Question: A process for methanol synthesis is shown in the flow diagram below. The chemical reactions involved are ( a ) Main former reaction: CH 4

A process for methanol synthesis is shown in the flow diagram
below. The chemical reactions involved are (a) Main former
reaction: CH4+2H2O = CO2+4H2(b) Reformed Side Reaction: CH4+
H2O = CO +3H2(c) CO Converter reaction: 2CO + O2=2 CO2(d)
Methanol synthesis reaction: CO2+3H2= CH3OH + H2O Ten percent
excess steam, based on the "main former reaction" is fed to the
reformer, and conversion of methane is 100%, with a 90% yield of
CO2. Conversion in the methanol reactor is 50% on one pass through
the reactor. A stoichiometric quantity of oxygen is fed to the CO
converter, and the CO is completely converted to CO2. Additional
makeup CO2 is then introduced to established a 3-to-1 ratio of H2
to CO2 in the feed stream to the methanol reactor. The methanol
reactor effluent is cooled to condense all of the methanol and
water, with the noncondensable gases recycled to the methanol
reactor feed. The H2/ CO2 ratio in the recycle stream is 3 to 1.
Because the methane feed contains 1% nitrogen as an impurity, a
portion of the recycle stream must be purged as shown in the figure
below to prevent the accumulation of nitrogen in the system. The
pruge stream analyzes 5% nitrogen. On the basis of 100 mol of
methane feed (including the N2) calculate: a. The number of moles
of H2 are lost in the purge b. The number of moles of makeup CO2
required c. The recycle-to-purge ratio in moles per mole d. The
methanol solution (in kilograms) of what strength (weight percent)
produced.

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