The use of biomass (primarily wood chips, wood pellets, MSW or agricultural residue) for Industrial application is becoming very popular. Primarily it is used to replace fossil fuels with the use of biomass.
Many companies across Canada and the USA have chosen to embrace Blue Flame Stoker™ technology to lower their operating costs and reduce their impact on the environment.
Solid fuel biomass combustion systems used in industrial system are more complex than fossil fuel systems and generally require additional components beyond the simple combustor/boiler system. The district heating system components must be carefully integrated to ensure successful, trouble-free operation.
Although not used in all systems, the main industrial heating system components generally include:
- biomass fuel receiving;
- biomass fuel storage;
- fuel transfer to the combustion system;
- combustion chamber – stoker;
- steam or hot water boiler;
- ash removal and storage;
- exhaust system with fly ash collection and exhaust stack;
- instrumentation, controls and safety systems;
- heat distribution network – hot water, steam or hot air.
This project was set out to demonstrate the viability of replacing oil fired direct drying system with biomass fired dryer technology. Choosing the right biomass fuel in direct combustion system is very critical to the system operation.
Industrial Drying is very energy intensive process. A considerable amount of energy is wasted at various stages of the process. The conventional fuels used in industrial drying technologies are coal, heavy oil and natural gas. Recently, there has been a trend to substitute conventional fuels with alternative fuels derived from biomass. Most biomass fuels have heating values lower than those of fossil fuels such as coal, oil and gas.
Typically, biomass fuels contain relatively high levels of moisture and ash. The presence of moisture in the fuel increases the gas flow in the system, which means that extra thermal energy has to be added to achieve the correct operational temperatures in the system.
With dry fuel, all the heat of combustion goes into heating the air used for drying. As a result, dry fuels have a flame temperature in range of 2300 – 2500°F, while wet fuels will have combustion temperatures at about 1800°F. However, higher combustion temperature increases the chance of ash fusion. If the ash starts to flow and form slag, this could be detrimental to the proper stoker operation.
Using dry biomass fuel in a direct combustion dryer result in improved efficiency, reduced fuel use, improved operation and lower emissions. The primary reason for these benefits is increased combustion temperature.