这项工作是由能源合同号DE-AC36-08GO28308美国能源部与美国国家可再生能源实验室的支持。通过能源效率的美国能源部办公室和可再生能源生物能源技术办公室提供资金。美国政府保留和发布，通过接受的文章发表，承认美国政府保留了非排他性的，缴足，不可撤销的，全球性的许可发布或转载本文的发表形式，或允许其他人这样做，对于美国政府的目的。

注意:请阅读开始之前所有相关的材料安全数据表（MSDS）。酒精是易燃品。所有相关化学品处理程序应遵循，以及所有适用的废一次性和处理程序。 1.试剂解决方案<ol><li>制备羟胺盐酸盐溶液（溶液A）:添加7.7克羟胺盐酸盐和50毫升去离子水至250毫升容量瓶中。当所有固体溶解，稀释用乙醇来标记。这导致在80％（体积/体积）乙醇中的0.55微米盐酸羟胺溶液。 </li><li>制备三乙醇胺溶液（溶液B）:加入17.4毫升的三乙醇胺到250毫升容量瓶中。添加10mL水，然后稀释到用乙醇标志。如果水的加入被跳过也可以使用95％的乙醇。这导致了0.48三乙醇胺的溶液在96％（体积/体积）乙醇</li><li>制备盐酸解。无论是购买0.1N的溶液或用10毫升浓准备HCl和1升的水。 </li></ol> 2.生物油采样和处理<ol><li>确保油样中抽取样品之前在室温下。 （通过剧烈振荡至少1分钟的混合，并目视检查样品以确保它是均匀的，有些生物油可能需要更长的振荡时间）充分均匀化生物油，得到有代表性的样品。 </li><li>为生物油样品中，使用生物油为100至150毫克。 </li><li>尽量减少暴露到氧气和热量，以防止在分析前样品降解。 </li></ol> 3.分析程序<ol><li> 碱溶液的标准化 <ol><li>干燥的 Na 2 CO 3中在105℃的烘箱主标准过夜以确保一干燥样品。允许的 Na 2 CO 3称重前冷却到室温。 </li><li>称重100至150毫克碳酸钠滴定容器，记录实际重量，加入搅拌棒和补充足够的水分，以覆盖pH电极灯泡和结。 </li><li>将样品转移至滴定容器中，用乙醇和水分别洗涤反应瓶多次比例使乙醇/水的最终的80％溶液。使用自动滴定到终点的酸溶液滴定。记录端点。端点被定义为滴定曲线上的拐点。 </li><li>重复该过程两次获得三分。 </li><li>使用该平均值作为该酸溶液的正常性。 </li></ol></li><li> 滴定空白的制备 <ol><li>对于空白答:加入0.5毫升二甲基亚砜（DMSO），以5毫升小瓶旋转叶片。 </li><li>加入2毫升盐酸羟胺溶液（溶液A）。 </li><li>加入2毫升三乙醇胺溶液（溶液B）。 </li><li>盖紧瓶盖，置于预热（80℃）热器块或水浴，搅拌2小时。 </li><li>使用自动滴定到终点记录端点酸溶液中，并滴定。 </li><li>为空白B:如果无机酸被怀疑存在于样本中，添加0.5mL的DMSO中，5毫升小瓶使用旋叶片。 </li><li>加入2毫升三乙醇胺溶液（溶液B）。 </li><li>帽密封和搅拌在80℃进行2小时。 </li><li>将样品转移至滴定容器中，用乙醇和水分别洗涤反应瓶多次比例使乙醇/水的最终的80％溶液。使用自动滴定到终点的酸溶液滴定。记录端点。 </li><li>重复过程三次以获得三点。 </li></ol></li><li> 使用公知的羰基的方法的验证 <ol><li>称取约100毫克4-（苄氧基）苯甲醛（4-BBA）到5毫升的小瓶，记录实际重量，增加一个旋转叶片。 </li><li>添加0.5毫升DMSO中。 </li><li>溶解在2mL盐酸羟胺溶液（溶液A）的样品。 </li><li>加入2毫升三乙醇胺溶液（溶液B）。 </li><li>关闭盖紧锅盖，搅拌在80℃2小时。 </li><li>将样品转移至滴定容器中，用乙醇和水分别洗涤反应瓶多次比例使乙醇/水的最终的80％溶液。使用自动滴定到终点的酸溶液滴定。记录端点。 </li><li>重复该过程三次，得到三点。 </li></ol></li><li> 生物油的分析使用方法 <ol><li>权衡接近100毫克生物油至5ml小瓶中，记录实际重量并添加旋叶片。 </li><li>添加0.5毫升DMSO中。 </li><li>溶解在2mL盐酸羟胺溶液（溶液A）的样品。 </li><li>加入2毫升三乙醇胺溶液（溶液B）。 </li><li>关闭盖紧锅盖，搅拌在80℃2小时。 </li><li>转让日Ë样品滴定容器中，在比例用乙醇和水分别洗涤反应小瓶几次，使乙醇/水的最终的80％溶液。使用自动滴定到终点的酸溶液滴定。记录端点。 </li><li>重复该过程三次，得到三点。 </li><li>坯料C:如果无机酸被怀疑存在于样本，称量接近100毫克生物油的成5毫升小瓶中，记录重量和添加旋叶片。 </li><li>添加0.5毫升DMSO中。 </li><li>加入2毫升三乙醇胺溶液（溶液B）。 </li><li>帽密封和搅拌在80℃进行2小时。 </li><li>将样品转移至滴定容器中，用乙醇和水分别洗涤反应瓶多次比例使乙醇/水的最终的80％溶液。使用自动滴定到终点的酸溶液滴定。记录端点。 </li><li>重复过程三次以获得三点。 </li></ol></li></ol> 4.计算<ol><li> 碱溶液的标准化 <ol><li>计算使用下面的公式的酸溶液（摩尔/升）的浓度。干碳酸钠以克的重量为w 1，纯度被写入为分数（ 即 ，99％是0.99），和端点处于毫升。 <img alt="式（1）" src="/files/ftp_upload/55165/55165eq1.jpg" /></li></ol></li><li> 使用公知的羰基的方法的验证 <ol><li>使用下列公式计算4BBA（摩尔/升）的样品中的浓度。该4BBA的以克的重量W 2，该4BBA纯度被写入为分数（ 即 ，99％是0.99），酸溶液（摩尔/升）的浓度为[酸]，三乙醇胺/羟胺•盐酸空白端点EP BA（三坯的平均值，以mL），并且端点是EP（以mL）。&lt;BR /&gt; <img alt="公式（2）" src="/files/ftp_upload/55165/55165eq2.jpg" /></li></ol></li><li> 生物油的分析 <ol><li>计算使用以下等式在生物油羰[CO]（毫摩尔/克生物油）的浓度。生物油的以克的重量为w 3，所述酸溶液（摩尔/升）的浓度为[酸]，三乙醇胺/羟胺•盐酸空白端点EP BA（三个坯料以mL的平均值） ，和端点是EP（以毫升）。 <img alt="公式3" src="/files/ftp_upload/55165/55165eq3.jpg" /></li></ol></li><li> 纠正酸 注:无机酸或有机酸与pKa值&lt;2的存在会引起人为的低羰基值由于与三乙醇胺的酸的反应。 <ol><li>如对此有怀疑，执行的部分3.2.6和3.4.8中详述的空白。生物油的样品中以克的重量是W 3，EP是样品的端点和EP，BA是三乙醇胺/羟胺空。 EP BB是空白B的终点，EP BC是空白C中使用的油空白C和重量（克）终点为W BC: <img alt="公式4" src="/files/ftp_upload/55165/55165eq4.jpg" /> 为主要包含乙酸生物油的样品，这是不必要的步骤。 </li></ol></li></ol>

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作者什么都没有透露。

代表滴定曲线示于图2。一个空白滴定，以及用于热解油样品滴定，被示出。此外，该滴定曲线（DPH / DV）的一次导数中示出，这允许容易识别滴定终点。关于图2中的插图表显示为热解油和空白滴定式三份的数据，以平均值和标准偏差。 （以mL）中所示的端点值在第4节用于计算所述热解油样中的总羰基含量（毫摩尔/克）。对于图2中所示的热解油滴定，生物油样品质量为0.1148克，酸的浓度为0.07032摩尔/升，坯终点是13.041毫升，并热解油终点是4.891毫升。这导致4.992毫摩尔/克生物油的羰基含量。 在方法开发过程，不干扰被视为对醋酸乙酯或cetic酸。我们已发现，加入的醇的引起干扰，但是它是依赖于链长度。这是因为，尚未确定，但与溶剂的醇的性质可以是相关的。值得一提的是，单糖都采用这种方法进行测定。该方法的选择性通过使用1-丁醇，1-戊醇，叔丁醇，2-丙醇，乙酸乙酯，乙酸，木糖和葡萄糖作为模型化合物，代表醇，酯，羧酸和碳水化合物的生物测试油。此方法已被用来可靠地分析至少20生热解生物油，新鲜和在80℃老化高达120小时。此外，一些加氢裂解生物油已被成功地分析。此方法以各种各样的生物油样品，具有高水平的准确性和可靠性的结合的适用性，可借此方法在以后的其他应用。例如，羰基含量可以使用在一个生物来代替粘度油老化测试。 在原来的方法，Faix 等。 8混合三乙醇胺和盐酸羟胺溶液，使原液。这导致三乙醇胺的形成•盐酸，这将导致测量误差。在该方法中，样品的滴定应立即以下肟化（搅拌2小时后）完成。如果滴定延迟下列肟化，三乙醇胺可以形成三乙醇胺•盐酸，这将导致在测量中的误差。 乙醇80％的溶液是没有必要的样品滴定容器的转移;仅需要80％的乙醇的最终体积。作为模型化合物，4-（苄氧基）苯甲醛（4-BBA）具有足够高的分子量约为使用相同量（约100毫克），为生物油样品。虽然我们建议使用4- BBA作为羰模型化合物，可以使用的其它化合物代替4- BBA的。最后，坯料B和C是不必要的，如果只有机酸存在于生物油样本。 如在引言中所讨论的，这里介绍的Faix方法比传统的羰基滴定法（尼古拉德斯方法）的许多优点。最近，尼古拉德斯和Faix滴定方法的比较表明，尼古拉德斯方法显著低估生物油9的羰基含量。此外，在2015年的实验室间研究的原始热解生物油进行，而这项研究既包括Faix和尼古拉德斯滴定法10。结果发现，这里介绍的Faix羰基法，尤其是可靠的，与所有参与实验室间的&lt;5％，相对标准偏差（RSD）变异。相比较而言，尼古拉德斯方法表明〜10％的RSD的实验室间的变异性。最后，虽然这种方法用于分析Ø开发˚F生热解生物油，它也被成功地用于在升级热解生物油羰定量。

而热解生物油是由大量的各种化合物和化学官能团，羰基的定量是特别重要的。羰基是公知的两个存储器1和处理2期间负责生物油的不稳定性。这里介绍的滴定法是一种简单的技术，它能够可靠地量化生物油的总羰基含量。只有醛和酮官能团使用这种方法量化;羧酸和内酯基团没有定量。 为生物油的分析，通过滴定羰基的量化历来使用尼古拉德斯3的方法来实现的。这种方法已在生物油文献4，5，6，7被广泛使用。这是一个简单的过程，其中羰基被转化为相应的肟（ 见图1）。释出的盐酸用吡啶到平衡强行完成反应。吡啶的共轭酸滴定用NaOH（碱滴定剂）的已知量。使用氢氧化钠的当量数是按化学计量当量存在于生物油羰的摩尔数。 所述尼古拉德斯方法，但是，有一些限制。它可以要求反应时间超过48小时，达到完成。这严重限制了样品通量。它利用吡啶，其是有毒的。的1〜2克样品重量是必需的。使用样品重量是依赖于羟胺盐酸的存在量和样品的羰基含量。如果所使用的样品重量的初始估计是不正确的，滴定必须重复。 Faix 等。 8开发已被修改h的方法ERE解决方法尼古拉德斯的问题。该反应在80℃进行2小时，从而增加样品通量。吡啶已被替换为三乙醇胺，它是一种毒性较小的化学物质。样本大小可以减小到100至150毫克。三乙醇胺消耗释放的盐酸，驱动反应完成和未消耗的三乙醇胺是直接滴定。羟胺的第二个滴定是不必要的。这些滴定方法的比较表明，尼古拉德斯方法显著低估生物油9的羰基含量。 此处所描述的方法已经从原来的方法8修改成更适用于热解生物油的分析。这种方法对原材料热解生物油的分析开发的，但它已被成功地应用到其它类型的生物衍生的油，包括加氢处理的生物油。阿迪tionally，这种方法已被用于同时监测老化和升级过程中羰基含量的变化。

<table><tbody><tr><td>Analytical balance</td><td></td><td></td><td>accurate to 0.1 mg</td></tr><tr><td>dry block heater with magnetic stirrer, or hot water bath with magnetic stirrer</td><td></td><td></td><td></td></tr><tr><td>Automatic titrator</td><td></td><td></td><td>We used a Metrohm Titrando 809 automatic titrator, though other equivalent systems are acceptable</td></tr><tr><td>Deionized water</td><td></td><td></td><td></td></tr><tr><td>Ethanol (reagent grade)</td><td></td><td></td><td>CAS # 64-17-5</td></tr><tr><td>Hydroxylamine hydrochloride&amp;nbsp;</td><td></td><td></td><td>CAS # 5470-11-1</td></tr><tr><td>Triethanolamine&amp;nbsp;</td><td></td><td></td><td>CAS #102-71-6</td></tr><tr><td>Hydrochloric acid (37%)&amp;nbsp;</td><td></td><td></td><td>CAS # 7647-01-0</td></tr><tr><td>Sodium Carbonate (primary standard)&amp;nbsp;</td><td>SigmaAldrich</td><td>223484</td><td></td></tr><tr><td>4-(benzyloxy)benzaldehyde&amp;nbsp;</td><td></td><td></td><td>CAS # 4397-53-9</td></tr><tr><td>Dimethyl sulfoxide</td><td></td><td></td><td>CAS # 67-68-5</td></tr><tr><td>5 mL glass Reacti-vials with solid lid and teflon spinvane</td><td>Thermoscientific</td><td>TS-13223</td><td></td></tr><tr><td>200 mL volumetric flask</td><td></td><td></td><td></td></tr><tr><td>Volumetric or mechanical pipettes</td><td></td><td></td><td></td></tr></tbody></table>

determination of carbonyl functional groups in bio-oils by potentiometric titration: the faix method

是已知的存在于生物油的羰基化合物是负责在贮存和升级过程中生物油属性更改。具体地，羰基引起粘度生物油的储存期间的增加（通常被称为"老化"）。因此，羰基含量以前已用作跟踪生物油的老化和缩合反应具有比粘度测量的变异较少的方法。此外，羰基还负责在生物油升级进程积炭。鉴于生物油羰基的重要性，它们的量化精确的分析方法可用于生物油社区非常重要的。长期以来被用于羰基含量在热解生物油的确定基于羰基肟化电位滴定方法。这里，我们提出的，其导致较少的反应时间的传统羰肟化的方法的改进，更小的样本大小，更高的精度，并且更ACC尿酸测定羰基。而传统的羰基肟化方法发生在室温下，这里提出的Faix方法时发生在升高的温度为80℃。

<html>一个典型的滴定曲线由一个单一端点的， 如图2。为原料的生物油样品，和一个空白滴定典型滴定，被示出。作为终点在于在滴定曲线的拐点;端点可以通过绘制滴定曲线的一阶导数（在右侧轴上，DPH / DV所示，在图2中）容易地识别。许多自动滴定系统具有计算滴定曲线，它有时被称为端点识别条件（ERC）的衍生物的软件。 <img alt="图1" src="/files/ftp_upload/55165/55165fig1.jpg" /> 图1:肟化反应。反应示意图表示的羰基化合物为相应的肟的转化。 尔斯/ ftp_upload / 55165 / 55165fig2.jpg"/&gt; 图2: 样品和空白滴定曲线。为原料的热解生物油代表滴定曲线，并一空白滴定。滴定曲线，DPH / DV的第一衍生物，还示出。 <a href="https://ecsource-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/55165/55165fig2large.jpg" target="_blank">请点击此处查看该图的放大版本。</a>

Watch this Scientific Journal Video about Determination of Carbonyl Functional Groups in Bio-oils by Potentiometric Titration: The Faix Method at JoVE.com

Determination of Carbonyl Functional Groups in Bio-oils by Potentiometric Titration: The Faix Method

Here we present a potentiometric titration technique for accurately quantifying carbonyl compounds in pyrolysis bio-oils.

该Faix方法:生物油羰基官能团通过电位滴定法测定

Carbonyl compounds present in bio-oils are known to be responsible for bio-oil property changes upon storage and during upgrading. Specifically, carbonyls ...

determination-carbonyl-functional-groups-bio-oils-potentiometric

Nanyang Technological University

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Education

JoVE Journal

JoVE Core

Organic Chemistry

Analytical Chemistry

Chemistry

Unit 1

Aldehydes and Ketones

Complexometric Titration, Precipitation Titration, and Gravimetry

SCIENTISTS IN ACTION

11.0K 次观看.  National Renewable Energy Laboratory. Here we present a potentiometric titration technique for accurately quantifying carbonyl compounds in pyrolysis bio-oils.

视频: Determination of Carbonyl Functional Groups in Bio-oils by Potentiometric Titration: The Faix Method

Identification of Fatty Acids in Bacillus cereus

The Bacillus species contain branched chain and unsaturated fatty acids (FAs) with diverse positions of the methyl branch (iso or anteiso) and of the double bond. Changes in FA composition play a crucial role in the adaptation of bacteria to their environment. These modifications entail a change in the ratio of iso versus anteiso branched FAs, and in the proportion of unsaturated FAs relative to saturated FAs, with double bonds created at specific positions. Precise identification of the FA profile is necessary to understand the adaptation mechanisms of Bacillus species.
Many of the FAs from Bacillus are not commercially available. The strategy proposed herein identifies FAs by combining information on the retention time (by calculation of the equivalent chain length (ECL)) with the mass spectra of three types of FA derivatives: fatty acid methyl esters (FAMEs), 4,4-dimethyl oxazoline derivatives (DMOX), and 3-pyridylcarbinyl ester (picolinyl). This method can identify the FAs without the need to purify the unknown FAs.
Comparing chromatographic profiles of FAME prepared from Bacillus cereus with a commercial mixture of standards allows for the identification of straight-chain saturated FAs, the calculation of the ECL, and hypotheses on the identity of the other FAs. FAMEs of branched saturated FAs, iso or anteiso, display a constant negative shift in the ECL, compared to linear saturated FAs with the same number of carbons. FAMEs of unsaturated FAs can be detected by the mass of their molecular ions, and result in a positive shift in the ECL compared to the corresponding saturated FAs.
The branching position of FAs and the double bond position of unsaturated FAs can be identified by the electron ionization mass spectra of picolinyl and DMOX derivatives, respectively. This approach identifies all the unknown saturated branched FAs, unsaturated straight-chain FAs and unsaturated branched FAs from the B. cereus extract.

Identification of Fatty Acids in Bacillus cereus

We propose a protocol to identify fatty acids without the need to purify them. It combines information on the retention times with the mass spectra of three types of fatty acid derivatives: fatty acid methyl esters (FAMEs), 4,4-dimethyl oxazoline derivatives (DMOX), and 3-pyridylcarbinyl esters (picolinyl).

脂肪酸鉴定<em&gt;蜡状芽孢杆菌</em

The Bacillus species contain branched chain and unsaturated fatty acids (FAs) with diverse positions of the methyl branch (iso or anteiso) and of the ...

科研

生物化学

A Toolkit to Enable Hydrocarbon Conversion in Aqueous Environments

This work puts forward a toolkit that enables the conversion of alkanes by Escherichia coli and presents a proof of principle of its applicability. The toolkit consists of multiple standard interchangeable parts (BioBricks)9 addressing the conversion of alkanes, regulation of gene expression and survival in toxic hydrocarbon-rich environments.
A three-step pathway for alkane degradation was implemented in E. coli to enable the conversion of medium- and long-chain alkanes to their respective alkanols, alkanals and ultimately alkanoic-acids. The latter were metabolized via the native &beta;-oxidation pathway. To facilitate the oxidation of medium-chain alkanes (C5-C13) and cycloalkanes (C5-C8), four genes (alkB2, rubA3, rubA4and rubB) of the alkane hydroxylase system from Gordonia sp. TF68,21 were transformed into E. coli. For the conversion of long-chain alkanes (C15-C36), theladA gene from Geobacillus thermodenitrificans was implemented. For the required further steps of the degradation process, ADH and ALDH (originating from G. thermodenitrificans) were introduced10,11. The activity was measured by resting cell assays. For each oxidative step, enzyme activity was observed.
To optimize the process efficiency, the expression was only induced under low glucose conditions: a substrate-regulated promoter, pCaiF, was used. pCaiF is present in E. coli K12 and regulates the expression of the genes involved in the degradation of non-glucose carbon sources.
The last part of the toolkit - targeting survival - was implemented using solvent tolerance genes, PhPFD&alpha; and &beta;, both from Pyrococcus horikoshii OT3. Organic solvents can induce cell stress and decreased survivability by negatively affecting protein folding. As chaperones, PhPFD&alpha; and &beta; improve the protein folding process e.g. under the presence of alkanes. The expression of these genes led to an improved hydrocarbon tolerance shown by an increased growth rate (up to 50%) in the presences of 10% n-hexane in the culture medium were observed.
Summarizing, the results indicate that the toolkit enables E. coli to convert and tolerate hydrocarbons in aqueous environments. As such, it represents an initial step towards a sustainable solution for oil-remediation using a synthetic biology approach.

A sustainable auto regulating bacterial system for the remediation of oil pollutions was designed using standard interchangeable DNA parts (BioBricks). An engineered E. coli strain was used to degrade alkanes via &beta;-oxidation in toxic aqueous environments. The respective enzymes from different species showed alkane degradation activity. Additionally, an increased tolerance to n-hexane was achieved by introducing genes from alkane-tolerant bacteria.

一个工具包，使水环境中的烃类转化

This work puts forward a toolkit that enables the conversion of alkanes by Escherichia coli and presents a proof of principle of its applicability. The ...

生物工程

Analyzing the Photo-oxidation of 2-propanol at Indoor Air Level Concentrations Using Field Asymmetric Ion Mobility Spectrometry

We demonstrate a versatile protocol to be used for determining the effectiveness of photocatalysts in degrading indoor air concentration (ppb) volatile organic carbons (VOCs), illustrating this with a titanium dioxide based catalyst, and the VOC 2-propanol. The protocol takes advantage of field asymmetric ion mobility spectroscopy (FAIMS), an analysis tool that is capable of continuously identifying and monitoring the concentration of VOCs such as 2-propanol and acetone at the ppb level. The continuous nature of FAIMS allows detailed kinetic analysis, and long-term reactions, offering a significant advantage over gas chromatography, a batch process traditionally used in air purification characterization. The use of FAIMS in photocatalytic air purification has only recently been used for the first time, and with the protocol illustrated here, the flexibility in allowing alternative VOCs and photocatalysts to be tested using comparable protocols offers a unique system to elucidate photocatalytic air purification reactions at low concentrations.

A protocol for determining the effectiveness of photocatalysts in degrading indoor air concentration (ppb) model volatile organic carbons such as 2-propanol is described.

用场不对称离子迁移光谱法分析 2-丙醇在室内空气浓度中的光氧化作用

We demonstrate a versatile protocol to be used for determining the effectiveness of photocatalysts in degrading indoor air concentration (ppb) volatile ...

化学

Original Experimental Approach for Assessing Transport Fuel Stability

The study of fuel oxidation stability is an important issue for the development of future fuels. Diesel and kerosene fuel systems have undergone several technological changes to fulfill environmental and economic requirements. These developments have resulted in increasingly severe operating conditions whose suitability for conventional and alternative fuels needs to be addressed. For example, fatty acid methyl esters (FAMEs) introduced as biodiesel are more prone to oxidation and may lead to deposit formation. Although several methods exist to evaluate fuel stability (induction period, peroxides, acids, and insolubles), no technique allows one to monitor the real-time oxidation mechanism and to measure the formation of oxidation intermediates that may lead to deposit formation. In this article, we developed an advanced oxidation procedure (AOP) based on two existing reactors. This procedure allows the simulation of different oxidation conditions and the monitoring of the oxidation progress by the means of macroscopic parameters, such as total acid number (TAN) and advanced analytical methods like gas chromatography coupled to mass spectrometry (GC-MS) and Fourier Transform Infrared - Attenuated Total Reflection (FTIR-ATR). We successfully applied AOP to gain an in-depth understanding of the oxidation kinetics of a model molecule (methyl oleate) and commercial diesel and biodiesel fuels. These developments represent a key strategy for fuel quality monitoring during logistics and on-board utilization.

Oxidation stability of transport fuels has become a concern for future fuel development. This work presents an original methodology developed by IFP Energies Nouvelles for assessing fuel stability using two different reactors. This methodology was successfully applied to gain an in-depth understanding of the oxidation kinetics and pathways of model molecules and commercial fuels.

评定运输燃料的稳定性原始实验方法

The study of fuel oxidation stability is an important issue for the development of future fuels. Diesel and kerosene fuel systems have undergone several ...

Using Capillary Electrophoresis to Quantify Organic Acids from Plant Tissue: A Test Case Examining Coffea arabica Seeds

Carboxylic acids are organic acids containing one or more terminal carboxyl (COOH) functional groups. Short chain carboxylic acids (SCCAs; carboxylic acids containing three to six carbons), such as malate and citrate, are critical to the proper functioning of many biological systems, where they function in cellular respiration and can serve as indicators of cell health. In foods, organic acid content can have significant impact on taste, with increased SCCA levels resulting in a sour or &#34;acid&#34; taste. Because of this, methods for the rapid analysis of organic acid levels are of particular interest to the food and beverage industries. Unfortunately, however, most methods used for SCCA quantification are dependent on time-consuming protocols requiring the derivatization of samples with hazardous reagents, followed by costly chromatographic and/or mass spectrometric analyses. This method details an alternate method for the detection and quantification of organic acids from plant material and food samples using free zonal capillary electrophoresis (CZE), sometimes simply referred to as capillary electrophoresis (CE). CZE provides a cost-effective method for measuring SCCAs with a low limit of detection (0.005 mg/ml). This article details the extraction and quantification of SCCAs from plant samples. While the method provided focuses on measurement of SCCAs from coffee beans, the method provided can be applied to multiple plant-based food materials.

Using Capillary Electrophoresis to Quantify Organic Acids from Plant Tissue: A Test Case Examining Coffea arabica Seeds

This article presents a method for the detection and quantification of organic acids from plant material using free zonal capillary electrophoresis. An example of the potential application of this method, determining the effects of a secondary fermentation on organic acid levels in coffee seeds, is provided.

利用毛细管电泳从植物组织量化有机酸:一个测试用例检查<em&gt;小粒种咖啡</em&gt;种子

Carboxylic acids are organic acids containing one or more terminal carboxyl (COOH) functional groups. Short chain carboxylic acids (SCCAs; carboxylic ...

Extraction of Lignin with High &#946;-O-4 Content by Mild Ethanol Extraction and Its Effect on the Depolymerization Yield

Lignin valorization strategies are a key factor for achieving more economically competitive biorefineries based on lignocellulosic biomass. Most of the emerging elegant procedures to obtain specific aromatic products rely on the lignin substrate having a high content of the readily cleavable &#946;-O-4 linkage as present in the native lignin structure. This provides a miss-match with typical technical lignins that are highly degraded and therefore are low in &#946;-O-4 linkages. Therefore, the extraction yields, and the quality of the obtained lignin are of utmost importance to access new lignin valorization pathways. In this manuscript, a simple protocol is presented to obtain lignins with high &#946;-O-4 content by relatively mild ethanol extraction that can be applied to different lignocellulose sources. Furthermore, analysis procedures to determine the quality of the lignins are presented together with a depolymerization protocol that yields specific phenolic 2-arylmethyl-1,3-dioxolanes, which can be used to evaluate the obtained lignins. The presented results demonstrate the link between lignin quality and potential for the lignins to be depolymerized into specific monomeric aromatic chemicals. Overall, the extraction and depolymerization demonstrates a trade-off between the lignin extraction yield and the retention of the native aryl-ether structure and thus the potential of the lignin to be used as the substrate for the production of chemicals for higher-value applications.

Here, we present a protocol to perform ethanol extraction of lignin from several biomass sources. The effect of the extraction conditions on the lignin yield and &#946;-O-4 content are presented. Selective depolymerization is performed on the obtained lignins to obtain high aromatic monomer products.

轻度乙醇萃取高β-o-4 的木质素及其对解聚产率的影响

Lignin valorization strategies are a key factor for achieving more economically competitive biorefineries based on lignocellulosic biomass. Most of the ...

Characterizing Lewis Pairs Using Titration Coupled with In Situ Infrared Spectroscopy

Lewis acid-activation of carbonyl-containing substrates is a fundamental basis for facilitating transformations in organic chemistry. Historically, characterization of these interactions has been limited to models equivalent to stoichiometric reactions. Here, we report a method utilizing in situ infrared spectroscopy to probe the solution interactions between Lewis acids and carbonyls under synthetically relevant conditions. Using this method, we were able to identify 1:1 complexation between GaCl3 and acetone and a highly ligated complex for FeCl3 and acetone. The impact of this technique on mechanistic understanding is illustrated by application to the mechanism of Lewis acid-mediated carbonyl-olefin metathesis in which we were able to observe competitive binding interactions between substrate carbonyl and product carbonyl with the catalyst.

Here, we present a method for the observation of solution interactions between Lewis acids and bases by employing in situ infrared spectroscopy as a detector for titration under synthetically relevant conditions. By examining solution interactions, this method represents a complement to X-ray crystallography, and provides an alternative to NMR spectroscopy.

使用滴定与原位红外光谱相结合，对刘易斯对进行特征化

Lewis acid-activation of carbonyl-containing substrates is a fundamental basis for facilitating transformations in organic chemistry. Historically, ...

Fast Pyrolysis of Biomass Residues in a Twin-screw Mixing Reactor

Fast pyrolysis is being increasingly applied in commercial plants worldwide. They run exclusively on woody biomass, which has favorable properties for conversion with fast pyrolysis. In order to increase the synergies of food production and the energetic and/or material use of biomass, it is desirable to utilize residues from agricultural production, e.g., straw. The presented method is suitable for converting such a material on an industrial scale. The main features are presented and an example of mass balances from the conversion of several biomass residues is given. After conversion, fractionated condensation is applied in order to retrieve two condensates &#8212; an organic-rich and an aqueous-rich one. This design prevents the production of fast pyrolysis bio-oil that exhibits phase separation. A two phase bio-oil is to be expected because of the typically high ash content of straw biomass, which promotes the production of water of reaction during conversion.
Both fractionated condensation and the use of biomass with high ash content demand a careful approach for establishing balances. Not all kind of balances are both meaningful and comparable to other results from the literature. Different balancing methods are presented, and the information that can be derived from them is discussed.

A procedure for thermochemical conversion of biomass residues is presented that aims at maximizing the yield of liquid products (fast pyrolysis). It is based on a technology proven on an industrial scale and especially suitable for treating a straw type of biomass.

在双螺杆混炼反应器生物残渣快速热解

Fast pyrolysis is being increasingly applied in commercial plants worldwide. They run exclusively on woody biomass, which has favorable properties for ...

Fractionation of Lignocellulosic Biomass using the OrganoCat Process

The shift from a petroleum-based to a more sustainable and bio-based economy requires the development of new refinery concepts to maintain the supply of raw materials and energy. For these novel and sustainable biorefinery concepts, it is important to use catalysts and solvents that are aligned with the principles of Green Chemistry. Therefore, the implementation of biogenic alternatives can be a promising solution. The lignocellulose pretreatment and fractionation process presented herein-OrganoCat-is an integrated fractionation of lignocellulose into its main components using biogenic acids such as 2,5-furandicarboxylic acid as catalyst. Hemicelluloses and other non-cellulosic polysaccharides are selectively depolymerized by the diluted acid and dissolved, while the crystalline cellulose remains in the solid pulp. In the presence of a second organic phase consisting of biogenic 2-methyltetrahydrofuran, disentangled lignin is extracted in situ. The process allows for the efficient fractionation of the three main components-lignin, cellulose, and non-cellulosic sugars. This helps to focus on the quality of the lignin, the improvement of enzymatic hydrolysis of the cellulose-enriched pulp, and the mild non-cellulosic sugar extraction with low degradation.

OrganoCat is a method for the pretreatment and fractionation of lignocellulose under mild conditions into lignin, fermentable sugars, and cellulose pulp. In a biogenic, biphasic solvent system of water and 2-methyltetrahydrofuran with 2,5-furancarboxylic acid as catalyst, the OrganoCat products are separated in situ for straightforward product recovery.

使用有机催化工艺分馏木质纤维素生物质

The shift from a petroleum-based to a more sustainable and bio-based economy requires the development of new refinery concepts to maintain the supply of ...

Ultrafast Lignin Extraction from Unusual Mediterranean Lignocellulosic Residues

Pretreatment is still the most expensive step in lignocellulosic biorefinery processes. It must be made cost-effective by minimizing chemical requirements as well as power and heat consumption and by using environment-friendly solvents. Deep eutectic solvents (DESs) are key, green, and low-cost solvents in sustainable biorefineries. They are transparent mixtures characterized by low freezing points resulting from at least one hydrogen bond donor and one hydrogen bond acceptor. Although DESs are promising solvents, it is necessary to combine them with an economic heating technology, such as microwave irradiation, for competitive profitability. Microwave irradiation is a promising strategy to shorten the heating time and boost fractionation because it can rapidly attain the appropriate temperature. The aim of this study was to develop a one-step, rapid method for biomass fractionation and lignin extraction using a low-cost and biodegradable solvent. 
In this study, a microwave-assisted DES pretreatment was conducted for 60 s at 800 W, using three kinds of DESs. The DES mixtures were facilely prepared from choline chloride (ChCl) and three hydrogen-bond donors (HBDs): a monocarboxylic acid (lactic acid), a dicarboxylic acid (oxalic acid), and urea. This pretreatment was used for biomass fractionation and lignin recovery from marine residues (Posidonia leaves and aegagropile), agri-food byproducts (almond shells and olive pomace), forest residues (pinecones), and perennial lignocellulosic grasses (Stipa tenacissima). Further analyses were conducted to determine the yield, purity, and molecular weight distribution of the recovered lignin. In addition, the effect of DESs on the chemical functional groups in the extracted lignin was determined by Fourier-transform infrared (FTIR) spectroscopy. The results indicate that the ChCl-oxalic acid mixture affords the highest lignin purity and the lowest yield. The present study demonstrates that the DES-microwave process is an ultrafast, efficient, and cost-competitive technology for lignocellulosic biomass fractionation.

Deep eutectic solvent-based, microwave-assisted pretreatment is a green, fast, and efficient process for lignocellulosic fractionation and high-purity lignin recovery.

超高速利格宁从不寻常的地中海木质细胞残留物中提取

Pretreatment is still the most expensive step in lignocellulosic biorefinery processes. It must be made cost-effective by minimizing chemical requirements ...

该Faix方法:生物油羰基官能团通过电位滴定法测定

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