Biomasspyrolysisrefinery: A Two Step Approach for Liquid Energy Carrier Production From Lignocellulose

BiomassPyrolysisRefinery:

A two step approach for liquid energy carrier production from lignocellulose

Schwaiger, N. Feiner, R. Pucher, H. Pucher*, P. Zahel*, K. E. Wilhelm⁺, P. Schroettner⁺, H. Siebenhofer, M. Graz University of Technology Institute of Chemical Engineering and Environmental Technology, *BDI-BioEnergy International AG, ⁺Graz University of Technology Institute for Electron Microscopy

Lignocellulose is expected to contribute to production of liquid and solid combustibles with high potential for CO₂ neutral processing. The “BiomassPyrolysisRefinery” is a two step concept for biomass liquefaction and hydrogenation, as shown in figure 1. First step of this concept is liquid phase pyrolysis: In this step a significant amount of oxygen is removed under thermal load and the calorific value of the lignocellulosic feed is partially condensed. Liquid phase pyrolysis is an exothermic process. During dehydration at T=350°C about 25-28% liquid CHO-products (biocrude) and about 38-42% BioChar is formed. [1]

Biocrude oil from liquid phase pyrolysis passes then a dewatering step where almost 90% of water from dehydration is separated. Afterwards the biocrude oil undergoes hydrodeoxygenation.

After liquid phase pyrolysis biochar is separated from the heat carrier and undergoes hydrogenation as well gasification and water gas shift reaction. Through hydrogenation of Biochar Hexane, Toluene (Asphaltenes) and THF (Preasphaltenes) solubles are formed.

Figure 1: BiomassPyrolysisRefinery concept

1.         Schwaiger, N., et al., Liquid and Solid Products from Liquid-Phase Pyrolysis of Softwood. Bioenergy Research, 2011. 4(4): p. 294-302.