Process for the Conversion of a Solid Material Containing Hemicellulose, Cellulose and Lignin

Abstract

A process for the conversion of a solid material containing hemicellulose, cellulose and lignin, which process comprises the following steps:(i) hydrolyzing, at a temperature equal to or less than 40° C., preferably equal to or less than 30° C., at least part of the hemicellulose of the solid material by contacting the solid material with a first aqueous hydrochloric acid solution, which first aqueous hydrochloric acid solution has a hydrochloric acid concentration in the range from equal to or more than 15.0 wt. % to less than 40.0 wt. %, based on the weight amount of water and hydrochloric acid in such first aqueous hydrochloric acid solution, yielding a remaining solid material and an aqueous first hydrolysate product solution;(ii) displacing aqueous solution from the remaining solid material with a non-aqueous displacement fluid;(iii) hydrolyzing, at a temperature equal to or less than 40° C., preferably equal to or less than 30° C., at least part of the cellulose of the remaining solid material by replacing the non-aqueous displacement fluid with a second aqueous hydrochloric acid solution, which second aqueous hydrochloric acid solution has a hydrochloric acid concentration in the range from equal to or more than 40.0 wt. % to equal to or less than 51.0 wt. %, based on the weight amount of water and hydrochloric acid in such second aqueous hydrochloric acid solution, yielding a residue and an aqueous second hydrolysate product solution,wherein the reactor in which step (i) takes place is flooded with a plug of intermediate prehydrolysate solution prior to step (i).

Description

FIELD OF THE INVENTION[0001]The present invention relates to a process for the conversion of a solid material containing hemicellulose, cellulose and lignin, more specifically it relates to a process for the conversion of a solid lignocellulosic material.BACKGROUND TO THE INVENTION[0002]With the diminishing supply of crude petroleum oil, use of sustainable, renewable biomass materials are becoming increasingly important for the production of fuels and / or chemicals. Lignocellulosic materials, such as wood or agricultural waste, are suitable examples of such renewable biomass material. The production of fuels and / or chemicals from non-edible sustainable, renewable biomass materials, such as solid lignocellulosic material, is preferred, as such non-edible solid lignocellulosic material does not compete with food production.[0003]Several processes have been examined to convert solid lignocellulosic materials such as wood or agricultural waste to saccharides, which saccharides in turn ca...

AI Technical Summary

Benefits of technology

The use of non-aqueous displacement fluids in the process of hydrolysis has several advantages. Firstly, it reduces the unwanted mixing of components from different hydrolysate solutions, which can lead to contamination. Secondly, non-aqueous fluids can compensate for volume losses during the process, which allows for continuous or semi-continuous operation and improves efficiency.

Problems solved by technology

This means that there will ideally not be any mixture of the hydrolysate solution having a heavier specific weight with the water having a lighter specific weight when there is a correspondingly slower and more even introduction.

US2015 / 0275320 warns that if introduction is too fast, that could lead to a situation in which the displacement is no longer uniform along the entire tube cross section.

This can be disadvantageous for several reasons.

This reduces the purity of a resulting product of the main hydrolysis step.

Unlike the C6-saccharides (also referred to as hexoses or C6-sugars) obtained in the main hydrolysis step, pentoses are for example difficult to ferment.

Secondly, hydrochloric acid can be carried over into the wash water used in a washing step and can only be removed from such washing water at great expense.

Images