Supporting the industry in scaling up biomass fast pyrolysis technology by building on pioneering work

Fundamental research related to fast pyrolysis of biomass dates back to the 60’s and the 70’s, when laboratory scale studies were carried out among others by F. Shafizadeh, A. Bradbury , A. Roberts, T. Nunn, W. Peters, J. Howard, M. Antal, T. Milne, E. Soltes, H. Stiles, and several others. Industrially driven efforts to produce liquid fuels employing fast pyrolysis were started after the first oil price crises. Occidental Petroleum built the first pilot scale pyrolysis unit in the 70’s. After this work, pioneering process development work especially by D. Scott (at the University of Waterloo), J. Diebold (at SERI and later NREL), and J. Lede (CNRS) are important milestones. In the 90’s, three pilot plants employing fluidized-bed (FB) technology were built in Europe, one based on UoW work in Spain (by Union Fenosa), and one based on the Ensyn technology in Italy (by ENEL). The third FB pilot plant in Europe was built in Finland by Fortum, based on its own technology. However, none of these developments were continued further, the low price of mineral oil being the major challenge at the time. While FB technologies were indebted to the work of Scott, the Dutch company BTG has developed and extended the ablative concept pioneered by Diebold and Lede. Interest in fast pyrolysis fuels was revived after the oil price increase starting around 2002, and three demonstrations plants were built, commissioned and taken into operation: those of Fortum, Joensuu, in Finland by Valmet (planned capacity 50 000 t/a bio-oil), Empyro, Hengelo, in the Netherlands by BTG (22 000 t/a), and Renfrew, Ontario, in Canada by Ensyn (15
000 t/a). Already during the 80’s, first patents on the production of transportation fuels using hydroprocessing of pyrolysis biooil were published (D. Elliott at PNNL). Numerous fundamental studies using various pyrolysis technologies have since been initiated for the production of higher value products. During the 90’s there was a rush of activities to (in-situ) catalytic pyrolysis: several European universities and institutes (BFH/TI, CERTH, University of Bilbao), UoW (collaborating with most groups on the field), C. Wang in Japan, and NREL. This technology has gained recently much new interest, and has been further developed among other by F. Agblevor (U of Utah), M. Olazar (UoB), I. Vasalos, and A. Lappas (CERTH). Employing zeolite catalyst to upgrade pyrolysis vapour (ex-situ) was developed by Diebold at NREL in the 90’s. Later more alternatives have been developed, both based on both in-situ and ex-situ upgrading approaches. Co-processing of pyrolysis bio-oil in mineral oil refinery was first suggested by W. Baldauf (Veba Oel) in the early 1990’s. Later this alternative has gained more interest. Co-processing of hydroprocessed (F. Mercader, University of Twente) and catalytic pyrolysis oils (F. Agblevor at Virginia Tech/USU) with vacuum gas oil in a refinery fluid catalytic cracking (FCC) unit has been proposed. Recently even thermal fast pyrolysis oil has been reported to be a potentially suitable co-feed in the FCC (A. Pinho, Petrobras). Also related to fast pyrolysis, in 2013 A. Boon at Shell has
proposed an even simpler alternative by introducing wood co-fed directly to a FCC riser. This alternative should be a relatively low cost technology, provided overall carbon efficiency from biomass to bio-fuel components, a significant CO2 emission reduction, and the remaining technical challenges are solved.