Chemical News

Friday, July 25, 2008

Chemicals for Increasing wood pulping yield

Unevenly processed wood chips in the pulp industry result in poor-quality pulp, often requiring reprocessing. ChemStone, Inc., in cooperation with the NICE3 Program, has demonstrated a cooking aid that reduces the amount of virgin wood feedstock needed to process wood chips. It also increases pulp yield and quality.

The cooking aid is a molecule that remains soluble in the highly alkaline and hot environment for cooking pulp. The molecules help pulp-cooking liquors penetrate the chips, resulting in more uniform cooking. The rate of penetration into the chips enables the mill to produce a more uniform fiber in less time and with less energy. This chemistry eliminates overcooking the external chip to effectively cook the internal chip and eliminates the need to reprocess the uncooked portion.


The reduction in cooking time translates into an energy savings of 125 thousand Btu per ton of wood clips processed.The process greatly reduces sulfur-based emissions, such as hydrogen sulfide and methyl mercaptans. Approximately 1-million tons of emission gases are eliminated. Eleven United States mills are currently using this novel chemistry either full time or for part of their production. ChemStone is establishing a distribution network in South Africa, Europe, Indonesia, Canada, and Mexico.

Benefits
1. Reduction in sulfur based emissions.
2. Results in 2-5% yield per MT of wood.
3. Reduction in rejected pulp depending on current processes.
4. Reduction in fiber required for paper quality.
5. Use of less bleaching chemicals.
6. Energy Saving 1.1 Trillion BTU/year.
7. Carbon reduction 17300 MT / year.

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