Please answer the following mutlipe choice questions 1 A mem

Please answer the following mutlipe choice questions:

1. A membrane 2 mm with a diffusion coefficient of trichloroethylene (TCE) of 1x10-9m2/s is to be used to permeate TCE out of a mixture with ethane. The unit is started upwith a new, unconditioned membrane. Approximately how long will it take to observe asignificant amount of TCE in the permeate stream?

a.) second

b.) minute

c.) hour

d.) day

2. A gas mixture of ammonia and nitrogen is in contact with liquid water. Ammonia will diffuse through the gas phase and into the water, whereas nitrogen can be considered insoluble in water. Given the partial pressure at some distance from the water surface and at the water surface, which of the following equations would be most accurate for calculating the flux of ammonia through the ammonia/nitrogen mixture?

All of the questions below ask about changes to the following membrane separation unit. You may assume the complete mixing model is valid. Note that the feed is a 50/50 mixture of carbon dioxide and methane, and the membrane has a higher permeability for CO2.

3. You are asked to get a purer CH4 stream in the retentate out of the same membrane unit (same membrane material and area). Which of the following options would accomplish this?

Increase p_l

Increase p_h

Increase LF

4. You have been asked to scale up the membrane separation unit to perform the sameseparation on a feed stream with a molar flow rate 100 times as large. How will the areaof the membrane in the larger unit (A_M) be related to the area of the original, smaller unit (A_M\')?

5. You plan to use the same unit to handle a feed at the same total flow rate, but with 75mol% CO2. The flow rate of the permeate will

a.) increase  

b.) decrease  

c.) stay the same

Will the required area of the membrane to perform the same separation

a.) increase   

b.) decrease

7. If the new membrane from (f) is used but the membrane area is not changed, the mole fraction of CO2 in the permeate will  

a.) increase  

b.) decrease

c.) stay the same

ammonia ammonia ammonia DAB(Pam ammonia-1. ammonia RTOz DAE POP ammonia-1 ammonia-2 RT BMC 2 Permeability(P ammonia-2 ammonia-1 RTOz

Solution

1.C , HOUR

2.C , PERMEABILITY *(p1-P2)/RT (Z2-Z1)

3.B , INCREASE ph

4. 0.05

5.A , increase

6.B, decrease

7.A , increase