FREMGANGSMÅDE TIL FREMSTILLING AF FURFURAL OG LEVULINSYRE AF LIGNOCELLULOSEBIOMASSE

摘要

The invention relates to a process for producing furfural and levulinic acid from lignocellulose-comprising biomass, said process comprising:
(a) adding water and optionally an acid to said biomass to form a slurried biomass;
(b) subjecting said slurried biomass to hydrolysis to form a hydrolysate comprising C5 and C6 sugars and further comprising (insoluble) cellulose and lignin;
(c) subjecting said hydrolysate comprising said C5 and C6 sugars and said (insoluble) cellulose and lignin to solid / liquid separation to yield a first aqueous fraction comprising at least part of said C5 and C6 sugars and a first solid fraction comprising at least part of said cellulose and lignin;
(d) optionally concentrating said first aqueous fraction;
(e) adding an organic solvent to the (optionally concentrated) first aqueous fraction to form a biphasic system;
(f) heating said biphasic system to a temperature within the range of 120 - 220°C and maintaining said biphasic system at that temperature range for a time sufficient to form furfural;
(g) cooling the biphasic system comprising furfural obtained in step (f);
(h) optionally subjecting the cooled biphasic system obtained in step (g) to solid / liquid separation and recovering the biphasic system;
(i) subjecting the cooled biphasic system obtained in step (g) or the recovered biphasic system obtained in step (h) to a separation step to yield an organic phase comprising at least part of said furfural and an aqueous phase comprising at least part of said C6 sugars and optionally further comprising furfural;
(j) optionally recovering furfural from said organic phase;
(k) optionally using the recovered organic phase obtained in step (j) to extract furfural from the aqueous phase obtained in step (i) by adding said recovered organic phase to said aqueous phase and repeating step (i) and optionally step (j);
(l) adding water and optionally an acid to the first solid fraction obtained in step (c) to form a suspension;
(m) subjecting the suspension obtained in step (I) to a temperature of between 140 and 220°C to form levulinic acid;
(n) subjecting the suspension comprising levulinic acid obtained in step (m) to solid / liquid separation to yield a second aqueous fraction comprising levulinic acid and a solid fraction; and
(o) optionally recovering said levulinic acid from the second aqueous fraction. The process advantageously allows for the production of both furfural and levulinic acid from lignocellulosic biomass, with no or little waste. Solvents and energy are used in an efficient way. The process can be done in a continuous fashion and gives less reactor fouling and results in less insoluble char. It benefits energy conservation.