Lesson 11 - Carbon Dioxide Recovery Technology SAQ
This lesson allows you to test yourself on the material covered in the CO2 Recovery Technology lesson and to determine the level to which you have met the learning outcomes.
Self-Assessment Questions
1. *What would be the idealised total quantity of CO2 produced by a four-brew fermenter if each brew length was 500 hL and the fermented range for the brand’s wort was from 12°P (1,048.4 kg/m3) to 2°P (1,007.8 kg/m3)?
2. *In one month, you have filled and fermented 25 of the fermenters described in question one above. Your CO2 recovery plant operated with a 50% overall collection efficiency. How much CO2 would you have collected into storage?
3. *Name the key principle by which a CO2 stripper reduces oxygen in liquid CO2?
4. **Your company’s flagship lager, Brand-X, has a fermentation profile as shown in the table below. Currently, the fermenter is vented for the first 48 hours post-filling. After that, CO2 is collected for the next 48 hours, then it is vented for the remainder of the fermentation. Your recovery plant operator wishes to increase the recovered CO2 into the storage tank by adopting one of three approaches:
a) Turning the tank onto collection 24 hours earlier only.
b) Venting for the first 48 hours, as-is, and then leaving the tank on collection until fermentation has completely ceased.
c) Or a combination of both a) and b).
For each approach, estimate the additional idealised quantity of CO2 which would be available for collection. Advise the plant operator of any changes in the raw gas composition which they would need to be aware of.
|
Time from tank-full (hr) |
Gravity (RE) °P |
Density (kg/m3) |
|
0 |
16.0 |
1,065.4 |
|
24 |
14.5 |
1,059 |
|
48 |
12.5 |
1,050.5 |
|
72 |
10.0 |
1,040 |
|
96 |
7.5 |
1,029.8 |
|
120 |
5.5 |
1,021.7 |
|
144 |
4.5 |
1,017.7 |
5. */**Describe the operation of the following two sub-processes of a recovery plant: a washer (scrubber) and a deodoriser.
6. */**An employee is conducting an audit of the CO2 recovery plant to identify running cost reduction opportunities. The employee has identified that the costs of compressing the CO2 to 14-20 bar a are significant and is proposing to reduce the compressor discharge pressure to 5 bar a. Extensive cost calculations support the case. How would you go about critiquing their proposal?
7. **Describe the means by which a CO2 condenser purifies the CO2.
8. */**Describe the principle of operation of a CO2 stripper.