EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT
DESIGN OF INTEGRATED INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT MANGOSUTHU UNIVERSITY OF TECHNOLOGY P. O BOX 12363 JACOBS 4026 Submitted to EXMINER : Dr. KANIKI TUMBA (MUT) MODERATOR : Mrs. ANUSHA SINGH (UKZN)
DEPARTMENT OF CHMICAL ENGINEERING
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT LETTER OF DECLARATION D 326 Masakhane Street UmlazI, Durban 4031 30 September 2016 Dr. K. Tumba Mangosuthu University of Technology P. O Box 12363 Jacobs 4026
From: Mr. Makhathini S. F (engineer in training)
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT LETTER OF DECLARATION D 326 Masakhane Street UmlazI, Durban 4031 30 September 2016 Dr. K. Tumba Mangosuthu University of Technology P. O Box 12363 Jacobs 4026
From: Mr. Makhathini S. F (engineer in training)
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT ACKNOWLEDGEMENT ACKNOWLED GEMENTS S I would like to extend my heartfelt gratitude to MR. S. Gcaba for his invaluable input in compiling this report. I would also like to thank Miss N Mkhize, since we teamed up in order to breakdown the given task. The above mentioned individuals have played a vital role in the completion of this report without their support this report might have not been successfully completed in time.
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT Contents LETTER OF DECLARATION ................................................................................................................... ii ACKNOWLEDGEMENTS ........................................................................................................................ iii List of Figures ............................................................................................................................................. v List of Tables .............................................................................................................................................. vi NOMENCLATURE ................................................................................................................................... vii SUMMARY ................................................................................................................................................. ix 1.0 INTRODUCTION ................................................................................................................................. 1 1.1 Aim ..................................................................................................................................................... 1 1.2 Background ....................................................................................................................................... 1 1.3 Production Methods ........................................................................................................................ 2 1.3.1 Compression and Condensing ................................................................................................... 2 1.3.2 Partial Condensing ....................................................................................................................... 3 1.3.3 Absorption and Acidification ....................................................................................................... 3 1.3.4 Sulphur Trioxide and Sulphur ..................................................................................................... 5 2.0 BACKGROUND THEORY ................................................................................................................. 7
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT 12.1.1 Material and Energy Balances ............................................................................................... 23 12.1.2 Condenser Design Sample of Calculation ........................................................................... 25 12.2 Correlation Charts ....................................................................................................................... 32 12.3 Material Safety Data Sheet ........................................................................................................ 53
List of Figures Figure 1: Condensation Temperature for Various Gas Concentrations of Sulphur Dioxide (Trickett, A.A., Horsley, D. and Talbot, M et al., 1986) ......................................................................... 4 Figure 2: Condensation Skid of Liquid Sulphur Dioxide Plant (Cameron, G.M. and Trickett, A.A.,) ............................................................................................................................................................ 4 Figure 3: Production of Sulphur Dioxide from Sulphur an Sulphur Trioxide .................................... 5 Figure 4: Flow Diagram for Sulphur Burning Liquid Sulphur Dioxide Plant ..................................... 6 Figure 5: Physical Properties of Sulphur Dioxide (Ashar N. G, Advances in Sulphonation Techniques, Springer Briefs in Applied Sciences and Technology, 2016) ....................................... 7 Figure 6: Down-flow vertical condenser with condensation inside tube ........................................... 9 Figure 7: Horizontal condenser with condensation outside horizontal tubes ................................. 10 Figure 8: Physical properties data bank .............................................................................................. 32 Figure 9: Overall coefficients (join process side duty to service side and read U from centre scale) .......................................................................................................................................................... 33
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT Figure 30: Shell and tube heat exchangers. Time base mid 2004 .................................................. 52
List of Tables Table 1: Table 2: Table 3: Table 4: Table 5:
Molar flow condenser and condenser separator calculations ........................................... 11 Mass flow condenser and condenser separator calculations ........................................... 11 Energy Balances ...................................................................................................................... 11 Condenser Specification Sheet, E-104 ................................................................................. 12 Hazop Study, Condenser ........................................................................................................ 14
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT NOMENCLATURE
A
Heat transfer area
A
Surface area
C
Clearance
m
Heat capacity at constant pressure
J/kg.K
Heat capacity at constant pressure
J/kg.K
Fluid density
Kg/
Bundle diameter
m
Inside tube diameter
m
Shell diameter
m
Outside tube diameter
m
Discharge pressure
kPa
Discharge temperature Duty
℃
nucleate boiling suppression factor
-
Equivalent diameter
m
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT
K
Film heat transfer coefficient inside a tube
W/
Nucleate boiling heat transfer coefficient
W/
Specific heat ratio of a compressor
℃ ℃ -
Thermal conductivity of fluid
W/m.K
Thermal conductivity of tube wall material
W/m.K
L
Pipe length
m
L
Liquid depth
m
Mean temperature condensate
℃
MM
Molecular weight of fluid
g/mole
NPSH
Net positive suction head
rpm
Number of tubes in a tube bundle
-
Total molar flow rate
kmol
Number of moles
/
Number of tubes in a row
-
N
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT SUMMARY The entire content of this report provides a thorough design and economic analysis for the manufacture of liquid Sulphur dioxide as part of a stand-alone package of Sulphuric acid plant in the Democratic Republic of Congo. Process flow sheet of the Sulphur dioxide cryogenic section is attached and a detailed process description of all utility requirements and equipment are provided and analyzed. With design commencing in 2017, the proposed plant will utilize liquid Sulphur dioxide from a Sulphuric acid internal upstream plant and will produce 90 tons of liquid Sulphur dioxide per day. Recalling the objective set forth, maximize the plant capacity by a factor of 1.35 which therefore ends up increasing the production of liquid Sulphur dioxide to 79.10 kmol/hr which corresponds to 121.5 tons per day. An environmental impact assessment report has been complied to raise awareness of the dangers of liquid Sulphur dioxide with inhabitants and other living organisms. Also Material Safety Data Sheet of liquid Sulphur dioxide is attached on the appendices to ensure that dangers and any possible fatalities are mitigated. It can be witnessed from the Material Safety Data Sheet that liquid Sulphur dioxide production plant can cause harm or even fatalities to inhabitants. But when handled with cautiousness, extra care human beings and other living organisms are not at any danger. Methods of dealing
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT 1.0 INTRODUCTION 1.1 Aim The main objective of this report, is to do a feasibility study on the integrated liquid Sulphur dioxide and sulphuric acid plant. The feasibility study includes design of condenser (equipment sizing), cost estimation of the condenser, environmental impact assessment of liquid Sulphur dioxide and material and energy balances as well as Hazop study.
It is also required to
maximize the plant capacity by scaling up the mass and energy balance calculations by a factor of 1.35.
1.2 Background Verri and Baldelli discovered that the production of liquid Sulphur dioxide from elemental Sulphur, by cryogenic condensation from a gaseous stream, can be easily integrated or combined with a sulphuric acid production plant. A portion of the SO 2-bearing gas that is fed to the first stage of the SO 2-SO3 catalytic converter can be diverted to a unit dedicated to the condensation of SO 2 at low temperature. The off-gas leaving this unit after condensation still
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT unit, and therefore need to be selected through an optimization exercise following the conceptual design phase”. Since the production of liquid Sulphur dioxide is a stand-alone package as regarded by Verri and Baldelli, the cryogenic unit will be fed with a portion of the gaseous stream from the Sulphur-burning section of an acid plant. In conducting their study certain considerations were to be taken into account, namely considering a standard Sulphur furnace capable of operating within an SO 2 concentration range of 10 –13% by volume. The higher the SO 2 concentration in the feed gas to the SO 2 unit, the lower the energy consumption and the better the efficiency of the unit. However, in practice, integration with a sulphuric acid plant limits the SO 2 concentration to 14% by volume with standard Sulphur furnace designs. Concentrations up to 18% are possible with major upgrades in the furnace design, although with such a high SO concentration, NO x production could be high and post-dilution with dry air could be necessary to achieve the optimal oxygen level at the converter inlet.
1.3 Production Methods There are several different processes for the production of liquid SO 2:
Compression and Condensing
2
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT 1.3.2 Partial Condensing Recent work from “Sulphur Dioxide – Technical Bulletin, CIL Chemicals ” show that when the concentration of SO 2 in the gas is low (typically 7-14%), it becomes impractical to attempt to fully condense all the SO 2 contained in the gas. Extremely high pressures re required in order to use cooling water to condense SO 2 from the gas. The alternative to full condensation is partial condensation of the SO 2 using refrigeration only. Refrigeration systems can achieve temperatures as low s -55 oC (-67oF). Typically, only 50% of the SO 2 can be condensed from the gas. The tail gas from the refrigeration process is used to pre-cool the incoming gas prior to being directed to some other process, such as a sulphuric acid plant, for further treatment.
1.3.3 Absorption and Acidification
Gas containing low concentration of SO 2 (typically 1-2% vol) is scrubbed using an ammonia solution to form ammonium bisulphite according to the following reaction:
+ ↔
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT
Figure 1: Condensation Temperature for Various Gas Concentrations of Sulphur Dioxide (Trickett, A.A., Horsley, D. and Talbot, M et al., 1986)
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT 1.3.4 Sulphur Trioxide and Sulphur Pure Sulphur trioxide (SO 3) will react with Sulphur to produce SO 2.
+2 → 3 The process was first developed in Germany. Molten Sulphur is mixed with oleum in a reactor operating at a temperature of 110 oC (230oF). The gas produced from the reactor passes through a column containing solid Sulphur where any remaining SO 3 is converted to SO 2. The pure SO2 gas is then condensed to liquid in a condenser circulating cooling water. Further development of this process involves feeding both oleum and liquid SO 3 to the reactor at the same time.
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT 2.0 BACKGROUND THEORY Cameron, G.M. and Trickett, A. A, highlights that liquid Sulphur dioxide (SO 2) is a versatile chemical with many uses, both in liquid form or as a source of gaseous SO 2. Liquid SO2 is used in the pulp and paper industry, mining industry, and in the food industry as a preservative. It can function as a reducing agent, an oxidizing agent, a pH controller, purifying agent, preservative, germicide and bleaching agent. SO 2 can also be used as a refrigerant, heat transfer fluid and selective solvent. Liquid SO 2 can be produced from gas containing SO 2 concentration in the range of 1% to 100% using different processes. The figure below which consists of physical properties of Sulphur dioxide witness the core functions of Sulphur dioxide as highlighted by Cameron, G.M. and Trickett, A. A.
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT According to (James R. Couper; W. Roy Penney, James R. Fair, Stanley M. Walas, Chemical Process Equipment: selection and design, Elsevier Inc., 2nd ed. 2005 ) the change from liquid phase to vapor phase is called vaporization and the reverse phase transfer is condensation. The change from liquid to vapor or vapor to liquid occurs at one temperature (called saturation or equilibrium temperature) for a pure fluid compound at a given pressure. The industrial practice of vaporization and condensation occurs at almost constant pressure; therefore the phase change occurs isothermally. Condensation occurs by two different physical mechanisms for example drop-wise condensation and film condensation. The nature of the condensation depends upon whether the condensate (liquid formed from vapor) wets or does not wet the solid surface. If the condensate wets the surface and flows on the surface in the form of a film, it is called film condensation. When the condensate does not wet the solid surface and the condensate is accumulated in the form of droplets, is drop-wise condensation. Heat transfer coefficient is about 4 to 8 times higher for drop wise condensation. The condensate forms a liquid film on the bare-surface in case of film condensation. The heat transfer coefficient is lower for film condensation due to the resistance of this liquid film. Drop-wise condensation occurs usually on new, clean and polished surfaces. The heat
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT
Horizontal condenser: The condensation may occur inside or outside the horizontal tubes (Figure (Figure 1.8). 1.8). Condensation in the tube-side is common in air-cooled condensers. The main disadvantage of this type of condenser is that the liquid tends to build up in the tubes. Therefore the effective heat transfer co-efficient is reduced significantly.
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT
Figure 7: Horizontal 7: Horizontal condenser with condensation outside horizontal tubes
2.2 Condenser Design
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT
3.0 MATERIAL AND ENERGY BALANCES Table 1: Molar flow condenser and condenser separator calculations Species
Condenser inlet
SO2 (liquid)
Molecular weight (kg/kmol) 64.06
-
Condenser output/ separator input 58.53886981
SO2 (vapor)
64.06
61.01989866
32 -
O2 Total (kmol/hr)
off-gas (separator)
Bottoms (separator)
-
58.53886981
2.481028846
2.481028846
-
6.034935032
6.034935032
6.034935032
-
67.05483369
67.05483369
8.515963878
58.53886981
off-gas (separator)
bottoms (separator)
-
1.041666667
Table 2: Mass flow condenser and condenser separator calculations Species
Condenser inlet
SO2 (liquid)
Molecular weight (kg/kmol) 64.06
-
Condenser output/ input 1.041666667
SO2 (vapor)
64.06
1.085815197
0.04414853
0.04414853
-
32
0.053643867
0.053643867
0.053643867
-
-
1.139459064
1. 139459064
0.097792397
O2 Total (kg/s)
Table 3: Energy Balances
Latent Heat of Vaporization (process fluid), J/mol
27697.45
Latent Heat of Vaporization (refrigerant), (refrigerant) , J/mol
23940.99
Duty (kW)
715.32
1.041666667
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT 4.0 DESIGN CALCULATIONS Table 4: Condenser Specification Sheet, E-104 Heat Exchanger Specifications ID Number:
531E2
Date: 30 September 2016
Description:
Column T-103 Condenser
Number Required:
1
Prepared by: Makhathini S. F Checked by: Mkhize N
Unit Performance and Fluid Properties Tube Side
Inlet
Shell Side
Outlet
Inlet
Cooling Water
Fluid
Outlet Process Fluid
Flow Rate - Vapor (kg/s)
1.578
0.131
0.508
0.508
Flow Rate - Liquid (kg/s)
-
1.448
0.508
0.508
Temperature ( )
℃
-54
-54
-70
-70
Pressure (kPa)
293
293
10.9
10.9
Density (kg/m 3) - (liquid)
630.39
630.39
-
674.72
Density (kg/m3) – Vapor
11.67
11.67
0.109
none
9.19×10− 8.7×10−
9.19×10− 8.7×10−
6.65 ×10− 2.26×10−
6.65 ×10− 2.26×10−
Viscosity - Vapor (Pa.s) Viscosity - Liquid (Pa.s)
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT Specific Heat capacity vapor (J/kg.K)
572
572
1023.79
1023.79
Specific Heat capacity liquid(J/kg.K)
1358.97
1358.97
4551.67
4551.67
Latent Heat (J/mol.K)
30199.95
30199.95
23940.99
23940.99
Thermal Conductivity – Vapor (W/m.K)
0.0182
0.0189
None
None
Thermal Conductivity – Liquid (W/m.K)
0.598
0.615
0.24
0.24
Pressure Drop calculated (kPa)
58.77
0.0825
Fouling Factor
6500
6000
Heat transfer Duty (kW)
Total Heat Transfer Area (m 2)
Heat Flux (J/m 2.s)
715.32
71.25
10039.58
Unit Construction
Tube Side
Shell Side
Number of Passes
4
1
Number of tubes
124
1
Material of Construction
Stainless steel
Stainless steel
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT 5.0 HAZOP STUDY Table 5: Hazop Study, Condenser HAZARD AND OPERABILITY STUDY REORT Project Title: Production of Sulphur Dioxide Report Number: 1
Date: 26 SEPTEMBER 2016
Drawing Number: 531E6 Cryogenic SO 2Condenser
Chairman: MR S. F Makhathini
Line Number: Intention: To convert processing stream from vapour/gaseous to liquid
Parameter: Flow
More
More cooling
Very low output temperature
Inlet cooling refrigerant (ammonia) valve
refrigerant (ammonia)
of process fluid
failed open
No refrigerant
Temperature is not lowered
Inlet cooling refrigerant (ammonia) valve
(ammonia) flow
accordingly
failed closed
Less refrigerant
High output temperature of
Pipe leakage
(ammonia) flow
process fluid
Valve partially closed
Reverse process fluid
Disturbed product quality
None
Install temperature indicators before and after the process line.
None
Regular inspection and maintenance on equipment. Install high
flow None
Less
Reverse
Process fluid inlet valve failed closed
temperature alarm None
Install low flow alarm. Regular inspection and maintenance on equipment inspect / repair / change valve.
None
Inspect / repair / change valve.
None
Periodically checking of the temperature
Increase cooling refrigerant (ammonia) flow rate.
Temperature and flow controls to be periodically inspected.
Equipment to be tested periodically
Decrease cooling refrigerant (ammonia) flow rate.
output Temperature
More temperature
Temperature is not lowered
Decrease in cooling water flow
accordingly.
Increase in cooling refrigerant (ammonia) temperature.
Less
Less temperature
Temperature not decreased accordingly
Too much cooling refrigerant (ammonia)
None
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT
6.0 PROCESS FLOW DIAGRAM SECTION 100: SULPHUR DIOXIDE CRYOGENIC PLANT
SULPHURIC ACID TO DRYING TOWER 528C1 531E1 HOT REHEAT
531E3
EXCHANGER
ACID COOLER
PROCESS GAS FROM 514H1
531E2 TO CONVERTER BED
COLD REHEAT
514R1*1BED
EXCHANGER 531C1
P-17
SO2 WASHING TOWER DILUTION WATER
531K1 GAS BOOSTER
531V1
531P1
ACID TANK
ACID PUMP
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT
6.1 PROCESS FLOW DIAGRAM SECTION 200: CONDENSATION OF SULPHUR DIOXIDE
531E6 CRYOGENIC SO2 CONDENSER CONDENSER SEPARATOR
CRYOGENIC PACKAGE
531R31
TO LIQUID SO2 STORAGE TANKS 531E7 531P2
LIQUID
LIQUID SO2
PREHEAT
PUMP
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT 9.0 COST ESTIMATION Cost estimation is a specialized subject and a profession in its own right. The design engineer, however, needs to be able to make quick, rough, cost estimates to decide between alternative designs and for project evaluation. Chemical plants are built to make a profit, and an estimate of the investment required and the cost of production are needed before the profitability of a project can be assessed. Happle and Jordan (1975) and Guthrie (1974), recommended the use of this method of cost projection using various components that make up the capital cost of a plant and the components of the operating costs are discussed, and the techniques used for estimating reviewed briefly. Simple costing methods and some cost data are given, which can be used to make preliminary estimates of capital and operating costs at the flow-sheet stage. Garrett (1989), further mentioned that for a more detailed treatment of the subject the reader should refer to the numerous specialized texts that have been published on cost estimation which is an alternative processing schemes and equipment.
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT 7.0 ENVIRONMENTAL IMPACT ASSESSMENT (EIA) 7.1 Safety Consideration The liquid SO 2 cryogenic section is considered as a stand-alone package according to Verri and Baldelli, therefore the plant design of Sulfuric acid production has an environmental impact in the form of pollution problems in the area where the plant is located. According to central environmental authority (CEA), it is the responsibility of the management to consider possible techniques to minimize the emission of gaseous compounds such as oxides of Sulfur or Sulfuric acid mist and other solid and liquid waste by complying with the emission standards and discharge limits which are provided by the. Waste generated mostly on the cryogenic section can be treated in house prior to discharging them into the environment. Possible pollutants in the liquid sulfur dioxide production using contact process include dust particles of raw sulfur, oxygen, oxides of sulfur, acid mist and liquid sulfuric acid apart from that spent catalyst and other waste from blow down. One of the main reason for the oxides and acid mist to release to the environment is poor conversion in the sulfur burning section and absorption in the cryogenic section process. Efficient processing methods will reduce the emission of these
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT 8.0 DISCUSSION The objective of this study is to make preliminary design of a stand-alone package (Sulphur dioxide cryogenic section) for a sulphuric acid production plant. The integrated liquid Sulphur dioxide and sulphuric acid plant produces 362 tons/day as 100% H 2SO4 and 90 tons/day of sulphuric acid and liquid Sulphur dioxide simultaneously respectively. In order to achieve this aim, the production process of integrated liquid Sulphur dioxide and Sulphuric acid plant includes the use of vanadium oxide as a catalyst, double-contact absorption (3+1 configuration), 99.7% conversion of Sulphur to Sulphur dioxide, condensation temperature of (54oC) t atmospheric pressure also using a ratio of 1.2 (by volume) of Sulphur dioxide to oxygen. This is considered as an initial design since the new design includes scale up values from the initial plant. The increment factor to be used to scale up the plant capacity is 35%. While heat transfer area calculations are conducted, overall heat transfer coefficients are determined with respect to nature of process. The material of construction chosen for the condenser is stainless nickel steel. Having noted that refrigerant on the shell side is ammonia which evaporates at a constant temperature of (-70 oC). In order to account for the heat transfer
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT Sulphur dioxide have been enclosed to ensure a safe and conducive environment for all as it is one of the key priority of this project. Economic analysis is crucial since it is the main factor to determine the success of a project. Economic analysis reveals the amount of profit under operating condition of a plant. In order to examine if the integrated liquid Sulphur dioxide and sulphuric acid plant is conducive or not, both capital investment cost and production cost must be examined for a successful economic analysis. For this project the study is based on the condenser only, therefore the preliminary cost of purchase of the condenser is estimated to be
1224
.
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT 10.0 CONCLUSIONS AND RECOMMENDATIONS In conclusion the, the main aim of this report was to design a grass root facility that will safely and efficiently produce 90 tons per day of liquid Sulphur dioxide as a stand-alone package from 360 tons per day of integrated Sulphuric acid plant. In achieving the goals set forth, sizing of equipment’s and a cost projection on each functional unit as well as an Environmental Impact Assessment report was also required to ensure that the production of liquid Sulphur dioxide would not harm the environment and human beings as well as any other living organisms. After gathering data from various sources as referenced, the environmental report displays that the production of liquid Sulphur dioxide may be harmful if handled inappropriately and can cause injuries and fatalities as well. Therefore adequate care must be taken to ensure safety. Cost of the equipment’s are satisfactory based on the current exchange rate. Also the design of integrated liquid Sulphur dioxide and Sulphuric acid plant includes a compilation of hazard and operability study around the condenser which is constructed according to heuristics and main results are summarized in specification sheets. Either material or energy balance is performed for each equipment participating in the production of liquid Sulphur dioxide. Because of the specified variables, material balances and energy balance is
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT 11.0 REFERENCES 1. Verri, M. and Baldelli, A., 2013. Integrated production of liquid Sulphur dioxide and sulphuric acid via a low-temperature cryogenic process. Journal of the Southern African Institute of Mining and Metallurgy, 113(8), pp.602-609. 2. Lindquit, B., “Recent Developments within the process Gas System at the Boliden Ronnskar Smelter Process Gas Handling 3. Cameron, G.M. and Trickett, A.A., “Liquid Sulphur Dioxide and Elemental Sulphur plants – Design an Operation”. Presented to A Professional Enhancement Seminar – Reduction of Sulphur Dioxide Emissions from Non-Ferrous Smelters, Toronto, Canada. August 16 1986. 4. Ashar, N.G., “Liquid Sulphur Dioxide without Compression or refrigeration – A New Technology Already in Operation”, Sulphur 99, Calgary, Alberta, Canada, October 17 20, 1999, pp. 173-181. 5. Trickett, A.A., Horsley, D. and Talbot, M., “Product Quality Aspects of liquid SO 2 Production from Metallurgical Off- Gases”
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT 12.0 APPENDICES 12.1 Sample of Calculations 12.1.1 Material and Energy Balances Balance around the condenser separator
V (Kmol/hr) n4=SO2(g) n5=O2(g)
F (Kmol/hr) n1=SO2(l) n2=SO2(g) n3=O2(g)
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT
6 = 1 = = 58.59 /ℎ
/ℎ = 66.88 /ℎ = 58.59 0.876 2 = 4 = 0.034×66.88 = 2.27 /ℎ 3 = 5 = 0.09×66.88 = 6.02 /ℎ Balance around the condenser Assumption is that in the condenser there is only a phase change, therefore the input to the condenser separator stream is the same as the condenser input stream.
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT 12.1.2 Condenser Design Sample of Calculation
Heat transferred from vapor
= ̇ × ∆ 2.974 ×27697.449 = 93600 = 715318.197 / 715.32×10 Cooling (refrigerant) medium flow From literature, it is said that the refrigerant is evaporating at a constant temperature. Therefore they is only a phase change no temperature change.
= = ̇ × ∆ 715318.197 = ̇ ×23940.99 ̇ = 0.508 /
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT Surface area of one tube (ignoring the tube sheet thickness)
= × × = 25×10− × ×7.32 = 0.575 Number of tubes
= = 60.3.58757 = 111.14 ≈ 111 Based on the standards of baffles and tubes, in accordance with the TEMA L (1 in OD on 1.1/4 in triangular pitch the number of tubes is 124 and shell diameter is 438 mm for a 1-4 shell and tube.
= 1.25× = 31.25 0.03125
Selection of square pitch arrangement as the tube layout,
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT
∆ = ∆ ∆ = 62 ℃ Mean temperature condensate
Physical properties at
.℃
= 70+70 2 = 70 ℃
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT Tube –side coefficient Tube cross-sectional area
= 4 × 4 = 4 20×10− × 1244 = 0.00974 Tube velocity
= ×̇ 1.57 = 11. 67×0. 00974 = 13.89 / Inside coefficient, for water
. 42001.35+0.02×∆ ℎ = .
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT
= 526.81 /℃ The value of overall coefficient obtained is close enough to the assumed (
700 ℃ = 526.81 /℃.
=
This value was obtained through various iterations.
Shell-side pressure drop The use of a pull-through floating head was chosen, therefore no need for close clearance. Baffle spacing = Shell diameter (45 per cent cut) Using the TEMA L standards of baffles and tubes the estimated shell diameter that corresponds to the number of tubes was found to be 438 mm. Using Ken’s method to make an appropriate estimate.
Cross-flow area Assumption made: Baffle spacing is equal to the shell inner diameter
=
=
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT Vapor viscosity Using the physical data bank in Coulson and Richardson volume 6, the vapor viscosity of the mixture was determined as follows:
log = ×1/1/ = 2.258 ×10− . = × 0178×0. 0 98 = 674.72×0. 2.258×10− = 52019.44 From Figure 11
= 3.8 ×10−
= ̇ × 0.508 = 674. 72×0. 00767
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT Tube-side pressure drop
Viscosity of process fluid
= 9.19×10− / = − 67×20×10 = 1 3.89×11. 9.19×10− = 352899.993.53×10 From Figure 11
= 3.6 ×10− Neglecting the viscosity correction (The viscosity correction factor will normally only be significant for viscous liquids, to apply the correction an estimate of the wall temperature is needed).
∆ = [8 − +2.5] 2
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT 12.2 Correlation Charts
Figure 8: Physical properties data bank
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT
Figure 9: Overall coefficients (join process side duty to service side and read U from centre scale)
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT
Figure 10: Convective boiling factor
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT
Figure 11: Tube-side friction factor
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT
Figure 13: Fouling coefficients
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT
Figure 14: Moody chart, friction factor
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT
Figure 15: Nucleate boiling suppression factor
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT
Figure 16: Temperature correlation chart (1-2 shell and tube heat exchanger)
Figure 17: Temperature correlation chart (2-4 shell and tube heat exchanger)
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT
Figure 18: Physical properties equation correlations
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT
Figure 19: Physical properties data bank (Coulson and Richardson vol.6)
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT
Figure 20: Discharge coefficient
Figure 21: Shell and tube clearance
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT
Figure 22: Shell-side friction factor, segmental baffles
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT
Figure 23: Tube-side transfer factor
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT
Figure 24: Heat-transfer factor for cross-flow tube banks
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT
Figure 25: Shell-side heat-transfer factors, segmental baffles
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT
Figure 26: Typical overall coefficient
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT
Figure 27: Toxicology details, Integrated Liquid Sulphur Dioxide and Sulphuric Acid
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT
gure 28: Transportation table of the integrated Sulphur Dioxide and Sulphuric Acid plant (http://www.sulphuricacid.com/techmanual/Plant_Safety/safety_sulphur.htm)
Fi
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT
Figure 29: Tanker specification for transporting liquid Sulphur dioxide and Sulphuric Acid (http://www.sulphuricacid.com/techmanual/Plant_Safety/safety_sulphur.htm
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT
Figure 30: Shell and tube heat exchangers. Time base mid 2004
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT 12.3 Material Safety Data Sheet SULFUR DIOXIDE MATERIAL SAFETY DATA SHEET SECTION 1. PRODUCT AND COMPANY IDENTIFICATION
Product Identity: Sulfur Dioxide Manufacturer:
Supplier:
Teck Cominco Metals Ltd.
Teck Cominco American Incorporated Industrial Chemicals
Trail Operations Trail, British Columbia
501 North Riverpoint Blvd., Suite 300,
V1R 4L8
Spokane,
WA.
99202
Emergency Telephone: 250-364-4214 MSDS Preparer :
Teck Cominco Metals Ltd. 600 - 200 Burrard Street Vancouver, British Columbia V6C 3L9 Date of Last Revision/Update: December 15, 2006. Product Use: Used in the manufacture of chlorine dioxide (a pulp and paper bleaching chemical), as a dechlorination agent
in the pulp and paper industry and waste water treatment plants, in the food processing industries as a preservative, as a chemical additive in the gold industry cyanide destruction process, in the manufacture of sodium bisulfite solution and in the manufacturing of sodium hydrosulfite.
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT SECTION 2. COMPOSITION/INFORMATION ON INGREDIENTS
Hazardous
Approximate
CAS
Occupational
Ingredient
Percent
Number
(OELs)
7446-09-5
OSHA PEL
by
Exposure
Limits LD50 / LC50 Species and Route
Weight
Sulfur Dioxide
99.9%
5 ppm (13 mg/m 3) 3
LD50
No Data
ACGIH TLV
2 ppm (5 mg/m )
LD50 ihl-rat
2520 ppm/1Hr
NIOSH REL
2 ppm (5 mg/m 3)
LD50 ihl-mouse
3000 ppm/30min
LD50 rat (calculated)
1260 ppm/4Hr
NOTE: OELs for individual jurisdictions may differ from OSHA PELs. Check with local authorities for the applicable OELs in your jurisdiction. OSHA - Occupational Safety and Health Administration; ACGIH - American Conference of Governmental Industrial Hygienists; NIOSH - National Institute for Occupational Safety and Health. OEL – Occupational Exposure Limit, PEL – Permissible Exposure Limit, TLV – Threshold Limit Value, REL – Recommended Exposure Limit Trade Names and Synonyms: Sulfurous acid anhydride, sulfurous oxide, Sulphur dioxide, SO
2
SECTION 3. HAZARDS IDENTIFICATION
Emergency Overview: A colorless gas or liquefied compressed gas with a pungent, irritating odor and taste. Sulfur dioxide
does not burn but cylinders or tanks may rupture and explode if heated, releasing clouds of irritating and toxic SO2 gas. Contact with liquid SO2 can cause freezing of tissue and frostbite. Wear full protective clothing and a positive pressure full face-piece SCBA in emergency situations involving SO2.
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT Potential Health Effects: Irritating to the eyes and upper respiratory tract, becoming a severe irritant at high concentrations.
Most inhaled SO2 only penetrates as far as the nose and throat because it dissolves so rapidly in the moist tissues of the upper airways. In severe cases at very high concentrations serious respiratory effects have been reported. Direct skin or eye contact with liquid SO2 may cause frostbite. Sulfur dioxide is not listed as a carcinogen by OSHA, NTP, IARC, ACGIH or the EU. (See Toxicological Information, Section 11) Potential Environmental Effects: Sulfur dioxide is a common air contaminant in most industrialized areas. Green plants are
extremely sensitive to atmospheric sulfur dioxide. It is also the precursor of acid rain. Release to the environment should be avoided if possible or minimized when necessary. (See Ecological Information, Section 12)
SECTION 4. FIRST AID MEASURES
Eye Contact: Avoid direct contact. Wear chemical protective gloves if necessary. Remove source of contamination or move
victim to fresh air. Immediately flush the contaminated eye(s) with lukewarm, gently flowing water for at least 5 minutes for the gas (20 minutes for the liquid) or until the chemical is removed, while holding the eyelid(s) open. Take care not to rinse contaminated water into the unaffected eye or onto the face. Quickly transport victim to an emergency care facility. Skin Contact: (Gas) If irritation occurs, flush contaminated area with lukewarm, gently flowing water for at least 5 minutes. If
irritation persists, obtain medical attention immediately. (Liquid SO2) Avoid direct contact. Wear chemical protective clothing, if necessary. Quickly remove victim from source of contamination and briefly flush with lukewarm, gently flowing water until the chemical is removed. DO NOT attempt to re-warm the affected area on site. DO NOT rub area or apply dry heat. Gently remove clothing or jewelry that may restrict circulation. Carefully cut around clothing that sticks to the skin and remove the rest of the garment. Loosely cover the affected area with a sterile dressing. DO NOT allow victim to drink alcohol or smoke. Quickly transport victim to an emergency care facility.
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT Inhalation: Take proper precautions to ensure your own safety before attempting rescue (e.g. wear appropriate protective
equipment, use the buddy system). Remove source of contamination or move victim from exposure area to fresh air immediately. If breathing is difficult, trained personnel should administer medical oxygen. DO NOT allow victim to move around unnecessarily. Symptoms of pulmonary edema can be delayed up to 48 hours after exposure. Quickly transport victim to an emergency care facility. Ingestion: Ingestion is not an applicable route of exposure for gases.
SECTION 5. FIRE FIGHTING MEASURES
Fire and Explosion Hazards: Sulfur dioxide is not flammable. However, heat from a surrounding fire can rupture vessels
causing a dangerous explosion and release of toxic sulfur dioxide gas. Cool any containers of sulfur dioxide that are exposed to heat or flames by the application of water streams until well after the fire has been extinguished since pressure will increase rapidly with temperature increase. For large fires that threaten tanks or cylinders of SO2 consider evacuating downwind areas. Use caution in applying water to an SO2 leak, as the run-off will be acidic and corrosive to other materials as well as harmful to the environment. Run-off may require collection and neutralization. Extinguishing Media: Use any fire- fighting agent appropriate for surrounding fire conditions such as water spray, carbon
dioxide, dry chemical, or foam. Fire Fighting: Toxic fumes of sulfur dioxide may be released during a fire. Fire fighters must be fully trained and wear full
protective clothing including an approved, self-contained breathing apparatus which supplies a positive air pressure within a full facepiece mask. Flashpoint and Method: Not Applicable. Upper and Lower Flammable Limit: Not Applicable. Auto-ignition Temperature: Not Applicable
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT SECTION 6. ACCIDENTAL RELEASE MEASURES
Procedures for Cleanup: Isolate hazard area and deny entry to unprotected personnel. Properly trained personnel equipped
with protective clothing and respiratory protection should locate and stop release. Can be neutralized with aqueous alkaline solutions of lime, caustic or soda ash. Dispose of waste material from neutralization process in accordance with applicable regulations. Thoroughly ventilate area before permitting re-entry. Personal Precautions: Protective clothing, gloves, and respirator equipment are recommended for persons responding to an
accidental release (see also Section 8). Close-fitting safety goggles and face shield may be necessary to prevent contact with liquid SO2. A positive pressure full-face self-contained breathing apparatus (SCBA) is required for emergency or planned entry into unknown high concentrations of SO2 that may exceed the IDLH level (100 ppm). Environmental Precautions: This product can pose a threat to the environment. Contamination of water should be
prevented. Liquid spills will produce high concentrations of SO2 gas. Such gas clouds would be heavier than air and may flow downhill or collect in low spots and not be easily dispersed.
SECTION 7. HANDLING AND STORGE
Store in a registered steel pressure vessel, constructed to comply with ASME Section 8 Code, at appropriate temperatures. Keep containers tightly closed and store outdoors or indoors in a dry, cool, well-ventilated fireproof area. Protect against physical damage. SO2 gas is heavier than air and leaked gas can accumulate in low areas. Do not store below ground. Flooring and sumps should be acid-proof and drain to a collection system. Avoid exposure to moisture, high temperatures and incompatible materials (see Section 10 - Stability and Reactivity).
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT
SECTION 8. EXPOSURE CONTROLS/PERSONAL PROTECTION
Protective Clothing: When handling liquid SO2, gloves and coveralls or other protective clothing are recommended to
prevent the skin from becoming frozen by contact with the liquid or from contact with very cold vessels and equipment handling the liquid (especially loading and off-loading of trucks and railcars). Face shield and close-fitting safety goggles must be worn when handling this material in liquid form. An eyewash and quick drench should be provided within the immediate work area for emergency use where there is any possibility of exposure to liquids that are extremely cold or rapidly evaporating. Ventilation: Use adequate local or general ventilation to maintain the concentration of sulfur dioxide gas in the working environment
well below recommended occupational exposure limits. Respiratory Protection: Where sulfur dioxide gas is generated and cannot be controlled to within acceptable levels by
engineering means, use appropriate NIOSH-approved respiratory protection equipment (a chemical cartridge respirator with cartridge(s) to protect against sulfur dioxide up to 20 ppm, a full face-piece chemical cartridge respirator or half mask PAPR or SAR up to 100 ppm).
For emergency or planned entry into an unknown concentration or IDLH condition, workers must be fully trained and wear full protective clothing including a NIOSH-approved, self-contained breathing apparatus which supplies a positive air pressure within a full face-piece mask. NOTE: - IDLH = Immediately Dangerous to Life or Health, PAPR = Powered Air Purifying Respirator, SAR = Supplied Air Respirator
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT
SECTION 9. PHYSICAL AND CHEMICAL PROPERTIES
Appearance
Odor
Physical State
pH
Colorless Gas or Liquid
Pungent and irritating
Liquid (liquefied compressed
Not Applicable
gas)
Vapor Pressure
Vapor Density
Boiling Point/Range
Freezing/Melting Point/Range
47.8 PSIG at 68°F, 20°C
2.26 @ 0°C
-10 °C, (14°F)
Specific Gravity
Evaporation Rate
Coefficient
-76°C, (-104°F)
of
Water/Oil Odor Threshold
Distribution
1.44 at 32°F, 0°C
Solubility in Water
11.9 % by weight at 60°F, 16°C
40.18 g/m2 /s at 70°F, 21°C
Unknown
1-3 ppm
EQUIPMENT DESIGN FOR INTEGRATED LIQUID SULPHUR DIOXIDE AND SULPHURIC ACID PLANT SECTION 10. STABILITY AND REACTIVITY
Stability & Reactivity: Stable under conditions of normal use. SO2 is extremely stable to heat even up to 2000°C. Forms a
moderately acidic solution (pH<3) on contact with moisture in the atmosphere or on the skin. Moist SO2 gas is corrosive to most common metals. Incompatibilities: Strong alkalis, ammonia, oxidizing agents, chlorates, powdered chromium, manganese or aluminum,
halogens (fluorine, chlorine) and interhalogens (chlorine trifluoride, etc.), metal oxides, hydrides, azides and acetylides, sodium carbide and acrolein. Hazardous Decomposition Products: None.
SECTION 11. TOXICOLOGICAL INFORMATION
General: Sulfur dioxide is a moderate to strong irritant gas and the major effects are on the upper respiratory tract.
Asthmatics may be particularly sensitive to the bronchospastic properties of sulfur dioxide. The major route of exposure to the gas is by inhalation. Skin and eye contact with liquid SO2 are also serious risks. Since sulfur dioxide is a gas at temperatures greater than 10 degrees Celsius, ingestion is unlikely to occur. Acute: Skin/Eye: Contact with liquid sulfur dioxide can cause frostbite and severe burns. Eye contact may result in severe burns and
corneal damage that can result in blindness. High concentrations of SO2 gas (>10 ppm) are very irritating to the eyes as well, causing smarting, stinging and tearing. The gas will react with moisture on the skin and cause irritation.