Goal and StrategyDevelop next-generation chemical pulping processes that preserve fiber strength and pulp performance attributes while achieving one or more of the following:
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R&D Needs
Break the bleachable-yield barrier
High-Priority Projects
Yield-protective pretreatment
Primary peeling of cellulose and glucomannan occurs during the initial phase of kraft pulping at high alkalinity and high temperatures. Peeling causes about 12.5% oven-dried weight yield loss for softwood. In this project, softwood and hardwood chips will be pretreated at low alkalinity and at relatively low temperature to minimize primary peeling.
Status: Launched February 21, 2017; a 3% yield increase in the lab has been reported, against the target of 5%. Year two is in progress with support from APPTI member companies. A related project to understand pre-treatment reactions is underway funded by the U.S. Department of Energy’s High-Performance Computing for Manufacturing (HPC4Mfg) Program.
PI: Adriaan Van Heiningen, University of Maine; Brandon Knott, NREL; Jerry Parks, ORNL
Catalytic Delignification of wood - High Performance Computing for Manufacturing Project
Catalytic methods offer a viable alternative to kraft pulping to increase cellulose fiber yield by improving selectivity, reducing energy use and eliminating the formation of odor-causing mercaptans associated with kraft pulping. This project will employ a coupled computational/experimental approach to develop cobalt-based catalysts that can delignify wood. Computational chemistry will be used to guide the rational design and predict the performance of prospective catalysts prior to synthesis, accelerating the development process.
Status: Launched October 1, 2017. ORNL has completed the computer modeling of the mechanism of a leading candidate catalyst. Company testing is currently being undertaken using developed protocols. Insights into mechanisms are being gained.
PI: Jerry Parks, Oak Ridge National Laboratory with University of Tennessee-Knoxville; US Forest Service
High-Kappa pulp - Improve oxygen delignification selectivity
This project seeks to increase pulp yield from 55 to 60% by raising the kappa # significantly. However, this increase in Kappa causes poor bonding and low board strength due to the lack of available bonding sites. Thus, this project will seek to substantially modify the surface lignin so that the fiber bonding can be improved without a concomitant significant loss in yield.
Status: Launched February 16, 2017. It has been demonstrated that pulping to a higher kappa number can increase the yield by 5%. However to get the strength to match lower kappa it was necessary to further treat the pulp. More refining energy was necessary. We feel that further improvements in strength may be possible by optimization of the refining strategy.
PI: Hasan Jameel, North Carolina State University
Break the bleachable-yield barrier
- Develop a cost-effective bleach sequence for higher Kappa pulping processes with similar or better loadings to the waste treatment plant compared to current bleach processes
- Develop non-chlorine-based lignin activators to improve O2 delignification selectivity
- Complete a computational chemistry study to screen categories of potential catalyst
- Identify higher-performing catalysts for strength, yield, and selectivity improvement
- Develop a chip activation method to facilitate pulping selectivity
- Explore oxidative alkaline pretreatments to remove a portion of hemicelluloses while activating lignin to subsequent kraft cooking conditions
High-Priority Projects
Yield-protective pretreatment
Primary peeling of cellulose and glucomannan occurs during the initial phase of kraft pulping at high alkalinity and high temperatures. Peeling causes about 12.5% oven-dried weight yield loss for softwood. In this project, softwood and hardwood chips will be pretreated at low alkalinity and at relatively low temperature to minimize primary peeling.
Status: Launched February 21, 2017; a 3% yield increase in the lab has been reported, against the target of 5%. Year two is in progress with support from APPTI member companies. A related project to understand pre-treatment reactions is underway funded by the U.S. Department of Energy’s High-Performance Computing for Manufacturing (HPC4Mfg) Program.
PI: Adriaan Van Heiningen, University of Maine; Brandon Knott, NREL; Jerry Parks, ORNL
Catalytic Delignification of wood - High Performance Computing for Manufacturing Project
Catalytic methods offer a viable alternative to kraft pulping to increase cellulose fiber yield by improving selectivity, reducing energy use and eliminating the formation of odor-causing mercaptans associated with kraft pulping. This project will employ a coupled computational/experimental approach to develop cobalt-based catalysts that can delignify wood. Computational chemistry will be used to guide the rational design and predict the performance of prospective catalysts prior to synthesis, accelerating the development process.
Status: Launched October 1, 2017. ORNL has completed the computer modeling of the mechanism of a leading candidate catalyst. Company testing is currently being undertaken using developed protocols. Insights into mechanisms are being gained.
PI: Jerry Parks, Oak Ridge National Laboratory with University of Tennessee-Knoxville; US Forest Service
High-Kappa pulp - Improve oxygen delignification selectivity
This project seeks to increase pulp yield from 55 to 60% by raising the kappa # significantly. However, this increase in Kappa causes poor bonding and low board strength due to the lack of available bonding sites. Thus, this project will seek to substantially modify the surface lignin so that the fiber bonding can be improved without a concomitant significant loss in yield.
Status: Launched February 16, 2017. It has been demonstrated that pulping to a higher kappa number can increase the yield by 5%. However to get the strength to match lower kappa it was necessary to further treat the pulp. More refining energy was necessary. We feel that further improvements in strength may be possible by optimization of the refining strategy.
PI: Hasan Jameel, North Carolina State University