256 15-20 (Fernández , 2008) 55 (Hartmann Ahring, 2006) (Kim Speece, 2002) (Hartmann Ahring, 2006) (Kim Speece, 2002) 2/1 (Martin , 2003) Plug flow reactor, PFR 30 (Hu Yu, 2005) Liquefaction 50-70