Provided is a method for producing a lignin degradation product that includes (1) a degradation step of degrading a raw material containing a plant biomass, in a mixed solvent of water and an aliphatic alcohol having from 4 to 10 carbon atoms, which separates into two phases at 0° C. or higher and 50° C. or lower, under the following conditions, and (2) after the degradation step, a liquid-liquid separation step of separating the lignin degradation product-containing organic phase from the solvent that has separated at the temperature for two-phase separation. The method produces a lignin degradation product at a high yield from lignin or a material containing lignin. Condition A: The concentration of the raw material to be in the mixed solvent is 1% by mass or more and 20% by mass or less. Condition B: The reaction temperature is 100° C. or higher and 350° C. or lower. Condition C: The reaction time is 0.1 hours or more and 10 hours or less.

Provided is a method for producing a lignin degradation product that includes (1) a degradation step of degrading a raw material containing a plant biomass, in a mixed solvent of water and an aliphatic alcohol having from 4 to 10 carbon atoms, which separates into two phases at 0° C. or higher and 50° C. or lower, under the following conditions, and (2) after the degradation step, a liquid-liquid separation step of separating the lignin degradation product-containing organic phase from the solvent that has separated at the temperature for two-phase separation. The method produces a lignin degradation product at a high yield from lignin or a material containing lignin. Condition A: The concentration of the raw material to be in the mixed solvent is 1% by mass or more and 20% by mass or less. Condition B: The reaction temperature is 100° C. or higher and 350° C. or lower. Condition C: The reaction time is 0.1 hours or more and 10 hours or less.

The invention is directed to compositions and processes concerning efficient downstream processing of products derived from organic acids pretreatment of plant materials.

The invention is directed to compositions and processes concerning efficient downstream processing of products derived from organic acids pretreatment of plant materials.

The method is for separation of lignin from original black liquor (BL.sub.IN) that has a first precipitation phase (PR1/PR2) for precipitation of lignin by a first acidification using acidifier, CO.sub.2, at alkaline conditions, then separating a lignin cake with subsequent suspension of the lignin cake in a strong acid in order to leach out metals from the lignin followed by dewatering and obtaining a clean lignin product LP. Lignin germ particles (LG) are added to the original black liquor in the first precipitation stage, preferably between two phases in said precipitation stage, in order to increase lignin particle growth on such lignin germ particles instead of spontaneous nucleation of lignin particles in said original black liquor. This results in improved filterability in subsequent dewatering and lignin cake formation and hence an increased lignin yield.

The method is for separation of lignin from original black liquor (BL.sub.IN) that has a first precipitation phase (PR1/PR2) for precipitation of lignin by a first acidification using acidifier, CO.sub.2, at alkaline conditions, then separating a lignin cake with subsequent suspension of the lignin cake in a strong acid in order to leach out metals from the lignin followed by dewatering and obtaining a clean lignin product LP. Lignin germ particles (LG) are added to the original black liquor in the first precipitation stage, preferably between two phases in said precipitation stage, in order to increase lignin particle growth on such lignin germ particles instead of spontaneous nucleation of lignin particles in said original black liquor. This results in improved filterability in subsequent dewatering and lignin cake formation and hence an increased lignin yield.

One example embodiment includes inserting a chemical reagent into a process stream that contains one or more lignins to form one or more modified lignins. The formed one or more modified lignins are different than the one or more lignins in the process stream. The one or more modified lignins can be formed in the process stream before a precipitation stage and then separated from the process stream. Also, contaminates can be removed from the separated one or more modified lignins and the one or more modified lignins can be pressed and dried.

One example embodiment includes inserting a chemical reagent into a process stream that contains one or more lignins to form one or more modified lignins. The formed one or more modified lignins are different than the one or more lignins in the process stream. The one or more modified lignins can be formed in the process stream before a precipitation stage and then separated from the process stream. Also, contaminates can be removed from the separated one or more modified lignins and the one or more modified lignins can be pressed and dried.

Low molecular weight sulfated beta-O4 lignin (SbO4L) are potent inhibitors of coagulation with high selectivity.

A method of depolymerising a lignin includes oxidising the lignin to provide an oxidised lignin wherein benzylic —OH of β-O-4 linkages have been converted to carbonyl. The oxidised lignin is depolymerised with a metal selected from the group consisting of zinc, magnesium, aluminium and titanium or mixtures thereof, in the presence of an ammonium salt or carbon dioxide. Also described are methods for manufacturing phenolic products from lignin and a method for the cleavage of a β-O-4 linkage in a substrate.