Effect of pH on Kraft Lignin Depolymerisation in Subcritical Water
Journal article, 2016

Softwood kraft lignin was depolymerized using subcritical water (623 K and 25 MPa) in a continuous small pilot unit. ZrO2 and K2CO3 were used as catalysts, and phenol was used as capping agent to suppress repolymerization. The effect of pH was investigated by adding KOH in five steps to the feed. The yield of water-soluble organics increased with pH. The yield of bio-oil was also influenced by the pH and varied between 28 and 32 wt %. The char yield on the zirconia catalyst showed a minimum at pH 8.1. The yield of suspended solids was low at pH below 8.1 but increased at higher pH values. The oxygen content in the bio-oil was only 15 wt %, compared to about 26 wt % in the kraft lignin.

Engineering

ethanol

hydrogen

chemicals

Energy & Fuels

alkali lignin

supercritical water

conversion

near-critical water

degradation

catalytic depolymerization

pyrolysis

Author

Tallal Belkheiri

Chalmers, Energy and Environment, Industrial Energy Systems and Technologies

Cecilia Mattsson

Chalmers, Chemistry and Chemical Engineering, Chemical Technology, Forest Products and Chemical Engineering

Sven-Ingvar Andersson

Chalmers, Chemistry and Chemical Engineering, Chemical Technology, Forest Products and Chemical Engineering

L. Olausson

Valmet

Lars-Erik Åmand

Chalmers, Energy and Environment, Industrial Energy Systems and Technologies

Hans Theliander

Wallenberg Wood Science Center (WWSC)

Chalmers, Chemistry and Chemical Engineering, Chemical Technology, Forest Products and Chemical Engineering

Lennart Vamling

Chalmers, Energy and Environment, Industrial Energy Systems and Technologies

Energy & Fuels

0887-0624 (ISSN) 1520-5029 (eISSN)

Vol. 30 6 4916-4924

Subject Categories

Chemical Engineering

DOI

10.1021/acs.energyfuels.6b00462

More information

Latest update

8/24/2018