Circular utilization method in pulping and papermaking processes with straw
US8778135B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 11, 2011 |
| Grant date | Jul 15, 2014 |
| Priority date | — |
| Expiry date | Mar 11, 2031 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S210/928
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
A circular utilization method in pulping and papermaking processes with straw Primary pulp is obtained by digesting straw raw material according to the ammonium sulfite method. Concentrated black liquor is extruded from the primary pulp; paper pulp and diluted black liquor. The concentrated black liquor and the diluted black liquor are mixed, and a contaminated condensate is obtained. A residual concentrate or the concentrated black liquor is used for preparing a fertilizer. The contaminated condensate is mixed with one or more of the waste material obtained from stock preparation, a crop byproduct or organic waste, and substrate or fertilizer is obtained by fermenting the nitrogen source of the contaminated condensate or ammonium sulfite, or using the contaminated condensate for desulfurizing flue gas. Ammonia and flue gas are reacted to obtain the ammonium sulfite as a digestion agent; and water from recycling is used in corresponding phases of the pulping process.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.