Process Calculations GATE-2007
Statement for Linked Answer Questions Q 1 & 2:
Q 1: A simplified flowsheet is shown in the figure for production of ethanol from ethylene. The conversion of ethylene in the reactor is 30 % and the scrubber following the reactor completely separates ethylene (as top stream) and ethanol and water as bottoms. The last (distillation) column gives an ethanol-water azeotrope (90 mol% ethanol) as the final product and water as waste. The recycle to purge ratio is 34.
The reaction is:
C_2H_4(g)+H_2O(g)\rightarrow C_2H_5OH(g)For an azeotrope product rate of 500 mol/hr, the recycle gas flowrate in mol/hr is
Q 2: For the same process, if fresh H2O feed to the reactor is 600 mol/hr and wash water for scrubbing is 20 % of the condensable coming out of the reactor, the water flowrate in mol/hr from the distillation column as bottoms is
Statement for Linked Answer Questions Q 3 & 4:
Q 3: 44 kg of C3H8 is burnt with 1160 kg of air (Mol. Wt. = 29) to produce 88 kg of CO2 and 14 kg of CO
C_3H_8+5O_2\rightarrow3CO_2+4H_2OWhat is the percent excess air used?
Q 4: What is the % of carbon burnt?