moisture reduction: why so important?

Researchers & scientists have known for decades: The reduction of moisture content in biofuel before conversion or combustion is a critical component in cost-effective power production and pollution reduction

Here are just a few examples of their findings:

"In combustion systems any water content in the fuel must be driven off before the first stage of combustion can occur, requiring energy, and thus reducing overall system efficiency... Reduction in combustion temperature below the optimum may result in incomplete combustion of the fuel giving rise to the emission of tars and creosote... High moisture content biomass has a much lower net energy density by mass..."

The Biomass Energy Centre of the UK

"Drying... is an important part of the conversion process from fuel to the useful end products of power and heat... Dry fuel contributes to: “boiler efficiency and the steam generation are raised - volume of flue gas is reduced - more flexible and stable boiler operation, using less or no support fuel - increased thermal output or steam generation - smaller size and cost for a new boiler of same thermal output - lower furnace emissions of particulate matter and volatile organic compounds...&

Thermal Drying of Wet Fuels: Opportunities and Technology — a report prepared by H.A. SIMONS LTD. — D. M. Bruce & M. S. Sinclair

Drying biomass fuel improves combustion efficiency, increases steam production, usually reduces net air emissions, and improves boiler operation... A biomass-fired boiler will perform better when fuel has an optimum dryness... without supplementary use of fossil fuels... air emissions are reduced... More complete combustion results in lower quantities of volatile organic compounds and ash produced... reducing entrained particulates in the flue gas, erosion of dryer surfaces... Reduced fuel requirements... smaller fuel handling equipment... drying reduces transportation costs... dry biofuels are less subject to microbiological degradation in storage.

Biomass Drying and Dewatering for Clean Heat & Power September 2008 Carolyn J. Roos, Ph.D. WSU Extension Energy Program