CHAPTER 1 1.0 INTRODUCTION Soap is a salt of a fatty acid. Soap is mainly used for washing, bathing, and cleaning, but soaps are also important components of lubricants. Soaps for cleansing are obtained by treating vegetable or animal oils and fats with a strongly alkaline solution. Fats and oils are composed of triglycerides: three molecules of fatty acids attached to a single molecule of glycerol. The alkaline solution, often lye, promotes a chemical reaction known as saponification. In saponification, fats are broken down (hydrolyzed) yielding crude soap. Fats are transformed into salts of fatty acids and glycerol is liberated, leaving glycerin as a byproduct. Soaps are key components of most lubrication greases, which are usually emulsions of calcium and lithium soaps in a mineral oil. Lithiumbased greases are widely used. Many other metal ions are used, including aluminium, sodium, and mixtures of various metal ions. Such soaps are sometimes classified as thickeners, meaning that they elevate the viscosity of the oil. In ancient times, lubricating greases were prepared by the addition of lime to olive oil. Toilet Soaps, to this class belongs to the finer kinds of scented soaps, which have emollient properties. They are rarely made direct by the perfumer, the body or basis being a well-selected white soap, subsequently cleaned and purified. For the choicest grades, the body should be made of a mixture of olive and sweet-almond oil, as the fat stock. Lard and beef tallow make the next best stock; and for palm soap a small quantity of bleached palm oil is to be added to them. Cocoa oil and pale yellow resin saponaceous matters also enter into the composition of certain toilet soaps. These body soaps may be obtained as wanted from any well-conducted soap factory. To be adapted to the purposes of perfumery they must be perfectly neutral, firm, free from unpleasant odor and all tendency to crust in cold, or sweat in damp weather. They should, moreover, give a rich lather without wasting too rapidly in the water. Soaps, generally, in their original condition, are usually deficient in many of those points; and must, for the purposes of perfumery, undergo a refining procests.
1
Main objective To design a plant to manufacture 50 tonnes/day of toilet soap from animal fat. Specific Objective The specific objectives are the processes we need to go through in order to achieve the main objective and these are as follows:
To select a suitable process for the manufacture of toilet soap.
To draw a process flow chart
To calculate for material and energy balance for all the equipment in the plant
To select a suitable site for the plant.
To determine the economic analysis of the plant.
2
CHAPTER 2 2.0 LITERATURE REVIEW The most popular soapmaking process today is the cold process method, where fats such as olive oil react with lye, while some soapers use the historical hot process. Handmade soap differs from industrial soap in that, usually, an excess of fat is used to consume the alkali (superfatting), and in that the glycerin is not removed, leaving a naturally moisturizing soap and not pure soap. Additional processing of this glycerin containing soap produces glycerin soap. Superfatted soap, which contains excess fat, is more skinfriendly than industrial soap, though if too much fat is added, it can leave users with a "greasy" feel to their skin. Sometimes an emollient such as jojoba oil or shea butter is added "at trace" (the point at which the saponification process is sufficiently advanced that the soap has begun to thicken) in the belief that it will escape the saponification and remain intact, or in the case of hot process soap - after most of the oils have saponified so that they remain unreacted in the finished soap. Superfatting can also be accomplished through a process called a lye discount, where, instead of putting in extra fats, the soap maker puts in less lye. In cold-process and hot-process soapmaking, heat may be required for saponification. Cold-process soapmaking takes place at a sufficient temperature to ensure the liquefication of the fat being used. The lye and fat may be kept warm after mixing to ensure that the soap is completely saponified. Unlike cold-processed soap, hotprocessed soap can be used right away because lye and fat saponify more quickly at the higher temperatures used in hot-process soapmaking. Hot-process soapmaking was used when the purity of lye was unreliable, and this process can use natural lye solutions, such as potash. The main benefit of hot processing is that the exact concentration of the lye solution does not need to be known to perform the process with adequate success. Cold-process soapmaking requires exact measurements of lye and fat amounts and computing their ratio, using saponification charts to ensure that the finished product is mild and skin-friendly. Saponification charts can also be used in hot-process soapmaking, but are not as necessary as in cold-process soapmaking.
3
Hot process In the hot-process method, lye and fat are boiled together at 80–100 °C until saponification occurs, which before modern thermometers, the soapmaker determined by taste (the bright, distinctive taste of lye disappears once all the lye is saponified) or by eye; the experienced eye can tell when gel stage and full saponification have occurred. Beginners can find this information through research, and classes. It is highly recommended to not "taste" soap for readiness. Lye, when not saponified is a highly caustic material. After saponification has occurred, the soap is sometimes precipitated from the solution by adding salt, and the excess liquid drained off. The hot, soft soap is then spooned into a mold. The soap lye is processed for recovery of Glycerine. Cold process A cold-process soapmaker first looks up the saponification value of the fats being used on a saponification chart, which is then used to calculate the appropriate amount of lye. Excess unreacted lye in the soap will result in a very high pH and can burn or irritate skin. Not enough lye, and the soap is greasy. Most soap makers formulate their recipes with a 4-10% deficit of lye so that all of the lye is reacted and that excess fat is left for skin conditioning benefits. The lye is dissolved in water. Then oils are heated, or melted if they are solid at room temperature. Once both substances have cooled to approximately 100-110 °F (37-43 °C), and are no more than 10°F (~5.5°C) apart, they may be combined. This lye-fat mixture is stirred until "trace" (modern-day amateur soapmakers often use a stick blender to speed this process). There are varying levels of trace. Depending on how additives will affect trace, they may be added at light trace, medium trace or heavy trace. After much stirring, the mixture turns to the consistency of a thin pudding. "Trace" corresponds roughly to viscosity. Essential oils, fragrance oils, botanicals, herbs, oatmeal or other additives are added at light trace, just as the mixture starts to thicken. The batch is then poured into molds, kept warm with towels, or blankets, and left to continue saponification for 18 to 48 hours. Milk soaps are the exception. They do not require insulation. Insulation may cause the milk to burn. During this time, it is normal for the soap to go through a "gel phase" where the opaque soap will turn somewhat 4
transparent for several hours, before once again turning opaque. The soap will continue to give off heat for many hours after trace. After the insulation period the soap is firm enough to be removed from the mold and cut into bars. At this time, it is safe to use the soap since saponification is complete. However, cold-process soaps are typically cured and hardened on a drying rack for 2–6 weeks (depending on initial water content) before use. If using caustic soda it is recommended that the soap is left to cure for at least four weeks. Molds Many commercially available soap molds are made of silicone or various types of plastic, although many soap making hobbyists may use cardboard boxes that are lined with plastic wrap. Soaps can be made in long loaves that are cut into individual bars, block molds that are cut into loaves and then bars, or individual molds. Purification and finishing The common process of purifying soap involves removal of sodium hydroxide, glycerol and some impurities. These components are removed by boiling the crude soap curds in water and re-precipitating the soap with salt. Most of the water is then removed from the soap. This was traditionally done on a chill roll which produced the soap flakes commonly used in the 1940s and 1950s. This process was superseded by spray dryers and then by vacuum dryers. The dry soap (approximately 6-12% moisture) is then compacted into small pellets. These pellets are now ready for soap finishing, the process of converting raw soap pellets into a saleable product, usually bars. The batch is then poured into molds, kept warm with towels, or blankets, and left to continue saponification for 18 to 48 hours. Milk soaps are the exception. They do not require insulation. Insulation may cause the milk to burn. During this time, it is normal for the soap to go through a "gel phase" where the opaque soap will turn somewhat transparent for several hours, before once again turning opaque. The soap will continue to give off heat for many hours after trace.
5
Soap pellets are combined with fragrances and other materials and blended to homogeneity in an amalgamator (mixer). The mass is then discharged from the mixer into a refiner which, by means of an auger, forces the soap through a fine wire screen. From the refiner the soap passes over a roller mill (French milling or hard milling) in a manner similar to calendering paper or plastic or to making chocolate liquor. The soap is then passed through one or more additional refiners to further plasticize the soap mass. Immediately before extrusion it passes through a vacuum chamber to remove any trapped air. It is then extruded into a long log or blank, cut to convenient lengths, passed through a metal detector and then stamped into shape in refrigerated tools. The pressed bars are packaged in many ways. Sand or pumice may be added to produce a scouring soap. The scouring agents serve to remove dead skin cells from the surface being cleaned. This process is called exfoliation. Many newer materials are used for exfoliating soaps which are effective but do not have the sharp edges and poor particle size distribution of pumice. Nanoscopic metals are commonly added to certain soaps specifically for both coloration and anti-bacterial properties. Titanium powder is commonly used in extreme "white" soaps for these purposes; nickel, aluminium and silver are less commonly used. These metals provide electron-robbing behavior when in contact with bacteria, stripping electrons from the organism's surface and thereby disrupting their functioning (typically killing the bacteria when it has lost too many electrons). Because some of the metal is left behind on the skin and in the pores, the benefit can also extend beyond the actual time of washing, helping reduce bacterial contamination and reducing potential odors from bacteria on the skin surface.
6
CHAPTER 3 3.0 EQUIPMENT LIST AND PROCESS DESCRIPTION 3.1 EQUIPMENT LIST Table 3.1 Equipment List
Item no.
Service
Quantity
Type
VE-101
NaOH Storage tank
1
Vertical Cylindrical
VE-105
Water Storage tank
1
Vertical Cylindrical
VE-110
Saponifier vessel
1
Vertical Cubic
VE-205
Lye Preparation tank
1
Vertical Cylindrical
DA-101
Soap dryer
1
Vacuum Shelf
HE-101
1st Soap Heater
1
SE-101
Static Seperator
1
CO-101
Washing Column
1
CE-201
Centrifuge
1
VE-105
Neutralizer Vessel
1
Tubular Centrifuge
7
Lye Saponification
Tallow
Static
wet soap
Lye
Separator
vessel
NaOH
Crude Soap (13% Glycerine)
Washing
Fresh lye
Glycerine
Column
35% Glycerine 65% lye Washed soap 20% lye
Lye Centrifuge
0.3% NaOH
wet soap
0.5% NaCl 68.2% Solids Salt produced Toilet soap
Additives Neutralizer Neutralizer
VacuumDryer Dryer Vacuum
31% H2O 88% Solids
68% Solid
12% H2O
1% Impurities Water
H3PO4 (Weak acid)
Fig. 3.1 Flow diagram for Toilet Soap Production
8
3.2 PROCESS DESCRIPTION This is a continuous process which uses a plant. The process is best understood in terms of two streams: soap flowing in the order given below against a counter-current of lye. Step 1 - Saponification The raw materials are continually fed into a reactor in fixed proportions. Tallow: 735.29 kg hr-1 NaOH solution: 272.33 kg hr-1 Lye: 35.22 kg hr-1 These ingredients alone would give a low water, high glycerine soap. Soap needs to be about 30% water to be easily pumpable, and even then needs to be held at around 70 oC, so excess lye is added to hydrate the soap and dissolve out some of the glycerine. The lye added is known as "half spent lye" and is the lye discharged from the washing column. This lye already contains some glycerine, but it is further enriched by that formed in the saponification reaction. Step 2 - Lye separation The wet soap is pumped to a "static separator" - a settling vessel which does not use any mechanical action. The soap / lye mix is pumped into the tank where it separates out on the basis of weight. The spent lye settles to the bottom from where it is piped off to the glycerine recovery unit, while the soap rises to the top and is piped away for further processing. Step 3 - Soap washing The soap still contains most of its glycerine at this stage, and this is removed with fresh lye in a washing column. The column has rings fixed on its inside surface. The soap solution is added near the bottom of the column and the lye near the top. As the lye flows down the column through the centre, a series of rotating disks keeps the soap / lye mixture agitated between the rings. This creates enough turbulence to ensure good mixing between the two solutions. The rate of glycerine production is calculated and the rate at which fresh lye is added to the washing column then set such that the spent lye is 25 - 35 % glycerine. Glycerine is almost infinitely soluble in brine, but at greater than 35% glycerine the lye no longer efficiently removes glycerine from the soap. The soap is allowed to overflow from the top of the column and the lye ("half spent lye") is pumped away from the bottom at a controlled rate and added to the reactor. Step 4 - Lye separation
9
The lye is added at the top of the washing column, and the soap removed from the column as overflow. As the lye is added near the overflow pipe the washed soap is about 20% fresh lye, giving the soap unacceptably high water and caustic levels. Separating off the lye lowers the electrolyte levels to acceptable limits. The soap and lye are separated in a centrifuge, leaving a soap which is 0.5% NaCl and 0.3% NaOH, and about 31% water. The lye removed is used as fresh lye. Step 5 - Neutralisation Although the caustic levels are quite low, they are still unacceptably high for toilet and laundry soap. The NaOH is removed by reaction with a weak acid such as coconut oil (which contains significant levels of free fatty acids), coconut oil fatty acids, citric acid or phosphoric acid, with the choice of acid being made largely on economic grounds. Some preservative is also added at this stage. Step 6 - Drying Finally, the water levels must be reduced down to about 12%. This is done by heating the soap to about 125oC under pressure (to prevent the water from boiling off while the soap is still in the pipes) and then spraying it into an evacuated chamber at 40 mm Hg (5.3 kPa). The latent heat of evaporation lost as the water boils off reduces the soap temperature down to 45oC, at which temperature it solidifes onto the chamber walls.The soap chips are scraped off the walls and "plodded" (i.e. squeezed together) by screws known as "plodder worms" to form soap noodles. The soap is now known as base or neat soap chip, and can be converted into a variety of different soaps in the finishing stages. The moisture evaporated off the wet soap is transported to a barometric condensor, which recondenses the vapour without the system losing vacuum. The moisture can contain soap dust (.Fines.) which is removed by cyclones and returned by augers to the spray chamber, while the water is recycled.
10
Fig.3.2 Process Flow Diagram of Toilet Soap Production
11
CHAPTER 4 4.0 MATERIAL AND ENERGY BALANCES 4.1 MATERIAL BALANCES 4.1.1 ASSUMPTIONS 1. The process is an open system 2. The process occurs at a steady-state condition.
4.1.2 PLANT ATTAINMENT This is defined as the percentage of available hours in a year that the plant operates usually between 90-95%. The process plant will operate three shifts of 8 hours per day. The total downtime (maintenance, shutdowns, and holidays) will take 35 days per year. 330 days
24hours
1 year
1 day
= 7920 hours
Basis chosen is in kg/hr Productivity is 50 tonnes per day In a year, productivity is 50tonnes x 330 days = 16500 tones per year Converting, 16500 tons
1 year
1 year
330 days
1 day 24 hours
1000kg 1 ton
= = 12
Material balance on saponification vessel
NaOH
Tallow SAPONIFICATION VESSEL
Lye
Table 4.1 Summary of material balance on saponification vessel INPUT
OUTPUT
Component
Amount (kg)
Component
Amount (kg)
Tallow
735.29
Wet soap
3707.62
NaOH
272.33
Lye
2700
Total
3707.62
Total
3707.62
13
Material Balance on Static Separator.
Wet soap
Lye STATIC SEPERATOR
Crude soap
Table 4.2 Summary of material balance on static separator. INPUT
OUTPUT
Component
Amount (kg)
Component
Amount (kg)
Wet soap
3707.62
Crude soap
3672.4
Lye
35.22
Total
3707.62
Total
3707.62
14
Material Balance on Washing Column.
Fresh lye
Crude soap
Washed soap WASHING COLUMN
Glycerin
Table 4.3 Summary of material balance on Washing Column. INPUT
OUTPUT
Component
Amount (kg)
Component
Amount (kg)
Crude soap
3672.4
Washed soap
3360.16
Fresh lye
2500
Glycerine
2812.26
Total
6172.4
Total
6172.4
15
Material Balance on Centrifuge.
Washed soap
Wet soap CENTRIFUGE.
Lye
Table 4.4 Summary of material balance on Centrifuge. INPUT
OUTPUT
Component
Amount (kg)
Component
Amount (kg)
Washed soap
3360.16
Lye
672.03
Wet soap
2688.13
Total
3360.16
Total
3360.16
16
Material balance on Neutralizing Vessel.
H3PO4 (Weak acid) Wet soap Salt NEUTRALIZING Additives
Soap
VESSEL.
Salt
Table 4.5 Summary of Material Balance on Neutralizing vessel. INPUT
OUTPUT
Component
Amount (kg)
Component
Amount (kg)
Wet soap
2688.13
Soap
2696.07
Additives
12.57
Salt
24.394
Weak acid
19.76
Total
2720.43
Total
2720.43
.
17
Material balance on Dryer.
Solid soap
Toilet soap DRYER.
Water
Table 4.6 Summary of Material Balance on Dryer. INPUT
OUTPUT
Component
Amount (kg)
Component
Amount (kg)
Soap
2696.07
Toilet Soap
2083.33
Water
585.79
Impurities
26.96
Total
2696.07
Total
2696.07
4.2 ENERGY BALANCE FOR THE VARIOUS UNITS ENERGY BALANCES The conservation of energy however differs from that of mass in that energy can be generated (consumed) in a chemical process. Material can change form and new molecular species can be formed by the chemical reaction, but the total mass flow into a process unit must be equal to the flow out at steady state. This is not true for energy. The total enthalpy of the outlet streams will not equal that of the inlet streams if energy is generated or consumed in the process due to heat of reaction. (Sinnott, 1999) 18
In process design, energy balances are made to determine the energy requirements of the process: the heating, cooling and power required. It shows the pattern of energy usage and suggests areas for conservation and savings. (Sinnott, 1999) 4.2.1ASSUMPTIONS: 1. No accumulation of material and energy; 2. Open systems only; 3. The type of process taking place is continuous; and 4. No change in density of material along the process line.
1.Energy Balance on Saponification Vessel
Where
But for,
[∫
∫
]
At reference state of 250c [∫
∫
]
Hence
19
[∫
]
Where Cp (wet soap)=1.22kj∕kg.k M(mass flow rate)=3707.48kg∕hr T at 250c=298.15 k T at 700 c=343.15k Then (
) |
|(
|)
Where (
) 69.04 kw is the amount of heat energy required by the saponification
vessel. 2. Energy balance on washing column
Where
But for,
Where Hout
: T at 80
0
c=353.15k 20
0 : T at 70 c=343.15k
For
∫
⟨
|
|(
) |
|⟩
⟨
|
|(
) |
|⟩
∫
∫
⟨
|
) |
|(
|⟩
∫
⟨
|
|(
) |
|⟩
21
Hence
(
)
(
)
Then
3. Energy balance on centrifuge The energy consumption of a tubular bowl centrifuge handling dilute slurries is 1.49kw Tubular centrifuge bowl diameter =4.25in Maximum centrifuge force × gravity =13200 Ref.(Robert H.Perry and Don W. Green,Perrys chemical engineershandbook, 7th edition ,page 18-112,table 18-12) Where Q=WS Q=1.49kw Separation factor (ks)
(
)
22
4. Energy balance on Neutralizer
Where
is by definition
(
Compound
NaOH
- 469.43
H3PO4
- 1294.23
)
- 1748.1
NaHPO4
- 285. 85
Hence
[ ∑
∑
]
*(
) (
[(
)+
(
)) [(
(
(
( ))
))] (
(
))] 23
(
)
(
)
Hence Q= -270.29kj/mol The negative value of Q means heat is removed from the reaction. 5.Energy balance on dryer (
) (
( )
(
)
(
)
(
)
)
Where
Then
24
Then total rate of heat transfer ( (
(
)
)
(
)
(
)(
(
)
(
) (
)( (
)( )(
)(
) )
)( )
( (
)
)
)
| |
Hence the enegy needed by the dryer is 15.94kw
25
CHAPTER 5 5.0 EQUIPMENT SPECIFICATION AND PIPELINE SCHEDULE 5.1 EQUIPMENT SPECIFICATIONS Equipment specification typically includes the determination of vessel dimensions and description of other internal parts of the equipment. It also involves the determination of parameters like speed, power and any other operating parameters pertaining to the particular equipment. Specification of equipment can be approached from a duty specification viewpoint. (Cheremisinoff, 2000)
Summary of equipment specification The major considerations under equipment specification are: 1. Identification of the equipment 2. Function of the equipment 3. Material handled 4. Basic design data 5. Material of construction Information and data used are from Peter and Timmerhaus, McCabe and Smith and Chemical Engineering handbook, 5th edition. Saponification vessel Duty: To react sodium hydroxide, tallow and lye. Type: Non reversible Capacity: 50 tonnes/hr Number required: 1
26
Static separator Duty: separates the soap from the lye. Type: a settling vessel which does not use any mechanical action Material of Construction: carbon steel Area: 2.0m2 Width: 1.15m Length: 1.725m Storage Tank 1 Duty: To serve as a stock pile for the tallow. Description: Vertical cylindrical tank with flat ends. Capacity: 1362 m3 Height: 24m Diameter: 8.5m Thickness: 7mm Number required: 6 Material of construction: Carbon Steel. Washing colunm Duty: To remove glycerine from the soap by introducing fresh lye. Type: column with rings fixed on its inside surface. Description: Cylindrical and slightly inclined to the horizontal Inside diameter of washing column: 1570m3 Length: 80m Diameter: 5 m Rotational speed of rings : 1.324 rpm Material of construction: Mild Steel Number required: 1 27
Storage Tank 2 Duty: To temporarily store sodium hydroxide. Description: Vertical cylindrical tank with flat ends. Capacity: 480.66 m3 Height: 17m Diameter: 6m Thickness: 7mm Number required: 2 Material of construction: Carbon Steel Thickness: 7mm Number required: 1 Material of construction: Carbon Steel Neutralizer Duty: to react weak acid with sodium hydroxide. Type: Continuous Stirred Tank Reactor Capacity: 185m3 Height: 8 m Diameter: 5m Material of Construction: Carbon Steel Storage Tank 3 Duty: To temporarily store lye solution before entering saponifier. Description: Vertical cylindrical tank with flat ends. Capacity: 124.8 m3 Height: 11m Diameter: 3.8m Thickness: 7mm 28
Number required: 1 Material of construction: Carbon Steel Dryer Duty: to reduce water levels to about 12% in the toilet soap Type: vacuum shelf dryer Number: 1 Capacity: 2083.33kg/hr Moisture content: 3% Column diameter: 0.9m Number of trays: 10 Hole diameter: 20mm Distance between trays: 20mm Centrifuge Duty: To separate soap and lye Type: Tubular centrifuge Diameter: 4.25in Number: 1 The energy consumption of a tubular bowl centrifuge handling dilute slurries is 1.49kw Tubular centrifuge bowl Maximum centrifuge force × gravity =13200 Separation factor ( kS ) ; 1037557.3
29
5.1 SPECIFICATION OF PIPELINES Table 5.1: Pipeline Specifications
Pipeline Location
Fluid
Mass Flow Fluid
Transported Rate,
Between
the Wet soap
Velocity,
(kg/hr)
m/s
3707.62
9.67
Diameter,
Schedule Material Of
In.
Number
Construction
8
40-S
304 Stainless
saponification vessel
Steel
and the
static separator Between the static Crude soap
3672.4
9.67
8
40-S
separator and the
304 stainless steel
washing column Between washing
the Washed soap
2812.26
2.73
6
40-S
colunm
304 stainless steel
and the centrifuge Between centrifuge Wet soap
2688.13
2.23
6
40-S
and neutralizer Between neutralizer Soap and
the
304 stainless steel
2696.07
2.22
6
40-S
vacuum
304 stainless steel
shelf dryer From vacuum shelf Toilet soap
2083.33
2.34
1.5
40-S
304 stainless
30
dryer
steel
31
CHAPTER 6 6.0 PLANT SITING AND LOCATION 6.1 PLANT SITING AND LAYOUT Application of sound engineering principles, exhaustive costing and profitability analysis only will not be enough for successful operation. The success and profitability of the plant is largely dependent on so many factors. These factors are: 1. Plant location 2. Availability of raw materials 3. Marketing areas 4. Maintenance 5. Availability of utilities: water, fuel, power, etc. 6. Availability of cheap labour 7. Personal safety measures 8. Control and instrumentation 9. Storage facilities 10. Pollution control 11. Quality control
6.1.1 PLANT LOCATION The geographical location of the plant has a strong influence on the success or failure of the plant. In other words, it has a crucial effect on the profitability of the plant, and the scope of future expansion. Therefore, a plant should be located where minimum cost of production, as well as distribution could be obtained, amongst other factors. 6.1.2 CHOICE OF LOCATION In order to make the design project realistic, the aspect of site selection must be given some consideration. There are a number of considerations concerning the choice of site locations for a toilet soap plant within the country. Some of these are general considerations whilst others relate directly to the process and its requirements. The following list contains a few of the important considerations. 30
a. Designation as a heavy industrial development area. b. Prior existence of similar chemical plants and location of other industrial centers c. Existing roads and services and also appropriate terrain, sub surface, drainage etc. d. Suitable access for transportation for transportation of raw materials and chemicals and for construction of a chemical plant. e. Availability of a local workforce and distance from local communities. f. Environmental discharge regulation and cost of land and services etc g. Climatic condition h. Proximity to both the raw materials supply and the market for the product chemical. i. Political and strategic considerations. j. Location community considerations. k. Proximity to major transportation networks e.g. roads, railways. l. Availability of suitable land etc. The importance of the geographical location of the plant cannot be over emphasized. The locations considered for the sitting of the toilet soap plant are Kumasi in the Ashanti Region, Tema in the Greater-Accra Region and Takoradi in the Wetern Region. After detailed analysis of the various locations appropriate for sitting the toilet soap plant has been done, the location of the toilet soap plant will be Takoradi in the Western Region of Ghana. Some of the factors considered were:
31
Availability of Raw Material The main raw materials for the toilet soap plant are tallow and Sodium hydroxide. Looking at the probable site location, Takoradi in the Western Region was selected as the most probable for this plant since it is the capital of the Western region. Takoradi and some of its surrounding towns produce a high level of animal fat which is obtained at the abattoir and thus imply a good availability of tallow in that area. It being a coastal town, NaOH can easily be imported from overseas for the purpose of soap production and thus if the plant is sited in Takoradi , raw materials will not be a problem.
Availability of Suitable land The suitability of land is judged based on some factors including: drainage, load bearing characteristics and flatness. The sites must therefore be evaluated to determine the need for any special foundations, and Takoradi qualifies because it has all this positive characteristics. Transportation Facilities The fact that Takoradi is a regional capital assures any investor of good transportation facilities. The town’s proximity to the port serves as a good means of easily transporting the sodium hydroxide by sea. Also the ease of moving the raw materials from the sites is assured. The region has a good railway and road network to transport some of the product; toilet soap, to some local customers. Utilities There exists a power line network connecting, Takoradi to the national source of hydroelectric power. With respect to the current trend of power outages, we envisage that the by the time the project is completed and ready to commence, this problem would have capsized. But if the worse happens, the plant would have to resort to the Thermal Plant or any other cheaper form of energy available. Moreover because some units will run on gaseous fuel (natural gas) it is a good site because of the West-African Gas pipeline project which is expected to be operational by the commencement of this 32
project. Water is also needed for the various processes involved in the production, as well as other non-production related purposes such as drinking, washing and sanitary purposes among others. Takoradi has a good source of water supply which is of good quality to our plant. All the major towns in and around the regional capital have their buildings well laid out with defined access routes and well planned layouts. Availability of labour Generally, skilled labour must be brought in for the construction of the plant. However, there must be adequate labour (skill and unskilled) in the locality for the operation of the plant. The availability of cheap labour in developing countries including Ghana and therefore, favours this possible plant location. Takoradi having attained metropolitan status and the region’s jubilee field (crude oil) sector in particular and agriculture in general attracts migrants to Takoradi. The migrant population shows that males are attracted to the town than females. With the advent of the toilet soap plant in that area, the youth will be employed on the plant site in various forms of casual work. Unemployment among the youth like any other densely populated area is high. Thus labour, especially unskilled labour will not be a problem. Skilled labour can also be brought in for special purposes. Market Areas The local consumption and export needs are the primary focus for production, since future expansion would seek to explore opportunities in the West African Region as well as other parts of the world. Because transportation cost takes up a significant fraction of the sales price, it is one of the reasons why our plant will be situated close to the primary market and closer to the seaport and habour which is also in this town Takoradi. Moreover the major market for the highly manufactured toilet soap is the foreign market. Since a higher percentage of the product would be exported out of the country. With the plant site being Takoradi which has a Sea Port renders the site very suitable. The local market can also be served with adequate supply of toilet soap by the means of good road and rail networks in the region and across the other regional and district capitals. 33
Climate This is considered a very important factor when choosing a location for the plant. Generally, adverse climate conditions at a plant site will increase cost. Ghana has two major seasons (dry and rainy seasons) which is common to all the possible plant location. This factor thus favours the possible plant location. Political and strategic considerations Sometimes, the choice of location provides certain benefits from the government in terms of capital grants, tax concessions and other inducements. For this factor however, since government benefits of this sort are spread around Ghana, the possible location is also favoured by this factor. Local community consideration It is important to locate the plant in a safe community and where it is accepted. The community should also be able to provide adequate facilities for plant personnel such as schools, banks, housing, and recreational and cultural facilities. Since Takoradi is the regional capital; schools, banks, housing and other recreational facilities are present with more to be created upon the establishment of the plant thus making it a favourable location.
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CHAPTER 7 7.0 ECONOMIC ANALYSIS This plant design project aims to present a process that is capable of operating under conditions which will yield profit. As a necessity the economic viability of this manufacturing business must be addressed considering the society and government with which it will operate. The primary concern of an investor lies in the rate of return (ROR) based on accurate cost estimates and sound data. Since net profit equals total income minus all expenses, it is essential that all the costs involved in manufacturing processes are considered. A capital investment is required for any industrial process and the determination of the process consists of fixed capital Investment of physical equipment and facilities in the plant plus necessary investment is an important part design project. The total investment for any working capital which must be available to pay salaries, keep raw materials and products on hand and handle other special items requiring a direct cash outlay. Thus in this analysis income tax is taken into consideration. Using the payback period, rate of return and unit product cost a profitability analysis will be conducted to see the viability of this plant design. Basis of economic analysis:
Start of construction: January, 2011
Completion of construction: January, 2012
Commencement of processing: Jan 2013
Plant operation: 3 shifts per day
Process: Continuous
Plant life: 15years (Peters et al,1986)
Plant production rate: 16,500 tonnes per annum
Working period: 330 days
Production capacity: varied over the years
Selling price of toilet soap: $1.50
Chemical Engineering Cost index for 2008 = 1495.7
Time value of money is not neglected
Exchange rate of dollar :GH ¢ 1.40 35
7.1 TOTAL CAPITAL INVESTMENT Before an industrial plant can be put into operation, a large sum of money is needed to purchase and install the necessary machinery and equipments, obtain land and service facilities and also the plant must be erected complete with all piping, controls and services. Many must also be available for the payment of expense and involved in the plant operation (peter et al). The total capital investment is the sum of the following: Fixed Capital Investment (FCI) is the capital needed to supply all manufacturing and plant facilities. FCI can also be defined as the total cost of the plant ready for start up (Coulson and Richardson, Volume 6). This includes:
Direct (manufacturing) fixed capital investment – the amount of money necessary for the installed process equipment with all auxiliaries needed for a complete process operation (e.g. purchased equipment cost, equipment installation cost, instrumentation and control cost, piping cost, electrical equipment and material cost, building (including services) cost, yard improvement cost, service facilities coat, land cost, etc)
Indirect (non manufacturing) fixed capital investment – construction overheads and all plant components which are directly related to the process operation. (e.g. engineering and supervision cost, construction expenses, contractors fee, contingency fees, warehouse, laboratories, transportation, utility etc)
Working Capital is the capital needed for the daily running of the plant. In other words , it is the additional investment capital needed over and above the fixed capital investment to start the plant, to operate it to the point when income is earned. This consists of the total amount of money invested in
Start up
Raw material and supplies carried in stock
Finished and semi finished products in stock
Accounts receivable and payable
Cash kept on hand for monthly payment of operating expenses
Taxes payable
It is estimated that working capital is approximately 15% of total capital investment.
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7.2 FIXED CAPITAL INVESTMENT The fixed capital investment is the capital needed to supply the necessary manufacturing and plant facilities (peter et al). It can also be defined as the total cost of the plant ready for start up (Coulson and Richardson, volume 6). The fixed capital investment can be divided into two. That is: 1. The direct fixed capital investment 2. The indirect fixed capital investment.
7.3 ESTIMATION OF DIRECT FIXED CAPITAL INVESTMENT Table 7.1: Cost of Equipment in 2009
Item no.
Service
Cost $
VE-101
NaOH Storage tank
14904
VE-105
Water Storage tank
6505
VE-110
Saponifier vessel
VE-205
Lye Preparation tank
8280
DA-101
Soap dryer
7300
HE-101
1st Soap Heater
2505.3
SE-101
Static Separator
649,600
CO-101
Washing Column
21,900
CE-201
Centrifuge
6900
VE-105
Neutralizer Vessel
146302
265,700
Source: Perry’s Total Equipment Cost = $1,129,896.3
Purchased Equipment Installation Cost The installation of the equipment includes factors directly related to the erection of purchased equipment (e.g. painting, platforms, insulation, formulation, construction expenses). This is estimated to be 25% of the purchased equipment cost (Peter et al, 1990). 37
Instrumentation and Control Cost Instrument cost, installation-labour cost and expenses of auxiliary equipment and materials constitute the major portion of the capital investment required for instrumentation (peter et al). This component is estimated to be 8% (for normal solidfluid chemical process plant) of the purchased equipment cost (Peter et al, 1990).
Piping Cost This refers to the cost for raw material, intermediate-product, finished-product, steam, water, and waste products piping (Peter et al). Items involved in the complete erection of all piping used directly in the process which include the labour, valves, fittings, pipe, support etc. The piping cost is estimated to be 30% of purchased equipment cost (Peter et al, 1990).
Cost of Electrical Systems The electrical system consists of the power wiring, lighting, transformation and services, and instrument and control wiring. This component is estimated to be 12% of the purchased cost (Peter et al, 1990).
Cost of Buildings and Structures The cost involved in the erection of all buildings connected with the plant (labour, materials and supplies). Cost for plumbing, heating, lighting, ventilation, and similar building services are included here. This component is estimated to be 47% (for solidfluid process plant, new plant and new site) of the purchased equipment (Peter et al, 1990).
Cost of Yard Improvement This involves costs for fencing, grading, roads, sidewalks, rail road sidings, landscaping and similar items. Yard improvement cost for chemical plant is estimated to be 10% of the purchased equipment cost (Peter et al, 1990). 38
Service Facility and Utility Cost Utilities for supplying steam, water, power and fuel are part of the service facilities of a chemical process plant. Services include the cost of waste disposal, fire protection, and miscellaneous service items (shop, first aid, cafeteria equipment etc). This component is estimated to be 30% of the purchased equipment cost (Peter et al, 1990).
Cost of Land The plant will be sited at Takoradi in the Western Region. The cost of land per plot (30mx30m) is GH¢600. The number of plots needed for the construction of the plant is 10, making room for future expansion of the company, 25% of the land needed will be added, and the total land needed is 11,025m2. The total cost will be GH¢7500 ($5357.14)
7.4 ESTIMATION OF INDIRECT FIXED CAPITAL INVESTMENT Engineering and Supervision Cost This involves construction design and engineering, drafting, purchasing accounting, construction and cost engineering, travel, reproductions, communications and home office expenses including overhead. This component is estimated as 8% of the total direct costs of the process plant (Peter et al, 1990). Construction Expenses This cost component involves construction and operation, construction tools and rentals, construction payroll, taxes, insurance and other overheads. This component is estimated as 10% of the total direct cost (Peter et al, 1990). Contractors’ Fee The contractors’ fee can be taken as 5% of the total direct cost (Peter et al, 1990).
39
Contingency Fees A contingency amount is included in all estimates of total capital investment in recognition of the fact that, there will be unexpected events and changes that will inevitably increase the cost of the project (i.e. strikes, price changes, small design changes, storms, floods etc). This component is estimated as 8% of the total direct and indirect cost (Peter et al, 1990).
Table 7.2: Summary of the Total Capital Investment Estimation Estimated Cost, Item
$
Purchased equipment cost
1129896.3
Purchased equipment installation
1955890.93
Instrumentation and controls
625885.1
Piping (installed)
2347069.116
Electrical (installed)
938827.65
Building (Including services)
3677075
Yard improvements
782356.37
Service facilities
2347069.116
Land
5357.14
Total Direct Cost(TDC)
13,809,426.72
40
TOTAL INDIRECT COST (TIC) Item
Estimated cost
Engineering and Supervision
1640247-531
Construction expense
2050309.414
Contractors Fee
1025154.707
Contingencies
1640247.531
TOTAL TIC
6355959.183
TOTAL FIXED CAPITAL INVESTMENT (TFCI) = (TDC) + (TIC)
20165385.90
WORKING CAPITAL (WC)= 15%(TFCI)
3024807.885
TOTAL CAPITAL INVESTMENT(TCP)$ = 23,190,193.79 (TFCI + WC)
7.5 ESTIMATION OF TOTAL PRODUCT COST The two basic components that affect product pricing are costs of manufacture and competition in selling. It is unprofitable to sell a product below the manufacturer’s production costs and unfeasible to sell it at a price higher than that at which comparable merchandise is being offered. Other variables also affect pricing. Company policy may require a minimum profit on new product lines or a specified return on investments, or discounts may be offered on purchases in quantity.
41
This involves the estimation of cost for operating the plant and selling the products. Total product cost is broken down into two: Total Product Cost = Manufacturing Cost + General Expenses The manufacturing cost (direct product cost) is also subdivided into the fixed charges, plant overheads and variable production cost. The fixed charges are costs that do not vary with production rate, where as the variable production cost is the cost dependent on the amount of product produced. Plant overheads comprise hospital and medical bills, general plant maintenance cost safety services among others (Peter et al, 1990). The general expenses comprise administrative expenses, distribution and marketing expenses and research and development expenses. An additional 12.5% 0f the total cost for direct and indirect labour is included to account for the social security contributions for each employee.
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Operating Labour Table 7.3: Direct and Indirect Labour Costs (DLC and ILC) Direct Labour Cost (DLC) Staff
Number
Annual Salary Per
Total Annual
Head, $
Salary, $
Plant Manager
1
80,000
80,000
Production Manager
1
70,000
70,000
Chemical Engineer
2
65,000
130,000
Mechanical
2
63,000
126,000
Electrical Engineer
2
63,000
126,000
Quality Assurance
1
55,000
55,000
Supervisors
5
45,000
225,000
Lab Technicians
5
18,000
90,000
Plant Site Workers
15
4,800
72,000
Total (DLC)
34
Engineer
Manager
974000
43
Indirect Labour Cost (ILC) Staff
Number
Annual Salary Per
Total Annual
Head, $
Salary, $
Managing Director
1
80,000
80,000
Human Resource
1
50,000
50,000
Sales Manager
1
45,000
45,000
Accountant
2
40,000
80,000
Store Keeper
2
15,000
30,000
Receptionist and
1
10,000
10,000
Cleaners
5
2,400
12,000
Drivers
6
3600
21,600
Security men
8
3000
24,000
Manager
Secretary
352600
Total (ILC) (DLC + ILC)
1326600
Social Security
12.5%(DLC +
165825
Contributions
ILC)
44
1492425
TOTAL LABOUR COST
7.6 DETERMINATION OF MANUFACTURING COST Raw Material The raw materials needed in this project are Table 7.4: Raw Materials Raw Material
Annual Quantity
Unit Cost/kg, $ Annual Cost ($)
Tallow
5823496.80 kg
0.714/20kg
207,898.84
Sodium hydroxide
2156853.60 kg
0.178
383,919.94
591,818.78
Total
Utilities This includes the cost of the total cost of electricity, process cooling water, and other forms of utility that is required to keep the plant in operation. This component is estimated as 10% of the total equipment cost. Maintenance and repairs If a plant is to be kept in efficient operating condition, a considerable amount of expenses is necessary for maintenance and repairs. Since the annual cost for the plant is high, this component is estimated as 6% of the fixed capital investment.
45
Operating supplies This includes the cost of items such as lubricants, test chemicals, charts etc, required to keep the plant functioning efficiently. It is assumed to be 15% of maintenance and repairs. Laboratory Charges This involves cost of laboratory tests for control operation and product quality control. It is taken as 20% of operating labour.
Table 7.5: Total Annual Direct Product Cost Description
Total Annual Cost, ($)
Raw Materials
591,818.78
Operating Labour
1,492,425
Operating Supplies
181,488.47
Power and Utilities
112,989.63
Maintenance and Repairs
1,209,923.15
Laboratory Charges
298,485
Total Annual Direct Product Cost
3,887,130.03
.
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CHAPTER 8 8.0 PLANT SAFETY AND POLLUTION CONTROL 8.1 PLANT SAFETY Every organisation (company or industry) has the moral and legal obligation to protect the health and welfare of its employees as well as that of the general public. Therefore, good safety measures have to be put in place to ensure the safety of lives and prevent damage to equipment. The primary aim of these safety measures therefore is to prevent or minimize workers exposure to the potential hazard, injury to workers, loss of lives, and destruction of properties. They are also needed to ensure safe as well as efficient operation. These safety measures are employed in industry mainly to prevent or control hazards. A hazard is a property which in particular circumstances could lead to harm. Common safety hazards in the manufacturing industry include; dangerous machinery, explosion to fires, faulty electrical connections and falling materials due to poor housekeeping among others. The potential hazards that could be present in the toilet soap plant include hazards due to materials handling and hazards due to the various processes. Hazards due to materials handling Potentially hazardous situations include handling and packaging operations, equipment cleaning and repair, decontamination following spills and equipment failure. Hazards that workers are likely to be exposed to can be prevented by a number of ways, example of which is the provision of PPEs (Personal Protective Equipment). These equipments include chemical splash goggles, overcoat/chemical suit, rubber boots, ear plugs, face shield, etc. These equipment are worn to protect the worker from the dangers of handling some of the chemicals especially sodium hydroxide. Hazards due to various processes Hazards that might be caused during processes in this plant include fire hazards, electrical and mechanical hazards.
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Fire Hazards: During the process of heating the raw materials, for example, heating takes place at high temperatures of about 600-650⁰C with the production of hot flue gases through a chimney. Care must be taken near or during operation of the saponification vessel for example the control of temperature. Labourers are so careless and tend to attempt checking temperature manually. This and many other careless practices may lead to a fire hazard. Overheating of vessel should also be avoided to prevent explosions or fire outbreak.
Electrical Hazards: The main source of energy for this plant is electricity since most of the process units would be powered by it .Care must be taken in dealing with electric powered units, power should be shut down immediately when faulty electrical connections are detected and alternative power source be sought for use. Workers must also be careful especially during power fluctuations as this might cause electrocution or explosions that might lead to fires.
Mechanical Hazards: These hazards may be due to improperly fixed or dangerous machinery. Some machines are designed in such a way that it picks everything in its path. For example packaging. Such equipment is likely to cause a mechanical hazard. Parts of machinery should not be left just anywhere on the plant site. Rather, good housekeeping of machine parts should be employed.
With the above mentioned safety measures, the plant can be safe to work on.
8.2 POLLUTION CONTROL Pollution according to the Dangerous Substances Directive 76/464/EEC of the European Union is the discharge by man directly or indirectly of substances or energy into the environment, the result of which causes hazards to human health, harm to living resources and to ecosystems, damage to amenities or interference with other legitimate uses of the environment.
Pollution in any industry is of major concern because the more or less it produces pollutants indicates the level of control measures in place. Pollution can either be abated by preventing it at the source or using the end-of-pipe technology. The concept of zero emissions and pollution prevention at source is the best and less expensive option for any industry. This is where raw materials are prepared and purified through initial cleaning processes before production. 48
However most of the pollution control measures are end- of- pipe technology where waste at the end of production is treated before released.
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CHAPTER 9 9.0 DISCUSSION At this end, one can envisage that the production process is a feasible one within the confines of the country. With the abundance of tallow in Ghana and its neighboring country, Ivory Coast, the possibility of raw materials shortage is extremely low. This plant can be duplicated in regions in the country in which the raw materials are readily available. The establishment of this plant in other locations will provide employment. From the literature, the tallow, when left to decompose, tend to be very toxic to the soil. This process introduces a way out whereby almost all of the tallow would be utilized in this very lucrative venture. The glycerine, also, obtained after the saponification process, serves as a valuable source of product for export and other purposes. With the advancement of this project some measures will have to be put in place to ensure that the quality of the toilet soap remains unaltered. Thus the farmers (animal rearers) will have to be motivated to produce a high quality of tallow required for efficient production. With the high rate of return over the plant life, this project is very viable and rewarding to investors and the nation (product is for exportation).
A continuous operation is preferred for the plant due to the following reasons (Peters et al, 1991): 1. A specific product (toilet soap) 2. The production rate is far greater than 16500 tonnes per annum. The chosen process for the production of toilet soap will be the best since the batch method will not be cost effective.
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CHAPTER 10 10.0 RECOMMENDATION
We recommend that, in the near future, the industry should partner with the abattoirs and oil companies to reduce the purchase cost of raw materials.
Due to the cost intensive nature of this project, a lower annual production rate should be used.
The issue of safety and control should be enforced at all levels and times to ensure the smooth running of the plant, to protect lives and the environment as a whole.
The marketing department should market the product to raise the profitability measure higher than as shown during the plant life.
The processes and product of the plant be subjected to ISO audit to give the company the needed recognition on the world market.
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REFERENCES
http://www.answers.com/topic/toilet soap. 14th March, 2011. 8:46 pm
Sinnott, R.K. (1999). Coulson and Richardson’s Chemical Engineering Design, Vol. 6, Third Edition, pp. 407, 435
Perry Robert H., Green Don W., (1999), Perry’s Chemical Engineer’s Handbook, 7th Edition, McGraw-Hill Companies Inc., pp. section 18-2 to 18-12.
Liddell, Donald M. 1922. Handbook of Chemical Engineering, Volume 1,1st edition, McGraw Hill.
Walas, Stanley M. (1990) Chemical Process Equipment (Selection and Design).In Mixing and Agitation Chapter 10, pp. 287-296.
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APPENDIX MATERIAL BALANCE ON THE PRODUCTION OF 50TONS TOILET SOAP PER DAY ASSUMPTIONS The process is an open system The process occurs at a steady-state condition. PLANT ATTAINMENT This is defined as a percentage of available hours in a year that plant operates usually between 90-95%. The process plant will operates three shifts of 8 hours per day. The total downtime (maintenance, shutdowns and holidays) will take 35days per year. 330days
24hrs
1year
1day
Basis: kg/hr Productivity is 50 tonnes per day In a year, productivity is 50 tonnes × 330days = 16500tonnes per year Converting, 16500
1year
1day 1000kg
1year
330days
24hrs 1ton
= 16500 000kg 7920hr =2083.33kg/hr
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BALANCES ON SAPONIFICATION VESSEL Reaction: (C17H35COO) C3H5 + 3NaOH
3[C17H35COONa] + C3H5(OH)3
Mass of soap to be produced = 2083.33kg/hr Molecular weight of soap = 306g/mol n = 2083.33kg hr
mol
1000g
306g
1kg
= 2083330 306 = 6808.27mol/hr Hence, 1 mol Tallow
6808.27mol/hr
3mol Soap = 2269.42mol/hr But, n= m/M
m=nM
m = 2269.42mol
324g
hr
mol
1kg 1000g
= 735293.16 1000 = 735.29kg/hr Also, n(NaOH) = n(Soap) n(NaOH) = 6808.29
m=n×M 54
= 6808.29mol 40g Hr
1kg
mol
1000g
= 272.33kg/hr Amount of lye to be used at the saponification vessel = 2700kg/hr
BALANCES ON STATIC SEPERATOR Wet soap = Lye + Crude soap Lye
= Wet soap – Crude soap
Lye
= 3707.48 – 3672.4
Lye
= 35.08kg/hr
BALANCE ON WASHING COLUMN Total Material Balance C.S + F.L = B + 3360.163 Where, C.S = Crude soap; F.L = Fresh lye B = Washed soap F.L = 2500kg/hr C.S + 2500 = B + 3360.163
Fresh Lye Component Balance F.L = 0.65B + 0.2 (3360.163) 2500 = 0.65B + 672.033 0.65B = 1827.967 B = 2812.257 From T.M.B, C.S + 2500 = 2812.257 + 3360.163 C.S = 2812.257 + 3360.163 – 2500 C.S = 3672.4kg/hr BALANCES ON CENTRIFUGE 55
Total Material Balance W.S = L + W.S Where, W.S = Washed soap L = Lye W.S = Wet soap WS = L + 2688.13------- (1) Lye Component Balance 0.2 W.S = L--------- (2) Substituting (2) into (1) W.S = 0.2W.S + 2688.13 0.85W.S = 2688.13 W.S = 3360.163kg/hr
BALANCES ON NEUTRALIZER Neutralization reaction NaOH + H3PO4
NaH2PO4 + H2O
Soap (Solid) Component Balance W.S (0.682) = 2656.96 (0.69) W.S (0.682) = 1833.302 W.S = 2688.126kg/hr
NaOH Balance 0.003 (2688.126) = 8.064kg/hr Therefore, 1 mol NaOH 1 mol H3PO4
But n = m
M (NaOH) = 40g/mol 56
M n (NaOH) = 8.064 kg
mol
Hr
1000g
40g 1kg
n = 201.6mol/hr Therefore, 1 mol H3PO4
201.6 NaOH
1mol NaOH n (H3PO4) = 201.6mol/hr m (H3PO4) = n × M = 201.6 mol Hr
98g mol
1kg 1000g
m (H3PO4) = 19.76kg/hr
From Stiochiometric Ratio 1mol NaH2PO4
201.6 NaOH
1 mol NaOH = 201.6mol/hr M (NaH2PO4) = 121g/mol n=m/M m (NaH2PO4) = 121g 201.6mol 1kg mol
hr 1000kg
m (NaH2PO4) = 24.349kg/hr Then, Total Material Balance W.S + H3PO4 + Additives = S + NaH2PO4 2688.13 + 19.76 + Additives = 2696.04 + 24.394 Additives = 12.54kg/hr
BALANCE ON VACUUM DRYER Total Material Balance 57
S = W + 2083.3kg/hr Where, S = Soap W = Water
Solid Component Balance S (0.68) = 2083.33 (0.88) 0.68S = 1833.33 S = 2696.07kg/hr
Water Component Balance 2696.07 (0.31) = 2083.3 (0.12) + W 835.782 = 249.996 + W W = 835.782-249.996 W = 585.79kg/hr
For Impurities 0.01 (2696.07) = 26.96kg/hr
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