バガスからの有用物質製造の技術実証

摘要

現在，木材残渣，トウモロコシ残渣，サトウキビ残渣(以下，バガス）などの食料と競合しないセルロース系バイォマスを分解して得られる糖を原料として，ェネルギー製品，化学製品やバイオ素材を生産する技術開発が世界的に進められている。しかし，既存技術は主にエタノール製造を目的とする技術であり，事業として経済的に成り立つためには商用機の大規模化が課題である。すなわち，既存技術において，糖はエタノール製造の中間体に過ぎず，エタノールを含む各種化学品の共通原料となる糖を，セルロース系バイォマスから大量かつ安価に製造する技術は未だ普及していないのが実情である。そこで，我々は国立研究開発法人新エネルギー·産業技術総合開発機構（以下，NEDO）の支援のもと，東レ株式会社（以下，東レ），三井物産株式会社（以下，三井物産）とともに，バイオエタノール製造が盛んであり，エネルギー，農業等に関する政策的後押しも期待できるタイ国において，製糖工場にある余剰バガスを原料として糖を製造するシステム技術の実証を行っている。本実証システムでは，バガスに含まれるセルロースを加水分解することで，グルコースを主成分とする糖液（以下，セルロース糖）を製造し，またその過程において付加価値の高いオリゴ糖，ポリフエノール類を同時に併産することから，小規模でも高い事業採算性が期待できる。%The technology of utilizing cellulosic biomass, which does not compete with food production, is now being developed worldwide. However, existing technologies are mainly for ethanol production. To make processing biomass an economically feasible business, large-scale processing machines need to be developed. Supported by the New Energy and Industrial Technology Development Organization (hereafter referred to as "NEDO"), along with Toray Industries, Inc. and Mitsui & Co., Ltd. in Thailand, we are now conducting a demonstration of a system technology that produces sugar (a basic material commonly used to produce various chemical products, including ethanol) using surplus bagasse from sugar factories as a raw material. This demonstration system hydrolyzes the cellulose contained in bagasse to produce a sugar concentrate, which contains glucose as a main component (hereafter referred to as "cellulosic sugar"). During this process, it simultaneously produces valuable oligosaccharides and polyphenols together with the cellulosic sugar, which may increase profitability in the process, even at a small scale. This demonstration project plans to construct and operate a demonstration plant facility. Further, we will market products so as to commercialize this operation in the future. We used the same production method as this demonstration system to prepare cellulosic sugar and obtained a nigh-quality sugar concentrate of low viscosity. This verifies that this cellulosic sugar can replace molasses as a raw material in ethanol production. The main component of oligosaccharides is xylooligosaccharide, which can be used in livestock feed and has intestine regulation and immunity improvement (as an alternative to antibiotics) effects. As polyphenols are thought to have various functionalities, such as antioxidant effects, we plan to develop a wide variety of applications, including food, stock feed, commodities, and cosmetics. In 2015, we started a feasibility study on the demonstration system. After NEDO decided to implement the demonstration project in 2016, the design and construction of the facility commenced. The plant was completed in July 2018. We plan to continue to evaluate and verify the data of this demonstration test until FY2022. During this period, we will conduct a study on marketing and commercializing these products with the aim of creating a new business that utilizes bagasse.