Chap 4: Dry grind process overview Flashcards
1
Q
Main product
A
-ethanol
2
Q
coproduct (2)
A
- corn oil to form poultry food
- DDGS for ruminant food
3
Q
percentage of three product
A
- 1/3 ethanol
- 1/3 CO2
- 1/3 coproduct
4
Q
6 steps
A
- grain receiving+control+cleaning
- grinding and mixing
- cooking and liquefaction
- saccharification+fermentation
- distillation + dehydration (molecular sieves)
- coproduct recovery
5
Q
why do they use heat for saccharification?
A
to break the starch and to kill bacteria to sterilize the slurry
6
Q
when does distillation stop?
A
when there is 190° Proof ethanol (95%)
7
Q
yeast propagation steps (4) during liquefaction
A
LAG
LOG (increase)
stationary
Death
8
Q
4 steps of transformation (états du début à fin)
A
corn - slurry - mash - beer
9
Q
what does distillation separate
A
Ethanol+CO2 from whole stillage (protein, pericarp, wet grain)
10
Q
end of the process for whole stillage
A
- centrifuge separates wet grains from thin stillage
- thin stillage goes into evaporator to form syrup
- centrifuge separates syrup in oil + DDGS (after drying and cooling)
