脂肪酶水解油脂

本文介绍了脂肪酶水解油脂制脂肪酸和甘油的新技术，评述解脂用脂肪酶的酶种选择、工艺要点及特色以及脂肪酶水解油脂的国内外进展，并对这项生物酶工程技术在我国应用的前景提出见解。     

固定化脂肪酶催化天然油脂水解和甘油解

概述了国外用于工业化生产的效水解、甘油解油脂的微生物脂肪酶和固定化酶的各种载体，讨论了固定化脂肪酸论油脂水解和甘油解的影响因素，介绍了三种固定脂肪酶生物反应器。     

油脂连续无催化水解甘油皂化值的控制

本文分析了油脂连续高压无催化水解法生产的甘油,在其回收过程中,对其皂化值的影响因素及控制方法进行了分析。     

油脂高压连续水解工艺

脂肪酸已成为一种重要的化工生产原料。本文介绍了油脂高压连续水解工艺工业化制备脂肪酸技术,本人对油脂水解原理及水解工艺进行了研究和消化,希望能对脂肪酸技术工作者有参考作用。     

生物法油脂水解新工艺

1前言脂肪酸和甘油均是重要的化工原料，应用范围十分广阔。为了获得这两类产品．在我国目前工业上油脂水解通常采取两种工艺：其一是常压皂化法，但工艺繁琐，消耗大量的酸碱，产品收率低Z其二是高压水解法，此法对设备条件要求较苛刻，设备投资费用大，能耗高，中小型企业不容易实现。本文介绍的是采用脂肪酶的生物化学方法对油脂进行水解的新工艺，其要点是开发利用微生物特有的强分解能力及促进反应专一的特点。分解反应式如下：本法反应历程短，且脂肪酶在我国已商品化，这就为改变传统的油脂水解工艺创造了有利的条件。2实验部分2．1…     

蓖麻油水解皂化制备甘油工艺优化

开展了蓖麻油碱水解制备甘油的方法研究,通过单因素和正交实验得出其最佳工艺条件是：蓖麻油与NaOH的质量比为3：5,皂化时间为60min,皂化温度为120℃。甘油含量可稳定在0．40g／mL左右。     

国外油脂水解工艺发展概况及趋势

油脂水解是油化产品开发的重要一环,本文介绍了近几年国外油脂水解工艺的发展概况及趋势,以供国内有关部门参考。     

Glycerolysis of Crude Methyl Esters with Crude Glycerol from Biodiesel Production

Glycerolysis of crude fatty acid methyl esters (FAME) with crude glycerol derived from biodiesel production was performed. The reaction was accomplished at temperatures ranging between 160 and 200 °C and molar ratios of FAME to glycerol ranging between 1.5 and 3.0. Increasing the temperature improved the formation rate of monoglycerides (MG) and diglycerides (DG). However, increasing both the temperature and the molar ratio of glycerol to FAME diminished the formation of MG. Best results (43 % MG and 26 % DG in 10 min) were obtained at 200 °C using the lowest concentration of glycerol. The effects of soap and NaOH present in crude glycerol were controlled by carrying out the reaction with pure glycerol. In comparison with NaOH-catalyzed reactions, soap-catalyzed reactions resulted in a slower formation rate of products. However, soap-catalyzed reactions were less prone to secondary reactions, affording maximum yields of MG and DG, which were higher than those obtained with NaOH-catalyzed reactions at 180 and 200 °C.     

Maleinization of Soybean Oil Glycerides Obtained from Biodiesel-Derived Crude Glycerol

Glycerides obtained from the glycerolysis of soybean oil with crude glycerol were acylated with maleic anhydride at 80–100 °C. Both uncatalyzed and catalyzed reactions with 2-methylimidazole (2-MI) were evaluated. Formation of maleated glycerides was confirmed by ¹H-NMR and FTIR analyses. Consumption of maleic anhydride as a function of time was followed by acid value titration. High conversion (ca. 95 %) of hydroxyl groups was obtained at 90 °C in 60 min without catalyst. Under these conditions, a product with 1.9 maleate moieties per glyceride molecule was obtained. Catalyzed reactions afforded lower conversions of hydroxyl groups and lower maleate yields compared to uncatalyzed reactions.     

Acrolein Production from Crude Glycerol in Sub- and Super-Critical Water

To better understand the effects of water properties on the reaction characteristics of acrolein production from glycerol, dehydration of refined glycerol and crude glycerol was comparatively conducted in both sub- and super-critical water states, and the effect of changing water properties was studied to optimize the reaction conditions. The effects of reaction temperature, pressure, residence time, water/glycerol ratio, and catalyst concentration on the yields and distribution of chemical products were also examined. Acrolein yield >80 mol% from both refined glycerol and crude glycerol can be achieved by controlling water properties in the sub-critical water state with the addition of sulfuric acid as a homogeneous catalyst and the formation of undesired acetaldehyde and propionaldehyde can be greatly restrained. These results provide valuable information for the production of value-added chemicals from crude glycerol.     

Elevating Phospholipids Production Yarrowia lipolytica from Crude Glycerol

Phospholipids (PLs) are a class of lipids with many proven biological functions. They are commonly used in lipid replacement therapy to enrich cell membranes damaged in chronic neurodegenerative diseases, cancer, or aging processes. Due to their amphipathic nature, PLs have been widely used in food, cosmetic, and pharmaceutical products as natural emulsifiers and components of liposomes. In Yarrowia lipolytica, PLs are synthesized through a similar pathway like in higher eukaryotes. However, PL biosynthesis in this yeast is still poorly understood. The key intermediate in this pathway is phosphatidic acid, which in Y. lipolytica is mostly directed to the production of triacylglycerols and, in a lower amount, to PL. This study aimed to deliver a strain with improved PL production, with a particular emphasis on increased biosynthesis of phosphatidylcholine (PC). Several genetic modifications were performed: overexpression of genes from PL biosynthesis pathways as well as the deletion of genes responsible for PL degradation. The best performing strain (overexpressing CDP-diacylglycerol synthase (CDS) and phospholipid methyltransferase (OPI3)) reached 360% of PL improvement compared to the wild-type strain in glucose-based medium. With the substitution of glucose by glycerol, a preferred carbon source by Y. lipolytica, an almost 280% improvement of PL was obtained by transformant overexpressing CDS, OPI3, diacylglycerol kinase (DGK1), and glycerol kinase (GUT1) in comparison to the wild-type strain. To further increase the amount of PL, the optimization of culture conditions, followed by the upscaling to a 2 L bioreactor, were performed. Crude glycerol, being a cheap and renewable substrate, was used to reduce the costs of PL production. In this process 653.7 mg/L of PL, including 352.6 mg/L of PC, was obtained. This study proved that Y. lipolytica is an excellent potential producer of phospholipids, especially from waste substrates.     

Synthesis of Edible Vegetable Oils Enriched with Healthy 1,3-Diglycerides Using Crude Glycerol and Homogeneous/Heterogeneous Catalysis

Commercial edible vegetable oils in which part of their triglycerides are substituted with 1,3-diglycerides are healthier for human consumption than the original oils. This is because the human metabolism of 1,3-diglycerides is believed to occur through a distinct pathway with less probability of being deposited as fat in the body tissues. To obtain these enriched oils, conversion of triglycerides into diglycerides is carried out by glycerolysis using commercial crude glycerol containing dissolved alkali cations that homogeneously catalyze the reaction. The addition of a food production-compatible MgO as a supplementary solid basic catalyst, shortens the reaction time by half due to a combination of homogeneous and heterogeneous catalysis processes. In either homogeneously or homogeneous-heterogeneously catalyzed glycerolysis, the increase of the reaction temperature in the range of 453–493 K increases the final 1,3-diglyceride content. Furthermore, in both glycerolysis processes the triglyceride content can be decreased in more than 60% with the consequent increase of total diglycerides to 50%, 70% of which are the 1,3-isomers. The glycerolysis reaction proceeds without altering the fatty acid distribution of the original oils.     

生物柴油副产物甘油的高附加值利用

生物柴油的生产过程中都会产生副产物甘油,随着生物柴油的规模化发展,副产物甘油的合理利用成为生物柴油产业发展的关键问题之一. 粗甘油的有效再利用有利于降低生物柴油的生产成本和解决环境污染问题. 粗甘油可以通过各种工艺路线转化为1,3-丙二醇、环氧氯丙烷、乳酸、聚羟基脂肪酸酯、氢、二羟基丙酮和1,2-丙二醇等具有市场前景的高附加值产品. 目前技术比较成熟并进入产业化阶段的粗甘油利用工艺路线是生物法生产1,3-丙二醇和化学法生产环氧氯丙烷,其他工艺路线多数还处在实验室研究阶段. 本文以粗甘油综合利用为中心对目前研究进展和产业现状进行了综述.     

生物柴油副产粗甘油的精制工艺研究

对生物柴油副产物粗甘油的分离精制工艺进行了研究。采用减压蒸馏结合活性炭吸附脱色的方法对粗甘油进行了精制提纯,并对操作条件进行了优化,同时,利用过程模拟软件AspenPlus进行了模拟计算,实验结果和计算结果吻合。实验所得的甘油产品的纯度为99.5%,甘油收率为91.8%,原料中的甲醇回收率为96.0%,纯度为99.5%。     

直接测汞仪测定粗甘油中微量汞

利用热解析冷原子吸收光谱汞直接测量法对粗甘油中微量汞含量进行检测,结果表明:检出限0.004 7μg/kg;相对标准偏差1.7%;加标回收率为99.9%~103.5%,该方法具有良好的精密度与准确度,适用于粗甘油中微量汞的测定。     

碘化铯催化二氧化碳与甘油合成甘油碳酸酯

以不同碱金属(铵)卤化物为催化剂,考察了其在二氧化碳与甘油合成甘油碳酸酯反应中的活性。采用环氧丙烷为溶剂及耦合剂,极大提高了反应的转化率。实验结果发现碘化物具有较好的催化活性。以碘化铯为催化剂,考察了反应温度、反应时间、反应压力、反应物摩尔比和催化剂用量对反应结果的影响。在最佳反应条件下(环氧丙烷0.3 mol,甘油0.1 mol,反应温度120℃,反应时间1.5 h,反应压力3.0 MPa,催化剂用量0.15 g),甘油的转化率为86.5%,甘油碳酸酯的产率为81.6%。     

微生物转化粗甘油制备高附加值产品的研究进展

随着生物柴油产业的发展,其主要副产物粗甘油的产量也逐年增加.大量粗甘油的产生不仅给环境造成了污染,也使精制甘油的市场价格大幅度下降.甘油是一种稳定的多功能化合物,可用作精细化工合成的基本原料.利用微生物转化甘油生产各种生物基化学品,因其具有绿色环保、可持续发展等特点,越来越受到人们的重视.本文简单介绍了甘油经微生物发酵...