MANUFACTURE OF NAPHTHALENE
Plant Safety Introduction
The significance of Safety & Health in chemical industries has been a vital issue in achieving productivity and an edge in the competitive world. All applicable laws and regulations on environmental protection or plant and industrial safety must be fully complied with. Compliance with all legislation to protect human beings and the environment is one of the company’s basic tenets for both legal and ethical reasons. This ap plies ap plies to our products as well as to our processes.
Areas of Concern Dangerous Materials
i)Explosives ii) Gases iii) Inflammable Liquids iv) Inflammable Solids v) Oxidising substances vi) Toxic and Infectious substances vii)Radio Active Substances viii)Corrosive Substances ix)Miscellaneous Dangerous Substances Hazards Of Pressure Vessels
1.Leakage or Bursting of Pressure Vessels 2.Design defects 3.Failure of Relief Systems 4.Lack of hydraulic testing. 5. Lack of Proper Instrumentation or Instrumentation Failure 6.Lack of N.D.Tests 7.Corrosion of Vessels. 8. Lack of routine inspections 9. Attempt of Pneumatic testing Hazardous Chemical Reactions
Understanding about the behaviours of reactions and adopting precautionary and emergency measures. Hazards of Unit operations
Understanding the hazards inherent in each unit operation and adopting precautionary and emergency measures
Heat Transfer
Surface fouling and leakage, Miscalculation in scaling, Mixing of fl
Size Reduction
Dust explosions, Dust release etc.
Flammable Gases, Vapours And Dust Hazards
Identification of potential areas, where possibility of flammable mixture are possible.
Efforts to avoid hazardous mixtures, by inert gas purging and other methods.
Declaring hazard zones and providing flame proof electrical fittings and equipments.
Providing Explosion Vents in spaces with possibility of air-vapour mixtures.
Explosive meter testing.
Providing adequate fire control devices.
Providing arrangements to avoid static sparks. Etc.
Health Hazards
Identification of potential health hazards.
Assessment of levels of physical and chemical health hazards.
Control of hazards by various techniques
Adequate awareness among the workers.
Periodic medical examination of the workers.
Personal protection for occasional exposures.
Proper hygiene and decontamination facilities. etc.
Entry into Confined Spaces
1.Oxygen
Deficiency
Environment4.Possibility
2.
Toxic of
Contamination
Electrocutions
3. through
Flammable electric
equipments5.Possibility of Toxic gas generation during the work 6.Lack of Ventilation 7.Difficulty in welfare monitoring 8.Failure to escape on emergency 9.Combustible Substances
Hazards Due To Corrosion
Weakening and falling of structures and sheds.
Falling of workers from height due to breaking of raised platforms, hand rails, toe boards, stairs and ladders.
Spills and toxic releases from pipelines due to corrosion.
Leakages and bursting of vessels due to corrosion.
Corrosion monitoring and control.
Testing and inspection of vessels and structures to ensure safety.
Hazards Due To Instrument Failures
Absence of fail safety instruments.
Lack of interlocks and trip systems.
Human failures in manual and semi automatic operations.
Need for safety analysis of the instrumentation systems
General Safety Rules
Smoking is not allowed in any part of the refinery area except in smoking booths.
Use of PPE is mandatory in the plant area.
Before entering deposit all the matches, lighter or any other spark producing device.
Only DCP or CO 2 extinguishers are to be used in cause of a fire around electrical equipment.
Never enter work area without safety helmet. When dangerous or unsafe condition is observed report to the supervisor or fire and safety division.
Job area should be cleaned as soon as job is completed.
Always use walkways instead of shortcuts.
All stairways, platforms and walkways must be kept clean at all times.
Compressed air must not be used except for process and system requirements.
Never look directly into the arc produced while welding without proper eye protection.
Defective equipment of any kind should not be used.
Keep the access to fire fighting equipment free of obstructions as these are required to be used in emergencies.
Polyester or nylon clothing should not be worn while on duty as these create hazards of static charge.
Protruding nails should be pulled out or bent over.
Goggles or shields must be used when working under any circumstances when there are possible eye hazards.
All stairways, platforms and walkways must be kept clean at all times.
Compressed air must not be used except for process and system requirements.
Never look directly into the arc produced while welding without proper eye protection.
Defective equipment of any kind should not be used.
Keep the access to fire fighting equipment free of obstructions as these are required to be used in emergencies.
Polyester or nylon clothing should not be worn while on duty as these create hazards of static charge.
Protruding nails should be pulled out or bent over.
Goggles or shields must be used when working under any circumstances when there are possible eye hazards.
When working around moving machinery the wearing of loose clothing such as lunges, dhoti etc are strictly prohibited.
Vehicles of all types must be equipped with approved type of spark arrest s and muffler system before entering in the production area.
Protective valve caps must be placed on all gas cylinders except when in use.
Do not enter into enclosed places without strictly observing the defined precautions.
Do not touch hot pipes without wearing suitable protective clothing.
Wear ear protection in areas of high noise levels.
Safety Signs
Plant Layout Introduction
A plant layout study is an engineering study used to analyze different physical configurations for an manufacturing plant. It is also known as Facilities Planning and Layout. A suitable site must be found for a new project, and the site and equipment layout planned. Provision must be made for the ancillary buildings and services needed for plant operation and for the environmentally acceptable disposal of effluent. Plant layout refers to the arrangement of physical facilities such as machinery, equipment, furniture etc. within the factory building in such a manner so as to have quickest flow of material at the lowest cost and with the least amount of handling in processing the product from the receipt of material to the shipment of the finished product. Factors affecting plant layout
While deciding a factory or unit or establishment or store, we should keep the following factors in mind: 1) Location with respect to the market area. 2) Raw material supply. 3) Transport facility. 4) Availability of labour. 5) Availability of utilities: water, fuel, power. 6) Availability of suitable land. 7) Environmental impact and effluent disposal. 8) Local community considerations. 9) Climate. 10) Political and strategic considerations.
Cost Estimation Estimation of total capital investment
The total investment “I” involves ::Fixed investment in process area “IF” Investment in auxiliary services “IA” Investment in working capital “IW” i.e. I = IF + IA + IW The approximate cost of various equipments used in the proposed plant are:Equipment
No.
Cost ( Rs. Lakh)
Gas Stripper
1
360
Hear Exchanger
2
300
Reactor
1
150
Equipment
Nos.
Cost (Rs. Lak
Furnace
1
120
Separator
1
200
Fractionator
1
350
Miscellaneous
1
700
Direct Cost Factors
Items
Cost (Rs. Lakh)
Purchased equipment cost
250
Equipment installation
80
Insulation
60
Instrumentation
300
Total Direct Cost = ((Equipment Cost)*(Direct Cost Factor))/100 = (3160*945)/100 = Rs. 20601 Lakh
Indirect Cost Factors
Indirect cost = ((Direct cost)*(Indirect cost factor))/100 = (20601*156)/100 (20601*156)/100 = Rs. 32137.56 Lakh Total fixed investment “IF” = Total direct cost + Indirect cost = 20601 + 32137.56 = Rs. 52738.56 Lakh
Auxiliary Investment Investment
Items such as steam generators, fuel stations & fire protection facilities are commonly stationed outside the process area & serve the system under consideration.
Items
% of total installed install ed cost
Investment total fixed
100
Auxiliary building
5
Water supply
2
Electric main substation
1.5
Process waste system
1
Raw material storage
1
Fire protection
0.7
Roads
0.5
Sanitary & waste disposal
0.2
Auxiliary cost (IA) = ((Total fixed investment)*(Auxiliary cost factor))/100 = (52738.56*112.3)/100 (52738.56*112.3)/100 = Rs. 59225.4 Lakh Total installed cost = Total fixed investment + Auxiliary cost = 52738.56+59225.4 52738.56+59225.4 = Rs. 111963.96 Lakh
Working Capital
This is the capital fixed up in the interest of the system in the form of ready cash to meet operating expenses, inventories of raw materials & the products. The working capital may conveniently be assumed as 15% of total investment made in plant. Working capital =111963.96*15/100 =111963.96*15/100 = Rs. 16794.59 Lakh Total capital investment = Total installed Cost + Working capital = Rs. 128758.55 Lakh
Estimation of manufacturing cost
The manufacturing cost can be divided into three items a) Proportional to total investment b) Anticipated production rate c) Labor requirement
Proportional Proportional to total investment
This includes the factors which are independent of the production rate & proportional to the fixed investments such as :
Maintenance
Property tax
Insurance
Safety expense
General services
Administrative services
This can be taken as 15% per year of total installed cost i.e. 52738.56*15/100 52738.56*15/100 = Rs. 7910.784 Lakh Anticipated production rate
The factors proportional to production rate are :
Raw material cost
Utilities cost
Maintenance cost
Chemical, warehouse and shipping
Assuming that the cost proportional to production rate is nearly 60% of the total capital investment. i.e. 128758.55*60/100 128758.55*60/100 = Rs. 77255.13 Lakh Labor Requirement
The manufacturing cost proportional to labor might amount to 10% of total manufacturing cost. i.e. (7910.784+ 77255.13)*10/100 = Rs. 8516.59 Lakh
Total Manufacturing cost = 7910.78 + 77255.13 + 8516.59 = Rs. 93682.5Lakh Sale price fixation
Rs. 80/Kg. Profitability analysis
Total sales income = 80*2000 = Rs. 160000 Lakh Depreciation
Using sinking fund method. R = (V-Vs)(i/((1+i)^n-1)) R = Uniform annual payment at the end of each year V = Installed cost of plant Vs = Salvage value of plant after n years n = Life period (Assumed to be 15 years)
i = Annual interest rate (taken as 15%) R = (11963.96-0)(0.15/((1+0.15)^15-1)) (11963.96-0)(0.15/((1+0.15)^15-1)) = 162296.39*0.021 162296.39*0.021 = Rs. 251.24 Lakh Gross profit
Gross profit = Net income from annual sales – sales – Annual Annual manufacturing cost = 160000 – 160000 – 93682.5 93682.5 = Rs. 66317.5 Lakh Net profit rate
It is defined as the expected annual return on investment after deducting depreciation and taxes. Tax rate is assumed to be 40% Net Profit = Gross profit – profit – Depreciation Depreciation – – (Gross (Gross Profit*Tax rate) = 66317.5 – 66317.5 – 251.24 251.24 – – (66317.5*40/100) (66317.5*40/100) = 20795.11 – 20795.11 – 9681.33 9681.33 = Rs. 39539.26 Lakh
Annual rate of return
Annual percent return on the total initial investment after income taxes = (Net profit/Total installed cost)*100 = (39539.26/111963.96)*100 (39539.26/111963.96)*100 = 35.31% Payout period
Payout period = Total installed cost/(Depreciation + Net profit) = 111963.96/(251.24 + 39539.26) = 2.813 years
References
Plant Design and Economics for Chemical Engineers Author: Max Peters, Klaus Timmerhaus, Ronald West
