It is known that pyrolysis is used for the production of fuels to drive Combined Heat and Power (CHP) engines. Examples are the Pytec process from Bremerhaven (Germany) and the Haloclean® process from Karlsruhe (Germany) and Turin (Italy). The countries are using wood or rape seed as a feedstock. France and the United Kingdom currently favour the direct use of pyrolysis liquids in petro refineries. Here, oils have to be converted to fit to the petro chemical belongings. The removal of oxygen can be carried out via catalysts. Studies and reviews by the UK´s Carbon Trust have shown the options but also the difficulties which have to be solved to reach a sustainable concept.
EBRI researchers have developed a Pyroformer which uses an intermediate pyrolysis technique. Intermediate pyrolysis is a special kind of pyrolysis and works in contrast to the existing slow and fast pyrolysis techniques. The reaction temperature for this process is typically around 450 - 500°C with a much reduced vapor residence time in the order of few seconds. The solids residence time can be varied as desired. The reaction occurs under controlled heating rates and thereby avoid the formation of tar. Another distinct advantage with intermediate pyrolysis is that no pre-treatment of the feedstock is required. The feedstock can be in any form and size ranging from chips, through to pellets and powder. The products from this process can be directly used for CHP engines.
This patented process can be used for different kinds of biogenic feedstock such as algae, residues from biogas plants, energy grass, wood residues, plastics, and other residues from agriculture, forestry and industry. These are converted into pyrolysis liquid, pyrolysis gas and pyrolysis char with a typical ratio of 20 to 30 wt % of char and 15 to 25 wt % of gas. The total pyrolysis vapours (about 60-75% of the energy of the input material) which are now low in ash are passed directly to a gasifier and gasified.