Anaerobic digestion reduces greenhouse effect, according to scientists

According to a recent story in Idaho’s Lewiston Morning Tribune, researchers at Washington State University believe the key to reducing the greenhouse effect lies in a certain technology – anaerobic digestion. The energy created by this process is often the focus, but the article also notes that anaerobic digestion also creates what’s referred to as a “fertilizer plant.”

According to the story:

A digester at a Lynden, Wash., dairy has been producing methane gas that is burned in a large Caterpillar engine to produce electricity. But the vast majority of research there has been focused on the recovery of nutrients like nitrogen and phosphorus to use as sustainable fertilizer….

“It’s a very significant emissions reducer, significant energy producer, and in quite a few cases, they’re very compelling projects from an economic standpoint,” Kruger said of anaerobic digesters.

Over the last seven years, the center has been studying other technologies and strategies that could reduce agricultural greenhouse gas emissions. One is using smarter tilling methods that keep carbon in the soil where it can help feed plants, and out of the air where it can trap heat and warm the planet.

The story points out that these “tilling practices” have a side effect. They can reduce direct emissions of greenhouse gases because farmers don’t have to drive tractors as often. Any chance to reduce greenhouse emissions is another way to improve our environment. When you can eliminate a pollutant at the same time, it’s truly a step forward.

Read the full story here and find the study from Washington State University here. Tell us what you think about both.

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New study suggests biochar can mitigate climate change

According to the journal Nature Communications, a new study released Aug. 10, 2010, and titled Sustainable Biochar to Mitigate Global Climate Change, suggests that the production of biochar can yield substantial benefits. Among them, it may have the power to remove carbon dioxide from the atmosphere over time, improving the fertility of degraded soils and allowing them to regain nutrients and water-holding capacity in some of the world’s poorest farming areas.

The study, conducted by Dominic Woolf, James E. Amonette, F. Alayne Street-Perrott, Johannes Lehmann and Stephen Joseph, explains that carbon dioxide levels have risen by 3 percent annually over the past 10 years, contributing to climate change and greenhouse gas emissions. But the study suggests biochar can be produced at any level – from individual farms to industrial facilities, making it an accessible option.

The abstract:

Production of biochar (the carbon (C)-rich solid formed by pyrolysis of biomass) and its storage in soils have been suggested as a means of abating climate change by sequestering carbon, while simultaneously providing energy and increasing crop yields. Substantial uncertainties exist, however, regarding the impact, capacity and sustainability of biochar at the global level. In this paper we estimate the maximum sustainable technical potential of biochar to mitigate climate change. Annual net emissions of carbon dioxide (CO2), methane and nitrous oxide could be reduced by a maximum of 1.8 Pg CO2-C equivalent (CO2-Ce) per year (12% of current anthropogenic CO2-Ce emissions; 1 Pg=1 Gt), and total net emissions over the course of a century by 130 Pg CO2-Ce, without endangering food security, habitat or soil conservation. Biochar has a larger climate-change mitigation potential than combustion of the same sustainably procured biomass for bioenergy, except when fertile soils are amended while coal is the fuel being offset.

Ultimately the study suggests this process could offset up to 107 billion metric tons of greenhouse gas emissions over 100 years.

For more information about biochar and the study itself, visit http://www.nature.com/ncomms/journal/v1/n5/full/ncomms1053.html. Let us know what you think about it.

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UK moves forward with renewable energy pledge

Anaerobic digestion is a hot topic in the United Kingdom these days when it comes to waste management. The Coalition government is forging ahead with its highly publicized plans to provide more anaerobic digestors to generate heat and electricity from organic waste.

According to an article in today’s BusinessGreen.com, ministers met with representatives across the industry to identify any barriers to the sustainable technology.

As reporter James Murray noted:

“The technology is fueled using biomass such as animal manure, sewage or food waste, which is digested by enzymes working in the absence of oxygen to produce methane. The methane is captured and can be burned off onsite to produce electricity and heat, converted into biofuel, or upgraded to biomethane which can be fed into the national gas grid. The resulting waste material can also be used as fertilizer.”

Anaerobic digestion is well suited to farms and businesses that produce large amounts of organic and food waste. As the article mentions, it also has the power to reduce the amount of organic waste going to landfills and can cut greenhouse emissions.

Roundtable discussions will tackle everything from the financial benefits and viability of using anaerobic digestion to ways the government can harness the power of biogas produced through this energy conversion technology.

If you were in attendance, what questions or concerns would you have? What would you most want to know about the addition of this technology on a much broader scale?