Diethyl Ether (DEE): Material balance

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Information about Diethyl Ether (DEE): Material balance

Published on November 10, 2016

Author: 100003690100228

Source: slideshare.net

1. 13 CHAPTER 3 MATERIAL BALANCE This chapter includes material balance of reactor flash vessels and distillation column also gives the final product purity and flowrate. By analysis of the import data in Chemical Weekly (June 2015, volume 29) we can assume the plant capacity as 50,000 tons per annum. Taking 340 working day of the plant for 3 shift of 8 hours plant capacity= 50000×1000 340×24 kg/hr =6127.4 kg/hr Product Diethyl Ether purity is 99.5% rest is water and ethanol, for convert mass flow rate into molar flow rate finding out average molecular weight of product M.W. of Diethyl Ether is 74.14 kg/kmol. M.W. of Water is 18.01528 kg/kmol. M.W. of Ethanol is 46 kg/kmol. Taking average molecular weight= 0.995(74.14) + 0.0025(18.01528) + 0.0025(46) = 73.9293 kg/kmol product molar flow rate = 6127.4 73.9293 kmol/hr =82.88 kmol/hr. REACTOR (1) For reaction 1 1 kmol diethyl ether (DEE) @ 2 kmol C2H5OH @ 1 kmol H2O For reaction 2 1 kmol C2H4 @ 1 kmol C2H5OH @ 1 kmol H2O

2. 14 Conversion = 52.5% [7] Yield of diethyl ether (DEE) = 96.19% [7] Feed = 0.13818 kmol/sec Ethanol = 0.12533 kmol/sec Water = 0.01285 kmol/sec Diethyl ether produced = conversion x Yield x Ethanol / 2 = 0.525 x 0.9619 x 0.12533/2 = 0.03164 kmol/sec Ethylene produced = conversion x (1 - Yield) x Ethanol = 0.525 x (1 – 0.9619) x 0.12533 = 0.00238 kmol/sec Water produced = conversion x Yield x Ethanol / 2 + conversion x (1 - Yield) x Ethanol = 0.525 x 0.9619 x 0.12533/2 + 0.525 x (1 – 0.9619) x 0.12533 = 0.03164 + 0.00238 kmol/sec = 0.03402 kmol/sec Total water in the product stream = 0.03164 + 0.01285 = 0.04449 kmol/sec Unreacted Ethanol = feed x (1- conversion) = 0.12533 x (1-0.525) =0.05953 kmol/sec For the reactor feed and product molar flowrate is given in table 3.1. Table 3.1: feed and product molar flowrate for reactor in kmol/sec Feed Product Ethanol 0.12533 0.05943 Water 0.01285 0.04449 Diethyl Ether 0.00000 0.03164 Ethylene 0.00000 0.00238 Total 0.13818 0.13794

3. 15 FLASH VESSEL (5) For the flash vessel feed, top and bottom molar flowrate is given in table 3.2. Table 3.2: flowrate of inlet and outlet stream for flash vessel in kmol/sec Feed Top product Bottom product Ethanol 0.05943 0.00003 0.05940 Water 0.04449 0.00009 0.04440 Diethyl Ether 0.03164 0.00063 0.03101 Ethylene 0.00238 0.00127 0.00111 Total 0.13794 0.00202 0.13592 DISTILLATION COLUMN: (3) Feed: 0.13592 kmol/sec Diethyl ether = 0.03101 kmol/sec Ethylene = 0.00111 kmol/sec Ethanol = 0.05940 kmol/sec Water = 0.04440 kmol/sec F = D + W XF x F = D x XD + W x XW For XF = 0.2258 XD = 0.9636 XW = 0.0029 From Diethyl Ether above equations D = 0.03153 kmol/sec W = 0.1043 kmol/sec In table 3.3 flowrate of distillate, residue (bottom) and feed is given for all compound

4. 16 Table 3.3: molar flowrate of inlet and outlet streams for distillation column (3) in kmol/sec Feed Top product Bottom product Ethanol 0.05940 0.00000 0.05940 Water 0.04440 0.00000 0.04440 Diethyl Ether 0.03032 0.03018 0.00014 Ethylene 0.00111 0.00111 0.00000 Total 0.13183 0.03153 0.10430 DISTILLATION COLUMN: (4) Feed: 0.1043 kmol/sec Diethyl ether = 0.00014 kmol/sec Ethylene = 0.0000 kmol/sec Ethanol = 0.05940 kmol/sec Water = 0.04440 kmol/sec F = D + W XF x F = D x XD + W x XW For Ethanol XF = 0.5578 XD = 0.8588 XW = 0.01563 From above equations D = 0.067 kmol/sec W = 0.03549 kmol/sec In table 3.4 flowrate of distillate, residue (bottom) and feed is given for all compound Table 3.4: molar flowrate of inlet and outlet streams for distillation column (4) in kmol/sec Feed Top product Bottom product Ethanol 0.05940 0.05753 0.00187 Water 0.04440 0.00915 0.03525 Diethyl Ether 0.00014 0.00014 0.00000 Ethylene 0.00000 0.00000 0.00000 Total 0.10430 0.067 0.03730

5. 17 FLASH VESSEL: (7) For the flash vessel feed, top and bottom molar flowrate is given in table 3.5. Table 3.5: flowrate of inlet and outlet stream for flash vessel in kmol/sec Feed Bottom Product Top Product Ethanol 0.00000 0.00000 0.00000 Water 0.00000 0.00000 0.00000 Diethyl Ether 0.03018 0.02336 0.00582 Ethylene 0.00111 0.00006 0.00105 Total 0.03153 0.02342 0.00870 Diethyl ether produced = 0.02342 kmol/sec = 0.02342 x 3600 x 24 x 340 kmol/sec = 687985.92 kmol/year = 687985.92 x 74 /1000 TPA = 50910.95 TPA Purity of Diethyl ether = 0.02336/0.2342 x 100 = 99.74 %

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