The concept of integrated forest biorefineries(IFBRs) has gained significant interest.The prehydrolysis kraft(PHK) dissolving pulp production process is a suitable example of IFBR concept for the production of dissolv...The concept of integrated forest biorefineries(IFBRs) has gained significant interest.The prehydrolysis kraft(PHK) dissolving pulp production process is a suitable example of IFBR concept for the production of dissolving pulp and utilization of dissolved hemicelluloses,acetic acid,and lignin in the prehydrolysis liquor(PHL).This review paper highlights recent progress related to the recovery and utilization of dissolved organics(e.g.,hemicelluloses,acetic acid,and lignin) in the PHL of the PHK dissolving pulp production process.Integrated multi-step recovery and separation processes have been developed for this purpose to accommodate the complex nature of the PHL.Potential products,including xylan-based compounds,acetic acid,and lignin,are also discussed in detail.展开更多
Prehydrolysis is a key step for the production of kraft-based dissolving pulp.The pre-hydrolysis liquor mainly contains hemicellulosic components.Lignin can also be released into the pre-hydrolysis liquor,which hinder...Prehydrolysis is a key step for the production of kraft-based dissolving pulp.The pre-hydrolysis liquor mainly contains hemicellulosic components.Lignin can also be released into the pre-hydrolysis liquor,which hinders the purification and utilization of these hemicellulosic components.In this work,wet oxidation of activated carbon with nitric acid was employed to enhance the adsorptive removal of lignin from the pre-hydrolysis liquor.Under mild oxidation conditions(2%nitric acid solution),the oxidization of activated carbon resulted in significant enhancement of lignin removal.Adsorption isotherms showed that the specific surface area and the amount of carboxyl groups were affected by the oxidation treatment.The selective removal of lignin fitted well with the pseudo-second order kinetics model.展开更多
文摘The concept of integrated forest biorefineries(IFBRs) has gained significant interest.The prehydrolysis kraft(PHK) dissolving pulp production process is a suitable example of IFBR concept for the production of dissolving pulp and utilization of dissolved hemicelluloses,acetic acid,and lignin in the prehydrolysis liquor(PHL).This review paper highlights recent progress related to the recovery and utilization of dissolved organics(e.g.,hemicelluloses,acetic acid,and lignin) in the PHL of the PHK dissolving pulp production process.Integrated multi-step recovery and separation processes have been developed for this purpose to accommodate the complex nature of the PHL.Potential products,including xylan-based compounds,acetic acid,and lignin,are also discussed in detail.
基金the financial support from the National Natural Science Foundation of China(Grant No.:31370580 and 31470602),and Taishan Scholars Project Special Funds.
文摘Prehydrolysis is a key step for the production of kraft-based dissolving pulp.The pre-hydrolysis liquor mainly contains hemicellulosic components.Lignin can also be released into the pre-hydrolysis liquor,which hinders the purification and utilization of these hemicellulosic components.In this work,wet oxidation of activated carbon with nitric acid was employed to enhance the adsorptive removal of lignin from the pre-hydrolysis liquor.Under mild oxidation conditions(2%nitric acid solution),the oxidization of activated carbon resulted in significant enhancement of lignin removal.Adsorption isotherms showed that the specific surface area and the amount of carboxyl groups were affected by the oxidation treatment.The selective removal of lignin fitted well with the pseudo-second order kinetics model.