(117c) Techniques to Improve the Use of Biomass Fuels Used to Provide Heating to the Facilities at the Natchez Trace Greenhouses

Natchez Trace Greenhouses (NTG) uses boilers to heat water, which is then sent through the greenhouses during colder months to maintain an adequate temperature at the facility. The manager of the facility recently began to use biomass fed boilers instead of natural gas boilers to reduce his reliance on more expensive natural gas. The boiler feed currently consists of a combination of planar wood shavings, blended with corn to give the necessary higher heating value. Given that the price of corn has risen significantly, and that the facility may lose its current source of planar shavings, other potential biomass feed sources must be investigated.

This investigation aims to discover and test possible local fuel alternatives that can be easily transported to NTG at a cost lower than the current fuels. Possible options include glycerol, off-spec flour, various wood wastes and cotton wastes. Combustion experiments were performed using bomb calorimetry. These results were combined with moisture and density analysis to obtain a BTU density to determine combustion efficiency. With these results, the optimum mixture of glycerol and solid fuel source can be obtained. The boilers at NTG also produce large quantities of bottoms ash. Samples of this ash have been collected and tested for their potential use as a soil amendment for plants at the facility. Using these results, a experimental matrix has been set up. It outlines the plan to grow begonia (Begoniaceae) plants at the greenhouse using this ash. There has also been a problem with slag build-up in the boilers, as well as fly ash emissions from the boilers at NTG. Solutions to these problems will be investigated as work with NTG continues. This study aims to evaluate the impact of these problems while providing real-world solutions that will allow the NTG to lower their overall heating costs.