Purification of Crude Glycerol from Waste Cooking Oil Based Biodiesel Production by Orthogonal Test Method

Purification of original crude glycerol obtained from biodiesel production was conducted in a laboratory scale equipment by means of a combined chemical and physical treatment method based upon repeated cycles of acidification of liquid phase to the desired pH value by using 5.85% H3PO4 solution for pH value adjustment, and the mixture was kept at 70 ℃ for 60 rain to make phase separation for obtaining a glycerol-rich middle phase. The yield of crude glycerol reached 81.2%. Subsequently, upon reaction of the obtained glycerol phase with 0.03% of sodium oxalate at 80 ℃ for 30 min the impurity removal rate was equal to 19.8%. The fraction boiling between 164 ℃ and 200 ℃ was collected by vacuum distil- lation followed by decolorization with 2% of active carbon at 80 ℃ for two times to yield the product glycerol with an ac- ceptable purity of 98.10%.

Biodiesel Production by Enzymatic Catalysis Process Using Two Analytical Ways： Gas Chromatography and Total Glycerol Determination

Currently, biodiesel is presented as one of the best alternatives for gradually replacing the use of fossil fuels, but it has some factors that make it economically impractical if it does not have a government support. For this reason, research efforts focused on this area have been responsible for optimizing the process of biodiesel production by different catalytic routes to achieve greater efficiency at a lower cost. In this case, the biggest problem has been the high cost generated by an investigation, which in many occasions is the main factor to decide if an investigation could be carried out. Trying to reduce these costs, in the current study, we are using a technique of glycerol quantification by volumetric methods and comparing obtained results with the chromatographic method, which is conventionally used and comparatively much more expensive. Biodiesel employee was obtained by an enzymatic catalysis process varying one of three process variables：oil：alcohol molar ratio, temperature and proportion of catalyst. The numerical differences obtained between the two quantification methods generated relative errors lower than 10%, resulting in some occasions lower than 1%. By gas chromatography analysis the best yield was obtained at the same conditions of the volumetric method, a temperature of 45 ℃, an oil：alcohol ratio 1：4 and 8 wt.% of catalyst, but a yield of 95.5% and 97.1%, respectively. Due to the high precision of gas chromatography, this method is used to carry out a surface response analysis obtaining as ideal operating conditions a temperature of 43.5 ℃, 8.9 wt.%. of catalyst and an oil：alcohol ratio 1：4.

Economic Analysis of Biodiesel and Glycerol Carbonate Production Plant by Glycerolysis

Techno-economic analysis of an indirect use of carbon dioxide within the route of glycerolysis of glycerol with urea is investigated. The results show that the net present value of the biodiesel-glycerol carbonate production by glycerolysis is higher than the biodiesel-glycerol carbonate production by direct carboxylationat at the end of the 12-year operation with similar capacities. The stochastic model has predicted that using glycerolysis route for the synthesis of glycerol carbonate production might increase the probability of getting positive net present value by about 15%.

高分散固体碱高效催化制备无甘油生物柴油

为实现无甘油生物柴油的高效制备,以共沉淀法制备的镁铝水滑石为载体,K_(2)CO_(3)溶液为浸渍液,通过等体积浸渍法制备高分散负载型固体碱催化剂,考察水滑石制备过程中金属盐种类以及物质的量比对其催化三组分(菜籽油、乙酸甲酯和甲醇)制备无甘油生物柴油性能的影响,并利用FTIR、XRD、TG、CO_(2)-TPD、BET、SEM技术对催化剂进行表征。结果表明:以MgCl_(2)和AlCl3为金属盐、镁铝物质的量比3∶1、K_(2)CO_(3)浓度2.0mol/L、焙烧温度500℃条件下制备得到的固体碱为催化剂,在油酯醇物质的量比1∶1∶10、催化剂用量10%、反应温度60℃、反应时间15min条件下,生物柴油的产率可达98%,产品性能指标均符合欧盟标准。催化剂表征发现以氯盐为金属盐制备的水滑石比表面积大,孔道结构丰富,暴露的碱性中心位点数目多。综上,金属盐种类对水滑石结构会造成影响,以MgCl_(2)和AlCl_(3)为金属盐制备的高分散负载型固体碱催化剂可高效催化油脂酯交换反应制备无甘油生物柴油。

餐饮废油生物柴油中甘油和硫含量的同步优化

为提高餐饮废油生物柴油的品质,降低其甘油和硫含量,分析了离心、静置、水洗-旋蒸3种方法的脱甘油效果,以及氧化、吸附(活性炭作吸附剂)2种方法的脱硫效果,并对甘油和硫含量进行同步优化研究。结果表明:在3种脱甘油方法中,水洗-旋蒸的脱甘油效果最好;氧化脱硫在将硫化物脱除的同时会导致生物柴油的损失,并降低生物柴油的氧化稳定性,与静置和超声氧化脱硫相比,搅拌氧化脱硫的效果较好,脱硫率和生物柴油损失率分别为28.5%和2.0%;在活性炭用量为2%时,脱硫率较高,为23.8%;水洗-旋蒸可以有效地对生物柴油中甘油和硫同时脱除,脱除后的硫、甘油单酯、游离甘油、总甘油含量分别为9.31 mg/kg、0.182%、0.008%、0.054%,脱除率分别达到11.9%、64.3%、78.9%和68.4%,符合GB 25199—2017附录C中BD100生物柴油标准要求。因此,实际生产中可以采用水洗-旋蒸的方法对生物柴油中的甘油和硫进行同步脱除。

Sustainable value-added C3 chemicals from glycerol transformations:A mini review for heterogeneous catalytic processes

It is of importance to convert glycerol,the primary by-product from biodiesel manufacturing,to various valuable C3 chemicals,such as acrolein via dehydration,lactic acid,1,3-dihydroxyacetone via oxidation,and 1,3-propanediol,allyl alcohol via hydrogenolysis.As compared to petroleum-based resources,C3 chemicals from glycerol provide a benign,sustainable and atomically economic feature.Extensive heterogeneous catalysts have been designed,prepared and tested for these transformations.In recent five years,great progress,including high yields to target products over appropriate catalysts,insight into reaction mechanism and network,has been achieved.The present review systematically covers recent research progress on sustainable C3 chemical production from catalytic glycerol transformations.We hope that it will benefit future research on transformations of glycerol as well as other polyols.

Biodiesel Production from Waste Edible Oils and Grease Containing Free Fatty Acids

Till now, most part of the biodiesel is produced from the refined vegetable oils using methanol as feedstock in the presence of an alkali catalyst. However, large amount of waste edible oils and grease are available. The difficulty with alkali-catalyzed esterification of these oils is that they often contain large amount of free fatty acids （FFA）, polymers and decomposition products. These free fatty acids can quickly react with the alkali catalyst to produce soaps that inhibit the separation of the ester and glycerine. An esterification and transesterification process is developed to convert the high FFA oil to its monoesters, The first step, the acidcatalyzed esterification with glycerine and these FFA reduces the FFA content of the oil and grease to less than 3%, and then an azeotropic distillation solvent is used to remove the water. The major factors affecting the conversion efficiency of the process such as glycerol to free fatty acid molar ratio, catalyst amount, reaction temperature and reaction duration are analyzed, The second step, alkali-catalyzed transesterificatiou process converts the products of the first step to its monoesters and glycerol, and then the glycerol is recycled for utilization in the first step. Technical indicators of the biodiesel product can meet the ASTM 6751 standard.

Optimization of Biosurfactant Production from Glycerol by Pseudomonas Aeruginosa EQ 109 Using Factorial Design 2^3

One possible application for the excess of glycerol, which is an exceeding byproduct in biodiesel industry, was used as carbon and energy sources for bioproducts synthesis. This work aims to evaluate biosurfactant production from glycerol by Pseudomonas aeruginosa EQ 109 isolated from crude oil-contaminated soil. Factorial design 2^3 was utilized to optimize the amount of biosurfactant produced, by using pH （A）, initial biomass concentration （B）, and initial glycerol concentration （C） as independent factors. The experiments were carried out in flasks containing 100 mL of mineral medium. Biosurfactant production was monitored by increase of the emulsification of aviation kerosene （E24） and surface tension reduction （STr）. The results have shown that, at pH = 7.0, in order to increase E24, variables as B and C are the most influential, leading to a maximum value of E24 = 79%, as well as for an increase of GC （GCmax = 49%）. STR was the variable with the best correlation factor for the proposed linear model （R2=0.96） and its maximum value was 48%. Xfwas not significant to the model, although it was influenced by pH and C, with C = 40g/L （Xfmax = 4.56 g/L）.

Production of glycerol carbonate via reactive distillation and extractive distillation: An experimental study

A process for the production of glycerol carbonate(GC) is proposed with the transesterification of glycerol(GL)and dimethyl carbonate(DMC) with CaO as catalyst by reactive distillation and extractive distillation. The performance of solvents in separating DMC-methanol azeotrope and the effects of operation parameters on the reactive distillation process are investigated experimentally. The results indicate that both the GL conversion and GC yield increase with the DMC/GL molar ratio, reflux ratio, final temperature of tower bottom, and CaO/GL molar ratio and decrease as the recycle number of CaO increases. The calcium concentration in the residual reaction mixture also decreases remarkably as the DMC/GL molar ratio increases. At DMC/GL molar ratio 4.0, reflux ratio 1.0, final temperature of tower bottom 358 K, and CaO/GL molar ratio 0.05, both the GL conversion and GC yield can reach above 99.0%, and the mass concentration of calcium in the product is less than 0.08%.

Utilization of Crude Glycerol by Yarrowia lipolytica IMUFRJ 50678 in Bioproduct Production

Transesterification is the most common production process for biodiesel. From this reaction, a glycerin phase is produced that is impure, thus lowering market value. However, because it is rich in carbon, it is an alternative for generating bioproducts with a higher added value through bioconversion by microorganisms. The aim of this study was to screen parameters, such as pH （4, 5, 6, 7 and 8） and the initial glycerol concentration at 30 ± ℃ with agitation at 150 rpm for bioemulsifier and lipid synthesis in a submerged medium by Yarrowia lipolytica IMUFRJ 50678 from crude glycerin. The best conditions for bioemulsifier production were 30 ± ℃ at pH： 6 with 50 g/L of initial substrate, which produced 2.7 g/L of lipids, from which the optimum 300.5 mg/L of triglycerides was produced over 48 h of microorganism growth.

Synthesis and Characterization of Bio-Glycerol from Cameroon Palm Kernel Seed Oil

Bio-glycerol was synthesized from Cameroon palm kernel oil (PKO) through the transesterification procedure. Palm kernel oil extracted from palm kernel seeds using mechanical expression and solvent extraction was purified and characterized by physico-chemical methods and used in the transesterification process to give biodiesel and bio-glycerol. The biodiesel was purified and characterized as reported in previous articles. Our focus in this article is on glycerol, an important by-product of the transesterification process which has potential pharmaceutical, cosmetic and engineering applications. The bio-glycerol was purified by acidification and the purified glycerol was subjected to physical and chemical characterization. The specific gravity of glycerol was obtained as 1.2 kg/L, viscosity at 40&degC gave 1500 cSt and 500 cSt at 100&degC;pH was 7.4;the flash point was 160&degC, and the ASTM color was 2.0 before purification and zero after purification. The sulfur content was 0.016%w/v. This sulfur content is low thus posing no environment threat. The chemical composition of the synthesized bio-glycerol determined using IR spectroscopy and gas chromatography-mass spectrometry (GC-MS) confirmed the known chemical structure of glycerol. The purification and analysis of bio-glycerol is important as it can find applications in the pharmaceutical, cosmetic and food industries inter alia.

Ca掺杂Mg/Al-LDO催化甘油制备碳酸甘油酯

通过共沉淀法制备了钙镁铝类水滑石(Ca/Mg/Al-LDH),并在高温(350~800℃)下煅烧4h得到焙烧态类水滑石催化剂Ca/Mg/Al-LDO,用于催化甘油与碳酸二甲酯(DMC)酯交换反应制备高附加值的碳酸甘油酯(GC)。采用N2吸附-脱附、X射线衍射、扫描电子显微镜和能谱元素分析、红外光谱等对催化剂进行表征分析。探究了催化剂Ca掺杂、煅烧温度及反应条件对反应活性的影响。结果表明,当催化剂中Ca/Mg/Al物质的量比为2∶1∶1,煅烧温度为650℃时,催化剂表现出最好的催化性能。在催化剂用量3%、n(DMC)∶n(甘油)=3、温度75℃、时间为90 min条件下,甘油转化率可达98.3%,GC收率可达96.2%。回收循环实验表明,催化剂在重复使用5次后仍能保持91.9%的甘油转化率和90.5%的GC收率,稳定性优异。

生物柴油副产物甘油精制新法

我国甘油一直供不应求,尤其是高纯度（99.5%）甘油几乎全部依靠进口.对生物副产物甘油的精制进行了研究.生物柴油反应下层液,经调pH为弱酸性（4.5～5.5）,离心分离,蒸馏去除甲醇得粗甘油;粗甘油再经活性炭脱色后以一定流速经过大孔强碱树脂和大孔弱酸树脂进行离子交换去除其中的阴阳离子,再减压蒸馏即可得无色透明、黏稠、纯度为99.6%的精制甘油.

棉籽油甲酯化联产生物柴油和甘油

介绍了在KOH催化剂作用下棉籽油与甲醇反应生成棉籽油甲酯即生物柴油的研究工作。用精棉籽油和毛棉籽油为原料 ,考察酯交换反应条件如醇油比、催化剂用量、反应温度、反应时间对棉籽油转化率和甲酯得率的影响。应用正交实验的方法得出精棉籽油酯交换反应的最佳反应条件为 :反应温度 4 5℃ ,醇油摩尔比为 6∶1,催化剂用量为 1 1% ,反应时间为 6 0min。采用常压蒸馏的方法回收酯交换反应中过剩的甲醇。同时研究了甘油分离精制的方法 ,所得甘油的纯度可达97 86 %。实验室制得的棉籽油甲酯生物柴油的主要性能指标符合ASTM制定的生物柴油的标准。

甘油生产环氧氯丙烷的发展概况

介绍了环氧氯丙烷的用途和生产技术概况。针对生物柴油生产过程中副产的甘油市场供过于求的现状,介绍了利用甘油制备环氧氯丙烷的国内外发展概况。并对此路线进行了预算,结果显示甘油生产环氧氯丙烷路线具有较大的市场竞争力。

甘油新用途研究进展

目前迅速升温的生物柴油投资热使生产过程副产大量甘油。每生产10kg生物柴油约产生1kg甘油,造成甘油供应的大量过剩。廉价甘油供应的增加,也将带动新的以甘油为原料产业的迅猛发展。因此,寻求甘油利用的新用途已引起全球的普遍关注,各化工公司开发的新技术也相继问世。概述了近几年来开发的有望工业化的一些甘油新用途,并提出了今后的研究方向和建议。

生物柴油生产及其副产物甘油的有效利用

甘油是生产生物柴油的主要副产品,随着世界范围内生物柴油需求量和生产量的迅猛增长,甘油的有效利用也成为紧迫课题。对生物柴油的生产及利用,生物柴油副产物甘油生产高附加值的新产品和新途径进行了介绍,以期充分利用天然再生资源。

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.

生物柴油副产物制备高纯度甘油的研究

通过建立一套简单、有效的测量生物柴油下层副产物组成的方法,并用此方法对菜籽毛油制生物柴油下层副产物中各成份进行了定量分析,结果显示生物柴油下层副产物中含有43.73%的甘油,21.73%的脂肪酸皂,14.23%的生物柴油,16.47%的甲醇和少量其它杂质。通过用硫酸的甲醇溶液酸化脱盐的预处理方法,考察了甲醇用量、溶液pH值对脱盐率、粗甘油的纯度及收率的影响,结果显示甲醇用量为下层副产物的0.5倍体积,溶液pH值为5时,可得到纯度为90%的甘油粗产品,脱盐率可达到90%,甘油的收率也在95%以上。在此基础上,用减压蒸馏和离子交换两种方法对粗甘油进行了精制。这两种方法均可得到纯度高于99.5%的精制甘油,但离子交换精制工艺的甘油总收率可达到85%以上,而减压蒸馏精制工艺的甘油总收率仅为70%。

地沟油制生物柴油副产甘油精制

采用草酸钠络合分离方法,对地沟油制生物柴油副产甘油的精制进行了研究。结果表明,加入85%磷酸调整体系pH值至5,反应温度为70℃,反应时间为60 min,粗甘油收率达到81.2%;草酸钠加入质量分数为0.03%,反应温度为80℃,混合时间为30 min,甘油的脱杂率达到19.8%。脱杂甘油经减压蒸馏收取164～200℃馏分,后经活性炭脱色得到纯度为99.5%的精制甘油。