ANDIG3 – Questions

1.  A passive system is defined as a system where biogas recovery is added to an existing manure treatment component.

a.  True

b.  False

2.  A __________ is an example of a passive system.

a.  High solids digester

b.  Covered lagoon

c.  Complete mix digester

d.  All of the above

3. A low rate system is defined as a system where feedstock stays in a digester for an extended period of time. Feed-stocks in low rate systems typically spend more time in the digester to maximize bio-gas output.

a.  True

b.  False

4. Examples of low rate systems include:

a.  Complete mix digester

b.  Anaerobic Sequencing Batch Reactor

c.  Plug flow digester

d.  Both a and c

5. A high rate system is defined as a system where liquids stay in the digester for a short period of time; whereas, solids are held longer.  This allows for a smaller reactor size, while maintain high gas production.

a.  True

b.  False

6. Examples of high rate digesters include:

a.  Fixed Film digester

b.  Induced Blanket Reactor digester

c.  Anaerobic Sequencing Batch Reactor digester

d.  All of the above

7.  Also known as “dry fermentation”, high solids digestion is used to treat stackable materials such as food scraps, yard debris, and municipal solids wastes.

a.  True

b.  False

8. High solids digesters work best with materials that have a solids content of :

a.  Less than 10%

b.  10% – 15%

c.  25% – 50%

d.  80% – 90%

9. The type of digester a particular farm needs depends on:

a.  The type of manure management system currently in use.

b.  The amount of water added to manure from milking parlors and flush systems.

c.  Climate.

d.  All of the above

10. Published digester economic assessments tend to show that the most successful digesters are those that:

a.  Have generated added value from separated manure fiber

b.  Charged tipping fees for accepting off-farm food processing wastes

c.  Had a nearby high-value use for the biogas or electricity

d.  All of the above