英文翻譯(化工)第二部分

Propane dehydrogenation will require a “C3 Splitter” to separate and recycle unreactedpropane. There are two grades of marketable propylene, polymer grade (99.5% propylene)and chemical grade (96% propylene). You must decide which grade to produce, or perhapsto produce some of each grade. Economics for the project are driven by the price differencebetween purchased propane at $1.50/gallon and product propylene (60 ¢/lb chemical grade,62 ¢/lb polymer grade). Also, what price would you have to pay for propane to achieve atarget rate of return equal to 15%?21A detailed equipment list, a spreadsheet available from W. D. Seider, is provided for thenumbered items in Figure 1. Note that the design pressure is limited to 350 psig. You willneed some equipment for removing ethylene from propylene. If you think the Depropanizermay be useful, details will be provided. There is no available refrigeration capacity at thesite.Catalysts for the reaction have been screened and the selected catalyst was tested in thelaboratory to provide kinetic data. The experiments were done with a fixed amount ofcatalyst held at constant temperature in a “sand bath”. Pure propane was fed at variousflowrates, and the exit concentrations of propylene and ethylene were measured with on-linespectroscopy. The results are in a spreadsheet available from W. D. Seider. Note that datawas collected with catalyst of different “ages” or coke deposition. Also included is a “lifestudy” of the catalyst to determine the rate of coking. The dehydrogenation reaction isreversible, and the mechanism is first-order in each component.Propane ���� Propylene + HydrogenThe decomposition reaction is irreversible, and first-order in propane:Propane ���� Ethylene + Methane