72 BIOMASS AND BIOENERGY 38 (2012)68-94 Table 2 (continued) Fast pyrolysis Industrial Units Max Research Max built size kg/h size kg/h Radiative-Convective CNRS-Nancy U.,France nk Entrained flow, Dalian U.of Technology,China nk Institute for Wood Chemistry,Latvia nk Shandong University of Technology 0.05 Microwave Carbonscape nk nk Chinese Academy of Sciences, nk New Zealand UK Dalian 116023,P.R.China Bioenergy 2020 gmbh, 1 nk National Inst.Advanced Industrial <0.1 Austria Sci.Technol.,Japan Shandong U.China <0.1 Technical U.Vienna,Austria nk U.Malaysia Sarawak <0.1 U.Minnesota,USA 10 U.Mississippi nk U.Nottingham,UK and China nk U.York,UK nk Washington State U.-Tricities,USA <1 Moving bed and Anhui Yineng Bio-energy 3 600 Anadolu University,Turkey nk fixed bed Ltd.,China U.Autonoma de Barcelona,Spain nk U.Science Technology of China -0.5 Ceramic ball Shandong University of 110 downflow Technology,China Unspecified U.Kentucky,USA nk U.Texas,USA nk Technical U.Compiegne,France nk Vacuum Pyrovac,Canada 3500 None known because of the scale-up limitations of different methods of at fast pyrolysis reaction temperatures,rapid and effective heat transfer.Fluid-bed pyrolysers give good and consistent char separation is important.This is usually achieved by performance with high liquid yields of typically 70-75 wt.% ejection and entrainment followed by separation in one or from wood on a dry-feed basis.Small biomass particle sizes of more cyclones so careful design of sand and biomass/char less than 2-3 mm are needed to achieve high biomass heating hydrodynamics is important.The high level of inert gases rates,and the rate of particle heating is usually the rate- arising from the high permanent gas flows required for fluid- limiting step. isation result in very low partial pressures for the condensable vapours and thus care is needed to design and operate efficient 2.2.1.2.Char.Vapour and solid residence time is controlledby heat exchange and liquid collection systems.In addition the the fluidising gas flow rate and is higher for char than for large inert gas flowrates result in relatively large equipment vapours.As char acts as an effective vapour cracking catalyst thus increasing cost. The byproduct char is typically about 15 wt.%of the Prepared Quench GAS products but about 25%of the energy of the biomass feed.It BIOMASS Cyclones cooler export can be used within the process to provide the process heat Dried and sized Gas requirements by combustion or it can be separated and recycle exported,in which case an alternative fuel is required. Depending on the reactor configuration and gas velocities, a large part of the char will be of a comparable size and shape Fluid as the biomass fed.The fresh char is pyrophoric i.e.it spon- bed taneously combusts when exposed to air so careful handling reactor and storage is required.This property deteriorates with time CHAR due to oxidation of active sites on the char surface process heat Electrostatic or export precipitator 2.2.1.3.Background.All the early work on fluid beds was ↓ carried out at the University of Waterloo in Canada,which CHAR BIO-OIL pioneering the science of fast pyrolysis and established a clear lead in this area for many years (e.g.[10-121).Bubbling fluid Recycle gas beds have been selected for further development by several heaterand/or oxidiser companies,including Union Fenosa [13],who built and oper- ated a 200 kg/h pilot unit in Spain based on the University of Fig.3-Bubbling fluid bed reactor with electrostatic Waterloo process which was dismantled some years ago; precipitator. Dynamotive,who operated a 75 kg/h and 400 kg/h pilot unitbecause of the scale-up limitations of different methods of heat transfer. Fluid-bed pyrolysers give good and consistent performance with high liquid yields of typically 70e75 wt.% from wood on a dry-feed basis. Small biomass particle sizes of less than 2e3 mm are needed to achieve high biomass heating rates, and the rate of particle heating is usually the rate￾limiting step. 2.2.1.2. Char. Vapour and solid residence time is controlled by the fluidising gas flow rate and is higher for char than for vapours. As char acts as an effective vapour cracking catalyst at fast pyrolysis reaction temperatures, rapid and effective char separation is important. This is usually achieved by ejection and entrainment followed by separation in one or more cyclones so careful design of sand and biomass/char hydrodynamics is important. The high level of inert gases arising from the high permanent gas flows required for fluid￾isation result in very low partial pressures for the condensable vapours and thus care is needed to design and operate efficient heat exchange and liquid collection systems. In addition the large inert gas flowrates result in relatively large equipment thus increasing cost. The byproduct char is typically about 15 wt.% of the products but about 25% of the energy of the biomass feed. It can be used within the process to provide the process heat requirements by combustion or it can be separated and exported, in which case an alternative fuel is required. Depending on the reactor configuration and gas velocities, a large part of the char will be of a comparable size and shape as the biomass fed. The fresh char is pyrophoric i.e. it spon￾taneously combusts when exposed to air so careful handling and storage is required. This property deteriorates with time due to oxidation of active sites on the char surface. 2.2.1.3. Background. All the early work on fluid beds was carried out at the University of Waterloo in Canada, which pioneering the science of fast pyrolysis and established a clear lead in this area for many years (e.g. [10e12]). Bubbling fluid beds have been selected for further development by several companies, including Union Fenosa [13], who built and oper￾ated a 200 kg/h pilot unit in Spain based on the University of Waterloo process which was dismantled some years ago; Dynamotive, who operated a 75 kg/h and 400 kg/h pilot unit Table 2 (continued) Fast pyrolysis Industrial Units built Max size kg/h Research Max size kg/h Radiative-Convective CNRS e Nancy U., France nk Entrained flow, Dalian U. of Technology, China nk Institute for Wood Chemistry, Latvia nk Shandong University of Technology 0.05 Microwave Carbonscape New Zealand & UK nk nk Chinese Academy of Sciences, Dalian 116023, P. R. China nk Bioenergy 2020 þ gmbh, Austria 1 nk National Inst. Advanced Industrial Sci. & Technol., Japan <0.1 Shandong U. China <0.1 Technical U. Vienna, Austria nk U. Malaysia Sarawak <0.1 U. Minnesota, USA 10 U. Mississippi nk U. Nottingham, UK and China nk U. York, UK nk Washington State U.-Tricities, USA <1 Moving bed and fixed bed Anhui Yineng Bio-energy Ltd., China 3 600 Anadolu University, Turkey nk U. Auto`noma de Barcelona, Spain nk U. Science & Technology of China w0.5 Ceramic ball downflow Shandong University of Technology, China 110 Unspecified U. Kentucky, USA nk U. Texas, USA nk Technical U. Compiegne, France nk Vacuum Pyrovac, Canada 1 3500 None known Fig. 3 e Bubbling fluid bed reactor with electrostatic precipitator. 72 biomass and bioenergy 38 (2012) 68 e9 4