Researchers see the interconnections between the systems in nature and how each component impacts the others. In Connecticut, rich in forests and farmland, experts see the potential that could position the state at the forefront of a climate-smart agriculture (CSA) approach using an emerging sustainable practice called biochar.
Man-made per- and polyfluorinated substances (PFAS), known as “forever chemicals,” withstand many treatment options and bioaccumulate in the environment, posing serious environmental and health concerns. With a three-year, nearly $1 million grant from the U.S. Department of Defense (DOD) Strategic Environmental Research and Development Program (SERDP), Illinois Sustainable Technology Center (ISTC) scientists are developing a new technology to remove and destroy PFAS from contaminated water using a designer biochar produced from woody biomass or agricultural residues such as corn stalks and cobs.
PFAS are a widely used class of chemicals found in many different consumer, commercial, and industrial products, including non-stick coatings and textiles. Since the 1970s, PFAS have also been used in firefighting foam, which is why the DOD is interested in finding new solutions to clean up contaminated sites where firefighters have trained, according to Wei Zheng, principal investigator of the project at ISTC, a unit of the Prairie Research Institute at the University of Illinois Urbana-Champaign.
Activated carbon, as a most common adsorbent, is typically used to treat PFAS-containing water. Once the activated carbon is saturated with the contaminants, the spent adsorbent is incinerated. However, incineration, even done at sufficiently high temperatures, cannot completely destruct PFAS and will create some hazardous and toxic byproducts. In 2022, the Office of the Assistant Secretary for Defense placed a temporary ban on incineration of materials containing PFAS until safe guidance for disposal of PFAS is issued.
“If incineration is not an option, the spent adsorbent ends up in the landfill where PFAS can leach to water sources and evaporate to air because they won’t degrade,” Zheng said. “So, PFAS will go back to the environment. In this way we just solve one issue but generate a new problem.”
In addition, wastewater treatment plants can’t solve the PFAS issue because these contaminants are never destroyed by conventional treatment techniques. That is why they are called forever chemicals.
In the new project, Zheng will develop a hydrothermal technology, likened to pressure cooking, that will destroy PFAS absorbed on low-cost designer biochar created at ISTC, and at the same time reactivate the biochar that has reached its sorption capacity for reuse. Thus, the designer biochar will act a double role as an adsorbent to remove PFAS from contaminated water and as a catalyst to destroy these compounds under a hydrothermal system.
“The most important and innovative aspect of the project will be the complete destruction of PFAS once they are removed from the water,” Zheng said. “PFAS are widely detected in the environment and in the atmosphere. Our project is designed to mitigate human exposure to PFAS, helping to find ways to indeed solve this problem.”
ISTC is collaborating with researchers at the U.S. Army Corps of Engineers Construction Engineering Research Laboratory on this project.
Chemical and environmental engineers detailed a method to convert plastic waste into a highly porous form of charcoal that has a whopping surface area of about 400 square meters per gram of mass. It could potentially be added to soil to improve water retention and aeration of farmlands.
The bioeconomy – the part of the economy driven by the life sciences and biotech, and enabled by engineering, computing, and information science – has the potential to revolutionize human health, climate and energy, food security and sustainability, and supply chain stability, as well as support economic growth and well-paying jobs across the entire country. The U.S. government has recognized this exceptional promise: The recent Executive Order on advancing the U.S. bioeconomy and relevant provisions in the CHIPS and Science Law and the Inflation Reduction Law have opened up an excellent opportunity to engage with the U.S. government to help develop and shape the implementation of policies to bolster the economic engine that is the biotech and biomanufacturing ecosystem.
The Day One Project now needs your help to generate innovative, specific, and actionable policy ideas that the U.S. government could use to supercharge the U.S. bioeconomy.
They are particularly focused on:
Leveraging financial or economic tools – such as loan programs, tax incentives, demand-pull mechanisms, and economic development challenges – to support and advance the U.S. bioeconomy in ways that enable and incentivize biotech or biomanufacturing to expand into new regions of the U.S., build new facilities, and engage in workforce development efforts;
Enabling better measurement of the U.S. bioeconomy’s contributions to the rest of the economy; and
Devising new authorities that may be needed at federal agencies in order to support a maximally-coordinated effort to advance the U.S. bioeconomy.
Submit your idea here. Submissions are due Monday, November 7th, and will be reviewed on a rolling basis, so submit today!
The climate crisis and years of unsustainable farming in the United States have resulted in soil erosion, pollinator loss, farmworkers and livestock exposed to extreme heat, and other harmful impacts. In 2019, 10 percent of U.S. greenhouse gas emissions came from agriculture. At the same time, farmers and the land they work are vulnerable to climate impacts such as drought and extreme weather.
Sustainable soil amendments such as biochar and compost are among the many agricultural practices that can help farmers mitigate and adapt to the climate crisis. This is the final article in EESI’s five-part series on sustainable agricultural practices including cover crops, agroforestry, no-till farming, sustainable livestock grazing, and soil amendments.
Heat up stalks, stems, leaves or wood in a reactor with little or no oxygen (in a process called pyrolysis) and you get bio-oil for fuel and biochar for fertilizer.
There’s always a market and a value for the liquid energy.
But efforts to study, develop and market the black powder as a fertilizer weren’t adding a lot of value to biochar – at least until there’s a carbon market that will pay a premium for the charcoal’s ability to store carbon.
Iowa State University’s Robert C. Brown and his collaborators thought there might be some new ideas and applications that could make biochar a more valuable and useful product, thus enhancing the economics of biorenewables.
The researchers say their latest project could one day provide “ecosystem services” such as reductions in manure odors, greenhouse gas emissions and fertilizer runoff to waterways.
“This new grant gives us opportunities to specifically study animal agriculture for ways to valorize biochar even further,” said Brown, an Iowa State Anson Marston Distinguished Professor in Engineering, the Gary and Donna Hoover Chair in Mechanical Engineering, the director of Iowa State’s Bioeconomy Institute and the leader of the latest biochar research project.
Biochar as a manure manager
Santanu Bakshi, an environmental research scientist at the Bioeconomy Institute, has spent about a dozen years studying biochar, everything from doctoral student efforts at the University of Florida to remove copper from the soils of citrus groves to Iowa State efforts to make phosphorus stick – adsorb – to the surface of biochar.
There’s a trick to the latter: Santanu found that pretreating biomass with iron sulfate, an inexpensive byproduct of steel production, modifies the surface of biochar, which has a mostly negative-charged surface, to adsorb, rather than repel, negatively charged molecules such as phosphorus. That biochar-phosphorus combination ended up creating a slow-release fertilizer.
“When we found biochar was useful to trap phosphorus, we thought it would be useful for recycling nutrients from animal manure,” Bakshi said.
The new project will continue to develop biochar technology for capturing phosphorus. It will also develop technology that uses a naturally occurring mineral called zeolite (which attracts positively charged molecules) to capture nitrogen. The two nutrients would then be processed into solid, slow-release fertilizer pellets.
The research team (see sidebar for the full team) will start in the laboratory. Next year, with the help of an industrial-scale pyrolyzer now under construction just west of Des Moines, they’ll have enough biochar for laboratory, farm and field studies.
Bakshi said the goal is to develop an automated bioreactor system. Manure would move through a series of biochar and zeolite chambers that separate, capture and process the nutrients. The resulting biochar and zeolite would then be made into pellets and applied to fields rather than raw manure with its potential for odor, transportation, runoff and greenhouse gas emission problems.
That switch could have big environmental impacts.
“The United States Environmental Protection Agency estimates that 15% of the greenhouse gas emissions are associated with animal manure management in the United States agricultural sector,” the researchers wrote in a project summary. “Hence, it is critical to develop enhanced nutrient management strategies to boost nutrient use efficiency in crop production, improve water quality, and reduce odorous and greenhouse gas emissions.”
Advanced manufacturing for biorenewables
The new project will start with biochar supplied by Iowa State’s existing pyrolysis pilot plant at the BioCentury Research Farm west of Ames.
Iowa State’s pilot plant – developed, in part, as part of RAPID, the country’s 10th Manufacturing USA Institute, supported by the U.S. Department of Energy and led by the American Institute of Chemical Engineers – tests the autothermal pyrolysis process developed at Iowa State.
The autothermal process adds a small amount of air to normally oxygen-free pyrolysis. That partially burns some of the biomass being processed and creates some heat for the reactor, dramatically increasing the rate that biomass can be converted to bio-oil and biochar.
One of the RAPID project’s industry partners, Stine Seed Co. of Adel, is working with Frontline BioEnergy of Nevada to build an industrial autothermal pyrolyzer plant based on Iowa State’s technology. It would also test the idea that small, efficient biorefineries could process local biomass, saving the cost and trouble of transporting large amounts of biomass to big biorefineries.
The Stine plant in Redfield will process 50 tons of biomass per day and create 10 tons of biochar per day; Iowa State’s pilot plant can process about a half ton of biomass per day.
“We’re looking forward to scaling up our technology in the Stine pyrolyzer,” Brown said. “That’s important because so much of our work has been done at the lab scale and with small pilot plant studies.”
But those studies have led to big ideas for the bioeconomy such as finding ways to provide ecosystem services in addition to biorenewable products. As a summary of the Bioeconomy Institute’s work says, “Biorenewable feedstocks are produced from an ecosystem that needs to be conserved and renewed in order to ensure future production capacity.”
Phoenixville has announced plans to build what it claims will be the first hydrothermal carbonization plant at a municipally-owned wastewater treatment center not only in Chester County, but in all of North America.
Hitachi Zosen Inova USA (HZIU) announced it has entered into an agreement with the Canadian technology company CHAR Technologies Ltd. to develop a test project to produce green hydrogen and biochar at HZIU’s San Luis Obispo, California biogas plant.
A believer in fresh perspectives and sustainable biological solutions, Victoria Augoustides has been the lead researcher on a project to add value and remediate waste products of pine and swine production in North Carolina.
You must be logged in to post a comment.