Grantee Research Project Results
Final Report: Producing Biochar on Small Farms to Enhance Soil Fertility and Provide Heat
EPA Grant Number: SU835319Title: Producing Biochar on Small Farms to Enhance Soil Fertility and Provide Heat
Investigators: Teel, Wayne , Spencer, Brett , Brown, Christopher , Sumpter, Collin , Mulford, Erica , McNabola, Jason , Coffman, Jennifer , Ferenbaugh, Joy , Kendle, Logan , Sniezek, Mary , Mello, Sarah , Wert, Tyler
Institution: James Madison University
EPA Project Officer: Hahn, Intaek
Phase: I
Project Period: August 15, 2012 through August 14, 2013
Project Amount: $15,000
RFA: P3 Awards: A National Student Design Competition for Sustainability Focusing on People, Prosperity and the Planet (2012) RFA Text | Recipients Lists
Research Category: Pollution Prevention/Sustainable Development , P3 Challenge Area - Sustainable and Healthy Communities , P3 Challenge Area - Air Quality , P3 Awards , Sustainable and Healthy Communities
Objective:
Soils are the most important agricultural resource. Improving the quality of our degraded soils is a task that requires the participation of a broad spectrum of actors and a willingness to seek new ways of managing soils, or reviving ways discovered long ago. One of these old ways implemented by Amazonian peoples thousands of years ago is now gaining attention around the world. It involves the use of charcoal made by cooking wood at high temperatures in a low oxygen environment. Charcoal is highly porous and has a large surface to volume ratio allowing it to capture and recycle nutrients and water even in environments where the surrounding soil is very nutrient poor. When used as an agricultural amendment, this charcoal is now referred to as biochar.
Biochar in soils does two complementary tasks. First, it is a highly recalcitrant material overall, losing about 50% of its weight in the first 100 years, and only very slowly decaying over thousands of years. This makes biochar an effective tool to sequester biologically captured carbon in the soil for centuries. Second, biochar serves as a means of holding both water and nutrients in an otherwise poor quality soil. Its high porosity and very high surface to volume ratio capture and hold nutrients on functional groups attached to the carbon structure. This porosity allows water to stay in the pores as well. These two functions in turn attract soil microorganisms, including bacteria and mycorrhizal fungi, enhancing nutrient flow and enabling improved growth of plants. Each of these actions lead directly to improvement in the environment, productivity of crops, and the wellbeing of people living on that land.
This project takes place in the Shenandoah Valley of Virginia, which historically has been a center of agricultural production on the east coast. Today, it is dominated by poultry production, which is a major contributor of nutrients, mostly nitrates and phosphates, to the Chesapeake Bay. Biochar’s ability to capture and retain nutrients could help reduce the leaching that accompanies the spreading of poultry litter on Shenandoah Valley farms.
With this background, the Integrated Science and Technology (ISAT) Department at James Madison University (JMU) began working with biochar in 2009. The objective is to develop a system that will make biochar in a batch pyrolysis unit that allows placement of the system inside a greenhouse or hoop house to capture and store heat for keeping these structures warm on cold nights and provide biochar for farm use with low labor demand. Student teams continued to work on this project through 2012. The EPA P3 grant allowed us to expand the project from two to four farms and improve the quality of our systems at the two existing sites. Our objectives were to reduce system smoke, increase heat capture, simplify and improve structural components and reduce overall cost.
Farmers can use the biochar on hand in combination with organic waste and manures such as poultry litter to make compost for use on their farms. This requires breaking the biochar into small pieces, much like grains of sand or small pebbles, to prepare it for mixing. This work is under way at three of the four farms.
Summary/Accomplishments (Outputs/Outcomes):
The progress made on the project includes:
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Improvement of the pyrolysis unit. We have eliminated the steel frame surrounding our first two units and now use the firebrick as direct structural support for the water tank top of the pyrolysis unit. The door was redesigned to eliminate the nut and bolt closure, replacing this with a hook and lever system similar to the door closures on trailers. Better insulation was added to the door, reducing weight. Also, we changed the air flow pattern from a floor supply to a side supply by leaving gaps in the first row of bricks. Overall, this has reduced steel use and resulted in a 15% reduction in cost per unit.
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System smoke was reduced by better placement of rock wool insulation during the construction process. In addition, improved masonry skills of students have made the units stronger and more airtight.
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Heat capture now is better documented, if not improved. Now that the systems are tighter and better designed, the main heat loss is occurring through the chimney. Some minor heat capture has come from having the chimney go through the water tank rather than through the brick at the back of the unit. We have not addressed heat loss through the remainder of the chimney. The improved number for the heat capture by the brick is 0.66j/g-°C. Presently, one student is working on total heat capture by the brick during a burn.
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Biochar now has been made on four farms and its use has begun. At Wildside and Avalon the biochar has been ground, composted and applied to planting beds for spring. Wildside biochar now is for sale in the farmer’s market in Harrisonburg, VA. The satisfaction of the farmers involved is considered a prime outcome.
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The pyrolysis unit at Avalon Acres Farm now is enclosed and strong progress has been made toward a consistent production recipe. We have not documented any improvement in heat capture due to problems with the pre-existing heat tank, but it appears to be doing well.
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The pyrolysis unit at Polyface Farm is fully operational although the recipe is not as well developed because of the large range of input wood type and moisture content. The farm is just beginning to use the biochar with the animal operation.
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Wildside Farm now has a fully functional unit producing biochar for farm use and sale. They have started farm trials with a biochar compost mixture. Although the pyrolysis unit cover has functioned well to date, at the end of the heating season it requires replacement to the cup style cover for the long term.
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The pyrolysis unit at Hermitage has been fully revised and completed very recently. Initial burns were done with a warping cover and amidst swirling winds, causing varied results. There also is a problem with moisture in the owner’s desired pyrolysis material, horse stable bedding. These issues still are under investigation and we hope for good results soon.
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Biochar produced from a number of wood types now has been analyzed using thermogravimetric analysis and new burn profiles have been developed. This collection of data is unavailable from any other known source and can make a strong contribution to understanding the pyrolysis process. The full analysis of these data is pending.
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All biochar types produced were subsequently examined using a scanning electron microscope. This has revealed major differences in the structure of various wood biochars and profiles for their decomposition under pyrolysis. Whether this effort leads to recommendations for superior types of biochar remains to be seen.
Conclusions:
In this project, we have made excellent progress toward development of a batch-type biochar production system that provides biochar for farm application and produces heat for hoop houses, barns or other on-farm uses. While the technology has progressed, it is not quite ready for wide dissemination. There remain questions about the quality of the door on the unit, the effectiveness of heat capture related to thermal mass and air supply, and the variability of the biochar production recipe related to the quality and type of wood used. At the same time, our scope of outstanding questions is reduced, and we are confident that the prototype unit is close to completion. That, combined with farmers’ readiness to use the biochar after initial trials, makes us confident that this idea will take root and grow among farmers in the region.
Journal Articles on this Report : 1 Displayed | Download in RIS Format
Other project views: | All 1 publications | 1 publications in selected types | All 1 journal articles |
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Type | Citation | ||
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Teel WS. Capturing heat from a batch biochar production system for use in greenhouses and hoop houses. Journal of Agricultural Science and Technology A 2012;2(12):1332-1343. |
SU835319 (Final) |
Exit Exit |
Supplemental Keywords:
biochar, pyrolysis, carbon sequestration, nutrient holding capacity, water holding capacity, thermogravimetric analysis, scanning electron microscope, soil amendment, agricultureThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.