This is a list of concepts related to biogas production. This includes explanations of different bacteria involved in the process, types of biogas digesters, and key processes like anaerobic digestion and hydrolysis.
- Acetogens
- Acetate producing bateria; these organisms take organics and produce CO2, H2, and acetate. All of these products can readily be used by methanogens.
- Acidogens
- Acid producing bacteria; these organisms take hydrolized products (soluble organics like sugar) and turn them into CO2, H2, and organic acids.
- Anaerobic Digestion
- A process, carried out by a community of microorganisms, that breaks down organic matter into biogas and mineralized nutrients.
- Batch Process
- A fermentation that you feed and unload once.
- Biodigester
- A sealed container that carries out the anaerobic digestion process; a biodigester needs to be able to separate and remove the liquid and gas phases and have an entrance/exit for the substrate.
- Biofilm
- An attached community of microbes in this case carrying out the anaerobic digestion process.
- Biogas
- A gaseous product of Anaerobic Digestion, this combustible gas is primarily made up of CH4 and CO2. The gas also contains trace amounts Hydrogen Sulfide (which is poisonous and corrosive), Ammonia and is saturated with water vapor.
- Bioreactor
- A container that carries out a biological process.
- Continuous Process
- A continuously fed fermentation.
- Floating Dome
- A biodigester where the gas is stored in a dome that rises with production. This is opposed to limited storage capabilities of flexible or fixed domes.
- Hydraulic Retention Time
- The amount of time liquid resides in the biodigester. Calculated by the volume of the biodigester divided by the volume fed each day. Units are in days. Hydraulic retention time controls your dilution factor.
- Hydrolysis
- A microbial process carried out by protozoa, fungi, and bacteria to take insoluble organics and convert them into soluble organics
- Loading Rate
- The amount of organic material you are adding per day. This can be expressed in volume units such as liters, or per the entire biodigester volume. Temperature, volume, type of biodigester, type of feed all control this parameter.
- Methanogens
- A class of Archaea that have the unique ability to metabolize acetate, CO2 and H2, formate, and methyl compounds into Methane.
- Plugflow Reactor
- A reactor that operates by significantly established flow, as material moves along it is broken down.
- Sludge Retention Time
- The retention time for the microbes in the anaerobic biodigester, often times controls the hydraulic retention time due to the slow rate of cell synthesis in a biodigester.
- Tank Reactor
- A biodigester that operates with a simple influent and effluent coming out of a tank where material is retained long enough to be broken down.
- Upflow Anaerobic Sludge Blanket
- A granulated sludge technology
AIDG Biogas- www.aidg.org