Slow pyrolysis of biomass in acidic or metallic catalysis

Abstract

Achieving the process of pyrolysis of biomass in mild conditions is a viable option for optimizing yield in liquid products and reducing coke yield. The partially dried digestate was stabilized by suspending in a reverse emulsion containing the lipid fraction resulting from the processing of the crude digestate, a hydrophobic surfactant of the polyethoxylated castor oil type and a hydrophilic sorbitol-polyethoxylated fatty acid ester type. The pyrolysis of the digestate was carried out in a continuous system, in a quartz tubular reactor, positioned in the central area of a vertical furnace provided with an automatic temperature control system. The experimental program was performed in the presence of two catalysts, Cu and respectively polyphosphoric acid at atmospheric pressure, temperature in the isothermal reaction zone 460 oC and liquid hourly space velocity of 0.33 h-1. The composition of the liquid fractions obtained on the two catalysts differs by the presence of a higher concentration of branched isomers in the case of the polyphosphoric acid catalyst.