Europe

Europe has only relatively recently become involved in direct production of liquid fuels from biomass. Up to 1989, a conventional (slow) pyrolysis demonstration plant of 500 kg/h was operated by Alten in Italy for liquid and char production with approximately 25% yield of each (4). The product was derived in relatively low yields from an undefined reaction system. It is likely that the product was at least partially secondary liquids due to the relatively slow reaction, probable high reaction temperature and long vapour residence time, Bio-Alternative in Switzerland operated a fixed bed carbonisation pilot plant fed with wood, waste and MSW for charcoal production with liquids as a low yielding by-product (5). Liquids were recovered in a direct contact scroll cooler with selective condensation of oil at around 120°C which gave low yields of secondary pyrolysis products that were also more tarry.

More recently, a 200 kg/h flash pyrolysis pilot plant based on the University of Waterloo (Canada) process has been constructed in Spain by Union Fenosa which started up in mid 1993 (6). Egemin in Belgium have built and operated a 200 kg/h entrained downflow pilot plant to their own design which started up in July 1991 and operated until late 1992 (7). ENEL are purchasing a 15 t/d Ensyn (Canada) RTPIll pilot plant to produce bio-oils for testing. All these processes and other exploratory studies sponsored by the EEC JOULE (8) and AIR programmes are included in Table 4.1 and described below.