DESIGN PROJECT CONTENT INTRODUCTION GLOBAL LINDANE USAGE ECONOMICS PROCESS FLOW DIAGRAM PROCESS DESCRIPTION SPECIFICATION CHEMCAL REACTIONS MATERIAL BALANCE USES EMERGENCY OVERVIEW SAFETY MEASURES REFERENCE INTRODUCTION IUPAC name of BHC is 1,2,3,4,5,6 Hexachlorohexane (benzene hexachloride) BHC is a cyclohexane derivative and nine stereoisomers are possible. However , only five of them have been actually isolated from the mixture. They are called 𝛼, 𝛽, 𝛾, ∆, 𝜀 𝑓𝑜𝑟𝑚𝑠. The mixture of stereo isomeric hexachlorides is an active component in BHC is 𝛾 isomer, called gammaxene or lindane. Market analysis shows that an annual production of 600 ton of crude BHC or up to 80 ton of lindane can be easily sold without undue competition. Corrosion can be a major engineering problem since both wet chlorine and HCl are corrosive to iron. Further, any iron chloride formed will catalyze substitution reactions rather than the desired addition chlorination. GLOBAL LINDANE USAGE Usage(tons) 350 000 300 000 250 000 287 160 200 000 150 000 100 000 73200 50 000 63570 0 Europe Asia America Usage(tons) 28540 1032 Africa Oceania ECONOMICS Purpose Amount (Rs.) Know how fee 80,000 Engineering fee 70,000 Imported equipment 4,60,000 Indigenous equipment 5,00,000 total 11,10,000 PROCESS FLOW DIAGRAM B1 F1 From tank car water L4 L3 F2 B A1 Flake NaOH Vent gas F3 L1 A2 G2 G1 F4 water L2 storage C H1 D3 Cl tank car D4 D2 H2 F5 J1 D1 Spent caustic to drain K1 I K2 BHC packing NOTATIONS A1-benzol transfer D4-conc HCl pump storage G2-solvent receiver A2-storage tank E-crude product pump H1-continuous centrifuge L1-fractional distillation B-chlorinator F1-caustic make up tank H2-wet crystal hopper L2-monochlor storage B1-vent gas separator F2-caustic transfer pump I-liquor receiver L3-wet benzol receiver C-decanter F3-caustic feeder K1-dry BHC hopper L4-wet benzol pump D1-dilute acid receiver F4-neutralizer K2-BHC packing D3-acid stripping still D2-acid still feed pump F5-spent caustic separator G1-flash still PROCESS DESCRIPTION Reaction of gaseous chlorine with liquid benzene at the refluxing temperature. Carried out on a continuous basis in a glass-lined reactor fitted with a refluxing system; I. conversion of chlorine expected to be 99% II. Reactor product consists of about 33% benzene hexachloride dissolved in chlorobenzene and unreacted benzene. Crude product is continuously removed for further processing. Accompanying 21.5% muriatic acid layer should be decanted and further concentrated to salable acid. Organic layer is neutralized with 1% NaOH solution and then concentrated to 56% BHC by evaporation of some of the volatile ingredients in a flash still. Overhead from the still is largely benzene and byproduct which are separated by fractional distillation. Benzene can be recycled and 𝐶6 𝐻3 𝐶𝑙3 is sold as by product. A large fraction of benzene hexachloride is crystallized out in a double pipe “chiller” and the crystals removed by means of a continuous centrifuge. The crystalline BHC product is to be dried in a rotary vacuum dryer with a solvent recovery system. The recovered solvents from various operations are to be combined and fractionated. The overhead distillate consisting primarily of benzene is to be reused in the process whereas the chlorobenzol solvents in the bottoms are to be stored for sale as crude byproducts. SPECIFICATIONS Raw materials: 1. Benzol , purified grade , considered as 99.5% benzene,0.5% toluene 2. Chlorine considered to be 100% pure 3. sodium hydroxide ,flake, 98% NaOH Chlorinator conditions: 1. Reaction temperature ,70℃ 2. Chlorine conversion , 99% Specific gravity: 1. Benzene - 0.876 2. BHC -1.87 CHEMICAL REACTIONS 𝐶6 𝐻6 + 3𝐶𝑙2 𝑎𝑏𝑠𝑒𝑛𝑐𝑒 𝑜𝑓 𝑎𝑐𝑡𝑖𝑛𝑖𝑐 𝑟𝑎𝑦𝑠 𝑎𝑛𝑑 𝑠𝑢𝑏𝑠𝑡𝑖𝑡𝑢𝑡𝑒𝑑 𝑐𝑎𝑡𝑎𝑙𝑦𝑠𝑡𝑠 𝐶6 𝐻6 𝐶𝑙6 +3𝑁𝑎𝑂𝐻 yields 𝐶6 𝐻3 𝐶𝑙3 + 3𝐻2 𝑂 +3𝑁𝑎𝐶𝑙 𝐶6 𝐻6 𝐶𝑙6 MATERIAL BALANCE Principal chemical reaction: 𝐶6 𝐻6 + 3𝐶𝑙2 𝑎𝑏𝑠𝑒𝑛𝑐𝑒 𝑜𝑓 𝑎𝑐𝑡𝑖𝑛𝑖𝑐 𝑟𝑎𝑦𝑠 𝑎𝑛𝑑 𝑠𝑢𝑏𝑠𝑡𝑖𝑡𝑢𝑡𝑒𝑑 𝑐𝑎𝑡𝑎𝑙𝑦𝑠𝑡𝑠 𝐶6 𝐻6 𝐶𝑙6 comparingwith molecular mass, 78 𝑘𝑔 + 213 𝑘𝑔 → 291 𝑘𝑔 For the basis of 600 tons of BHC , per year , 160.824 𝑡𝑜𝑛𝑠 + 439.175 𝑡𝑜𝑛𝑠 → 600 𝑡𝑜𝑛𝑠 Since only 33% of BHC is formed , 0.33𝑥 = 600 Total weight of the product = 1818.18 tons. Since only 99% conversion of 𝐶𝑙2 takes place, 𝐶𝑙2 supplied = 439.175 0.99 = 443.611 tons 1818.18 tons total 200.24 tons 𝐶6 𝐻6 5 tons 𝐶𝑙2 1374.569 tons 𝐶6 𝐻6 443.611 tons Cl reactor 600 tons BHC 1013.324 tons 𝐶6 𝐻6 In the product , 443.611 − 439.175 = 4.436 𝑡𝑜𝑛𝑠 𝑜𝑓𝐶𝑙2 is present . Hence the amount of benzene unreacted = 1818.18 – (4.436+600) = 1213.564 tons Amount of benzene supplied =1818.18 – (443.611) = 1374.569 tons compound Reactant (tons) Product (tons) 𝐶6 𝐻6 1375 1214 𝐶𝑙2 444 5 600 𝐶6 𝐻6 𝐶𝑙6 Total 1819 1819 Considering crude BHC, of 33% of BHC, (600 tons of BHC) 23.44 ∗ 600 = 426.18 𝑡𝑜𝑛𝑠 33 𝛼 23.44% 426.18 tons 𝛽 2.04% 37.09 tons 𝛾 4.22% 76.73 tons ∆ 3.3% 60 tons Through the vent gas separator ,𝐶𝑙2 and 16.5% of unreacted benzene is removed , 200.24 tons 𝐶6 𝐻6 , 5 tons 𝐶𝑙2 . Towards the decanter ,600 tons of BHC(crude ) and 1013.324 tons of 𝐶6 𝐻6 is directed , where 26.4% 𝐻𝐶𝑙is added and concentrated further to receive bottom product of 20 % 𝐻𝐶𝑙. 600 tons BHC 1013.324 tons 𝐶6 𝐻6 Total-1075.14 tons 1613.324 tons total decanter 80% 264.48 tons 𝐻𝐶𝑙 810.66 tons 𝐶6 𝐻6 stripping 99% 8.11 tons 𝐶6 𝐻6 63.84 𝐻𝐶𝑙 storage 802.55 tons 𝐶6 𝐻6 200.6375 tons 𝐻𝐶𝑙 neutralizer 215.781 tons 𝑁𝑎𝑂𝐻 Spent 𝑁𝑎𝑂𝐻 − 24.861 tons 𝑁𝑎𝐶𝑙 -279.2 tons Water -80.9 tons Neutralizer 𝐻2 𝑂 88% 288.77 tons byproduct 5 tons water 60.29 tons 𝛼, 𝛽, ∆ 𝐵𝐻𝐶 137.02 76.73 tons 𝛾 𝐵𝐻𝐶 202.664 𝐶6 𝐻6 Still 98% 𝐶6 𝐻6 𝐶𝑙6 +3𝑁𝑎𝑂𝐻 yields 𝐶6 𝐻3 𝐶𝑙3 + 3𝐻2 𝑂 +3𝑁𝑎𝐶𝑙 291 𝑘𝑔 + 120 𝑘𝑔 → 181.5 𝑘𝑔 + 175 𝑘𝑔 + 54 𝑘𝑔 𝛼 + 𝛽 + ∆ 𝐵𝐻𝐶 = 426.18 + 37.09 + 60 = 523.27 𝑡𝑜𝑛𝑠 523.27 𝑡𝑜𝑛𝑠 + 215.781𝑡𝑜𝑛𝑠 = 326.37 𝑡𝑜𝑛𝑠 + 315.58 𝑡𝑜𝑛𝑠 + 97.101 𝑡𝑜𝑛𝑠 Only 88%conversion of 𝑁𝑎𝑂𝐻 takes place , 0.88 × 215.781 = 190.92 tons 462.98 𝑡𝑜𝑛𝑠 + 190.92 𝑡𝑜𝑛𝑠 = 288.77 𝑡𝑜𝑛𝑠 + 279.2 𝑡𝑜𝑛𝑠 + 85.9 𝑡𝑜𝑛𝑠 Spent 𝑁𝑎𝑂𝐻 = 215.781 − 190.92 = 24.861 tons Residual 𝛼, 𝛽, ∆ 𝐵𝐻𝐶 = 523.27 − 462.98 = 60.29 𝑡𝑜𝑛𝑛𝑒𝑠. 𝛾 = 76.73 𝑡𝑜𝑛𝑛𝑒𝑠 Total BHC = 60.29 + 76.73 = 137.02 𝑡𝑜𝑛𝑛𝑒𝑠 𝛾 𝐵𝐻𝐶 → 56% 𝑜𝑓 𝑡ℎ𝑒 𝑡𝑜𝑡𝑎𝑙 𝐵𝐻𝐶 Spent waste – 279.2 tons NaCl, 80.9 tons water . Feed for the still coming from neutralizer include : 288.77 tons 𝐶6 𝐻3 𝐶𝑙3 5 tons Water 60.29 tons 𝛼, 𝛽, ∆ 𝐵𝐻𝐶 76.73 tons 𝛾 𝐵𝐻𝐶 202.664 tons 𝐶6 𝐻6 633.454 tons Total From the flash still, the product leaving towards the chiller contains 56% BHC, with a conversion of 98% of byproduct. Towards the chiller : 0.56𝑥 = 76.39 𝑥 = 137.02 𝑡𝑜𝑛𝑠 𝐶6 𝐻3 𝐶𝑙3 → 288.77 − 282.9 = 5.87 𝑡𝑜𝑛𝑠 𝑊𝑎𝑡𝑒𝑟 − 5 𝑡𝑜𝑛𝑠 𝐶6 𝐻6 = 137.02 − 76.39 + 5.87 = 49.76 𝑡𝑜𝑛𝑠 Benzene at fractional distillation column =202.664 − 49.76 = 152.904 𝑡𝑜𝑛𝑠 Fractional distillation 59.1 tons 𝛼, 𝛽 1.53 tons 𝛾 282.9 tons byproduct 152.909 tons 𝐶6 𝐻6 202.164 tons 𝐶6 𝐻6 61.82 tons BHC 75.2 tons 𝛾 𝐵𝐻𝐶 1.19 tons 𝛼, 𝛽 5 tons water 5.87 tons byproduct 49.76 tons 𝐶6 𝐻6 282.9 tons by product 1.19 tons 𝛼, 𝛽 𝐵𝐻𝐶 49.26 tons 𝐶6 𝐻6 0.06 tons bypdt separation 75.2 tons 𝛾 𝐵𝐻𝐶 1.19 tons 𝛼, 𝛽 𝐵𝐻𝐶 49.26 tons 𝐶6 𝐻6 0.06 tons bypdt rotary 0.2 tons water Still 98% Chiller 99% 0.5 tons 𝐶6 𝐻6 5.81 tons byproduct 5 tons water 75 tons 𝛾 𝐵𝐻𝐶 Assuming 99% at chiller ,from centrifuge , 𝐴𝑡 𝑙𝑖𝑞𝑢𝑜𝑟 𝑟𝑒𝑐𝑒𝑖𝑣𝑒𝑟 = 0.99 × 5.87 = 5.81 𝑏𝑦 𝑝𝑟𝑜𝑑𝑢𝑐𝑡 𝑤𝑎𝑡𝑒𝑟 = 5 𝑡𝑜𝑛𝑠 𝐶6 𝐻6 = 0.01 × 49.76 = 0.5 𝑡𝑜𝑛𝑠 Towards the rotary drier drum, 75.2 tons 𝛾 𝐵𝐻𝐶 1.19 tons 𝛼, 𝛽 𝐵𝐻𝐶 0.99 × 49.76 = 49.26 𝑡𝑜𝑛𝑛𝑒 𝐶6 𝐻6 5.87 − 5.81 = 0.06 𝑡𝑜𝑛𝑛𝑒 𝑏𝑦 𝑝𝑟𝑜𝑑𝑢𝑐𝑡 𝐶6 𝐻3 𝐶𝑙3 0.31% is the amount of water in BHC,which is removed by crystallization and further processing to rotary drum,i.e., 0.31 × 75.2 = 0.23 100 The 𝛾 𝐵𝐻𝐶 (product ) leaving the drum for packing is , 75.2 − 0.2 = 75 𝑡𝑜𝑛𝑠. Whereas, the feed for fractional distillation column is also provided from the materials left over at the rotary drum. 1.19 tons 𝛼, 𝛽 49.26 tons 𝐶6 𝐻6 0.06 tons 𝐶6 𝐻3 𝐶𝑙3 Total feed entering to fractional distillation column , 59.1+1.53+1.19 60.29 tons BHC 282.9+0.06 282.96 tons Byproduct 152.904+49.26 202.164 tons 𝐶6 𝐻6 From which the overhead consists of benzene which can be reused, whereas the bottom primarily consisting of by-product is stored for sale. USES Broad spectrum insecticide- for both agricultural and non-agricultural purposes. Larvicide Acaricide Seed and soil treatment ,foliar applications ,tree and wood treatment and against ectoparasites in both veterinary and human applications. EMERGENCY OVERVIEW Toxic if swallowed-excite the central nervous system,causing shortness of breath, cough, headache, dizziness, vomiting, coma, fever, kidney damage etc. Limited evidence of a carcinogenic effect Harm to breastfed babies Serious damage to health by prolonged exposure Toxic to aquatic organisms. Environmental pollution. SAFETY MEASURES Wear protective clothing when risk of exposure occurs. Do not enter confined spaces till atmosphere has been checked Avoid contact with incompatible materials. Always wash hands with soap and water after handling Keep containers securely sealed when not in use Store away from food stuff containers No smoking, naked light or ignition sources. REFERENCE Wikipedia http://www.nkpatel.co.in Dryden’s outline of chemical technology –M.Gopala Rao, Marshall Sittig Shreve’s Chemical Process Industries – George.T.Austin THANK YOU
