About Biogas and Biomass

Biogas is manufactured from biomass. Various definitions of potential can apply to biogas in relation to biomass. These are outlined below.

Theoretical potential refers to the total amount of solar energy embodied annually in plants as a result of the process of photosynthesis. It is defined according to the rainfall and sunlight a given region receives during a given season.

Technical potential is that portion of the theoretical biomass potential that is harvestable for biogas under existing technical and structural conditions. The parameters that define technical potential, in addition to rainfall and sunlight, include available crop technologies, the distance between the biomass growing site and the biogas generation site, and the transportability of the biomass.
Economic potential is that portion of the technical potential that can be produced economically.

Economic potential depends on the prices of biomass and biogas, as determined in the market by supply and demand. Demand for biomass for energetic and above all material uses (such as food for humans and livestock) plays a deciding role in determining economic potential.

Realisable potential takes into account, among other things, price supports and administrative restrictions on biomass production. Due to these factors, it is often about half of economic potential.
 

Biomass Production

Because biogas can in principle be generated from any organic compound, the biomass feedstocks that can be used to produce biogas are diverse.
Some biomass feedstocks come from farms in the form of plants. Others come from other processes, or from animals, in the form of waste materials like household garbage and sewer sludge. Biomass suitable for use in biogas production is called “feedstock.”

Waste’s suitability for use as a feedstocks brings every available organic material into question. Especially useful for biogas generation are sewer sludge, kitchen rubbish, and liquid manure, which as waste products are abundant and affordable.

Energy plants

The term “energy plants” refers to crops that are cultivated especially for the purpose of energy production. These generally include crops with high photosynthetic rates that grow quickly in the climatic conditions of a given region. In central Europe, such plants include corn, rapeseed, and rye. Many tropical countries use sugarcane extensively as an energy plant.

Energy plants for biogas generation

Corn is especially well-adapted for use in biogas facilities, though cereals (such as rye) and/or grass cuttings are also acceptable. The plants most suitable for use in biogas generation vary from region to region; they must be chosen with consideration for local conditions. It is important to ensure that local land use changes associated with energy plant cultivation do not yield negative ecological effects.