biogas

Food Waste And The Environment | Earth Wise

November 25, 2022 By EarthWise Leave a Comment

It is tragic that 31% of the world’s food production goes uneaten. About 14% isn’t distributed after it is harvested. Another 17% ends up wasted in retail or by consumers. Worldwide, the amount of food that is wasted is enough to feed more than a billion people while at least 828 million people continue to be affected by hunger. To make matters worse, food waste accounts for 8 to 10% of global greenhouse gas emissions, which is at least double that of aviation. Food waste, rotting away in landfills, produces methane gas, a major source of global warming.

Around the world, there are efforts being launched to try to improve the situation. California now has a law that requires grocery stores to donate edible food that would otherwise be disposed of or they face fines. The state’s cities and counties are required to reduce the amount of organic waste going into landfills by 75% by 2025 and compost it instead.

In London, grocers no longer put date labels on fruits and vegetables because the labels were leading people to trash perfectly good food. France now requires supermarkets and large caterers to donate food that is still safe to eat.

South Korea has little space for landfills. So, the country has been campaigning against throwing away food for 20 years. Nearly all organic waste in the country is turned into animal feed, compost, or biogas. Koreans even have to pay for throwing out food waste. There are now trash bins equipped with electronic sensors that weigh food waste.

All of these things can help. There is no single magic bullet for reducing food waste, but it is essential to do for so many reasons.

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Inside the Global Effort to Keep Perfectly Good Food Out of the Dump

Photo, posted November 30, 2020, courtesy of Marco Verch via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Electricity From Bacteria | Earth Wise

June 3, 2022 By EarthWise Leave a Comment

Microbiologists at Radboud University in the Netherlands have demonstrated in the laboratory that methane-consuming bacteria can generate electrical power. Their study was recently published in the journal Frontiers in Microbiology.

The bacteria studied is called Candidatus Methanoperedens and in the natural environment it consumes methane in water sources that are contaminated with nitrogen including places like water-filled ditches and some lakes. The bacteria in the study make use of the nitrates in the water to break down and digest the methane. Methanogens, which are bacteria that reduce carbon dioxide to form methane, are the source of the methane in these places.

The researchers exploited these complex interactions of bacteria to create a source of electrical power that is essentially a kind of battery with two terminals. One of the terminals is a chemical terminal and one is a biological terminal. They grew the bacteria on one of the electrodes where the bacteria donate electrons that result from its conversion of methane. (Other microbiologists at the same institution had previously demonstrated electrical generation from a similar battery containing anammox bacteria that use ammonium rather than methane in their metabolic processing).

In the study, the Radboud scientists managed to convert 31% of the methane in the water into electricity but they are aiming at higher efficiencies.

This approach represents a potential alternative to conventional biogas electricity generation. In those installations, methane is produced by microorganisms digesting plant materials and the methane is subsequently burned to drive a turbine to generate power. Those systems in fact have an efficiency of less than 50%. The researchers want to determine whether microorganisms can do a better job of generating electricity from biological sources than combustion and turbines can do.

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Bacteria generate electricity from methane

Photo, posted December 3, 2008, courtesy of Martin Sutherland via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Renewable Natural Gas

September 30, 2019 By EarthWise Leave a Comment

Small-scale biogas systems have collected methane from landfills, sewage plants, and farms for decades. Here in the US, biogas is finally catching up with modern techniques with the advent of third-party operators introducing more sophisticated technology to capture methane and pump it directly into pipelines.

Renewable methane or natural gas represents a significant mostly unexploited source of energy. Examples include the vast amounts methane generated by manure from some of the 2,300 hog farms in eastern North Carolina, biodigesters that can turn clusters of large California dairy farms into energy hubs, as well as diverting food waste from landfills and transforming it into vehicle and heating fuels.

According to a 2014 EPA study, the U.S. could support at least 13,000 biogas facilities, fed by manure, landfill gas, and biosolids from sewage treatment plants. Those facilities could produce over 650 billion cubic feet of biogas per year – enough renewable energy to power 3 million homes.

A study by the World Resources Institute estimated that the 50 million tons of organic waste sent to landfills or incinerated every year in the U.S. has the energy content of 6 billion gallons of diesel fuel, amounting to 15% of all diesel consumed by heavy-duty trucks and buses.

Utilizing all that biogas could help lower greenhouse gas emissions from some of the most difficult sectors to decarbonize – transportation, industry, and heating buildings. In addition, ramped up renewable gas could keep organic waste out of landfills and prevent manure runoff into rivers and water supplies.

Renewable natural gas could be the next big thing in green energy.

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Could Renewable Natural Gas Be the Next Big Thing in Green Energy?

Photo, posted June 19, 2013, courtesy of Alan Levine via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Virtual Power Plants

September 22, 2016 By WAMC WEB

The traditional model of the electricity grid is one where centralized large power plants send power through transmission lines to substations and then on to homes and businesses. As localized renewable energy sources, energy storage systems, and efficiency systems proliferate throughout the system, a new concept is emerging: that of the virtual power plant.

[Read more…] about Virtual Power Plants