved productively. Normally, HAZOP team is come from individuals with their own expertise in equipment processes.

8.6 Hazard Identification, Risk Assessment and Risk Control (HIRARC) HIRARC is a compound word which is made up of three consecutive activities running one after the other. The activities consist of hazard identification, risk assessment and risk control. Hazard identification is the recognising of things which may cause injury or harm to a person. Risk assessment is the looking at the possibility of injury or harm occurring to a person if exposed to a hazard. The introduction of measures which will eliminate or reduce the risk of a person being exposed to a hazard is known as risk control.

8.6.1

Hazard Identification Hazard identification is the identification of undesired events that lead to the

materialisation of the hazard and the mechanism by which those undesired events could occur [2]. In the simplest way, it is to make sure whether the exposure from certain incident give bad effect to human health. In petrochemical plant, it is focus on the analysing the scientific data of the chemical used or chemical produce and the related it to the effect. The people who have potential to get adverse effect from the over expose to the chemical can be shown in form of birth defect, death, cancer and others.

30

HIRARC is the basic practice in management and operation in petrochemical plant. HIRARC are important to determine because the main purpose of HIRARC are [2]; i)

To identify all the factors that may cause harm to employees and others (the

hazards). ii)

To consider what the chances are of that harm actually be falling anyone in the circumstances of a particular case and the possible severity that could come from it (the risks).

iii)

To enable employers to plan, introduce and monitor preventive measures to ensure that the risks are adequately controlled at all times. The HIRARC process involving both the employer and employees representative. Both representative must have excellent communication in order to get the workplace free from hazard. The employer must monitor the employee to follow up them and keep recording the action. Classify work activities in accordance with their similarity, such as: i.

Geographical or physical areas within/outside premises

ii.

Stages in production/service process

iii.

Not too big e.g. building a car

iv.

Not too small e.g. fixing a nut

v.

Defined task e.g. loading, packing, mixing, fixing the door.

8.6.2

Risk Assessment Risk is something that people as individuals live with on a day-to-day basis.

People are constantly making decisions based on risk. Risk assessment means the process of evaluating the risks to safety and health arising from hazards at work. Two component of risk assessment are risk determination and risk evaluation. Risk is the combination of the likelihood and severity of a specified hazardous event occurring. Likelihood is an event likely to occur within the specific period or in specified circumstances. Assessing likelihood is based worker experience, analysis or measurement. Likelihood levels range from “most likely” to “inconceivable”. Table 4.1 below indicates likelihood using the following values.

31

Table 4.1 Likelihood of an event [2] LIKELIHOOD

EXAMPLE

RATING

The most likely result of the hazard / event being

5

(L) Most likely

realized Possible

Has a good chance of occurring and is not

4

unusual Conceivable

Might be occur at some time in future

3

Remote

Has not been known to occur after many years

2

Inconceivable

Is practically impossible and has never occurred

1

Severity is outcome from an event such as severity of injury or health of people, or damage to property, or insult to environment, or any combination of those caused by the event. Severity can be divided into five categories. Severity are based upon an increasing level of severity to an individual’s health, the environment, or to property. The level of severity can be evaluate by Table 4.2 below.

Table 4.2 Severity of an event [2] SEVERITY (S)

EXAMPLE

RATING

Catastrophic

Numerous fatalities, irrecoverable property damage 5 and

5

productivity Fatal

Approximately one single fatality major property damage 4 if

4

hazard is realized Serious

Non-fatal injury, permanent disability

3

Minor

Disabling but not permanent injury

2

Negligible

Minor abrasions, bruises, cuts, first aid type injury

1

For risk analysis that uses likelihood and severity in qualitative method, presenting result in a risk matrix is a very effective way of communicating the distribution of the risk throughout a plant and area in a workplace. Risk can be calculated using the following formula: Lx S

= Relative Risk

(4.1)

Whereby 32

L

= Likelihood

S

= Severity Table 4.3 Risk analysis matrix Severity (S)

Likelihood

1

2

3

4

5

5

5

10

15

20

25

4

4

8

12

16

20

3

3

6

9

12

15

2

2

4

6

8

10

1

1

2

3

4

5

(L)

High Medium Low

In order to use this matrix, first find the severity column that best describes the outcome of risk. Then follow the likelihood row to find the description that best suits the likelihood that the severity will occur. The risk level is given in the box where the row and column meet. The relative risk value can be used to prioritize necessary actions to effectively manage work place hazards. Table 4.4 show the level of the risk and the action required.

Table 4.4 Description of risk [2] RISK

DESCRIPTION

ACTION

15 - 25

HIGH

A HIGH risk requires immediate action to control the hazard as detailed in the hierarchy of control. Actions taken must be documented on the risk assessment form including date for completion.

5 - 12

MEDIUM

A MEDIUM risk requires a planned approach to controlling the hazard and applies temporary measure if required. Actions taken must be

33

documented on the risk assessment form including date for completion 1-4

LOW

A risk identified as LOW may be considered as acceptable and further reduction may not be necessary. However, if the risk can be resolved quickly and efficiently, control measures should be implemented and recorded.

8.6.3

HIRARC The HIRARC table, Table 4.5 is the summary of the safety analysis for the

operation plant. It can be divided into three column which are hazard identification, risk analysis and risk control. The first column is the hazard identification where the type of the activity may cause the hazard is selected and also the type of hazard will involve. For an activity, the hazard can be only one and sometime maybe a few. The hazard need to identify from different view. For the second column, the risk analysis is placed. The risk analysis is to identify the effect of the hazard either to the building, human or environment. If the existing risk control already available, it can be place together in the analysis. The level of severity, likelihood and risk based on the level from table 4.1, 4.2 and 4.4. For the last column which is risk control, the recommended control measure are suggested. This recommended control are should able to help in reduce or prevent the hazard from happen.

34

Table 8.7: HIRARC summary

1. Hazard Identification

No

Work activity

2. Risk Analysis

Hazard

Effect

3. Risk Control

Existing risk control (if

Likelihood

Severity Risk

Recommended Control Measures

any) 1

Handling and

Small / large

Fire or

SMALL FIRE: Use DRY

storage of

spillage

explosion

chemical powder

2

1

2



ignition

Isopropyl



Alcohol as raw

LARGE FIRE: Use

material

alcohol foam, water

(Source:

spray or fog

Keep away from sources of

Keep container in a cool, well-ventilated area



Avoid all possible sources of ignition (spark or flame)

MSDS)



Keep container tightly closed and sealed until ready for use

Exposure of

eyewash



2

1

2



Be sure to use an

chemicals to

stations and

approved/certified

workers

safety showers

respirator or equivalent



Splash goggles,



Provide exhaust ventilation

lab coat and

or other engineering

vapor respirator

controls to keep the

35

airborne concentrations of vapors below their respective threshold limit value. 2

Storage and

Small / large

Fire or

SMALL FIRE: Use DRY

handling

spillage

explosion

chemical powder

2

1

2



Keep away from heat




Acetone as

ignition

product

LARGE FIRE: Use

(Source:

alcohol foam, water

MSDS)

spray or fog



Wear suitable protective clothing



Store in a segregated and approved area (flammables area)




Skin and

Absorbed



Splash goggles,

2

1

2



Be sure to use an

eye contact,

through skin,

full suit, boots

approved/certified

ingestion

dermal

and gloves.


and

contact, eye

inhalation of

contact,

and safety

apparatus should be used

chemical

inhalation

shower.

to avoid inhalation of the



Eyewash station



A self-contained breathing

product.

36

airborne concentrations of vapors below their respective threshold limit value. 2

Storage and

Small / large

Fire or

SMALL FIRE: Use DRY

handling

spillage

explosion

chemical powder

2

1

2



Keep away from heat




Acetone as

ignition

product

LARGE FIRE: Use

(Source:

alcohol foam, water

MSDS)

spray or fog



Wear suitable protective clothing



Store in a segregated and approved area (flammables area)




Skin and

Absorbed



Splash goggles,

2

1

2



Be sure to use an

eye contact,

through skin,

full suit, boots

approved/certified

ingestion

dermal

and gloves.


and

contact, eye

inhalation of

contact,

and safety

apparatus should be used

chemical

inhalation

shower.

to avoid inhalation of the



Eyewash station



A self-contained breathing

product.

36

3

Storage and

Gas leaking

handling

Fire or



explosion

2

1

2

Use only non-sparking tools

spray

as product



fog or fine water

Hydrogen gas

4

Reduce gas with



Wear leather safety

Remove all

gloves and safety

(Source:

sources of

shoes when handling

MSDS)

ignition

cylinders



Handling and

Skin and

Slightly

storage of

eye contact,

hazardous in

Raney Nickel

ingestion

case of skin

as catalyst

and

contact

and safety

surface water or

(Source:

inhalation of

(irritant), of

shower.

sanitary sewer system

MSDS)

chemical

eye contact



Move to fresh

2

1

2



air 



Use personal protective equipment

Eyewash station



Splash goggles,



Do not flush into

Wear appropriate

(irritant), of

full suit, boots

protective eyeglasses

ingestion, of

and gloves.

or chemical safety

inhalation.

goggles 

Handle in accordance with good industrial hygiene and safety practice.

Small / large spillage

Fire



Do not breathe vapors or spray mist 37

2

1

2



Keep in a dry, cool and well-ventilated place

3

Storage and

Gas leaking

handling

Fire or



explosion

2

1

2

Use only non-sparking tools

spray

as product



fog or fine water

Hydrogen gas

4

Reduce gas with



Wear leather safety

Remove all

gloves and safety

(Source:

sources of

shoes when handling

MSDS)

ignition

cylinders



Handling and

Skin and

Slightly

storage of

eye contact,

hazardous in

Raney Nickel

ingestion

case of skin

as catalyst

and

contact

and safety

surface water or

(Source:

inhalation of

(irritant), of

shower.

sanitary sewer system

MSDS)

chemical

eye contact



Move to fresh

2

1

2



air 



Use personal protective equipment

Eyewash station



Splash goggles,



Do not flush into

Wear appropriate

(irritant), of

full suit, boots

protective eyeglasses

ingestion, of

and gloves.

or chemical safety

inhalation.

goggles 

Handle in accordance with good industrial hygiene and safety practice.

Small / large

Fire



spillage

Do not breathe

2

1

2



vapors or spray

Keep in a dry, cool and well-ventilated place

mist 37



Use explosion-



proof equipment 

Use only nonsparking tools



Minimize dust generation and accumulation

38

Keep away from heat and sources of ignition



Keep at temperatures below 40°C.



Use explosion-



proof equipment 

and sources of ignition

Use only non-



sparking tools 

Keep away from heat

Keep at temperatures below 40°C.

Minimize dust generation and accumulation

38

8.7

Plant Layout

The definition of plant layout is the arrangement of physical facilities such as furniture, equipment, tools and machines in such a manner so as have quickest flow of a material with the least amount of handling in processing the product from the raw material to the delivery of final product. The plant layout is the one of main important criteria in designing the Acetone plant production. Generally, the process units and ancillary buildings should be laid out to give the most economical flow of material and personnel around the site. Hazardous process must be located at a safe distance from other buildings. Consideration must be also being given to the future expansion of the site. Table below explains the factors that need to be considered in designing plant layout.

Table 8.8: Consideration in designing plant layout Consideration

Description

Process

This is the stage where convenient layout is based on the order in which items would appear on the process flow sheet

8.7

Plant Layout

The definition of plant layout is the arrangement of physical facilities such as furniture, equipment, tools and machines in such a manner so as have quickest flow of a material with the least amount of handling in processing the product from the raw material to the delivery of final product. The plant layout is the one of main important criteria in designing the Acetone plant production. Generally, the process units and ancillary buildings should be laid out to give the most economical flow of material and personnel around the site. Hazardous process must be located at a safe distance from other buildings. Consideration must be also being given to the future expansion of the site. Table below explains the factors that need to be considered in designing plant layout.

Table 8.8: Consideration in designing plant layout Consideration

Description

Process

This is the stage where convenient layout is based on the order in which items would appear on the process flow sheet

Economics

In plant layout, economic is considered mainly with steelwork, concrete, piping and electric cabling. Structures and therefore deep foundations can be greatly reduced by having most equipment on the ground. Where structures have to be used, more than one item should be supported.

Operational

Operational convenience is very important in achieving safe and reliable operation. It would reduce the chances of making mistakes and increase the problem ability of malfunction being detected earlier.

Maintenance

The

layout

designer

should

look

for

equipment

arrangements, which assist safe maintenance. Maintenance that is made safe and easy is more reliable, is often quicker and saves downtime which in the long run provides plenty repayment for the thought and care given at the layout stage. Construction or

Construction factor is a must in layout consideration. A

destruction of any

building is a necessity for process and operating reasons but

department

it will reduce construction access although it will provide weather protection during construction.

39

Future expansion of

Expansions of structures must be taken into consideration,

the plant

such equipment and pipe work so that the additions can be erected and tested with the minimum interference to plant operations. One approach to this is to draft the likelihood that the conditions on a permit to work and then see if the layout can be altered so that the conditions will be less restrictive on both operators and the construction teams.

Appearance of the

As a rule of thumb, an attractive laid out plot with the

plant

equipment in rows is also economically laid out. Buildings, structures and groups of equipment should form a neat balanced layout consistent with keeping piper runs to a minimum and allowing proper access for maintenance. Maintenance road is provided parallel to the pipe bridge and process equipment.

8.7.1

Objectives

In plant layout, there are certain objectives that should be achieved in order to get the beneficial and good plant layout. The objectives are listed below: 1) Ensure the workers safety and health in the best condition 2) Ensure the works, management and other parties are convenient with the layout 3) Build the best location of each equipment and facilities 4) Utilize labour efficiently 5) Reduce material handling costs 6) Improve productivity 7) Proper utilization of production capacity 8) Transportation of work from one point to another point without any delay 9) Provide for volume and product flexibility 10) Allowance of easy maintenance of machines and plant

8.7.2

Criteria of Plant Layout

The proper layout of industrial facilities is an important factor in the prevention of catastrophic fires. In spite of ancillary buildings and services required on the site, 40

others additional main processing units also must take consideration, which may include: 1) Storage for raw materials and products (e.g. tank farms and warehouse) 2) Maintenance workshop 3) Stores for maintenance and operating supplies 4) Laboratories for process control 5) Fire station and other emergency services 6) Utilities; steam boilers, compressed air, power generation, refrigeration and transformer station 7) Effluent disposal plant 8) Offices for administration 9) Canteen and other amenity buildings, such as medical centre 10) Car parks and bicycle sheds

41

TANK TANK

1

2

TANK 3

Nearest evacuate road Main gate Restricted area Wind direction

Figure 8.7: General Plant Layout of Acetone Plant 42

8.7.3 Plant Layout of Acetone Production Plant

Mo sq ue

Acetone Plant

Parking Area / Assembly Area

Power Generation

Ca nte en

Laboratory

Wastewater Treatment Plant

Control Room

Waste Storage

Control

Workshop

2

3

1

Food Court

Mosque

Medical Centre Future Expansion Area

Parking Area Administrative Building / Training Centre

Parking Area / Assembly Area

Loading Area Fire Dept.

Warehouse

Wind Direction

43

8.7.4

Acceptable Area of Plant Layout

An acceptable of plant layout is concerned with the spatial arrangement of processing equipment, storage vessels, their interconnecting pipe work, workplace and warehouse. It is an important aspect in the designing a production plant. A good layout will ensure that the plant functions properly, safely and efficiently. It considers the design constraints arising from safety, environment, construction, maintenance, and operation with an economical balance. The major consideration is the main production plant is located below the wind direction. The plant is covered by water treatment area in some distances. In safety issues, in case fire is happening, the fire supposedly not affect the other building by following the wind direction. The area is also divided into two area which are restricted area, which shown by the red zone, and also public area which can be assessed by public. The restricted area which involved production plant and wastewater treatment plant is guarded by a security post 2 there. Any visitor must register their selfinformation and must have the visitor pass before entering restricted area.

8.7.5

Plant Area Zone

8.7.4

Acceptable Area of Plant Layout

An acceptable of plant layout is concerned with the spatial arrangement of processing equipment, storage vessels, their interconnecting pipe work, workplace and warehouse. It is an important aspect in the designing a production plant. A good layout will ensure that the plant functions properly, safely and efficiently. It considers the design constraints arising from safety, environment, construction, maintenance, and operation with an economical balance. The major consideration is the main production plant is located below the wind direction. The plant is covered by water treatment area in some distances. In safety issues, in case fire is happening, the fire supposedly not affect the other building by following the wind direction. The area is also divided into two area which are restricted area, which shown by the red zone, and also public area which can be assessed by public. The restricted area which involved production plant and wastewater treatment plant is guarded by a security post 2 there. Any visitor must register their selfinformation and must have the visitor pass before entering restricted area.

8.7.5

Plant Area Zone

The plant production is separated into divided section. There are processing area, administrative area and waste management and control area. For administrative building, canteen, mosque and medical centre are located in distances from processing area. It is on safety purposed by avoiding people away from potentially hazard area at the processing section. For raw materials, there are located in at the storage area. The product from the production also is located at the storage area as well as warehouse which used as a storekeeping for any other material, chemical and spare components for the plant. The storage area is mainly at the second main entrance to make sure an easy transportation operation and delivering purpose. In addition, the location of loading area is placed far from attraction area. This can avoid any accident towards human while handling heavy equipment.

44

8.7.6

Possible Facility

In the plant area, a complete facility is required to enhance employees to work without any lack of facilities requirement. This is to ensure a maximum productivity of the workers along with a maximum level of safety. Food court have been constructed at both public zone and restricted zone so that the facility are near to processing area which are production plant and administrative building. Same goes to prayer room or mosque, which are provided at both zone. There are also three parking areas provided near to attraction location such as near to administrative building, processing plant and wastewater treatment plant. Medical centre has been located, in case there are personnel injured or infected by chemicals or radiation. The medical centre must be located in distances from the hazardous process to avoid infection to other patients.

8.7.7

Entrance and Exit Points

The entrance and exit point is the main point for production plant. Without the specific and strategic location of the entrance and exit, it will increase the risk of the danger. The exit point needs to be more than one point to ensure employees to reach out the exit safely with shorter time. In plant, a main entrance and exit is built close to the other facilities than processing plant. This strategic location is t o make sure that any vehicles entering plant will not close to the processing plant to avoid any sparkles that may cause to fire and explosion. In this plant, there are two main entrance/exit points which are located for some purpose. The first point is at the security post 1, which generally accessed for public vehicles. The second point is located at security post 3, which near to the loading area and warehouse. This route particularly accessed by heavy transportation such as trucks to deliver raw material at warehouse or to transfer out product. This discrete route can avoid any possible incident between vehicles or personnel.

8.7.8

Evacuation and Assembly Point

During an emergency, emergency response team is responsible to help and lead the workers to the assembly area by following the evacuation route made. It is important to all workers to know the evacuation route for the different area since different area will have a different route. An evacuation plan needs to be fully understood by not 45

only to employees of the plant but to all personnel inside the plant such as customers and suppliers. In this plant, there are two assembly points provided for both zone. Each assembly area are located near to main area and accessible for every personnel. In case of emergency happened, the nearest assembly points are reachable by following the red arrow routes.

8.8

Emergency Response Plan

The definition of emergency response plan (ERP) is plan of action for the efficient deployment and coordination of services, agencies and personnel to provide the earliest possible response to an emergency. The ERP is mainly focus on defensive health and safety employees and the public as well as assets and the environment. This ERP is very important in considering about health and safety because with ERP, the possible accident scenario or possible disaster can be predicted together along with the ways to overcome or faced the situation. The ERP must take a look in all aspects whether it is natural disaster or technically from the plant production includes explosions, floods, fires, leakage, power or utilities features and transportation accidents

8.8.1

Objective

In order to get the good emergency response plan for the production plant, there are several objectives that need to be achieved as shown as follows: 1. Reduce human injury and damage to property and environment in an emergency. 2. Develop hazard identification and risk assessment for plant production which all people in the plant will ready of all the hazard and risk that they will faced and the way to reduce the risk into the low level. 3. Significant impact has been identified during the production of acetone.

46

8.8.2

Hazard Identification and Risk Assessment

Hazard Identification is the process of determining whether exposure to a stressor can cause an increase in the incidence of specific adverse health effects and whether the adverse health effect is likely to occur in humans. In the case of chemical stressors, the process examines the available scientific data for a given chemical (or group of chemicals) and develops a weight of evidence to characterize the link between the negative effects and the chemical agent. It is needed to consider the potential of hazards that might be occurred when production plant is on operation. To manage risk, hazards must first be identified, and then the risks should be evaluated and determined to be tolerable or not. The earlier in the life cycle that effective risk analysis is performed, the more cost effective the future safe operation of the process or activity is likely to be. The risk understanding developed from these studies forms the basis for establishing most of t he other process safety management activities undertaken by the facility. An incorrect perception of risk at any point could lead to either inefficient use of limited resources or unknowing acceptance of risks exceeding the true tolerance of the company or the community. In hazard identification and risk assessment, there are procedures that need to be followed as shown in the Figure 8.8 below.

Classify work activities

Employer

Consultation

Worker

Identify Hazard

Risk Assessment

Prepare Risk Control Action Plan

R e v i e w

Implement

Figure 8.8: Procedure for hazard identification and risk assessment process 47

8.8.3 Potential Incident Hazard In any chemical plant, the possibility of accidents to occur is very high. These potential hazards can be identified based on the equipment and chemical substances involved. Thus, by identifying potential hazard, preventive measure can be taken. The possible accidents happen are shown in the table below with its steps taken for those emergencies.

Table 8.8: Types of Hazards and Action Should Be Taken During Emergencies Type of hazard Chemical Spills and Leaks

Action Should be Taken Firstly, evacuate the area, close the door and call the emergencies response number. Don’t forget to activate the alarm to alert all the person in the plant about the emergencies happens. Then shut down all the equipment in the plant and restrict the area where those emergencies happen. Remove the contaminated clothing as well as rinse the skin, eyes and all exposed body with water quickly. Do not enter the restricted area back until the emergency response team take an action and confirmed back that the production can be continued as usual

Explosions

First thing first, immediately hide under tables or other objects that can be our protection against the breaking

glasses

or

chemical

spills

from

explosions. Activate the alarm and notify them do not panic and do not take self-risk actions. Immediately

call

the

emergencies

response

number such as fire fighter or ambulance in cased there are injuries from the people. After that, exit towards the emergencies exits and never used the elevators. After successfully exits, never return to the emergencies area unless been authorized by the emergency response team.

48

Fire

Activate the fire alarm. To ensure our safety, make sure that take a proper way of precautions. As explosions,

do

not

use

the

elevators

and

immediately exit towards the nearest door that is free from the fire. When we successfully exit, call the Fire Department immediately to overcome the fire happens in the plant industry. If there is only a small fire happens, used the fire extinguishers to put down the fires. Lastly, never returns to the emergencies area unless been authorized by the emergency response team.

8.8.4 Possible Emergencies Devices There are certain possible emergencies devices that can be used in order when the emergencies situation comes to the production. 1) Smoke Detectors 

Smoke detectors are installed to detect any undesired smoke occurred in the plant operation. Basically the smoke alarms include the light source (incandescent bulb or infrared LED), a lens to collimate the light into a beam, and a photodiode or other photoelectric sensor at an angle to the beam as a light detector. If there is smokes detected by smoke detectors, the LED will keep on beeping then it will immediately triggered the fire alarm.

2) Fire Alarm 

Fire alarm is the most important devices in order to reduce the risk and in jury levels when emergencies occurred in production plant. Fire alarm normally is come in two ways of operation which is automatic or manual. The fire alarm will started automatically when it is t riggered by the smoke detectors. If there is failure from smoke detectors, fire alarm can be activated manually to alert the people there is emergencies happened in the plant.

49

CHAPTER 8

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