BIOREFINERY AT THE LANDFILL

The concept is local energy independence for communities.

Proposed is establishing a mechanism whereby communities become self sufficient in electricity and fuel by using the wastes and renewable residues in their backyard.  Using this concept also reduces greenhouse gas emissions and the carbon footprint for the community.  This is a new concept.  Warrenton and Fauquier would be the first to do this, but there is a great deal of state, national and international interest in following that lead.  This mechanism is known as an “integrated biorefinery.”

A feasibility study done by Antares Group and Pacific Northwest National Labs (PNL) concluded that a small scale integrated biorefinery sited at the landfill to take the incoming trash, both MSW and non-recyclable C&D, and convert it via gasification to either electricity or liquid fuel was economically and technically feasible.  The feasibility study was framed within the scope of a process which allowed conversion to both electricity and fuel simultaneously, and this co-production was determined to be theoretically possible; theoretical being the operative word.

Antares Group is a leading consulting firm on analyzing different types of biomass for conversion to energy or fuel. Antares  is one of 211 listed “partners” in the US Environmental Protection Agency’s Combined Heat and Power national partnership program. PNL is the leading research firm on gasification technologies, and receives its funding from the US Department of Energy (DOE).
 

FEASIBILITY

The Office of Biomass Programs of DOE and Rural Development Assistance Program of USDA provided financial assistance to the Town of Warrenton, which contributed a 10% cost share, and commissioned the feasibility study.

The study looked at the different types of biomass in the area, including utilizing agriculture residues from local farms such as corn stover and soybean stubble; planting of new energy crops such as switchgrass on idled farmland and CRP land; using woody biomass such as forest timbering and felled tree residues, wood chips and tree clippings; using current and mined municipal solid waste (MSW) from the county landfill as well as separated construction and demolition waste (C&D) brought to the landfill; and other types of high BTU waste from sources within a 50 mile radius that could be delivered to the landfill site, such as used tires, auto shredded material and food processing wastes.

Also a brief examination was made of high moisture or wet feedstocks such as horse manure, poultry litter and sewer sludge.  These feedstocks are normally converted through anaerobic digesters to produce a biogas but could, after being dried out in a drying shed, be gasified with the low moisture feedstocks

The preliminary results of the study recommends that the project begin with a biomass plant which initially processes the MSW and non-recyclable C&D coming into the landfill but maintains of potential of expansion to other sources and fuelstock.  This limited startup facility would provide for a 250 ton per day plant size, and be within State permitting guidelines.  The facility would process approximately 55,000 tons of the 70,000 tons of MSW, 24,000 tons of wood chips and 8,000 tons of asphalt shingles from the C&D now being received at the County landfill.

TECHNOLOGY AND PROCESS

The project envisions a thermo-chemical conversion process, not a biochemical process.

Several types of thermo-chemical gasification processes are available.  Of the various types of thermo-chemical processes, PNL recommends plasma arc technology.  Plasma arc gasification is a high heat process, up to 20,000 degrees F, that burns the feedstock in an oxygen deprived chamber to produce a synthetic gas (syngas).  Because of the high heat, large quantities of steam are produced which is turned into electricity to provide the internal power requirements for the plant and produce a surplus for export to the grid. 

The syngas is then to be used either to produce electricity and/or it can be converted via a catalyst such as Fischer Trophe into a fuel: ethanol, methanol, biodiesel or jet fuel.  The unique aspect of the proposed project is combining the production of electricity and a fuel; this has never been tried on a commercial scale. However, the technology has been determined to be feasible for the process.

Other types of gasification processes work in a similar manner, producing a syngas which is then utilized to produce electricity and/or an alternative fuel.

Gasification process facilities are closed loop plants with few, if any, emissions. They are not the “traditional” waste-to-energy plants such as the massive Covanta plant in Arlington. Physically they are much smaller in size, often being designed in module formats, and virtually all processes can be sequestered under one roof. 

Further the gasification process plant proposed would use very little, if any, fossil fuels.  Every other biofuel or bioenergy process uses some, usually a large amount, of fossil fuels. Unlike other biofuel process plants such as corn to ethanol or soybean oil to biodiesel and unlike the traditional waste to electricity plants that are simply huge trash burners or incinerators, the proposed plant would not run on a fossil fuel like natural gas or coal.  It produces its own electricity.  Furthermore, the gasification process can be started by the methane gas now being captured at the landfill or by biogas produced from an anaerobic digester being fed horse manure and sewer sludge sited next to the plant.

Although Warrenton/Fauquier County would be the first community to embark on a project to achieve energy independence by producing both electricity and alternative fuel from a renewable resource such as its own waste, there are other projects getting started which are gasifying trash into electricity or ethanol.  A project is starting up in Toms River, NJ that will process 150 tons per day of used tires into 25 million gallons of ethanol using a plasma arc technology.  GeoPlasma will be plasma torching 2,500 tons of garbage at St. Lucie, Florida into electricity; GeoPlasma will receive the entire tipping fee from the county to make the economics viable since their estimated project cost is $450 million.  An Hyundai  plant in Japan, also using Westinghouse’s plasma torch, has been converting 250 tons/day of auto shredded material into electricity for the last three years.   Siemens  is starting a 200 ton/day plant at the US Air Force in Abilene, Texas to convert their garbage into electricity.  The Los Angeles City Council just greenlighted a plan to establish a plant at one of its landfill to convert 1,000 tons a day of MSW and C&D into electricity.  Several wood chips to ethanol plants like Range Fuels in Georgia are starting up. A turkey offal to ethanol is set for Iowa, and at least two plants in England are converting via anaerobic digesters manures and sewer sludge into biogas.
 

ENERGY PRODUCTION

A 250-ton per day waste gasification plant could produce 8MW of surplus electricity or 12 million gallons of ethanol. 

8MW of electricity would more than power every single home and building in Warrenton with at least 2MW to spare. The annual consumption rate for the rest of the County was not available to be included in the calculations.   

12 million gallons of ethanol would as an E-15 blend (15% ethanol, 85% gasoline, which is more ethanol than the most common blend today, E-10)  provide enough fuel for every single vehicle in Fauquier County.  Until there is sufficient interest and capability by local motorists to use it all, the ethanol may be sold into the Virginia market. Virginia is required to utilize 165 million gallons pursuant to federal mandate. Presently, ethanol is not produced in Virginia, it is all imported, and locally produced ethanol helps to reduce costs for imported fuel and increases regional economic and fuel security.

The existence of a local electric energy generation facility, or the establishment of several community based electric generation facilities, connected to the grid in the Northern Virginia area would function as part of a “distributed generation” system. While also reducing a need for the importation of electric power capacity from outside the locality, these “distributed” small generation facilities also lend increased stability to the overall power distribution system and provide increased security to available electric power resources. This stability in fact enables the power lines to maintain constant delivery and allow for flux.
 

COSTS AND BENEFITS

The capital investment for a gasification plant is substantial.  It is more than traditional biofuel or waste to energy incineration plants.  The cost for a 250-ton per day plant using a plasma torch technology is estimated at $35 to $45 million.  Since the capital cost is higher, the operating costs must be lower than other bioenergy plants in order to be economically viable.  This is possible if there is no feedstock cost or a negative feedstock cost.

Obviously, if the wastes received which were not recyclable and were subject to gasification processes were simply channeled into the plant rather than being buried, the plant received feedstock at no cost and the County gains the tangible benefits of no longer having to bury that mass volume as well as the intangible benefit of eliminated or reduced GHG emissions.    

The county now receives a tipping fee of $46 per ton for landfill waste.  There are several landfill operating expenses that could be avoided if the trash was diverted to a waste gasification plant as proposed.  For example, it would avoid the $1 million contract annually to bury the trash.  These avoided costs represent somewhere between $10 to $20 per ton of waste.  A possible funding scheme would allow the County to retain most of the tipping fee to pay for other operating expenses now that much of the waste need not be buried or otherwise dealt with, and to make a contribution to the General Fund but also allocate a portion of the tipping fee balance to the plant operations so it could have a negative feedstock cost.

It should be noted that so-called “green energy” can also be sold at a premium through international markets. Local Fauquier County businesses in addition to other outside vendors exist which broker such electric power contracts. Further, the so-called “carbon credits” associated with the proposed processes are also now being internationally marketed for profit. No dollar figure has yet been determined for these factors, but they will be available in calculating a final cost/benefit ratio.

In addition, the inescapable environmental and community security benefits of community energy independence are immense and can only increase with time based upon present world conditions.  

CONCLUSION

To date, two companies have said they would finance, build, own and operate a small scale (250 ton/day) biorefinery to produce either electricity or a liquid fuel and without federal assistance.  They would require that the plant be sited at or near the landfill to take advantage of existing infrastructure and to have a long term (life of the plant) contract from the County to supply all the incoming MSW and non-recyclable C&D.

Since it is likely that either DOE or USDA will approve an application for a grant and/or loan guarantee under the $2 billion program to “commercially demonstrate new technologies or projects,” we would try to insist with the companies interested in participating that they experiment with different processes, i.e., catalysts, so as to co-produce electricity and fuel and the risk would be covered by a federal grant or loanguarantee for that portion of the project cost.

We would like to send out letters of solicitation as soon as possible to companies that we believe would be interested or, like Chevron, have already expressed an interest.  In addition to the obvious companies – the oil companies, the energy companies, the utilities, the equipment manufacturers like GE and Siemens, it would also include companies that want to strategically partner in a project.  Wal-Mart for example is looking for a project(s) because they are planning on having ethanol pumps at their stores.  There are others who just want to “greenwash” themselves for PR purposes. 

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