共查询到20条相似文献,搜索用时 15 毫秒
1.
木质纤维素是地球上最丰富的可再生有机碳资源,将其高效转化为化学品或燃料,对缓解全球能源危机和解决环境污染问题具有重要意义。离子液体因对木质纤维素具有独特的溶解性能,近年来作为新型溶剂在生物质转化中获得广泛应用。综述了离子液体用于木质纤维素预处理及化学转化的最新研究进展,包括纤维素溶解、木质纤维素组分分离、纤维素水解制葡萄糖、六碳糖及纤维素催化转化制5-羟甲基糠醛以及碳水化合物的其他转化途径等,同时对基于离子液体平台的生物质转化技术存在的挑战、未来发展趋势及工业化前景进行了展望。 相似文献
2.
糖类是生物质的重要组成部分,可经催化转化制得一系列高附加值化学品,具有经济价值高、对环境友好和可持续性强等优点。葡萄糖异构为果糖是该过程的关键步骤。本文合成了四种碱功能性离子液体,用红外光谱、核磁共振谱仪和热重分析进行了表征,并用于催化葡萄糖异构化制备果糖,结果表明碱性离子液体具有较好的催化活性,但易使果糖进一步催化降解,同时加入硼酸钠可提高葡萄糖的转化率和果糖的产率,说明硼酸钠既起配合保护剂的作用,也有一定的协同催化作用。考察了离子液体用量、硼酸钠用量、时间、温度等因素对果糖选择性和产率的影响,结果表明,在离子液体和硼酸钠与葡萄糖的摩尔比分别为3∶1和0.08∶1、反应温度为70℃、反应时间为7 min的最佳反应条件下果糖的产率可高达64.7%,选择性为73.1%。 相似文献
3.
Ye Wang Minglei Tian Wentao Bi Kyung Ho Row 《International journal of molecular sciences》2009,10(6):2591-2610
Ionic liquids, considered “green” chemicals, are widely used in many areas of analytical chemistry due to their unique properties. Recently, ionic liquids have been used as a kind of novel additive in separation and combined with silica to synthesize new stationary phase as separation media. This review will focus on the properties and mechanisms of ionic liquids and their potential applications as mobile phase modifier and surface-bonded stationary phase in reversed-phase high performance liquid chromatography (RP-HPLC). Ionic liquids demonstrate advantages and potential in chromatographic field. 相似文献
4.
Zhen‐Zhen Yang Liang‐Nian He Cheng‐Xia Miao Sbastien Chanfreau 《Advanced Synthesis \u0026amp; Catalysis》2010,352(13):2233-2240
A series of easily prepared Lewis basic ionic liquids were developed for cyclic carbonate synthesis from epoxide and carbon dioxide at low pressure without utilization of any organic solvents or additives. Notably, quantitative yields together with excellent selectivity were attained when 1,8‐diazabicyclo[5.4.0]undec‐7‐enium chloride ([HDBU]Cl) was used as a catalyst. Furthermore, the catalyst could be recycled over five times without appreciable loss of catalytic activity. The effects of the catalyst structure and various reaction parameters on the catalytic performance were investigated in detail. This protocol was found to be applicable to a variety of epoxides producing the corresponding cyclic carbonates in high yields and selectivity. Therefore, this solvent‐free process thus represents an environmentally friendly example for the catalytic conversion of carbon dioxide into value‐added chemicals by employing Lewis basic ionic liquids as catalyst. A possible catalytic cycle for the hydrogen bond‐assisted ring‐opening of epoxide and activation of carbon dioxide induced by the nucleophilic tertiary nitrogen of the ionic liquid was also proposed. 相似文献
5.
生物质资源的开发利用是解决资源危机和能源危机的重要途径,但传统的生物质组分分离工艺效率较低且污染严重,极大地制约了生物质资源的高值化利用。作为一类新型溶剂,离子液体可以溶解纤维素、木质素和天然生物质材料,为生物质的组分分离及加工转化提供了有力的工具。本文简述了离子液体在生物质组分分离中的应用,包括离子液体作为溶剂直接从木质纤维素类生物质中提取分离纤维素和木质素,以及在离子液体介质中通过化学反应降解生物质来分离主要组分的方法。从离子液体优选、反应路径设计、生物质预处理、溶解条件和再生剂等方面分析了生物质组分分离工艺。成本高、效率低且容易引起二次污染是阻碍离子液体用于生物质组分分离的主要因素。为了提高生物质组分分离的经济性和绿色性,今后应着力设计低成本、低黏度、热稳定性强和低毒的离子液体,研发绿色高效的生物质组分分离工艺和离子液体再生方法。 相似文献
6.
生物质是自然界中最丰富的可再生资源之一,将生物质转化为高附加值化工产品首先要进行生物质预处理,即利用物理、化学和生物等手段削弱细胞壁分子之间的作用,使生物质更容易降解。离子液体具有诸多优异的物理和化学性质,在众多领域引起了广泛关注,近年来在生物质预处理过程中同样展现出良好的效果。综述了近年来离子液体作为木质纤维素溶剂的主要研究成果,重点介绍了溶解机理方面相关研究。介绍了阴阳离子种类及氢键的影响,总结了木质纤维素与离子液体在分子水平上的相互作用机制,最后探讨了离子液体溶解生物质方面的发展前景。 相似文献
7.
8.
Mehmet Isik Haritz Sardon David Mecerreyes 《International journal of molecular sciences》2014,15(7):11922-11940
Due to its abundance and a wide range of beneficial physical and chemical properties, cellulose has become very popular in order to produce materials for various applications. This review summarizes the recent advances in the development of new cellulose materials and technologies using ionic liquids. Dissolution of cellulose in ionic liquids has been used to develop new processing technologies, cellulose functionalization methods and new cellulose materials including blends, composites, fibers and ion gels. 相似文献
9.
概述了近几年离子液体在医药、食品添加剂、农药等精细化学品合成中的应用。离子液体表现出的主要优势在于:它无毒无害,对环境友好,可以替代有毒、腐蚀性的溶剂或催化剂;反应速度快,条件温和,收率高,选择性好,特别适合高纯产物的合成;中间体无需分离,多步合成操作过程可以连续进行,简化了合成工艺;产物易分离,离子液体/催化剂可循环使用;离子液相有机合成具有比固相合成担载量高的优势,适用于药物的组合化学合成中。设计合成高效、多功能、价廉、易降解的离子液体,将加速离子液体由基础研究到中试研究和工业应用的步伐,使之在精细化学品合成中带来更大的经济、环境效益。引文36篇。 相似文献
10.
With the objective of a more sustainable circular economy, one long‐term goal is the utilization of renewable resources as feedstock for the production of polymer‐based materials. In order to successfully process such materials using existing industrial‐scale technologies or even recycling processes, the natural polymers must have thermoplastic properties. With only a few exceptions, natural polymers are not thermoplastic. However, chemical and physical modification techniques are able to induce thermoplasticity in natural polymers from biomass resources such as cellulose, lignin, and chitin. Modification techniques focus on masking the hydroxyl groups to disrupt dense hydrogen bonding and so enable polymer chain mobility upon heating. The introduction of long alkyl chains into the polymer backbone effectively improves the thermoplastic processing of natural polymers. With regard to polymer blending, chemical grafting and graft copolymerization are powerful tools for enhancing compatibility. For both chemical and physical modification, solvents such as ionic liquids and deep eutectic solvents are currently being explored for biomass and fiber processing and show promise for the future development of thermoplastic biopolymers. This review describes possible modifications, potential processing difficulties, and gives a summary of relevant studies described in the scientific literature. 相似文献
11.
12.
13.
14.
Due to their negligible volatility,reasonable thermal stability,strong dissolubility,wide liquid range and tunability of structure and property,ionic liquids have been regarded as emerging candidate reagents for CO2 cap-ture from industries gases.In this review,the research progresses in CO2 capture using conventional ionic liquids,functionalized ionic liquids,supported ionic-liquids membranes,polymerized ionic liquids and mixtures of ionic liquids with some molecular solvents were investigated and reviewed.Discussion of relevant research fields was presented and the future developments were suggested. 相似文献
15.
K. N. Sorokina Yu. V. Samoylova A. V. Piligaev Uthandi Sivakumar V. N. Parmon 《Catalysis in Industry》2017,9(3):264-269
Part 2 of the review discusses modern processes for biotechnological conversion of lignocellulosic biomass into the valuable chemicals. It also recognizes the new approaches toward the development of more efficient enzymes for the depolymerization of biomass and the properties of the microorganisms employed in the fermentation of the biomass-derived sugars. Various biotechnological approaches to the fermentation of the depolymerized biomass products are described, including SHF, SSF, NSSF, SSFF, SSCF, and CBP. It is demonstrated that that the main tendencies for development of the new technologies for biotechnological biomass processing are the application of genetic engineering, synthetic biology and reduction of the number of processing steps. Application of one-pot processing of lignocellulosic biomass is promising for development of the new and efficient manufacturing technologies for production of valuable chemicals. 相似文献
16.
17.
18.
Yun Hee Moon Sang Mok Lee Sung Ho Ha Yoon-Mo Koo 《Korean Journal of Chemical Engineering》2006,23(2):247-263
Ionic liquids have been suggested as potential “green solvents” due to their unique properties such as non-volatility, nonflammability,
and a wide temperature range for liquid phase. This review describes recent advances of biocatalyst reactions in ionic liquids.
Enzyme-catalyzed reactions in ionic liquids-transesterification, synthesis, conversion, ammoniolysis, hydrolysis, epoxidation,
resolution, and oxidation are presented. The use of ionic liquids for protein folding/refolding and the toxicity of ionic
liquids are also discussed. 相似文献
19.
20.
离子液体作为一种新型的绿色溶剂,在重金属离子萃取分离方面较传统的有机溶剂有显著的优势。本文系统综述了近年来使用离子液体萃取重金属离子的研究进展,详细讨论了离子液体萃取重金属离子的原理和影响因素,包括螯合剂浓度、萃取时间、萃取温度、离子液体组成、溶液pH值、金属离子初始浓度、干扰离子以及水/离子液体质量比等。进一步介绍了提高离子液体萃取性能的措施以及金属离子的脱除与离子液体的回收状况,以及该萃取方法在废水处理、重金属离子分析和冶金中的研究与应用现状,最后指出其未来发展方向是合成功能化离子液体、提高萃取效率,以实现其工业化应用。 相似文献