Pyrolysis

 The pilot system at Scott Brothers’ converts about 88 percent of the dairy’s gasified manure into biochar and other products

Sustainability in farming is a phrase that’s used a lot these days. In its simplest form, it’s about continual operation with minimal impact on the environment. At Scott Brothers’ Dairy Farms in Moreno Valley, Calif., sustainability has reached a never-before-achieved level, one that’s attracting attention from around the globe.

Manure plays a central role in the farm’s ‘Circle of Energy’ concept: the 1,100-strong herd eats high-quality feed produced from the farm’s 700 acres, harvested with machinery powered by a no-sulfur diesel fuel derived from the cows’ manure. If that wasn’t impressive enough, the system also produces irrigation water, potable water, fertilizer, high-value wax, sulfur and valuable nutrients, which, according to Steve McCorkle, enables these and future farmers to truly control their own destinies.

McCorkle is the CEO of Ag Waste Solutions (AWS) of Westlake Village, Calif., the designer and installer of the system at Scott Brothers. He got the idea of making diesel from manure during years travelling the globe working in the energy sector.

“It appeared to me that farmers all over the world seemed to share two very strong, common goals: a desire to be the best possible stewards of their land, and a desire to be as independent as possible,” he says.

At the same time, when McCorkle was working in remote deserts in the Middle East with no infrastructure for hundreds of miles, he and his colleagues had to convert waste gases into electricity and recycle wastewater.

“I realized that if we could economically convert wastes into diesel fuel, we could literally fuel our own petroleum exploration – and also achieve what farmers wanted, to be much more independent of the world outside their farms,” he says.

It seemed to him that there were two main factors that would make small-scale on-farm diesel production viable. One was modular and portable refining equipment, and, the second, a waste feedstock with a consistent chemical composition to make pre-conditioning less costly. With manure fitting the feedstock bill, McCorkle began in 2006 to work on the refining technology. By 2012, he was collaborating with the Scott brothers, who were looking hard at that point for solutions to deal with new groundwater and watershed salt load regulations – and an impending ban on applying manure to forage crops to boot. With some funding help from the California Energy Commission (CEC), the current pilot system was up and running at Scott Brothers by April 2015.  

How it works
The system first removes almost all suspended solids and 40 percent of dissolved solids from the dairy’s liquid manure. Some of the extracted water is further purified to make it potable (and therefore satisfy manure application requirements specific to a regional state regulatory agency). The solids go into a pyrolysis gasifier and the resulting syngas is purified. Using the well-proven 90-year-old Fischer-Tropsch (FT) process, the hydrogen and carbon in the gas is converted to completely sulfur-free renewable diesel products. A refined wax (worth up to three times the price of diesel) can be processed further and/or blended with fuels such as kerosene – a significant additional farm revenue stream. AWS can also recover elemental sulfur and other nutrients from the process for either sale or re-use on farm.

Challenges along the way
As might be imagined, significant hurdles presented themselves during the years of AWS tech development, with conventional thinking and regulations topping the list.

“Operating permits are very difficult to obtain when the technology is new,” McCorkle explains. “Grants and incentives are generally available for new concepts and commercially-proven systems, but it’s not easy for ‘in-between’ tech concepts like what we’ve developed, using new enhancements to make the FT process economically viable on a small-scale, to gain financial support.”

When it was time to install at Scott Brothers, more permit and funding issues came up.

“We were not allowed to even move the AWS equipment to the farm until the ‘lead permit’ was secured (South Coast Air Quality Management District, SCAQMD),” McCorkle remembers. “Although AWS had obtained one of these permits at another farm site previously, and paid to expedite the Scott Brothers’ permit applications, it took a long time to obtain. We finally received help from the Governor’s Office of Business and Economic Development.”

The CEC grant required that the project obtain an exemption from CEQA (California Environmental Quality Act), and the only way to do that was to build a temporary structure to shelter the AWS equipment.

“This is a large fabric-covered structure that we anchored to the ground with standard shipping containers,” explains McCorkle. “The county stipulated that we needed to supply engineering drawings of the entire facility, including the stresses that the shipping containers would encounter. We had to hire an engineer to design modifications to address the wind and other transverse forces the shipping containers would encounter on the farm.”

Taking the long view, AWS made sure its system exceeds the most stringent California regulations.

“Scott Brothers convinced us that if we could meet and exceed these requirements, we could then meet and exceed any standards across the globe,” says McCorkle. “An example of this would be the Zero Total Dissolved Solids (TDS) mandate and salt loading restrictions in the watershed. We are proving that we can meet these tough requirements through technology alone, as we have done at Scott Brothers, by removing all of the salts and TDS from the water and producing a potable water discharge. Once that has been recognized, we may be able to prove that we can add certain amounts of TDS into the soil in the form of biochar.”

McCorkle adds the AWS biochar combines the two key elements of healthy soil amendments, carbon and micronutrients, into one product, with the same content as raw manure but without the potential surface and groundwater issues. This is why he decided to concentrate the gasification efforts on producing a nutrient-rich biochar product, and capitalize on that before other manure gasifiers could get permitted in California to produce it.

Currently, the pilot system at Scott Brothers converts about 12 percent of the dairy’s gasified manure to diesel fuel per day, and about 88 percent into biochar and other products. To be a commercially viable, 24-7 operation and complete the ‘Circle of Energy,’ the liquid fuels production module will have to be upsized.

“We are now applying for a Phase II CEC grant to accomplish this,” says McCorkle. “We will then go to market with our new gasifier design, starting with biochar systems on farms to help farmers meet their permit requirements while selling and/or stockpiling biochar as a feedstock for future FT biofuel production at central plants. Biochar is an excellent feedstock for FT biofuel production that does not have a shelf life.”  

In reflecting on the entire process, McCorkle has nothing but praise for Scott Brothers, which he describes as “an outstanding partner in overcoming the numerous challenges.” And while it was onerous, he believes the process of helping regulators understand the advantages of the AWS concept was very worthwhile because of the new standards and regulations that are being created.

“Although this approach can be very time consuming and costly,” he notes, “we believe that working directly with regulators and stakeholders is ultimately the best way to have the AWS solution become standard for creating future profit centres from manure.”

McCorkle strongly believes that creating viable profit centers from manure will have the highest impact towards making livestock operations more sustainable.

“Once the AWS ‘Circle of Energy’ concept is working well on individual livestock farms, the circle will grow to include other farms and organic biomass feedstocks in the community, thereby reducing the carbon footprint of the entire community,” he says. “This will raise the resulting carbon credits and funding opportunities for sustainable solutions that will improve the agricultural economy as well as the environment. Many such community opportunities exist world-wide, and the AWS solution can be scaled and tailored to meet the needs of any community.”

Biochar and water from food waste digesters
AWS is also working to accept materials for its systems from anaerobic digesters that process food and other organic waste. In late July, AWS signed an agreement to perform a series of controlled greenhouse vegetable trials using biochar and fertigation water from an AWS system processing ‘food waste anaerobic digestate,’ in addition to biochar and fertigation water processed from manure. McCorkle says this is very exciting because anaerobic digestate is usually considered a waste that is increasingly difficult to permit for land application in its raw form, but value-added biochar and fertigation water can be readily permitted.

 

 

 

September 1, 2015, Wicomico County, MD – Wicomico County will be the site of Maryland’s biggest attempt yet to find alternative uses for the Eastern Shore’s overabundance of poultry litter, state agricultural officials say.

Renewable Oil International, an Alabama company, has received a $1.2 million state grant to test technology it says can reduce the volume of manure by 50 to 63 percent. The grant comes from the Maryland Department of Agriculture’s Animal Waste Technology Fund. READ MORE

April 22, 2015 - Scientists at the U.S-based company Battelle recently succeeded at the United States Department of Energy (DOE) challenge of making commercially viable transportation fuels from biomass pyrolysis. The team demonstrated the durability of a continuous hydrotreatment process that converts bio oil from biomass pyrolysis into transportation and aviation fuels.

The DOE's specific challenge was to demonstrate at least 1,000 hours of bio oil hydrotreatment on a single catalyst charge, while producing a fuel product suitable as a transportation fuel-blend stock at commercially realistic yield. Longevity of hydrotreatment catalysts has long been the Achilles' heel for converting biomass pyrolysis oils to biofuels. Battelle, with its proprietary process and the help of Pacific Northwest National Laboratory (PNNL), was able to overcome and surpass this hurdle relatively quickly, and now has successfully registered more than 1,200 hours on its hydrotreatment catalysts. Scientists and engineers have set their sights on achieving the commercial standard of 4,000 hours in the near future.

Zia Abdullah, Institute Fellow at Battelle, was the principal investigator on the project.

"I am grateful to the DOE for their partnership in this effort and to Battelle's leadership for their ongoing commitment," says Abdullah.

Marathon Petroleum Corporation provided Battelle with some support in the DOE and helped in assessing the biofuel product. Scientists at PNNL developed bio oil stabilization catalysts for Battelle's process.

John Holladay, manager of the biomass sector at PNNL, agrees. "This is how public-private partnerships are supposed to work and it couldn't have happened without DOE's support," he says.

Battelle's leadership is committed to biofuels but see the best near term market opportunities in biochemicals. "Biochemicals to enable biofuels," notes Drew Bond, vice president for technology commercialization for Battelle's energy, health and environment business. "Simply put, that's our strategy. And we're not alone in this but I can say that we are quite far along thanks to the foresight of our leadership."

Since 2011, Marty Toomajian, president of Battelle's energy, health and environment business, has led Battelle's efforts to commercialize a distributed pyrolysis system for bio oil production.

"Energy security is all about energy supply diversity," he says. "We have tremendous fossil reserves in our country that should not be taken for granted. But neither should we take our renewable resources for granted. That's why our work at Battelle spans across both, with the goal to maximize our fossil and renewable resources, which aligns with the President's "all the above" strategy in the energy sector."

Battelle has also made significant progress towards commercializing its modular pyrolysis systems. It already has scaled up its proprietary technology from concept to a pilot system that processes more than one ton of biomass per day. 

It was Battelle's ton-per-day pilot system that supplied the bio oil for its DOE-funded hydrotreating project. Adding to the achievements and near-term commercial focus, late last year Battelle entered into a strategic partnership with Equinox Chemicals, a specialty chemical manufacturer. Together, they seek to use the platform pyrolysis technology for the production of biopolyols and biochemicals with applications in multiple, rapidly growing, high-value markets.

ARS scientists at Wyndmoor, Pennsylvania, are developing this mobile pyrolysis processing system that may one day be used on farms to produce bio-oil. Photo by Charles Mullen.

April 17, 2014 - Innovations at the U.S. Department of Agriculture (USDA) are bringing researchers one step closer to developing "green" biofuel production systems farmers can use to meet on-farm energy needs, or to produce renewable fuels for commercial markets. These findings by Agricultural Research Service (ARS) scientists Charles Mullen and Akwasi Boateng promote the USDA priority of finding new bioenergy sources. ARS is USDA's chief intramural scientific research agency.

Fast pyrolysis is the process of rapidly heating biomass from wood, plants and other carbon-based materials at high temperatures without oxygen. Using pyrolysis to break down tough feedstocks produces three things: biochar, a gas, and bio-oils that are refined to make "green" gasoline.

The bio-oils are high in oxygen, making them acidic and unstable, but the oxygen can be removed by adding catalysts during pyrolysis. Although this adds to production costs and complicates the process, the resulting bio-oil is more suitable for use in existing energy infrastructure systems as a "drop-in" transportation fuel that can be used as a substitute for conventional fuels.

In 2013, the ARS team filed a patent application for a new pyrolysis process called Tail Gas Reactive Pyrolysis (TGRP), which removes much of the oxygen from bio-oils without the need for added catalysts. The team conducted a pilot-scale study using three types of biofeedstock with different characteristics: oak, switchgrass, and pressed pennycress seeds.

The researchers modified the standard pyrolysis process by gradually replacing nitrogen gas in the processing chamber with the gases produced during pyrolysis. The TGRP process was very effective in lowering oxygen levels and acidity, and no additional catalysts were needed.

Bio-oils produced from oak and switchgrass by the new process had considerably higher energy content than those produced by conventional fast pyrolysis. The energy content of the oak bio-oil was 33.3 percent higher and contained about two-thirds of the energy contained in gasoline. The energy content for switchgrass was 42 percent higher, slightly less than three-fourths of the energy content of gasoline.

The scientists, who work at the ARS Eastern Regional Research Center in Wyndmoor, Pa., published results from their research in 2013 in Energy Fuels.

Read more about this research in the April 2014 issue of Agricultural Research magazine.

Dec. 17, 2012 - New research from North Carolina State University provides molecular-level insights into how cellulose – the most common organic compound on Earth and the main structural component of plant cell walls – breaks down in wood to create "bio-oils" which can be refined into any number of useful products, including liquid transportation fuels to power a car or an airplane.

Using a supercomputer that can perform functions thousands of times faster than a standard desktop computer, NC State chemical and biomolecular engineer Dr. Phillip Westmoreland and doctoral student Vikram Seshadri calculate what's occurring at the molecular level when wood is rapidly heated to high temperatures in the absence of oxygen, a decomposition process known as pyrolysis.

The results, which could help spur more effective and efficient ways of converting farmed and waste wood into useful bio-oils, appear in a feature article on the cover of the Dec. 13 print edition of the Journal of Physical Chemistry A.

Much of the energy that can be extracted from wood exists in the cellulose found in cell walls. Cellulose is a stiff, rodlike substance consisting of chains of a specific type of a simple sugar called glucose. The paper describes a mechanism for how glucose decomposes when heated. The mechanism is somewhat surprising, Westmoreland says, because it reveals how water molecules and even the glucose itself can trigger this decomposition.

"The calculations in the paper show that although the decomposition products and rates differ in glucose and cellulose, the various elementary steps appear to be the same, but altered in their relative importance to each other," Westmoreland says.

Knowing the specifics of the decomposition process will allow researchers to make predictions about the ease of extracting energy from different types of wood from various soil types.

The researchers are now conducting experiments to verify their calculations.

Because the United States is the world’s largest producer and exporter of poultry meat and second largest egg producer, there can be little doubt that managing poultry litter is no yolk.

Oct. 8, 2010, Ames, Iowa – Iowa State University's Christopher Williams was just trying to see if adding bio-oil to asphalt would improve the hot- and cold-weather performance of pavements. What he found was a possible green replacement for asphalt derived from petroleum.

April 23, 2010 – Turning solid wood into liquid fuel sounds like an interesting concept.  One way to do this is by pyrolysis, which involves placing biomass such as sawdust or wood chips into a reactor and rapidly heating it at extreme temperatures without oxygen.

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