The feed to the reactor contains ethylene, steam and an inert gas. A sample of t

Question

The feed to the reactor contains ethylene, steam and an inert gas. A sample of the reactor effluent gas is analyzed and found to contain 43.3 mol% ethylene, 2.5 mol% ethanol, 0.14 mol% ether, and 9.3 mol% inserts. Determine the molar flow rates of each component in both the feed and effluent streams required to for the effluent stream to contain 100 kg/min of ethanol (see data in problem (Therefore)below) Liquid ethanol (see problem (Therefore) below) is fed to a space heater at a rate of 12.0 L/hr and burned with excess air. The product gas is analyzed and the following dry-basis mole percentages are determined: C_2H_5OH = 0.45%, CO_2 = 9.03%, and CO = 1.81%. Determine the molar flow rates of each component in both the feed and effluent streams. Maltose is converted (via fermentation) to ethanol by the following reaction: For every 1 kg of ethanol formed, 0.0794 kg of yeast is produced in the above reaction. For every 1 kg of yeast formed. 0.291 kg of water is produced in the above reaction. 80-proof whiskey produced by this process contains 40% (by volume) ethanol. Com fed to the process contains 60.84 wt% starch (precursor of maltose) and 15.5 wt% water. It is estimated that 101.2 bushels of corn can be harvested from an acre of corn, that each bushel is equivalent to 25.4 lb_m of corn, and that 6.7 kg of ethanol can be obtained from a bushel of corn. Assume whiskey contains primarily only ethanol and water. The specific gravity of ethanol is 0.789. The molecular weights of water and ethanol are 18.016 g/mol and 46.07 g/mol respectively. Assume a fractional conversion of maltose of 0.89. What acreage of farmland is required to produce 10^6 barrels barrel = 119.240 L) of 80 proof whiskey per year? What is the mole fraction of ethanol in 80-proof whiskey? How much yeast would be formed (in kg) in producing 10^6 barrels of 80 proof whiskey? How many moles of CO_2 would be produced by making 10^6 barrels of 80 proof whiskey? How many moles of maltose would be required to make 10^6 barrels of 80 proof whiskey?

Explanation / Answer

The two reactions taking place are

a) Ethanol formation from ethylene

C2H4 + H2O = C2H5OH

b) Ethanol converted to diethyl ether (side reactions)

2 C2H5OH = (C2H5)2O + H2O

The feed stream stream contains Ethylene , Steam, and Inert

and the effluent stream contains:

C2H4 - 43.3 mol%

C2H5OH - 2.5 mol%

(C2H5)2O - 0.14 mol%

Inert - 9.3 mol%

and the remaining must be steam, hence H2O in effluent stream is

100 - (43.3+2.5+0.14+9.3) = 44.76 mol%

It's given that effluent stream contains 100 kg/min of ethanol

The molecular weight of ethanol is 46 kg/kmol

hence we get ethanol in effluent stream as

100/46 = 2.17 kmol/min

which is 2.5 mol% of effluent stream.

Hence the total effluent stream is 2.17/0.025 = 86.96 kmol/min

So we can calculate the composition of effluent stream as

The feed stream contains C2H4, H2O and Inert

Since the inert is not taking part in the reaction, the molar flow rate of inert in inlet and effluent stream would remain constant throughout the reactions.

Hence inert in feed steam is 8.09 kmol/min

from the reactions mentioned above, it is inferred that ethylene in the feed stream reacts to form ethanol and unreacted ethylene in the effluent stream.

1 mol of ethanol is formed by 1 mol of ethylene and 1 mol of water.

hence ethylene required for 2.17 kmol/min of ethanol is 2.17 kmol/min.

and the unreacted ethylene is 37.65 kmol/min in effluent stream

Hence the feed stream would contain (37.65+2.17 =) 39.82 kmol/min of C2H4

Similarly,

from the reactions mentioned above, it is inferred that steam in the feed stream reacts to form ethanol, while effluent stream contains steam from unreacted steam and steam from side reaction.

1 mol of ethanol is formed by 1 mol of ethylene and 1 mol of water.

hence steam required for 2.17 kmol/min of ethanol is 2.17 kmol/min.

and the steam is 38.92 kmol/min in effluent stream out of which steam formed by side reaction is

in side reaction, 2 mols of ethanol reacts to form 1 mol of ether and water each.

hence steam formed in side reaction is 0.12 kmol/min

Hence the feed stream would contain (38.92+2.17-0.12 =) 40.97 kmol/min of H2O

Hence the feed stream composition is

Component mol% Molar flow rate (kmol/min) C2H4 43.3 37.65 C2H5OH 2.5 2.17 (C2H5)2O 0.14 0.12 Inert 9.3 8.09 H2O 44.76 38.92 Total 100 86.95

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.