Analysis of Dispersed On-Farm Systems to Produce Energy from Biowaste using Thermochemical Conversion Technology

Yuanhui Zhang
Lance Schideman
Ted Funk
Agricultural and Biological Engineering
Contact: Yuanhui Zhang
1304 West Pennsylvania Avenue
Urbana, IL, 61801


We propose to conduct a systematic life-cycle analysis (LCA) on a small scale, dispersed system to converting rural biowaste (including livestock manure, sewage sludge and crop residue) into crude oil centered on thermochemical conversion technology. The ultimate goal of the research team is to develop a technology and system that can be implemented on individual farms or small rural communities, to convert biowaste into bioenergy, to protect the environment, and to improve rural economic development.

This proposed project fits well within Dudley Smith Initiatives. Its approach will naturally progress from a DSynergy project to a DSystems project. Our proposal is built on our on-going research, namely, that we have successfully converted swine manure into crude oil, and we are researching conversion of other waste streams including food waste and crop residue. Industry partners have already licensed the TCC technology from UIUC. One TCC pilot plant for municipal sewage sludge has been in testing, and one TCC pilot plant for animal waste is in development.

Strength of Investigators

The investigators currently have something major to offer, knowledge and experience with the thermochemical conversion process, considerable research backing and industrial involvement. We have sufficient experience with the process, and have achieved national preeminence because of our success, which gives us confidence in the outlook for this technology

Consider: we are able to convert 70% (dry matter) of total volatile solids in swine manure to a crude oil product which has a heating value between 32,000 and 38,000 kJ/kg, which is approximately 85% of the heating value of “natural petroleum” crude oil. Other properties of the TCC oil are similar to a low-grade crude oil. The pilot plant developed by an industry licensee for processing municipal sewage sludge has achieved similar efficiency. The economic and environmental benefits will be tremendous – at this conversion efficiency, the manure produced by one pig raised to slaughter weight (up to 250 lb. body mass) can be converted to 15 gallons of crude oil with a gross value of $15/pig. We have found the ratio of energy in the oil to the energy used for the conversion process to be at least 3:1, much more favorable than ethanol production from corn, and TCC avoids any complaints about diverting food to energy production.

UIUC has a world-renowned position with this technology that is supported by successful licensing to industry partners who are developing two pilot plants, and by the international interest in utilizing this technology. The three investigators encompass three key areas for this system analysis: feedstock conversion (Zhang), post process aqueous stream treatment (Schideman) and outreach (Funk).

Potential Synergies

We envision that the greatest growth opportunities for sustainable agriculture in Illinois lie in value-added products and bio-based energy production, in an environmentally friendly fashion. This proposed project will promote growth by actually converting negative-cost waste products into desirable value-added end products. It will lay out a framework for a small scale, dispersed waste-to-energy system with the TCC technology as the centerpiece, to effectively, economically and in an environmentally friendly manner convert bio-waste streams into crude oil and other value-added products. Through this DSynergy project, we will be able to obtain key analytical results to outline a holistic picture for a later stage DSystem implementation. This project will provide opportunities for various disciplines within the College of ACES and UIUC to work together on researching and utilizing renewable bio-based energy while enhancing 2 environmental quality. This is a crucial time in our nation’s quest for energy independence and environmental stewardship. The TCC process has provided us with a leading position in a timely area that our nation is tapping at the moment.

The System Opportunity

We anticipate an extremely promising system-implementation opportunity that will result from this DSynergy project. We will collect much needed information from this systematic life-cycle analysis. Currently, one pilot plant is being tested for a small municipal sewerage plant and another pilot plant for a swine farm is in development by industry licensees. Much needed technical and operational information has been and will be collected from those pilot plants. Together, we will have ample information to plan a DSystem-level project. We envision that a TCC system can be developed for an individual farm, or a small rural community, or a combination of both, to have their waste streams converted into energy, to have their post process water treated, and to have the remaining nutrients utilized as crop fertilizers, all locally. These types of small scale, dispersed energy systems have great advantages that foster enhanced homeland security, energy independence, reliability and rural economic development. These important benefits will be accompanied by environmental benefits associated with recycling a potentially polluting waste product into useful co-products and careful management of TCC residuals.

Major DSystems Project Tasks

First, we will take a traditional planting-to-utilization approach to analyze the life-cycle of biowaste streams: animal, human and crop residue, for their collection, conversion and utilization in terms of: (a) technical feasibility, (b) economic viability, (c) associated environmental risks/benefits, (d) supplies of and geographic locations of feedstocks, and (e) interactions among production, collection, transport, conversion, refining, storage, utilization and distribution costs and approaches that affect potential business models. This lifecycle analysis (LCA) will be performed based on standard methodologies including inventory analysis, impact analysis and integrated evaluation throughout the development of the energy resources. The domain being covered in the primary analysis will consist of the production of each feedstock, its harvest/collection and transportation to appropriate storage facilities, its subsequent use in the computer modeled biofuel plants, and all systems associated with any intermediate processing. The boundaries of the analysis will extend from the production of feedstock through delivery of fuels at the pump.

Second, we will conduct a nutrient balance analysis. The TCC process leaves an aqueous stream that still has a significant organic content (10,000 mg/L of COD) and nutrients (N, P and K). This represents another valuable opportunity for income recapture from the post process aqueous stream. Of particular concern are the environmental and regulatory implications of the trace compounds that remain in the aqueous residual stream of the TCC process. This must be considered and addressed before this material can be offered as a fertilizer ingredient. While we have not found it possible to convert all the organic matter into oil in the TCC process, other processes can be used to harvest residual organics and recover the nutrients after the thermochemical treatment. Anaerobic digestion of the residual organics can yield additional gaseous fuel products such as methane and hydrogen. In addition, different options for nutrient recovery will be analyzed including steam stripping, membrane separation of P and K (reverse osmosis), regenerable adsorption processes, and chemical precipitation as struvite (MgNH4PO4).

Third, a techno-economic analysis for each waste stream will be conducted including: Flowcharting with materials and energy balance: A preliminary flow sheet detailed enough to include all major processing equipment will be developed for the System Model. Major process parameters will be determined based on the state-of-the-art performance of the technology. Process simulations with equipment sizing: An appropriate simulation software package will be selected to simulate process mass and energy balances. The impact of the process scale will be examined with equipment sizing 3 calculations. Economic evaluation of the process: The cost estimation will be conducted based partly on the built-in cost data in the selected software package and supplemented with information from the scientific literature and handbooks. The standard approach of engineering economics will be followed based on a scale of a 2,000 animal unit farm and/or a 5,000 population rural community.

Results of the project will be integrated into Extension presentations, media releases, and web sites to raise public awareness of the approach, broaden public knowledge of the scope of bioenergy, and invite public input to refinement of the systems analysis and approach. The project will also be featured in the UI Center for Advanced Bioenergy Research (CABER) resources offerings, in order to enhance exposure of the project to the public and to encourage interested parties to become involved in the field of research.

The Potential of Leveraged Funding for Future DSystems

In the past 10 years, the TCC team has accumulated skills, and leveraged $1.8 million funding for TCC research, including DOE, Grainger Foundation, C-FAR, National Pork Board, and industries such as ADM, BioCrude and Worldwide BioEnergy. We have developed three Lab-scale TCC reactors. Since the license of the TCC to industry partners last year, we have entered a new era of TCC development – from laboratory to pilot scale plant. Currently, a pre-proposal to USDA NRI Bioproduct and Bioenergy program has been accepted and, working with our industry licensee, we are developing another pilot plant proposal for DOE.

Key Milestones and Project Timeline

    1. Data collection; basic process simulation model built and deficits identified (Month 1-4).
    2. Most promising post-treatment, auxiliary treatment, transport, and other features identified; complete

process simulation model built (Month 5-8).

  1. Life-cycle analysis completed (Month 9-11); reports and technical/business plans written; extension education materials developed (Month 12).

The Deliverables

  • A detailed report of the system analysis for small scale, dispersed waste-to-energy system utilizing local biowaste streams centered on thermochemical conversion technology.
  • A technical and a business plan for DSystems based on this DSynergy project, and in collaboration with industry partners and UI Extension.

Project Resources