Process for hydrolyzing cellulose-containing material with gaseous hydrogen fluoride

US4589924A · kind A · utility

Assignee

• Hoechst GmbH · DE

Inventors

• Rudiger Erckel · Eppstein, DE
• Raimund Franz · Kelkheim, DE
• Rolf Woernle · Bad Soden am Taunus, DE
• Theodor Riehm · Heidelberg, DE

Key dates

• Filing date: Mar 12, 1985
• Grant date: May 20, 1986
• Expiry date: Mar 12, 2005

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C13K13/002
• WIPO field: Food chemistry
• WIPO sector: Chemistry

Abstract

The semi-continuous process according to the invention for hydrolyzing cellulose-containing material (substrate) with gaseous hydrogen fluoride comprises sorption and subsequent desorption of HF in a total of n steps. The substrate is divided into n batches in n reactors (1a, 1b, 1c, . . . ); each batch passes through the n process steps in one reactor (1a, . . . ). Initially, sorption is carried out in the first to the (n/2)th step by the action of HF-inert gas mixtures, having an HF concentration which increases from sorption step to sorption step, at a temperature above the boiling point of HF. Subsequently, desorption is brought about in the ((n/2)+1)th to nth step by treating with heated HF-inert gas mixtures having an HF concentration which decreases from desorption step to desorption step; n is an even number from 4 to 12 and the n steps each take place in the same time segments (periods). The sequence of steps is displaced by one period from each batch to the next batch. During each period, the batch in the first step is connected to the batch in the last step and the batch in the second step with the batch in the penultimate step and the batch in the (n/2)th step with the …