Grantee Research Project Results
Final Report: Biomass Gasification for Agricultural Energy Sources and Soil Enrichment
EPA Grant Number: SU834319Title: Biomass Gasification for Agricultural Energy Sources and Soil Enrichment
Investigators: Domermuth, David , Raichle, Brian W. , Martin, John H. , Uchal, Michael J. , Urban, Eric J. , Law, Daniel Allen , Doll, Susan , Houser, James , Hobbs, Zach , Labowitz, Ethan , Williams, Landon , Flynt, Asher , Kinsey, Heather , Gonzales, Eva , Madritch, Mike
Institution: Appalachian State University
EPA Project Officer: Page, Angela
Phase: I
Project Period: August 15, 2009 through August 14, 2010
Project Amount: $9,991
RFA: P3 Awards: A National Student Design Competition for Sustainability Focusing on People, Prosperity and the Planet (2009) RFA Text | Recipients Lists
Research Category: P3 Awards , Sustainable and Healthy Communities , Pollution Prevention/Sustainable Development , P3 Challenge Area - Sustainable and Healthy Communities , P3 Challenge Area - Air Quality
Objective:
The primary goal of the Biomass Gasification project was to design and develop an affordable Combined Heat, Power, and Biochar (CHPB) system that uses agricultural byproducts, such as woodchips and pelletized grasses, as fuel to produce electricity, heat, and soil enrichment for small-scale crop production in greenhouses during cold months. Such a system can allow farmers to connect to the power grid, thereby providing an additional revenue stream from the production of electricity. The farmer also can recover the heat generated by the system and use it to create an efficient growing environment within a greenhouse. During the process of producing usable gas from biomass, a biochar substance, or soil enriching byproduct, is left behind and can potentially be used as a sustainable substitute for fertilizer.
The Appalachian State University (ASU) P3 team has achieved its primary goal during Phase I of the Biomass Gasification Project. In order to achieve that goal, the following major tasks have been completed:
Gasification System
- Design and create detailed CAD drawings for a gasifier, a centrifugal filter, and an organic-medium filter based on proven designs with some key improvements.
- Fabricate the gasification system based on the CAD drawings.
- Successfully run an internal combustion engine on gas produced via biomass gasification.
Biochar Retort
- Design an inexpensive barrel system for creating large quantities of biochar to be used for testing.
- Construct the retort from two barrels and 2 steel tubes.
Biochar
- Produce biochar using the retort.
- Test the biochar for the ability to stimulate plant growth.
Soil Heating System
- Design and build a system to recover heat from the gasification process and the engine, store the heat, and use it to keep soil in a greenhouse warm.
Greenhouse Structure
- Design a greenhouse conducive to gasification system research.
- Build the greenhouse testing facility at the site of a local waste wood reclamation business in order to test the system with a real world wood waste stream.
Feedstock Sorter
- Replace the screens on a rotating sorter for use with various biomass feedstocks.
Biomass Dryer
- Design and build a solar biomass dryer and a vertical rack-style open-air dryer.
Integration into University Courses
- Develop projects to be carried out by students in related courses including Solar Thermal Technology, Biofuels Technology, and Water and Waste Water Technologies.
Impact Analysis
- Determine the potential impact of the adoption of CHPB technology by community members.
The ASU P3 team met its primary goal with great success. Additional goals require further funding and/or more time before they can be fully realized. These goals include:
- Purchase a generator and interface it with the engine to generate electricity.
- Develop a system for capturing and recirculating CO2 to stimulate plant growth.
- Record and analyze temperature data related to gasifier performance.
- Design a low-cost biomass densifier/pelletizer.
- Conduct long-term (1-2 year) plant growth study to determine the soil enrichment attributes of biochar.
- Perform a life-cycle cost analysis including savings for electricity, heat, and fertilizers.
Summary/Accomplishments (Outputs/Outcomes):
Phase I of the Biomass Gasification Project gave birth to many success stories and demonstrated enormous potential for members of the local agricultural community and for students within the university.
Community-building
Watauga County Cooperative Extension is willing to promote the technology and help set up educational workshops for local growers. One local business owner in particular, Bucky Black, President of Resource Wood Incorporated, is enthusiastic about the work the ASU P3 team has accomplished thus far and sees a CHPB gasification system as an ideal way to put his waste stream to use. He also plans to expand his business by collecting waste wood from the surrounding community and gasifying it to produce and sell electricity, creating jobs in the area in the process. The greenhouse testing facility was built on Mr. Black’s land and will be used by students and Mr. Black for many years.
Aspects of the project have been incorporated into three different ASU undergraduate courses (solar biomass dryer for Solar Thermal Technology, water purification with biochar filters for Water and Waste Water Technologies, and feasibility of gasification of construction waste for energy for Biofuels Technology) and two senior capstone projects.
Heat recovery for soil heating
The heat recovery system actually comprises several subsystems. One subsystem draws heat from the produced gas after it exits the gasifier, another one draws heat from the engine where the produced gas is combusted, and the third subsystem circulates the exhaust from the blower and the engine through the feedstock hopper to preheat and dry the biomass before it enters the gasification chamber. Excess heat is stored in a standard water heater. From the water heater, the heat is transferred to the soil in the flower beds via a network of water‐filled PEX tubes embedded in the soil.
The heat recovery system has been built and will be tested. There is strong evidence that the system will perform adequately. The following can be estimated:
- each pound of dry biomass that is gasified produces around 7,000 Btu of theoretical recoverable heat (Bliss and Black, 1977),
- the gasifier consumes about one pound of biomass per hour,
- the heat exchange system transfers 70% (low estimate) of the recoverable heat from the gas to the storage water, and
- the stored water and the soil start at 30°F (-1°C).
Following from the above estimates, the gasifier will need to operate for 3 to 4 hours for the heat recovery system to provide enough heat to raise the soil temperature to around 70°F (21°C), which is near the optimal soil temperature for minimizing germination time for most vegetables (University of Minnesota, 1999). At that point, the system will be able to easily maintain that temperature.
Greenhouse testing facility
The greenhouse is a semi-permanent structure with space for growing plants in soil beds and a separate housing for the gasification system and data-logging equipment. The housing is fireproof and well-ventilated, thus providing a perfect environment for conducting research in a safe manner. The greenhouse is structurally sound and can be reproduced inexpensively.
Gasifier
A working gasifier capable of processing multiple sizes, shapes, and types of feedstock was designed and built from scratch. The air intake nozzles and hearth are fully customizable so as to allow compatibility with a wide range of feedstock and engine sizes. The gasifier design and fabrication methods as well as the heat recovery system design will be shared with ALL Power Labs
Conclusions:
During Phase I of the Biomass Gasification Project, the ASU P3 team has demonstrated its ability to create and maintain partnerships; be involved with the community and the university; design equipment and experiments; build components, systems, and facilities; and carry out scientific studies. The support of Watauga County Cooperative Extension and one of only a few residential-scale gasifier manufacturers in the country will help to bring this closed-loop, sustainable technology and environmental awareness to people across the country and perhaps beyond.
PROPOSED PHASE II OBJECTIVES AND STRATEGIES
The main strategy for Phase II of the project focuses on two equally important efforts. One focus is to extend the work from Phase I and complete the peripheral goals mentioned above. The other focus is to create more partnerships, develop a detailed plan for transferring our technology to the community, and make our system economically viable for manufacturers and users. The following is a list of proposed Phase II objectives, broken down by focus:
Focus 1: Additional Goal Completion and Phase I Extension
Additional goals
- Purchase a generator and interface it with an Internal combustion engine to generate electricity.
- Develop a system for capturing and recirculating CO2 to stimulate plant growth.
- Record and analyze temperature data related to gasifier performance.
- Design a low-cost biomass densifier/pelletizer.
- Conduct a long-term (1 to 2 year) plant growth study to determine the soil enrichment attributes of biochar.
- Perform a life-cycle cost analysis including savings for electricity, heat, and fertilizers.
Phase I extension
- Pelletize multiple types of feedstocks, and determine the economic viability of pelletization.
- Expand the greenhouse testing facility to allow for growing a variety of crops.
- Research the CHPB system efficiencies.
- Analyze the energy balance of the system.
- Acquire data for all of the subsystems (gasifier, heat recovery, generator, etc.).
- Carry out cold weather greenhouse crop growth studies.
- Experiment with different organic filter media.
- Expand heat recovery system storage capacity.
Focus 2: Outreach and Technology Transfer
- Identify growers who are willing to use a CHPB system during a winter season and report qualitative and quantitative benefits.
- Identify business owners with constant organic waste streams who are interested in developing sustainable business practices and want to test a CHPB system.
- Identify possible biochar markets, and investigate soil amendment standards.
- Hold workshops and demonstrations for students, growers, and other community members.
- Incorporate the greenhouse testing facility and CHPB system into ASU projects and courses from several different departments, including Technology, Biology, Chemistry, Physics, and Business.
Supplemental Keywords:
Syngas, Producer Gas, Wood Gas, Wood Gasification, Sustainable Agriculture, Radiant Heating, Solar Thermal, Biochar, Hydrogen, Carbon Sequestration, Renewable, Greenhouse, Biomass, Combined Heat and Power, CHP, CHPB, RFA, Air, climate change, Air Pollution Effects, AtmosphereRelevant Websites:
P3 Phase II:
Biomass Gasification for Agricultural Energy Sources and Soil Enrichment | 2011 Progress Report | Final ReportThe 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.