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AES to Put $325M into Bio-digester Joint Venture

Aesagriverde_digester
AES AgriVerde anaerobic digester.

Global power company AES and AgCert International plc have formed a joint venture—AES AgriVerde—to deploy AgCert’s anaerobic bio-digester technology to capture methane from agricultural and animal waste products. This is AES’ first significant direct investment in projects and technologies to help reduce and offset greenhouse gas emissions.

The resulting biogas will either be flared or used to generate electricity, heat or both. Applying it as a transportation fuel would require further scrubbing.

Methane is one of six greenhouse gases controlled under climate change regulations, the others being carbon dioxide, nitrous oxide, hydrofluorocarbons, perfluorocarbons and sulfur hexafluoride. Methane accounts for about 16% of all greenhouse gas emissions globally, and is responsible for the second-largest radiative forcing in the atmosphere (behind carbon dioxide, the leader by far).

Methane is about 21 times more powerful (global warming potential—GWP) at warming the atmosphere than carbon dioxide by weight, and has a relatively short chemical lifespan of about 12 years.

Methane accounts for about 16% of all greenhouse gas emissions globally; carbon dioxide represents the majority.

In the system, manure flows into the bio-digester from a confined animal farm operation. Bacteria and chemical reactions decompose the manure into methane, solid residue, and nitrate-rich liquids over a process of 22 to 28 days. The residual liquids from the digesters flow to a secondary lagoon and can be used for field fertilization.

Under the terms of the relevant agreements, AES will maintain a majority interest in the joint venture and plans to invest approximately US$325 million into the joint venture over the next five years. In addition, AES has invested approximately €40 million (US$51.1 million) to acquire an approximate nine percent equity interest in AgCert.

By 2012, AES AgriVerde intends to create an annual production volume of 20 million tonnes of greenhouse gas emission reductions through the reduction of methane emissions created by agricultural and animal farm waste.

Use of the AES AgriVerde digesters will reduce net greenhouse gas emissions from the manure management process by approximately 95 percent. This application reduces emissions by preventing the animal sewage and other agricultural waste from being disposed in large open lagoons where it would otherwise decay, releasing large volumes of methane.

AES AgriVerde will register the bio-digesters it installs at farms with designated regulatory agencies at the country and United Nations level to earn greenhouse gas emission reductions under the Joint Implementation or Clean Development Mechanism contemplated under the Kyoto Protocol.

AES AgriVerde will sell the greenhouse gas emission reductions on international markets and share an agreed portion of the sale proceeds with farm owners.

AES is committed to helping address climate change issues as part of our broader alternative energy strategy. We believe that greenhouse gas emissions will continue to face increasing regulation, and expect that offsets will remain a significant component of those regulations. This methodology not only mitigates important environmental impacts, it enhances our ability to meet new power needs.

—William Luraschi, AES Executive Vice President for Business Development

Luraschi is also head of AES’ recently announced alternative energy business. (Earlier post.)

AES is one of the world’s largest global power companies, with 2005 revenues of US$11.1 billion. AgCert International plc was founded in 2002 to produce and sell greenhouse gas emissions offsets from agricultural sources on an industrial scale. These offsets are intended to satisfy the requirements of the Kyoto Protocol and be capable of being traded on the European cap and trade system, the European Union Emissions Trading Scheme (EU-ETS).

Comments

allen zheng

The "to secondary lagoon" could be an algae pond. The nitrogen/mineral salts and some of the organic compounds could be put to use in making bio oil from algae. Additionally, further methane producing could be done in later stages. Composting/fertilizing of fields would be the last step as indicated.

Tony

If they are selling the reductions to offset emissions from other greenhouse gas emitters, aren't they merely creating a market to move the pollution to another part of the world, in lieu of creating a green product?

SJC

It sounds like they are turning methane into CO2. "Methane is about 21 times more powerful (global warming potential—GWP) at warming the atmosphere than carbon dioxide by weight.." "The resulting biogas will either be flared or used to generate electricity, heat or both." Let's hope they use it to make electricity rather than just flare it.

rexis

A little doubts here guys!

"Methane accounts for about 16% of all greenhouse gas emissions globally; carbon dioxide represents the majority."

Does this mean that reduction of 1% methane equals to reduction of 21% CO2?

Or just that methane totalled 16% of greenhouse effect?

Thomas Pedersen

1 kmol CH4 (methane) = 14 kg
1 kmol CO2 (carbondioxide) = 44 kg

Since CH4 is 21 times stronger by weight, it is 6.68 times stronger by mol (volume). Hence, by flaring the gas, i.e. converting one molecule of methane (plus oxygen) into one molecule of carbondioxide (plus water), the greenhouse effect is reduced by a factor of 6.68, i.e. to 15% of the original.

-Thomas

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