One (or more) of the following is TRUE for biogas production (Anaerobic digestion process):Select one or more:a.Batch production is based on simpler and low cost digester design, but suffers from the lower efficiency compared to the continues productionb.The gas collected from the digester has high CH4 content up to 90%c.The gas has to pass through gas cooling and cleaning system to remove tar before it can be used in IC engined.It is based on biological fermentation of biomass in the absence of oxygen at low temperature

The correct answers are:

a. Batch production is based on simpler and low cost digester design, but suffers from the lower efficiency compared to the continuous production

d. It is based on biological fermentation of biomass in the absence of oxygen at low temperature

Explanation:

a. In batch production, the digester is filled with organic material and then sealed for the duration of the process. This is a simpler and less expensive design, but it is less efficient than continuous production, where new material is continuously added and digested material is removed.

d. Biogas production, or anaerobic digestion, is a process that occurs in the absence of oxygen. It involves the breakdown of organic material by microorganisms at low temperatures, typically between 20 and 40 degrees Celsius. This process produces biogas, which is primarily composed of methane and carbon dioxide.

b. The gas collected from the digester typically contains 50-75% methane (CH4), not up to 90%.

c. While it's true that the gas often needs to be treated before use, this is typically to remove carbon dioxide, hydrogen sulfide, and other impurities, not tar.