Combined Heat and Power and Bio-gas Utilization

Quick Tip:  Turbine exhaust gases can be used to supply heat to industrial systems
Quick Tip:  An average dairy could generate 70% of its electricity needs with biogas (ATTRA Publication #IP219)

General Description:

Many large industrial facilities are finding that it can be economical to generate electricity on-site and use the exhaust gases from the combustion process to generate steam or supply heat to existing industrial processes.  Similarly, facilities with large amounts of bio-waste are finding that it is becoming feasible to use that waste as fuel for process heating or electricity generation or both.  The advances in combined heat and power (CHP), sometimes called co-generation, are an exciting development in the energy engineering field.

Combined heat and power (CHP) is not feasible for many industries.  Facilities must have simultaneous electricity and process heat requirements; otherwise, the plant cannot take advantage of the exhaust gases and will find that buying a gas turbine simply to provide power is not economical when compared to purchasing electricity from a local utility.  The costs of these projects can be significant, with capital investments of millions of dollars required for large systems, but the savings can be significant as well.  For example, a manufacturing plant in Arkansas invested $6.1 million in a combined heat and power system and they are currently saving almost half a million dollars annually on steam and electricity.

Biogas is the gas that is released from organic matter during decomposition.  The gas is generally a mixture of methane and carbon dioxide that can be used as a low-grade heating fuel.  Biogas is considered a renewable energy resource.
Energy Conservation Opportunities

Potential Energy and Cost Savings Opportunities:
The below energy conservation opportunities or energy efficiency actions (EE ACTIONS) are provided as a partial list of potential savings opportunities in your plant.  They are grouped as no-to-low cost, moderate cost, and long-term cost investments.  Consider each for your plant and feel free to contact us for clarification or any assistance you may need in assessing specific projects.

Long-Term Investment

EE Action: Natural gas turbine to provide both heat and electric power
The capital investment is large, but the combined efficiency can result in a solution that is friendly to the planet and your pocketbook.  The U.S. Department of Energy is providing resources to assist companies through the CHP economic feasibility process.

EE Action: Anaerobic Digestion of Bio-Waste
While much of Arkansas’ bio-waste is produced on farms, there may be opportunities for food processing facilities or similar industries to use their bio-waste as a fuel source.  While this is a source of CO2 emissions, it’s much more eco-friendly than simply letting the methane escape into the atmosphere. 

EE Action: Furnace to burn waste materials
Wood chips, saw dust, and other biomass waste products can be burned in a furnace and the waste heat can be used for all kinds of process heating applications.  The CO2 emissions may be more eco-friendly than you think. 

EE Action: Landfill gas extraction
Another large-scale project that can result in big reductions of greenhouse gases, and significant energy cost savings.  This is being down at several landfills across Arkansas.