Biobased alkylphenols from lignins via a two-step pyrolysis – Hydrodeoxygenation approach

•Two-stage approach for thermochemical conversion of lignin into biobased aromatics.•Successful pyrolysis of various technical lignins into a phenolic bio-oil.•Catalytic hydrodeoxygenation of bio-oils into alkylphenolics and other aromatics.•For comparison, direct HDO of Kraft lignin for depolymerisation and deoxygenation.•Relatively high product concentrations in bio-oil after two-stage approach. Five technical lignins (three organosolv, Kraft and soda lignin) were depolymerised to produce monomeric biobased aromatics, particularly alkylphenols, by a new two-stage thermochemical approach consisting of dedicated pyrolysis followed by catalytic hydrodeoxygenation (HDO) of the resulting pyrolysis oils. Pyrolysis yielded a mixture of guaiacols, catechols and, optionally, syringols in addition to alkylphenols. HDO with heterogeneous catalysts (Ru/C, CoMo/alumina, phosphided NiMO/C) effectively directed the product mixture towards alkylphenols by, among others, demethoxylation. Up to 15wt% monomeric aromatics of which 11wt% alkylphenols was obtained (on the lignin intake) with limited solid formation (