Anaerobic Digestion Technology (ADT)

About anaerobic digestion (AD)

What is biogas

What is anaerobic digestion

A brief history of anaerobic digestion technology development in the world

- Anaerobic digestion is a microbiological process that anaerobically (in the absence of oxygen) decomposes biodegradable materials.

- It consists of three main phases (hydrolysis, acidogenesis, and methanogenesis).

- The products of anaerobic digestion include biogas and biodegraded organic wastes (digestate).

- Biogas is a combustible mixture of gases and a renewable energy.

- It also has other names such as manure gas, methane gas, marsh gas, etc.

Burning of biogas in a stove (image from internet)

- 10 BC: marsh gas to heat bath water in Assyria

- (not dated): marsh gas to make salt from sea water in China

- 1859: first biogas system in Bombay (Mumbai), India

- 1895: biogas lighted street in Exeter, U.K.

- 1920s -1930s: application in sewage systems in Europe, USA, Latin America, and China

- 1950s: application in rural areas in some countries, e.g., China

- 1970s-1980s: worldwide application in response to the energy crisis

- 1990s: sluggish development

- 2000s - now: application steadily increasing in many countries and technology improved

Biogas digester design in Indian in the 1970s

1 MW dairy biogas system in China in 2007 (Photo: Hangzhou Energy & Environmental Engineering Co. Ltd., China )

Feedstock for anaerobic digestion

Most often used feedstock:

- Animal manure

- Agro-industrial wastes

- Municipal wastes

- Food wastes

It must Have:

- Enough quantity

- Long term stability

- Sufficient concentration