Shamshina Julia L, Berton Paula
Mari Signum, Richmond, VA, United States.
Chemical and Petroleum Engineering Department, University of Calgary, Calgary, AB, Canada.
Front Bioeng Biotechnol. 2020 Jan 31;8:11. doi: 10.3389/fbioe.2020.00011. eCollection 2020.
Lignocellulosic biomass biorefinery is the most extensively investigated biorefinery model. At the same time, chitin, structurally similar to cellulose and the second most abundant polymer on Earth, represents a unique chemical structure that allows the direct manufacture of nitrogen-containing building blocks and intermediates, a goal not accomplishable using lignocellulosic biomass. However, the recovery, dissolution, and treatment of chitin was fairly challenging until the polymer's easy dissolution in ionic liquids (salts that are liquid at room temperature) was discovered. In this systematic review, we highlight recent developments in the processing of chitin, with a particular emphasis placed on methods conducted with the help of ionic liquids used as solvents, co-solvents, or catalysts. Such use of ionic liquids in the field of chemical transformations of chitin not only allows for shorter times and less harsh reaction conditions, but also results in different outcomes and higher product yields when compared with reactions conducted in "traditional" manner. Valorization of biomass in general, and chitin in particular, is a key enabling strategy of the circular economy, due to the importance of the sustainable production of biomass-based goods and chemicals and full chain resource efficiency. Economics is driven by the production of high-value chemicals or chemical intermediates from various biomasses, and chitinous biomass is a valuable potential resource. A fundamental "paradigm shift" will radically change the balance of oil-based chemicals to biopolymer-based chemicals, and chitin valorization is a necessary step aimed toward its full market competitiveness and flexibility.
木质纤维素生物质生物精炼是研究最为广泛的生物精炼模型。与此同时，几丁质在结构上与纤维素相似，是地球上第二丰富的聚合物，它具有独特的化学结构，能够直接制造含氮的结构单元和中间体，而这一目标无法通过木质纤维素生物质来实现。然而，在发现几丁质能轻松溶解于离子液体（室温下呈液态的盐）之前，几丁质的回收、溶解和处理颇具挑战性。在这篇系统综述中，我们重点介绍了几丁质加工方面的最新进展，特别强调了借助离子液体作为溶剂、共溶剂或催化剂所开展的方法。在几丁质的化学转化领域中，离子液体的这种应用不仅能缩短反应时间、缓和反应条件，而且与以“传统”方式进行的反应相比，还能产生不同的结果并提高产物收率。总体而言，生物质的增值利用，尤其是几丁质的增值利用，是循环经济的一项关键支撑策略，这是因为可持续生产生物质基产品和化学品以及全链资源效率至关重要。经济发展取决于从各种生物质中生产高价值化学品或化学中间体，而含几丁质的生物质是一种宝贵的潜在资源。一场根本性的“范式转变”将从根本上改变油基化学品与生物聚合物基化学品之间的平衡，而几丁质的增值利用是实现其全面市场竞争力和灵活性的必要步骤。
