生物质热化学转化制备生物燃料及化学品

生物质是环境友好的可再生能源.近年来相关研究不断升温,文献报道量激增.本文在现有文献综述及近期报道的基础上,从利用热化学方法由生物质获得燃料油及化学品的角度对各方案进行了归纳、适当补充及简要述评,重点介绍了生物油催化裂解精制、水相重整制备烷烃、超临界水/水热制备化学品3个领域.     

生物质热化学转化制备生物燃料及化学品

生物质是环境友好的可再生能源。近年来相关研究不断升温,文献报道量激增。本文在现有文献综述及近期报道的基础上,从利用热化学方法由生物质获得燃料油及化学品的角度对各方案进行了归纳、适当补充及简要述评,重点介绍了生物油催化裂解精制、水相重整制备烷烃、超临界水/水热制备化学品3个领域。     

生物质平台分子γ-戊内酯的研究进展

生物质是自然界存量丰富的可再生资源.随着化石资源的日渐枯竭,由生物质制备燃料和化学品引起人们关注.把生物质转化为燃料和化学品通常经过生物质平台分子步骤.在众多生物质平台分子中,γ-戊内酯(GVL)具有广泛的用途,有关γ-戊内酯的合成和转化的研究成为一个热点课题.由木质纤维素制备GVL已经开发出多种催化体系,将GVL转化为燃料、化学品以及高分子材料也有大量文献报道.着重从不同的原料、催化体系归纳GVL的合成路线和方法,为探索高效、经济、绿色、可持续的GVL合成途径提供思路,并对GVL的高效转化的研究加以总结,为发展新的转化技术,拓展应用范围提供参考.     

生物质利用新途径:多元醇催化合成可再生燃料和化学品

日益严重的全球性能源和环境问题促使开发利用可再生的生物质资源成为当前研究的一个热点.本文概述了生物质基多元醇合成燃料和化学品来实现生物质转化利用的一些最新进展,特别是集中介绍了甘油和山梨醇等多元醇催化水相重整合成氢气和液体烃等燃料、催化选择氢解和氧化合成高附加值化学品或化学中间体等方面的进展,分析了存在的问题和可能的解决措施以及今后的发展趋势,指出生物质基多元醇将成为今后合成可再生燃料和化学品的新型平台分子.     

生物质利用新途径:多元醇催化合成可再生燃料和化学品

日益严重的全球性能源和环境问题促使开发利用可再生的生物质资源成为当前研究的一个热点。本文概述了生物质基多元醇合成燃料和化学品来实现生物质转化利用的一些最新进展,特别是集中介绍了甘油和山梨醇等多元醇催化水相重整合成氢气和液体烃等燃料、催化选择氢解和氧化合成高附加值化学品或化学中间体等方面的进展,分析了存在的问题和可能的解决措施以及今后的发展趋势,指出生物质基多元醇将成为今后合成可再生燃料和化学品的新型平台分子。     

生物质水热催化制备重要含氧化学品研究进展

作为唯一可再生、 分布广泛的绿色含碳资源, 生物质的高值化利用尤其是制备高品质含氧化学品日益引起研究者的广泛关注, 其中生物质水热催化制备重要含氧化学品是当前的一个重要研究方向. 本文对生物质经水热催化加氢、 脱水和水解制备多元醇、 5-羟甲基糠醛和乳酸的研究进展进行了系统总结和评述, 分析了催化剂的作用机制和产物生成机理, 并对生物质水热催化的研究前景进行了展望.     

木质生物质转化高附加值化学品

本文阐述了木质生物质转化为主要化学品的类型及其转化途径,提出了从木质生物质转化高附加值化学品的新思路.木质生物质通过一定的降解或分解途径,可产生很多有重要价值的有机小分子化合物,这些有机小分子化合物有葡萄糖、木糖、苯丙烷单体及二聚体,气态小分子如CH4和CO,液态小分子如有机酸、醛、醇,重要基础平台化合物糠醛、乙酰丙酸、木糖醇、乙醇等.通过这些小分子有机化合物的转化,可产生替代石油基产品的高附加值化学品,对可持续发展具有重要意义.     

基于二氧化钛光催化剂生物质转化制备氢气和化学品的研究进展

随着化石能源的枯竭和环境问题的日益严重,发展可再生资源变得越来越重要.太阳能和生物质是自然界中的两大可再生资源.利用太阳能转化生物质制备H2和化学品可以缓解对化石能源的依赖,是解决能源和环境问题的途径之一.本文作者概述了基于TiO2催化剂的光催化生物质制备H2和化学品的研究进展;着重介绍了甲醇、乙醇、甘油和葡萄糖的光催化反应选择性问题和机理研究,分析了存在的问题和可能的解决措施,并就其发展趋势进行了展望.     

生物质利用新途径:多元醇催化合成可再生燃料和化学品

日益严重的全球性能源和环境问题促使开发利用可再生的生物质资源成为当前研究的一个热点.本文概述了生物质基多元醇合成燃料和化学品来实现生物质转化利用的一些最新进展,特别是集中介绍了甘油和山梨醇等多元醇催化水相重整合成氢气和液体烃等燃料、催化选择氢解和氧化合成高附加值化学品或化学中间体等方面的进展,分析了存在的问题和可能的解决措施以及今后的发展趋势,指出生物质基多元醇将成为今后合成可再生燃料和化学品的新型平台分子.     

单糖化学催化制取运输燃料

农作物秸秆和林业废弃物是资源量大、可再生的非粮生物质。它们由半纤维素、纤维素和木质素组成,源于这些生物质的单糖不仅可以经过生物催化过程制备纤维乙醇,还是化学催化法制备传统烃类运输燃料的重要平台。本文首先介绍了木质生物质酶法和酸催化法水解制备单糖的工艺特点,然后详细介绍了近几年来开发的从单糖出发制取烃类生物燃料的各种新型催化方法,如单糖直接HZSM-5分子筛催化重整制备液体烃类,以及单糖经乙酰丙酸和酯化加氢工艺、经多元醇和水相脱水加氢（APD/H）工艺、经糠醛类化合物和羟醛缩合加氢工艺、经单官能团化合物和催化提质工艺。对这些催化方法的工艺条件、催化剂组成和化学反应进行了总结评述。考虑到由单糖制备C₆以上烃类可以直接或混配为传统的液体燃料,本文对这两条工艺路线进行了重点介绍,总结了过程所发生的反应和脱氧机理,并探讨了工业化过程中需要注意的科学难题。     

Influence of structural and functional modifications of selected genotoxic carcinogens on metabolism and mutagenicity – a review

Alterations in molecular structure are responsible for the differential biological response(s) of a chemical inside a biosystem. Structural and functional parameters that govern a chemical's metabolic course and determine its ultimate outcome in terms of mutagenic/carcinogenic potential are extensively reviewed here. A large number of environmentally-significant organic chemicals are addressed under one or more broadly classified groups each representing one or more characteristic structural feature. Numerous examples are cited to illustrate the influence of key structural and functional parameters on the metabolism and DNA adduction properties of different chemicals. It is hoped that, in the event of limited experimental data on a chemical's bioactivity, such knowledge of the likely roles played by key molecular features should provide preliminary information regarding its bioactivation, detoxification and/or mutagenic potential and aid the process of screening and prioritising chemicals for further testing.     

Influence of structural and functional modifications of selected genotoxic carcinogens on metabolism and mutagenicity - a review

Alterations in molecular structure are responsible for the differential biological response(s) of a chemical inside a biosystem. Structural and functional parameters that govern a chemical's metabolic course and determine its ultimate outcome in terms of mutagenic/carcinogenic potential are extensively reviewed here. A large number of environmentally-significant organic chemicals are addressed under one or more broadly classified groups each representing one or more characteristic structural feature. Numerous examples are cited to illustrate the influence of key structural and functional parameters on the metabolism and DNA adduction properties of different chemicals. It is hoped that, in the event of limited experimental data on a chemical's bioactivity, such knowledge of the likely roles played by key molecular features should provide preliminary information regarding its bioactivation, detoxification and/or mutagenic potential and aid the process of screening and prioritising chemicals for further testing.     

Defining the Human-Biota Thresholds of Toxicological Concern for Organic Chemicals in Freshwater: The Proposed Strategy of the LIFE VERMEER Project Using VEGA Tools

Several tons of chemicals are released every year into the environment and it is essential to assess the risk of adverse effects on human health and ecosystems. Risk assessment is expensive and time-consuming and only partial information is available for many compounds. A consolidated approach to overcome this limitation is the Threshold of Toxicological Concern (TTC) for assessment of the potential health impact and, more recently, eco-TTCs for the ecological aspect. The aim is to allow a safe assessment of substances with poor toxicological characterization. Only limited attempts have been made to integrate the human and ecological risk assessment procedures in a “One Health” perspective. We are proposing a strategy to define the Human-Biota TTCs (HB-TTCs) as concentrations of organic chemicals in freshwater preserving both humans and ecological receptors at the same time. Two sets of thresholds were derived: general HB-TTCs as preliminary screening levels for compounds with no eco- and toxicological information, and compound-specific HB-TTCs for chemicals with known hazard assessment, in terms of Predicted No effect Concentration (PNEC) values for freshwater ecosystems and acceptable doses for human health. The proposed strategy is based on freely available public data and tools to characterize and group chemicals according to their toxicological profiles. Five generic HB-TTCs were defined, based on the ecotoxicological profiles reflected by the Verhaar classes, and compound-specific thresholds for more than 400 organic chemicals with complete eco- and toxicological profiles. To complete the strategy, the use of in silico models is proposed to predict the required toxicological properties and suitable models already available on the VEGAHUB platform are listed.     

Simulation of chemical metabolism for fate and hazard assessment. I. Approach for simulating metabolism

Information regarding the metabolism of xenobiotic chemicals plays a central role in regulatory risk assessments. In regulatory programmes where metabolism studies are required, the studies of metabolic pathways are often incomplete and the identification of activated metabolites and important degradation products are limited by analytical methods. Because so many more new chemicals are being produced than can be assessed for potential hazards, setting assessment priorities among the thousands of untested chemicals requires methods for predictive hazard identification which can be derived directly from chemical structure and their likely metabolites. In a series of papers we are sharing our experience in the computerized management of metabolic data and the development of simulators of metabolism for predicting the environmental fate and (eco)toxicity of chemicals. The first paper of the series presents a knowledge-based formalism for the computer simulation of non-intermediary metabolism for untested chemicals, with an emphasis on qualitative and quantitative aspects of modelling metabolism.     

CATALOGIC 301C model – validation and improvement

In Europe, REACH legislation encourages the use of alternative in silico methods such as (Q)SAR models. According to the recent progress of Chemical Substances Control Law (CSCL) in Japan, (Q)SAR predictions are also utilized as supporting evidence for the assessment of bioaccumulation potential of chemicals along with read across. Currently, the effective use of read across and QSARs is examined for other hazards, including biodegradability. This paper describes the results of external validation and improvement of CATALOGIC 301C model based on more than 1000 tested new chemical substances of the publication schedule under CSCL. CATALOGIC 301C model meets all REACH requirements to be used for biodegradability assessment. The model formalism built on scientific understanding for the microbial degradation of chemicals has a well-defined and transparent applicability domain. The model predictions are adequate for the evaluation of the ready degradability of chemicals.     

QSAR models for P450 (2D6) substrate activity

Human Cytochrome P450 (CYP) is a large group of enzymes that possess an essential function in metabolising different exogenous and endogenous compounds. Humans have more than 50 different genes encoding CYP enzymes, among these a gene encoding for the CYP isoenzyme 2D6, a CYP able to metabolise drugs and other chemicals. A training set of 747 chemicals primarily based on in vivo human data for the CYP isoenzyme 2D6 was collected from the literature. QSAR models focusing on substrate/non-substrate activity were constructed by the use of MultiCASE, Leadscope and MDL quantitative structure–activity relationship (QSAR) modelling systems. They cross validated (leave-groups-out) with concordances of 71%, 81% and 82%, respectively. Discrete organic European Inventory of Existing Commercial Chemical Substances (EINECS) chemicals were screened to predict an approximate percentage of CYP 2D6 substrates. These chemicals are potentially present in the environment. The biological importance of the CYP 2D6 and the use of the software mentioned above were discussed.     

Using green chemistry to progress a circular fashion industry

The fashion industry is strongly connected to consumer affluence and with more and more people worldwide, the demand for new and ever more sophisticated clothes seems inexhaustible. This translates into the production and consumption of very large quantities of natural and synthetic materials, and treatment chemicals. The lack of an established recycling industry to deal with the resulting waste streams coupled with the increasing complexity of the products means that we are losing most of the consumed resources as wastes. The presence of so many chemicals in these wastes can exaggerate the problem. Here, we look at the scale of the problem but also of the opportunity for waste valorisation. Particular attention is given to the different types of recycling that are possible and including the conversion of these wastes into valuable chemicals. Some methods to improve apparel lifecycles upstream are also considered.     

Investigation of Degradation of Structural Adhesives under Influence of Chemicals

Structural adhesives are used for joining materials also under conditions, where they through the application will be influenced by many different chemicals. The adhesives can – if not protected from the chemical influence – be degradated of the chemicals. The degradation can because of the different structures of the polymers in the adhesives result in lower strength of the joining area, but can also give higher strength but brittleness. Information of the structures of the structural adhesives used in the project have been taken from the data sheets from the manufacturers and have been compared with investigation of the structures by FTIR and DSC. In the laboratory the HSP's (Hansen Solubility Parameters) of the adhesives has been determined and compared with the theoretically estimated HSP's. The estimation has mainly been done by Lydersens group contribution method. The chemical resistance of the adhesives have been foreseen by using HSP's of the adheisves and compared them with the HSP's of the chemicals. The structural adhesives were most of the epoxy types and of the polyurethane types with different curing systems. The structural adhesives should all have high strength and an opening time of more than 30 minutes. They were in the laboratory cured up after the specifications from the manufacturer and were stored one week after curing before they were influenced by hte chosen chemicals. The chemicals were chosen from their functional groups. In the laboratory the adhesives were influenced by different chemicals at room temperarture and under elevated temperature and under different periods to develope the degradation curves for the different chemicals and to foresee the degradation time of the adhesives before their properties were not acceptable any more. The structure after influence of the chemicals is studied by FTIR. The results of the investigations have been that it is possible to estimate the degradation by using the HSP's of the adhesives and the chemicals, but to estimate the time before degradation has been so serious that the properties of the adhesives are not acceptable any more, it is necessary to add laboratory investigations to the HSP comparisons of adhesives and chemicals. The comparison of the HSP and of the chemicals by which the adhesives can be in its lifetime has seen to be usefull especially if the chemicals are pesticides.     

化学品数据信息搜索引擎ChemDB Portal

化学品的性质、用途、安全使用等相关的知识是专业人员、特别是工业界的从业人员最大程度地降低健康和环境风险,合理地合成新化学品以及利用已有化学品的基础,也是公众消除对化学的误解、客观认识化学品在日常生活中功用和使用限度的前提。利用网络化、可公开访问的化学数据库资源获取化学品数据信息日益成为首选的途径,但目前对这些数据库的检...