Manure treatment-Biogas production

Question 1

You see a sketch of the biogas plant. Fill in the missing words, name the part of the plant what is what?

Answer 1

PIC

Question 2

List the main steps of Methane/Biogas Formation.

Answer 2

1. Anaerobic Digestion: The prepared feedstock is introduced into an anaerobic digester, which is a sealed container or tank where anaerobic bacteria break down organic matter in the absence of oxygen. Anaerobic digestion occurs in four stages:
   a. Hydrolysis: Complex organic compounds are broken down into simpler compounds such as sugars, amino acids, and fatty acids.
   b. Acidogenesis: Acid-forming bacteria convert the simpler compounds produced in hydrolysis into organic acids, alcohols, and volatile fatty acids.
   c. Acetogenesis: Acetic acid and hydrogen are produced from the organic acids and alcohols by acetogenic bacteria.
   d. Methanogenesis: Methanogenic archaea convert the acetic acid, hydrogen, and carbon dioxide produced in the previous stages into methane (CH4) and carbon dioxide (CO2) through biochemical reactions.

Question 3

2. List four factors of your choice which influence the biogas yield: How do they affect the process: “the higher the higher, or the higher the less, or the less the less, the less the higher…)”

Answer 3

• Composition of material and easy degradable content (sugars, starch, proteins) The higher, the higher the biogas yield
• particle size –> silage best yield, the smaller the higher the methane yield
• temperature –> the higher the temperature, the higher the methane yield (best: thermophilic, 50-55 °C)

Question 4

List four main benefits of your choice of biogas production

Answer 4

• Efficient conversion of biomass to energy (conversion of high grade energy out of collected sun-energy stored in biomass)
• Use of a broad spectrum of substrates (liquid to solid) = high grade energy resource (high energy-output per ha)
• Waste and crops, byproducts
• Different technical systems for anaerobic conversion of biomass
• Close nutrients cycle loops when the digested residue is spread over cultivated areas
• Environmental and climatic benefits