byproduct

Biochar and poultry farm pollution

July 23, 2025 By EarthWise Leave a Comment

Poultry farms are a significant source of air and water pollution. In the US, they are the largest source of ammonia emissions, followed by dairy and non-dairy cattle farms. Poultry farms emit over two million tons of ammonia per year. Ammonia is not directly produced or excreted by the birds but is a common by-product of poultry wastes.

Poultry manure is a rich source of phosphate and large amounts of it are used in agricultural land as an organic fertilizer. This poses an environmental risk when phosphates are washed into rivers and streams by rainwater. Phosphates lead to the proliferation of algae, harming other aquatic life and resulting in toxic conditions.

Researchers at the UK Centre for Ecology & Hydrology are investigating the use of biochar as a means of reducing air and water pollution from poultry farms in the UK. Biochar is produced by heating biomass – typically wood – to high temperatures in the absence of oxygen. The resultant material is effective at absorbing nutrients and other substances.

In laboratory experiments, adding biochar to birds’ bedding has been shown to reduce ammonia emissions from droppings by 58%. The biochar binds ammonium to its surface, preventing release into the atmosphere as ammonia gas.

Modified biochars are also proven to be highly efficient at adsorbing phosphorous. Adding a cost-effective biochar to poultry manure fertilizer could support the safe use of an important and otherwise renewable fertilizer. The biochar binds phosphates in the manure to its surface, preventing leaching and run-off into waterways.

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Biochar could help restore River Wye

Photo, posted May 15, 2023, courtesy of Ark. Agricultural Experiment Station via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Energy From Rice Straw | Earth Wise

February 3, 2023 By EarthWise Leave a Comment

Rice straw is produced as a byproduct of rice production. Globally, as much as a billion tons of rice straw is produced each year, three-quarters of it in Asia. Straw incorporation in soil for fertilization is not practical in most places because with multiple crops per year, there is not enough time for the material to decompose and become good fertilizer. As a result, open-field straw burning is increasingly the standard practice.

Scientists at Aston University in Birmingham in the UK are embarking on a project to convert rice straw in Indonesia into low-cost energy on a commercial scale.

Indonesia produces 100 million tons of rice waste each year, of which 60% is burned in open fields, causing air pollution.

The Aston researchers are developing a biomass conversion process based on pyrolysis. This involves heating the rice straw to high temperatures over 900 degrees Fahrenheit to break it down, producing vapor and solid products. Both of these things can be used to generate electricity.

A new combustion engine designed by a company called Carnot Limited is capable of converting 70% of the thermal energy extracted from the rice straw into electricity.

Energy extracted in this way could help low and middle-income countries to create their own locally generated energy, thereby reducing emissions, creating jobs, and improving human health. The biomass electricity is predicted to be cheaper than solar, geothermal, wind, coal, or even subsidized gas-generated power.

The Aston University project will help develop a business model that could support companies and communities to produce local, cheap energy in Indonesia and other countries with biomass capacity.

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Aston University to help power Indonesia with affordable energy made from rice straw

Photo, posted September 11, 2006, courtesy of Kristen McQuillin via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Getting Rid Of Hydrogen Sulfide | Earth Wise

December 20, 2022 By EarthWise Leave a Comment

Hydrogen sulfide gas produces the characteristic smell of rotten eggs, sewers, stockyards, and landfills. The petroleum industry produces thousands of tons of the stuff each year as a byproduct of the processes that remove sulfur from petroleum, natural gas, coal, and other products. The industry faces substantial fines for emitting hydrogen sulfide, but remediation is expensive.

Researchers at Rice University have developed a method for turning hydrogen sulfide into hydrogen gas and sulfur in a single step. Called plasmonic photocatalysis, it not only gets rid of an undesirable substance, it does so by producing valuable byproducts.

The established way of getting rid of hydrogen sulfide is called the Claus process. It requires multiple steps, including some that require combustion chambers heated to 1,500 degrees Fahrenheit. The end product is sulfur and water.

The Rice University process gets all of its energy from light. A surface of grains of silicon dioxide is dotted with tiny gold nanoparticles. These particles interact strongly with a specific wavelength of visible light and cause plasmonic reactions that create short-lived, high-energy electrons that drive the catalysis of hydrogen sulfide. Given that the process requires only visible light and no external heating, it should be relatively straightforward to scale up using solar energy or very efficient LED lamps.

The new hydrogen sulfide remediation technology has been licensed by a Houston-based startup company with more than 60 employees whose founders include some of the Rice researchers. The process may end up being efficient enough and cheap enough for cleaning up non-industrial sources of hydrogen sulfide such as sewers and animal waste.

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New catalyst can turn smelly hydrogen sulfide into a cash cow

Photo, posted July 8, 2021, courtesy of Doug Letterman via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Turning Plastic Into Protein | Earth Wise

November 18, 2022 By EarthWise Leave a Comment

Our planet is choking on plastic. According to the United Nations, 79% of the 6.3 billion tons of plastic produced every year accumulates in landfills. Half of all plastic produced is actually designed to be used just once and thrown away. But plastic is not only accumulating on land. In fact, the world’s oceans are projected to contain more plastic by weight than fish by the year 2050.

According to new research, solving the plastic waste issue could help address another prominent global issue: hunger. A multidisciplinary team of engineers, chemists, and biologists led by researchers from Michigan Tech University has developed a process to break plastics down to be recycled into useful products, including edible protein powder.

The research team’s process converts plastic into compounds using heat and a reactor that deconstructs the material’s polymer chains. The oil-like substance is then fed to a community of oil-eating bacteria. The bacteria grow rapidly on the oily diet, producing more bacterial cells composed of roughly 55% protein. This majority-protein byproduct is then dried out and turned into an edible powder. The end result doesn’t look like plastic at all. In fact, it resembles a yeast byproduct that comes from brewing beer.

This research is funded by an award from the US Department of Defense. The DoD often deploys soldiers in areas where access to food is challenging. Converting plastic to protein could be part of a solution to that problem.

While eating something that began as plastic might take some getting used to, it could be part of the solution to both plastic pollution and global hunger.

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Turning Trash Into Treasure: The Plastic to Protein Powder Solution

Beat Plastic Pollution

Photo, posted February 2, 2022, courtesy of Ivan Radic via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Rock Dust And Carbon | Earth Wise

May 25, 2022 By EarthWise Leave a Comment

According to a new study by Cardiff University in the UK, Britain could achieve nearly half of the carbon removal needed to meet its climate goals by adding basalt rock dust to crop fields. The process is known as enhanced weathering and has been the subject of ongoing research in the U.S. at Cornell University and the University of California, as well as in the UK, Canada, and Australia.

Adding rock dust to agricultural lands speeds up the chemical reactions that lock up carbon in soil. Basalt contains magnesium, calcium, and silica, among other components. When basalt is pulverized and applied to soils, magnesium and calcium are released and dissolve in water as it moves through the soil. The minerals in the soil react with the water, and the carbon that would otherwise end up in the atmosphere instead forms bicarbonates, which can hang around in water for thousands of years. It can also eventually make its way to the oceans where it precipitates out as limestone and can stay on the seafloor for millions of years.

Basalt is a waste stream byproduct of mining and manufacturing and is found all over the world. Mining waste is the largest waste stream in the world, so there is no shortage.

According to the U.N. Intergovernmental Panel on Climate Change, applying rock dust to agricultural lands on a global basis could theoretically remove 2 to 4 billion tons of carbon dioxide from the air each year, which is between 34-68% of the global greenhouse gas emissions produced by agriculture annually.

The added rock dust would in fact be good for the soil and for crops. Whether the economics of producing and transporting it make sense remains to be determined.

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Adding Rock Dust to Farmland Could Get UK Almost Halfway to Its Carbon Removal Goal

Photo, posted April 24, 2011, courtesy of the State of Israel via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Hacking Photosynthesis

February 25, 2019 By EarthWise Leave a Comment

There is an enzyme known as RuBisCo that is involved in carbon fixation, the process plants use to convert carbon dioxide into sugar molecules. The RuBisCo molecule is inside the leaves of most plants and is probably the most abundant protein in the world.

RuBisCo picks up carbon dioxide from the air and uses energy from the sun to turn the carbon into sugar molecules. This process of photosynthesis is pretty much the foundation of life on Earth.

Wonderful as it is, the process is not perfect. RuBisCo is not very selective in grabbing molecules from the air. It picks up oxygen as well as CO₂ and it produces a toxic compound when it does that.

Plants operate a whole other complicated chemical process to deal with this toxic byproduct and uses up a lot of energy along the way, leaving less energy for making leaves or food that we can eat.

A research program at the University of Illinois called Realizing Increased Photosynthetic Efficiency (or RIPE) has been trying to correct this problem; they have been trying to hack photosynthesis. And they may well have succeeded.

Using genetic modification on tobacco plants, they have shut down the existing detoxification process and set up a much more efficient new one. The result is super plants that grow faster and up to 40% bigger.

The next step is to get it to work on plants that people actually rely upon for food, like tomatoes, soybeans and black-eyed peas (which are a staple food crop in sub-Saharan Africa where food is scarce.)

It will be years before we know if the process can really produce more food and be safe, but it may end up leading to a major increase in crop productivity.

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Scientists Have ‘Hacked Photosynthesis’ In Search Of More Productive Crops

Photo, posted June 10, 2013, courtesy of Boon Hong Seto via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Edible Tableware

July 4, 2017 By EarthWise

The problems caused by plastics in the environment continue to mount. Major companies around the world are endorsing and promoting efforts to combat the problem including the New Plastics Economy Initiative which aims to have 70% of plastic packaging reused and recycled globally, which is five times more than the current percentage.

[Read more…] about Edible Tableware