求助翻译外文资料Standard manufacturing process descr ...？ 如题，共计两页 请盖德帮助为盼，在线等 Standard manufacturing process description Dept 233-MCB& dept 701-cl2 handling Section 1 synopsis of the process Benzene handling Nitration grade benzene is shipped by barge to the plant and pumped into the benzene storage tank (item101) .after the transfer is complete ,the line is purged with nitrogen .benzene from this tank is pumped continiuously to the process through the benzene/water separator (item187) Chlorine handling The chlorine handling system supplies chlorine vapor to the monochlorobenzene unit,dapartment 233. the MCB unit maximum consumption is 20100 ibs/hr of chlorine Liquid chlorine is delivered to the plant in 90-ton rail cars.the chlorine handling unit,department 701,has the capability to handle four rail cars. Liquid chlorine is unloaded from the rail cars through a surge tank to a vaporizer. The chlorine is vaporized and then transferred to Department 233 Relief devices are provided on various pieces of equipment to prevent catastrophic failure in the event of extreme over-pressurization. All chlorine relief devices plus the sniff lines from the rail cars are routed to the chlorine Neutralization tower (item556) to be neutralized using NaOH caustic. There are 20 chlorine fugitive emissions sensors with alarms located throughout the chlorine handling area to warn of a chlorine leak in the area. Chlorination The dry benzene is fed to a three-stage continuous process. Benzene is reacted with gaseous chlorine in the presence of ferric chloride or ferric chloride-sulfur catalyst. Hydrogen chloride (HCl) gas is produced as a by-product of the reaction. The reation is typically carried out at 45 -65 ℃ and 10-12 psig pressure. The products of the reation are Monochlorobenzene (MCB) and all the isomers of dichlorobenzene (DCB). The reation is controlled to give the desired conversion to MCB and DCB by regulating the amount of chlorine and benzene fed to the reatiors. The instantaneous MCB CB tatio attainable at the chlorinators varies from 0.9:1 to 10:10 (weight basis). The product from the chlorination reation typically cintains 3-45% unreated benzene, 55-65%MCB and 5-25%DCBS. The para isomer of DCB, para-dichlorabenze(PDCB), is produced in amounts of 60-77%of the total DCB produced, and the ortho isomer, ortho-dichlorobenze(ODCB), makes up approximately 22-40%. The meta isomer,meta-dichlorobenze(mdcb),is controlled by the addition of a sulfur co-catalyst. MDCB comprises 0.4%of total DCBs when sulfur is added and 3.5% when sulfur is not added. The sulfur co-catalyst also controls the PDCB:ODCB ratio :~3:1 with sulfur, and 1.5:1 without sulfur. The reation equations are as follows: Stabilization In the stabilizer Area, the material from the chlorinators (items 202/205/220) is flash-distilled to remove the catalyst,tars,highboilers,and dissolved HCl gas from the chlorinated material. The chlorinated material and unreacted benzene are then routed to intermediate storage in the Rfining Area. The tars and catalyst are concentrated in the Residue Still (item 408)and taken by tank truck to be incinerated. The HCl gas is vented back to the Chlorinators for recovery as Muriatic acid. The refining aera is a two stage,continuous distillation unit. In the first distillation tower, the benzene column(item 502) unreacted benzene is separated from the chlorinated material and recycled to the Azeo column (item 111). The bottom stream from the benzene column is fed into the second tower,the MCB column. this feed stream is essentially free of unreacted benzene and contains only mcb and dcb. The second stage of the distillation separates the mcb from the dcb. The mcb is taken from the top of the mcb column and the dcb from the sump. Both products fiow to storage. Crude dcb from the Department 233 distillation columns is transferred to dapartment 224 for resolution into pdcb and odcb . HCL purification / muriatic acid The HCl gas stream from the chlorinators carries vapors of unreacted benzene, mcb and dcb out of the system. This stream is sent to the HCl recovery Area where Muriatic acid is produced. The HCLgas is absorbed into condensate water to make Muriatic acid using a two-stage falling film absorber system and tail tower. Organic are recovered through decantation (HCLgas stripping) and are recycled back to the benzene drying area. The muratic acid is further by the use of a two-stage activated carbon treatment process that removes trace organic from the acid. Nominal 220baume(Be) acid strength is produced. Sodium sulfite is add to the Muriatis acid to minimize halogen formation and the acid is pumped through an ion exchange resin bed to remove color bodies and then filtered prior to storage. Muriatic acid is filtered again as it is loaded for customers into tank cars and trucks. Tank trucks can be diluted to 220baume(Be) acid if needed. Vent recovery and treatment Department 233 has a vent recovery system that is designed to capture gases vented from process and storage vessels that might contain benzene.many of these vent stream also contain HCL gas or other organic compounds (mcb dcb aliphatics). The majority of the vent stream are routed through a vent gas scrubber, the vapors are fed to the Thermal oxidizer (item 148) , which destroys a minimum of 95% of the benzene (along with the other organic). Wastewater pretreatment Per OCPSF (organic chemical plastic synthetic,fiber effluent standard )regulations,all process wastewater must have organic materials removed (to meet a regulated concentration limit for the site) prior to their expulsion to the plant sewer leaving the plant boundaries. These linits can be found in the plant wastewater discharge permit and are updated every three years. Process water and rainwater is routed to the rainwater storage tank prior to being recycled back to the benzene drying area or sent to the wastewater carbon treatment system. The organics are removed from the water by pumping the stream through a two-bed activated carbon adosorption process. The effluent from the adsoption process is routed to the plant sewer. 我的邮箱 BYZJPZB@126.COM 先谢谢大家了 查看更多0个回答 . 2人已关注
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