• Gas

  BioGas (methane and carbon dioxide) is the primary output product of the bioconversion process. As produced, BioGas is a medium-BTU gas. BioGas and/or its components may be utilized in a variety of applications.

  • Methane

    Methane (CH₄) is the main component of BioGas, representing the energy produced from the bioconversion of wastes. This energy is recovered by using the gas in one or more of the following ways:

    • Electricity

      BioGas may be consumed in an engine generator set to produce electricity. Typically, this is the lowest value option. The revenue from such use is dependent upon prevailing local rates and how the produced electricity is distributed. Generally, the electricity is sold at a wholesale rate to the local utility through an independent meter. Such arrangements/rates are governed by an area's utility commission. "Net metering" (exporting electricity through an existing meter for the "retail" rate) is a reality in many states, but the size of most BioConversion systems exceeds applicable limits. "Wheeling" (power purchase agreements between geographically separate generators/consumers with access to a common power grid) is one method of achieving higher value for generated power which has begun to be put into practice. Another method is to provide the power "in-house", thereby reducing the amount of electricity which would otherwise need to be purchased. The best loads for consideration are "lighting only" or "motor only" types where the decreased-quality power provided by an "islanded" generator set will not negatively impact personnel or operations.

    • Thermal Energy

      With equipment modification, BioGas may replace the thermal energy in propane or natural gas for cooking, heating, refrigeration and/or lighting. This provides increased value when replacing propane, but once converted, the selected equipment won't be able to use it's original fuel unless it is "converted back". However, equipment can be converted or purchased to use two types of fuel (bi-fuel), which would preserve the equipment's function if one fuel source was interrupted.

    • Transportation Fuel

      With further processing, the methane in BioGas can replace standard transportation fuels. This use presents one of the greatest values, both economically and environmentally. Energy is never produced or consumed, it is only converted from one form to another. Our fossil-fuel-based economy is rapidly depleting solar energy stored long ago in the form of plant and animal tissue (coal and oil, respectively). Also, for every conversion step there are associated losses (efficiencies). Pollution is inversely proportional to energy efficiency. One of the least efficient (most polluting) uses of energy is as gasoline for vehicle fuel. MAC recommends replacing the least efficient use of non-renewable energy with a form of renewable energy, BioGas. This option provides the greatest environmental benefit at the same time it (usually) provides the greatest economic return. Vehicles can be purchased or converted to use compressed gas as fuel, instead of gasoline or diesel. As with appliances, functionality can be preserved by converting to or purchasing vehicles which are capable of bi-fuel operation.

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  • Carbon dioxide

    Carbon dioxide (CO₂), the other major component of BioGas, has several uses when separated from the total gas stream. This option is exercised when there is a market for the products and an economic return is indicated relative to the capital equipment required to produce them.

    The standard uses of CO₂ are for carbonation of beverages and for dry ice production. Dry ice is used in transportation of frozen perishables. Chipped dry ice replaces grit and sand used in sandblasting operations without polluting the immediate environment. Additional uses include freeze tunnel applications for meat, fish, vegetable, and fruit processing.

    As a supercritical fluid, CO₂ is used as an extraction solvent in the food and pharmaceutical industries for products such as coffee, tea, tobacco, hops, corn oil, flavors, and colors. It's use is also recommended in industrial processes and for in-situ remediation of halogenated hydrocarbons and other solvents.

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• Solid

  Several solid co-products are available from the bioconversion process:

  • BioSoil

    Fibrous, undigested solids which remain in the liquid effluent are screened and conditioned in a dryer. The resulting BioSoil is a low-nutrient amendment similar in appearance to compost, yet superior in function. BioSoil can be used in a variety of ways, including amending, fertilizing, mulching, dressing, planting, etc.

  • BioFert

    Depending on the feedstock materials, sufficient nutrients may remain in the BioSoil to qualify it as a fertilizer (N + P + K => 6). This would increase the market value of the product dramatically. Filter-separated bacterial biomass may also be recombined with the BioSoil, which would also result in a more valuable product (enhanced nutrient content).

  • BioFeed

    The process of bioconversion could also be described as bacterial "agriculture". As the bacteria consume the feedstock, they grow and multiply, eventually die off and are removed in the effluent stream. These organisms are a source of high quality protein, which can be captured by separating the bacterial biomass from the screened effluent with a filter. The "emulsion" from filtering is then directed to a dryer to remove most of the remaining moisture. The resulting BioFeed contains significant levels of amino acids, peptides, and growth factors, which makes it an excellent feed additive for agri- or aquaculture.

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• Liquid

  Liquid co-products are also available from the bioconversion process:

  • BioGreen

    The process of bioconversion results in a naturally-balanced liquid product containing ammonium (fast-acting) and amino-protein (slow-release) nitrogen, in addition to phosphorous, potassium, calcium, iron, sulfur, and magnesium. This liquid is screened and pasteurized to create BioGreeen.

  • BioActivator

    By further processing the screened effluent with a filter, a concentrated, slow-release plant food is produced. BioActivator feeds the soil microenvironment because 70% of it's nitrogen is available as amino acids, protein, and polysaccharides chelated to phosphorous, potassium, calcium, iron, sulfur, and magnesium.

  • BioTonic

    The other product from filtering is a fast-acting foliar, which improves bud and flower production while increasing root development. Seventy percent of BioTonic nitrogen is in the readily-available ammonium form, along with soluble phosphorous and potassium.

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