As the price of biomass fuels is becoming more competitive with traditional fuels such as coal, oil and gas, the need for boilers to fire biomass fuels is steadily increasing.
To meet this need and the growing demand for a cleaner and more sustainable environment, and to verify boiler design and combustion parameters, John Thompson, the Cape Town based designer and manufacturer of industrial boilers and associated plant has, in the past few years, carried out a series of tests firing a variety of biomass fuels on sites and on the boiler installed in their Boiler Development and Training Centre. These fuels included: wood-pellets, wood-chips, wood-pucks, grape pomace, nut shells, sunflower seed husks, corncobs, dried-hops and torrefied biomass.
Torrefaction of Biomass
More recently, in an exciting joint development project, John Thompson and a technology partner are working together in the rolling out of large-scale production of torrefied material, a form of charcoal. The torrefied material is produced from woody biomass by controlled pyrolysis to produce a friable material that can easily be pelletized. This product has a calorific value and volatile content comparable to coal, but contains zero sulphur and has a lower ash content. Torrefaction provides a method to beneficiate woodchips and other woody biomass as a fuel by increasing the energy density of the material by a factor around 3. This reduces the transport cost to move renewable biomass fuels over long distances from source to end-users.
The technology partner has achieved an important breakthrough by developing a continuous process for production of torrefied material, in place of the “stop-start” batch-process applied until now. This significant advance enables large-scale production of torrefied material, greatly enhancing its viability as an alternative fuel to coal for industrial boilers such as John Thompson’s Europac package firetube and MicroGen cogeneration watertube designs.
The aim of the joint project is to ramp up and accelerate production of torrefied material for extensive use in industry for generation of process steam. John Thompson’s role in the partnership is to design and manufacture larger scale production plants at their Bellville Works, following on the earlier establishment of their partner’s pilot plant in which the effectiveness of its continuous production process was demonstrated.
Industries generally use steam as a heating medium, and the most cost effective fuel currently locally available for firing their boilers is coal, which in turn requires expenditure on expensive pollution control systems to reduce particulate emissions and in some cases, to manage the release of SOx into the atmosphere. The production of torrefied material as a viable and competitive alternative to coal promises to remove these difficulties.
John Thompson is the Power division of ACTOM the largest manufacturer, solution provider, repairer and distributor of electro-mechanical equipment in Africa. They have over 80 years of service to South Africa’s industries.
For further information please contact:
Etienne de Villiers, Technical Manager
Tel: 021-959 8400