Effects of oil type on products obtained by cracking of oils and fats

This paper deals with cracking of vegetable oils and animals fats in the presence of zeolite catalysts, the objective being preparation of liquid products similar in their properties to fossil diesel. The effects of oil/fat type on the liquid condensate yields and parameters were monitored. The tests were carried out with rapeseed, sunflower, soybean and jatropha oils as well as with used frying oils. Liquid condensates with yields of 85 to 90% relative to the input oil were obtained at temperatures of 350 to 440 °C applied for the period of 20 to 30 min in the presence of zeolite catalysts NaY and clinoptilolite. The input oil types had no significant effect on the yields and characteristics of the treated condensate. In this respect, used frying oils (UFO) as a feed material match other types of fresh oils and fats. Treated condensates blended with fossil diesel (5-7% of the condensate by volume) are compliant with the EN 590 standard and can thus be used as a component of diesel fuels.     

Studying the Influence of Alumina Catalysts Doped with Tin and Zinc Oxides in the Soybean Oil Pyrolysis Reaction

The pyrolysis of vegetable oils consists of cracking triglycerides to produce smaller molecules. A mixture of hydrocarbons and oxygenated compounds, such as carboxylic acids and aldehydes, is obtained as the product and which can be separated by fractional distillation. When the reaction is carried out in the absence of catalysts (thermal cracking), a great quantity of these oxygenated compounds is obtained. Thus, the presence of those oxygenated compounds in the products results in a high level of acidity, which can be a problem when using them as fuels in combustion engines. The aim of this work was to study the composition of the products obtained by cracking of vegetable oils assisted by γ-alumina doped with zinc and tin oxides. The products were analyzed by FT-IR, GC-MS and GC-FID and the acid number was determined by titration with alcoholic KOH solution. The acid number, infrared spectra and chromatograms of the resulting hydrocarbon mixtures indicated a significant reduction in oxygenated compounds when compared with the mixtures obtained by the thermal cracking process, thus decreasing the acidity of the mixture.     

Conversion of exhausted fluid cracking catalysts into zeolites by alkaline fusion

Na₂CO₃ fusion was used to improve the conversion of exhausted fluid cracking catalysts into NaA zeolite. Experiments were performed varying the catalyst/Na₂CO₃ mass ratios and the heating treatment. X-ray diffraction analysis was used to identify the different crystalline phases present in the starting material as well as in the products. Quantitative determination of crystalline phases was performed by Rietveld analysis. Particle sizes and morphology were observed by electronic scanning microscopy. The proposed activation methodology led to high crystallization rates and good conversion in NaA zeolite_.     

氨基硅油乳液中乳化剂的分析

将氨基硅油乳液用柱层析法分离后,采用红外光谱仪扫描了氨基硅油乳液中乳化剂的各组分,用碘代法结合气相色谱/质谱联用仪对脂肪醇聚氧乙烯醚进行定性分析,采用邻苯二甲酸酐-吡啶法测定聚乙二醇的平均摩尔质量,并用质量法对各组分定量.结果表明,氨基硅油乳液中的乳化剂由非离子表面活性剂组成,主要成分为脂肪醇聚氧乙烯醚[结构为C12H25O(CH2CH2O)H0的质量分数为9.25%;结构为EO=5.02,C12H26:C14H30=3:1的质量分数为37.24%;结构为EO=8.92,C12H26:C14H30=2:1的质量分数为1.80%;结构为EO=11.27,C16H34∶C18H38=2∶3的质量分数为44.15%]及聚乙二醇[质量分数为2.6%,结构为HO(CH2CH2O)7.44H].     

海金沙挥发油的指纹图谱和GC/MS分析

通过水蒸气蒸馏法制备海金沙挥发油,用GC/MS分析了挥发油乙醚萃取物的化学成分,构建了海金沙的气相色谱指纹图谱,并进行了方法学考察。指纹图谱由14个特征峰构成,不同产地样品的图谱有一定差异;指纹图谱相对保留时间的精密度、稳定性和重现性的RSD分别在1.8%,1.76%和2.45%以下。挥发油用GC/MS共检出20个化学成分,主要成分是α-油酸单甘油酯和油酸二羟基乙酯,相对含量分别为47.82%和42.77%。     

New path in the thermal cracking of triacylglycerols (canola and soybean oil)

Triacylglycerols (TGs) are naturally occurring oils abundant in many crops. A series of batch uncatalyzed thermal decomposition experiments were performed using canola and soybean oils to explore pathways of TG cracking. A detailed gas chromatographic protocol based on mass spectrometric identification and flame ionization quantification was applied to the organic liquid product generated upon cracking. Reaction conditions were identified that resulted in a novel organic liquid product (OLP) composition compared to previously reported work. Under these conditions (temperatures within a 420-440 °C range) a new route for TG thermolysis was discovered in which cracking reactions of original TG-bound fatty acids were nearly complete and led to the formation of 15-25 wt.% C₂-C₁₀ linear saturated monocarboxylic acids and ca. 30% linear alkanes. Less than 2 wt.% C₁₆-C₁₈ fatty acids which were originally present in the feedstocks as glycerol triesters were found in the OLP. These reactions appear to be kinetically controlled due to abundant hydrogen formation. This route provides a significant enrichment of low-MW compounds in the OLP (65-70 wt.% being <C₁₁) and thus may be considered as a new option for the production of replacement products for petroleum-based fuels and chemicals.     

Experimental investigation of mineral diesel fuel, GTL fuel, RME and neat soybean and rapeseed oil combustion in a heavy duty on-road engine with exhaust gas aftertreatment

The effects of mineral diesel fuel, gas-to-liquid fuel, rapeseed methyl ester, neat soybean and neat rapeseed oil on injection, combustion, efficiency and pollutant emissions have been studied on a compression ignition heavy duty engine operated near full load and equipped with a combined exhaust gas aftertreatment system (oxidation catalyst, particle filter, selective catalytic NO_x reduction). In a first step, the engine calibration was kept constant for all fuels which led to differences in engine torque for the different fuels. In a second step, the injection duration was modified so that all fuels led to the same engine torque. In a third step, the engine was recalibrated in order to keep the NO_x emissions at an equal level for all fuels (injection pressure, injection timing, EGR rate). The experiments show that the critical NO_x emissions were higher (even behind the exhaust gas aftertreatment systems) for oxygenated fuels in case of the engine not being recalibrated for the fuel. GTL and the oxygenated fuels show lower emissions for some pollutants and higher efficiency after recalibration to equal NO_x levels.     

Rapid transesterification of soybean oil with phase transfer catalysts

Biodiesel is a renewable, non-toxic and biodegradable alternative fuel for compression ignition engines. Biodiesel is produced mainly through base-catalyzed transesterification of animal fats or vegetable oils. However, the conventional base-catalyzed transesterification is characterized by slow reaction rates at both initial and final reaction stages limited by mass transfer between polar methanol/glycerol phase and non-polar oil phase.In our study we used phase transfer catalysts (PTCs) to facilitate anion transfer between polar methanol/glycerol phase and non-polar oil phase to speed up transesterification. The benefits of transesterification by PTCs include no need for expensive aprotic solvents, potentially simpler scaleup and higher activity (shorter reaction time). Various PTCs were investigated for base-catalyzed transesterification. Experimental results showed that base-catalyzed transesterification was enhanced with an effective PTC, indicated by the formation of high methyl ester (ME) content within a relatively short time. Individual operating variables such as molar ratios of methanol to oil, total OH⁻ to oil, PTC to base catalyst and agitation including ultrasound were investigated for transesterification with PTC. Product analyses showed that ME content higher than 96.5 wt.% was achieved after only 15 min of rapid transesterification with PTC (tetrabutylammonium hydroxide or tetrabutylammonium acetate as PTC, MeOH/oil molar ratio of 6, total OH⁻/oil molar ratio of 0.22, PTC/KOH molar ratio of 1 and 60 °C). Free and total glycerol contents in the final product from 15 min rapid transesterification with PTC were lower than maximum allowable limits in the standard specification for biodiesel.     

优化裂解炉日常操作 有效提高乙烯收率

针对影响裂解炉平稳、长周期运行的主要因素,提出采取稳定裂解炉进料,调整COT平稳,优化日常工艺操作,加强管理,精心维护等有效措施,进一步确保裂解炉的长周期平稳运行,有效提高产品收率。     

The influence of oxygenated fuels on emissions of aldehydes and ketones from a two-stroke spark ignition engine

A spark-ignited two-stroke chainsaw engine was used to study the influence of pure oxygenated fuels on exhaust emissions of carbonyls (aldehydes and ketones) and regulated emissions, i.e. hydrocarbons (HC), carbon monoxide (CO), and nitrogen oxides (NO_x). Three fuels—methanol, methyl tert-butylether (MTBE), and ethyl tert-butylether (ETBE)—were used in the tests, each at three air/fuel ratios (λ) and the generated emissions were compared to those observed in previous tests with ethanol, aliphatic gasoline, and regular gasoline. Use of all four oxygenated fuels (ETBE, ethanol, methanol and MTBE) resulted in substantially higher total carbonyl emissions (11, 11, 8.9 and 7.8 g/kWh, respectively) than use of both aliphatic and regular gasoline (2.1 and 2.6 g/kWh, respectively). Further, up to 44-fold higher levels of specific carbonyls were generated from the oxygenated fuels than from regular gasoline: significant amounts of formaldehyde were produced from all of the oxygenated fuels, but they were especially high from methanol and MTBE; acetaldehyde was formed in high amounts from ethanol and ETBE; while acetone and methacrolein were formed from both MTBE and ETBE. In addition, increases in λ increased exhaust emissions of formaldehyde, acetaldehyde, acetone, and methacrolein in cases where these were the main carbonyls formed. Increasing λ also variously increased, reduced or had no significant effect on emissions of other measured carbonyls. Lower amounts of CO and NO_x emissions were formed from all oxygenates (especially methanol) than from regular gasoline.     

The thermal cracking of soybean/canola oils and their methyl esters

Triacyl glycerides (TGs) are naturally occurring oils produced by a significant variety of crops, microorganisms (bacteria and algae), and animals (certain fats). The diversity and prevalence of the sources of these compounds suggest that they may serve as an attractive alternative to crude oil as the feedstock for the production of transportation fuels and certain industrial chemicals — organic compounds with carbon chain lengths in the range of C₇ to C₁₅. In the present study a series of batch thermal cracking reactions was performed using soybean oil and canola oil under reaction conditions leading towards attractive yields of potentially valuable (as fuels and/or chemicals) shorter chain products. An attractive yield of alkanes and fatty acids (from oil cracking) or esters (from biodiesel) was obtained. From a parametric study reaction temperature, followed by residence time, was found to have the most significant effect. Significantly, cracking under increased pressures in a hydrogen atmosphere did not improve the yields of desirable species.     

低温煤焦油的基本特性及综合利用

以陕西神木和山西大同的4种工业生产煤焦油为样品,对其基本特性进行系统的分析研究,对焦油中酚类化合物含量进行了测定,并应用GC—MS色质联用检测手段鉴定了碱洗提取的粗酚,并在此基础上简要概述低温煤焦油的综合利用。     

Structural properties and HDS activity of NiMo catalysts supported on lanthana modified zeolite type X and Y

In the search for the active catalysts of hydrodesulfurization reaction, an attempt was made to use zeolites as supports. A series of NaLaX, Mo/NaLaX and NiMo/NaLaX as well as NaLaY, Mo/NaLaY and NiMo/NaLaY catalysts was prepared and their performance in this reaction was studied. It was shown that crystalline structure of the lanthana forms of the above zeolites only little collapsed after ion-exchange and impregnation with active Mo and NiMo components. The NiMo catalysts supported on the zeolites studied were found active in thiophene hydrodesulfurization. The catalysts with lanthana after the first step of ion exchange were the most active.     

Catalytic conversion of canola oil to fuels and chemicals over various cracking catalysts

The catalytic conversion of canola oil to fuels and chemicals was studied over HZSM-5, H-mordenite, H-Y, silicalite, aluminum-pillared clay (AL-PILC) and silica-alumina catalysts in a fixed bed micro-reactor. The reactor was operated at atmospheric pressure, a temperature range of 375?500°C and weight hourly space velocity (WHSV) of 1.8 and 3.6 h^?1. An organic liquid product (OLP), light hydrocarbon gases and water were the major products. The objective was to maximize the amount of OLP and its hydrocarbon content as well as optimize the selectivity for gas phase olefinic hydrocarbons. In addition, the performance of each catalyst in terms of minimizing the coke formation was examined. Among the six catalysts, HZSM-5 gave the highest amount of OLP of 63 mass% at 1.8 WHSV and 400°C. The hydrocarbon content of this OLP product was 83.8 mass%. With the exception of silica-alumina and aluminum-pillared clay catalysts, the other catalysts gave high concentrations of aromatic hydrocarbons which ranged between 23.1–95.6 mass% of OLP. The gas products consisted mostly C₃ and C₄ hydrocarbons. Ethylene, propylene and butanes were some of the valuable hydrocarbon gases. The olefin/paraffin ratio of the gas products was highest for AL-PILC catalysts but it never exceeded unity. The results showed that it was possible to significantly alter the yield and selectivity for the different hydrocarbon products by using different catalysts or changing the catalyst functionality such as acidity, pore size and crystallinity. Reaction pathways based on these results are proposed for the conversion of canola oil     

羯布罗香木精油化学成分研究

采用水蒸汽蒸馏方法收集羯布罗香挥发性成分,所得到的羯布罗香精油用GC/MS分离并分析鉴定其成分及质量分数,共鉴定出34个化合物,占总峰面积的90.03%.主要挥发性成分有δ-榄香烯(9.50%);α-王古王巴烯(2.90%);α-古芸烯(27.87%);石竹烯(1.98%);β-荜澄茄烯(1.09%);β-愈疮木烯(1.02%); α-石竹烯(1.08%);β-古芸烯(1.51%);γ-木罗烯(8.10%);α-杜松烯(3.70%);δ-瑟林烯(1.58%);α-木罗烯(7.02%);γ-杜松烯(2.05%);δ-杜松烯(8.75%);α-甜旗烯(1.17%);α-杜松醇(2.20%).     

Development of catalysts for the fluid catalytic cracking process: An example of CYTED-D program

The present paper describes the development of a catalyst for the fluid catalytic cracking process of gasoils. The catalyst produced is to maximize the high octane components in the gasolines and the liquefied gases for petrochemical use. The results obtained in the riser type pilot plants of the Compañia Española de Petróleo, S.A. (CEPSA), and INTEVEP, S.A., R&D Center of Petróleos de Venezuela, S.A. are also reported. Finally, information is given on the technical-economic feasibility of a prototype plant for manufacturing this type of catalyst with an annual capacity often thousand tons.This project has been performed under the Ibero-American Science and Technology Program for Development, CYTED-D, in which 25 researchers from five Ibero-American countries have participated: Argentina, Brazil, Mexico, Spain, and Venezuela, offering an example of multinational cooperation.The present work is an abstract of the final project report. The results of the different phases and activities described will be published by the authors separately.     

水溶性生物油丙酮萃取物的光催化氧化反应

在超声辐射下用等体积的水萃取了稻壳生物油,离心分离后得到水溶物,并对水溶物依次用石油醚、CS2、CCl4、氯仿和丙酮进行萃取,分析发现得到的丙酮萃取物(E0)萃取率很高,但在气相色谱/质谱联用仪(GC/MS)上不显示化合物信息。为提高E0的利用效率,以TiO2作为催化剂,考察了温和条件下该生物油水溶组分丙酮萃取物的光催化氧化反应。通过活性炭吸附从反应混合物中分离了有机成分并依次用石油醚和丙酮萃取,得到萃取物1和2(E1和E2),继而用GC/MS分析了E1和E2。结果表明,在E1和E2中检测到大量的酚类、酸类、酮类和酯类等含氧化合物,且多为羟基和烷氧基取代物,这对生物油的高效利用具有重要意义。     

Influence of Fe or Zn loading method on toluene methylation over MFI-type zeolite catalysts

Toluene methylation with methanol was investigated on MFI-type zeolite catalysts containing Fe or Zn within the range of 0-2% by weight as an active component. The catalytic performances were compared on catalysts to which Fe or Zn was introduced by different methods, i.e., ion-exchanged and incorporation methods. The prepared catalysts were characterized by XRD, XRF, BET, FTIR and pyridine adsorption technique on in-situ FTIR. The results showed that the incorporated samples, H-Fe, Al-silicate (Si/Fe=150) and H-Zn, Al-silicate (Si/Zn=150), exhibited catalytic activity and xylene selectivities approximately equivalent to those from the ion-exchanged samples, Fe(0.8)/H-MFI and Zn(1.0)/H-MFI, containing nearly the same amount of Fe or Zn. The higherp-xylene selectivity was achieved with H-Fe, Al-silicate (Si/Fe=150) and H-Zn, Al-silicate (Si/Zn=150) because of Brönsted acid strengths weaker than Fe(0.8)/H-MFI and Zn(1.0)/H-MFI. Therefore, the isomerization ofp-isomer produced primarily was suppressed on the incorporated catalysts better than the ion-exchanged ones.     

Catalytic activity of Co,Mo and CoMo supported on NaY zeolite: hydrodesulfurization of gas oil at high pressure

Three series of Co/NaY, Mo/NaY and CoMo/NaY zeolite catalysts with variable metal content, prepared by a conventional impregnation method, were characterized by XRD, IR spectroscopy (oxide state) and acidity measurements (sulfide state), and tested in hydrodesulfurization (HDS) of gas oil at high pressure in the temperature range 275–350°C. The combined results of surface area, XRD and IR showed that in the catalysts with high metal loading a small loss in crystallinity and a partial blockage of the zeolite supercages were produced by Mo oxide species. The number of acid sites, which was lower for the Co/NaY than for the Mo/NaY catalysts, increased with increasing Co or Mo loading, but the strength of the acid sites was stronger for the Co/NaY series. HDS specific activities of the Co/NaY and Mo/NaY monometallic catalysts reached a maximum at very low loadings of Co ( 0.10 at. nm^–2) or Mo ( 0.16 at. nm^–2) by the double action of the metal sulfide species and the strong acid sites generated on the zeolite by the Co or Mo incorporation. In the binary CoMo/NaY catalysts, the synergy between Co and Mo species was significant for high Mo contents only.