Monitoring Moisture and Inorganic Contents of Forest Harvest Residues for Energy Production Purposes

Mahdi Vaezi, Ruhul Kabir and Amit Kumar
Department of Mechanical Engineering, University of Alberta, Edmonton, Alberta, Canada

The burning of forest residues is a traditional method of ground clearance following a harvesting operation. However it comes with limitations like burn restriction/suspension and environmental concerns. Forest residues have been recently introduced as a replacement for fossil resources in plants and refineries to produce power, fuels, and chemicals, as well as help in mitigating GHG. However, the key barriers to bring this idea into reality are high transportation/operating cost and presence of inorganics in residues. Moisture content contribute noticeably in transportation/operating cost, as a large moisture content increases the forest residue bulk density and reduces its calorific value. Inorganic contents, while burning the forest residues, cause slag deposition on furnace walls and heat transfer surfaces. This research work is aimed at investigating the variation of inorganic and moisture contents in forest harvest residues generated in the boreal forest of Alberta, developing rigorous analytical models able to forecast the inorganic and moisture contents under different combination of climatic variables, and determining the optimum time during the year to move the residues off the forest in order to get the minimum moisture and inorganic contents. According to the results obtained out of the first year of study, late in September is the best time to transport the residues. Now on the second year of study, we are developing the model to correlate moisture and inorganic contents to time of the year, also temperature, humidity, and precipitations in considered forest area.