Biomass is a renewable energy resource and is often defined as 'the biodegradable fraction of products, waste and residues from agriculture (including vegetal and animal substances), forestry and related industries, as well as the biodegradable fraction of industrial and municipal waste' (source EU Directive 2001/77/EC, Article 2). Biomass differs from MSW (Municipal Solid Waste) or RDF (Refuse Derived Fuel) in that it does not contain plastics, textiles, rubbers, contaminates or non-organic matter which can lead to dioxins, furans and other harmful emissions. In fact, plastics, textiles, metals and other non-organic materials should be recycled where possible.
Biomass is also considered carbon neutral and contains little to no sulphur, mercury and other pollutants (unlike coal and other fuels). Therefore biomass can also generate valuable credits (renewable energy, CO2, environmental, GHG, 'Green', etc) for the client.
Unfortunately, the moisture content of biomass has a great impact on its effectiveness as a fuel source. Most readily available biomass sources will have a moisture content of 40% to 90% MC. Considerable energy must be consumed (2444 kJ/kg) just to evaporate this water without doing any useful work in the process. In addition, the amount of water in the biomass also increases transportation and handling costs. Therefore, drier biomass has a greater heating value, burns hotter, more vigorously and more efficiently.
Typical Calorific Values for Biomass (Organic Feedstocks)
Drying the biomass would help to improve its heating value and performance but traditional thermal drying technologies (rotary dryers, fluidized bed, steam, paddle, etc) use fossil fuels, are energy intensive and expensive to build and operate, require pollution control systems, are prone to fires and are often difficult to site and permit (combustion process, emissions, natural gas piping, etc).
In comparison, a biological dryer (Biodryer®) is designed to take advantage of nature's biological oxidation process to cost effectively reduce moisture content of the organic wastes and resulting biomass fuel to less than 20%; without the need for natural gas, oil or steam heating and with minimal capital, labor, maintenance and operating costs.
Typically, Wright's biomass product will have a heating value of about 14,000 kJ/kg to 20,000 kJ/kg; depending on the organic feedstock and the desired moisture content of the fuel (bomb calorimeter, ultimate or proximate analysis, etc)
The Biodryer standard product has the appearance of a mulch or 'hog fuel', but it can also be densified (pellets, briquettes, etc) to meet the specific transportation, handling and feed requirements of the client.
This Biomass fuel can be used in direct combustion, gasification, cofiring or calcination energy conversion processes to produce heat, steam or power while reducing operating costs and emissions.