The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 20, 1986
Filed:
Mar. 12, 1985
Rudiger Erckel, Eppstein, DE;
Raimund Franz, Kelkheim, DE;
Rolf Woernle, Bad Soden am Taunus, DE;
Theodor Riehm, Heidelberg, DE;
Hoechst Aktiengesellschaft, , DE;
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 batch in the ((n/2)+1)th step, by HF-inert gas circulations.