Question

Purge CO Makupreactor Onygen SEM. Il 2018-19 The pertinent chemical reactions involved are: CH, +2H20 CH+H20 CO +3H2 CO2 4H2 (main reformer reaction) (reformer side reaction) (CO converter reaction) (methanol synthesis reaction) 2co +02 2C02 (d) co2 + 3H, CH,OH + H20 Ten percent excess steam, based on Reaction (a), is fed to the reformer, and conversion of methane is 10%, with a 90% yield of CO2-A stoichiometric quantity of oxygen is fed to the CO converter, and the CO is completely converted to CO2. Additional makeup COz is then introduced to establish a 3-to-1 ratio of Ha to CO2 in the feed stream to the methanol reactor. Single-pass conversion in the methanol reactor is 55%. The methanol reactor effluent is cooled to condense all of the methanol and water, with the non-condensablegases recycled to the methanol reactor feed. The Ha/CO2 ratio in the recycle stream is also 3 to 1 . Because the methane feed (to the reformer) contains 1% nitrogen as an impurity, a portion of the recycle stream must be purged as shown in the figure to prevent the accumulation of nitrogen in the system. The purge stream analyzes 5% nitrogen. On the basis of 100 mol of methane feed (including N2) and using atomic balance a) b) c) d) How many moles of H2 are lost in the purge? How many moles of makeup COz are required? What is the recycle-to-purge ratio in moles per mole? How much methanol solution (in kilograms) of what strength (weight percent) is produced?

Answer 1

Sy Recycle f poYy· Nveanu andains-HL.tr ca.Ytlo ost in puvąc 14.25 Mo.of CO MoO

128, 7 ї.wolea ea_ 31v41mrr! CH3oH. Reeyele 96 nual 407 topoye ,iteo Recyel 01. ס20.35 - 123.15 mo 123.9 5x3 L 3%6.34.9 3966-3442131 o4