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:
Oct. 03, 2017
Filed:
Mar. 16, 2012
Fredrik Ohman, Gavle, SE;
Hans Theliander, Göteborg, SE;
Per Tomani, Huddinge, SE;
Peter Axegard, Solna, SE;
Fredrik Ohman, Gavle, SE;
Hans Theliander, Göteborg, SE;
Per Tomani, Huddinge, SE;
Peter Axegard, Solna, SE;
VALMET AB, Sundsvall, SE;
Abstract
The method is for separation of lignin from original black liquor (BL) that has a first precipitation phase (PR1/PR2) for precipitation of lignin by a first acidification using acidifier, CO, 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.