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.
chemicals
hydrogen
supercritical water
Engineering
catalytic depolymerization
ethanol
pyrolysis
degradation
near-critical water
alkali lignin
Energy & Fuels
conversion
Author
Tallal Belkheiri
Chalmers, Energy and Environment, Industrial Energy Systems and Technologies
Cecilia Mattsson
Chalmers, Chemistry and Chemical Engineering, Chemical Technology
Sven-Ingvar Andersson
Chalmers, Chemistry and Chemical Engineering, Chemical Technology
L. Olausson
Valmet
Lars-Erik Åmand
Chalmers, Energy and Environment, Industrial Energy Systems and Technologies
Hans Theliander
Chalmers, Chemistry and Chemical Engineering, Chemical Technology
Wallenberg Wood Science Center (WWSC)
Lennart Vamling
Chalmers, Energy and Environment, Industrial Energy Systems and Technologies
Energy & Fuels
0887-0624 (ISSN) 1520-5029 (eISSN)
Vol. 30 6 4916-4924Subject Categories
Chemical Engineering
DOI
10.1021/acs.energyfuels.6b00462