Produccion De Cumeno

AUTONOMOUS NATIONAL UNIVERSITY OF MEXICO CHEMISTRY SCHOOL

CUMENE PRODUCTION PROJECT

Briones Juárez Luis Ángel Chavarría Rodríguez José Antonio Fortis Cortez Castulo Omar

Submission date: February 21st 2011

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Index             Presentation (p. 1) Index (p. 2) Summary (p. 2) Introduction (p. 2) Constraints (p. 2) Approach (p.2) Solution (p. 2) Results (p. 3-5) Costs (p.6) Discussion (p. 6) Conclusions and recommendations (p. 6) Appendix (p. 7-8)

Summary Cumene is produced by reacting propylene with benzene. It is primarily used as raw material for the manufacturing of phenol and acetone. A plant where phenol is produced is seriously considering the option of producing its own cumene for the process, owing to the potential profit it could make from it. Anengineering group has been called on to analyze the feasibility of such project and has been told to indicate whether major modifications can be performed to optimize the process they were tasked with. The plant is constrained to generate 100 000 tons of cumene per year. The original scheme is depicted in figure 1. Process modifications would consist of recirculating the unreacted benzene to the purebenzene stream, in order to use less of it. It has been estimated that profits amounting to 14.07 MUSD/year would be made if no recirculation were implemented, but if so, the figure would soar up to 21.7 MUSD/year (approximately 54.2% more than in the original process). Hence, we recommend such an implementation. Introduction Cumene (isopropyl benzene) is produced by reacting propylene and benzeneover an acid catalyst. Cumene may be used to increase the octane in gasoline, but its primary use is as a feedstock for manufacturing phenol and acetone. Constraints - 100 000 cumene tons/year have to be produced. - Cumene purity has to be no less than 99.9 %. - Distilled benzene has to be at least 98.1 % pure. - The ratio of fed benzene to fed propylene has to be 2:1. - The catalytic reactor isto convert 99% of the incoming propylene; simultaneously, DIPB will be generated; the catalyst will favor cumene production to DIPB production in a 31:1 ratio. Approach For the problem to be sorted out, a material balance in stationary state, where all constraints were taken into account, was carried out. No pressure or temperature data were deemed relevant to the balance. Process Modifications Inorder to increase profits significantly without altering the production volume or process specifications, we are no longer going to purchase cumene and will use unreacted process materials, specifically we propose to recirculate all benzene coming out from tower T-201. Figure 2 shows this. Solution

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For the original scheme, on having written down all material balance equations, weproceeded to compute compositions and some flows by means of the assumption of an incoming flow of 100 k moles/year and a previously programmed spreadsheet whose cells were populated by the input we assigned. Likewise, this procedure was used for the proposed modification, always watching out for cycling references. Results

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C

Figure.1
R-201
Propane Propylene E Benzene D G Cumene S-201F P T-201 H T-202 R DIPB
E x iE F G x iF x iG H x iH P x iP R x iR R-201 CATALYTIC REACTOR 25 ATM, 350°C 0 0.981 0 0.019 0 1 0 0 0 833333.3 28394.6 861727.9 0 0 0 0.967 0.033 1 0 0 0 833333.3 834.2 834167.5 0 0 0 0.999 0.001 1 0 0 0 0 27560.4 27560.4 0 0 0 0 1 1 S-201 FLASH SEPARATOR 25 ATM, 40°C T-201 E F x iF G x iG H x iH P x iP R x iR TOWER SEPARATION 1 x iD 0.005 0.505 0.026 0.45 0.015 19178 0 48305.5 0 0 57483.5 0.16 0 0.84 0 0 1 0 955376.9 0 851837.1 28394.6 1835608.5 0 0.52 0 0.464 0.015 1 0 955376.9 0 18503.7 0 973880.6 0 0.411 0 0.564 0.025 1 0 0.971 0 0.029 0 1 0 0 0 0.956 0.044 1 0 0 0 0.999 0.001 1 0 0 0 0 1 1 T-202 TOWER SEPARATION 2 x iD 0.002 0.405 0.012 0.556 0.025 1 385.5 0 2125.4 0 0 2510.9 25 40 G 0 74519.4 0 102220.4 4599.9 181339.8 L BY DATE 18-feb-11 ChE. LUIS...