著者

佐田 栄三 浅岡 宏

出版者

JAPAN TECHNICAL ASSOCIATION OF THE PULP AND PAPER INDUSTRY

雑誌

紙パ技協誌 (ISSN:0022815X)

巻号頁・発行日

vol.43, no.8, pp.751-767, 1989-08-01 (Released:2009-11-16)

参考文献数

66

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Although lignin in wood materials is to be separated as much as approximately a half of the amount of pulp through pulping processes, currently the chemical value of isolated polymeric lignin has not yet been effectively utilized. It has been desired to develop the processes for utilization of lignin in view of its chemical substance, i.e. highly complex polymer.In this review, first the outline of the present situation of lignin utilization in pulp and paper industries is presented in Section 1. Afterwards, the following three sections have been devoted from the standpoints of effective and potential utilization of lignin : Present situation of utilization of effective components and possibility or potentiality of utilization of derived components as chemical feedstocks (Section 2) Decomposition processes of lignin (Section 3) Possibility of utilization of decomposed components (Section 4).In Section 2, two typical reactions of lignin utilized for separation, i.e. acid catalyzed decomposition of ether likages and reductive decomposition of β-ether have been briefly described and the features of both reaction sequences offered along with practical applications. The necessity to clarify both the decomposition and condensation reactions quantitatively, that is, from the view point of chemical kinetics has been pointed out, because active sites for condensation reaction are apt to be still left after completion of both the reactions. Further, the steam explosion process of lignin, which is a practical process utilizing decomposition reaction of ether linkages is outlined and reactions and separations of derived components are explained to search for a possibility of their effective utilization.The first part of Section 3 is devoted to introduce several trials to degradate lignin chemically and thermally (pyrolysis) for chemical utilization. Hydrogenated decomposition, oxidative decomposition and production of catechol through a nucleophilic substitution reaction are reviewed as to chemical degradation. In the remaining part of this section, the biodegradation of lignin, i.e. the microbiology of lignin degradation, specifically lignin-degrading microbes and enzyme systems of lignin degradation, is reviewed. The latest trend and problems in the relevant fields are outlined and the long-term goals of biological processing of lignin are pressented.In Section 4, a feasibility study for production of polyoxyphenylene (or polyphenylene oxide, PPO) which is an important engineering plastic is given. The production of PPO is regarded as one of the promising processes for utilization of lignin-derived chemicals when the cost of lignin as well as the marcket scale of the product is taken into account.