Biodiesel production from waste oil feedstocks by solid acid catalysis

Biodiesel is a non-toxic and biodegradable substitute for petroleum-based diesel. However, it is impractical to use refined edible oils to produce biodiesel due to its high cost and priority for food products, especially in China, while waste oils with high free fatty acids (FFAs) can be considered as the raw materials. In the present work, a solid acid catalyst comprising SO₄²⁻/TiO₂–SiO₂ was prepared, characterized and studied for its activity for the production of biodiesel from several low cost feedstocks with high FFAs. The solid acid catalyst can be recycled, easily removed and can simultaneously catalyze esterification and transesterification. The influence of reaction parameters was studied, and the optimized reaction parameters are reaction temperature 200 °C, molar ratio of methanol to oil 9:1 and catalyst concentration 3 wt.%. The catalyst showed good stability. A continuous process for biodiesel production from cheap raw feedstocks was proposed, and a 10,000-tonnes/year biodiesel production demonstration plant has been built.     

Integration of safety instrumented system with automated HAZOP analysis: An application for continuous biodiesel production

Integration of a human-machine interface (HMI) with hazard and operability (HAZOP) analysis is proposed in this work. This concept can potentially lead to the identification of some unexpected deviations, and radically decreases the time necessary for hazard identification. A continuous biodiesel production was simulated. This can be divided into two cases, covering both conventional and reactive distillation. Soybean oil (trioleic, trilinoleic and tripalmitic) at 1000 kg/h as raw material is converted to 99 wt% pure biodiesel. The HMI was designed to improve these processes by combining automatic HAZOP analysis. With this approach, users can receive sufficient information from the simulation to analyze the optimum operation and safety. Severity levels are also provided to classify the actions in the process. Severity levels 1 and 2 are concerned with operating conditions, which are 58-64 °C, and 50-150 kPa. If the analysis shows severity level 3, the safety instrumented system (SIS) will automatically manage the operation in order to reduce/restrain the amount of damage at this level. This proposed system could minimize the damage and also improve the overall quality of the process.     

Optimization of biodiesel production from the waste cooking oil using response surface methodology

In this research, transesterification of the waste cooking oil has been studied. Response surface methodology (RSM) based on Box–Behnken design was used to investigate the effects of the main operating parameters, including the methanol to oil molar ratio, catalyst concentration, and reaction temperature, on the biodiesel yield. The results revealed that the catalyst concentration is the most important parameter. The maximum biodiesel yield under the optimized conditions was 99.38 wt.%. Thermogravimetric analysis (TGA) was used for the determination of biodiesel conversion and the results were compared with that of gas chromatography (GC) analysis, showing a very small difference. Furthermore, an empirical quadratic equation has been presented to show the relation between biodiesel conversion and product viscosity.     

Studies on design of heterogeneous catalysts for biodiesel production

The production of biodiesel is gaining momentum with the ever increasing demand of the fuel. Presently, limited literature is available with respect to well designed solid heterogeneous catalyst for biodiesel production considering all the characteristics, process and operation parameters. Hence, a study was conducted to design effective heterogeneous catalyst for biodiesel production. Further, the significant impact of different catalysts, different feed stock, various reaction conditions such as temperature, methanol oil molar ratio, catalyst concentrations and stability/inactivation of the catalysts, are detailed out for transesterification process of biodiesel production. Based on the studies it can be concluded that well designed heterogeneous catalyst can yield high throughput of biodiesel.     

新型吸收剂的制备及其对甲苯废气的吸收性能研究

针对工业排放的大量有机废气,制备了一种新型吸收剂.首次以水和生物柴油为原料,经乳化形成稳定的乳液,可提高生物柴油的吸收性能.考察了油水比、乳化剂HLB值、乳化剂添加量、乳化时间和乳化温度对乳液稳定性的影响.将乳液作为甲苯废气的吸收剂,通过实验室模拟废气,考察了其对甲苯废气的去除率.结果表明,在油水比(质量比)为7:3,乳化剂HLB(亲水亲油平衡值)值为10,乳化剂质量分数为5%,乳化时间为0.5 h,乳化温度为室温时,乳液的稳定性最好,且对甲苯废气的去除率可达到90.3%.     

Performance evaluation of biodiesel from used domestic waste oils: A review

Global warming, high-energy demand and availability of new technologies are among the factors catalyzing the search for alternative sources of energy. Currently, there is renewed interest in obtaining energy from wastes hitherto meant for disposal. Increased costs of disposal and their attendant problems of heavy environmental loading are some aspects making the disposal option unattractive. These wastes are sources of energy and among the several sources of generating this energy are the waste-to-energy (WTE) categories with potentials for useable fuel production. The WTE materials are mainly used domestic waste oils (UDWOs), municipal solid waste (MSW), agricultural and industrial wastes. However, the latter wastes are not attractive as they consist of innumerable hazardous contaminants. The UDWOs are arguably a safe and cost effective source of useable fuel. Their conversion offers the merits of a reduction in greenhouse gas emission (GHG), enhancing fuel diversification and a qualitatively comparable energy output to fossil diesel fuels. Thus, UDWOs could significantly contribute towards achieving the 2020 and 2030 goals of substituting approximately 20% and 30% of petro-diesel with biofuels in US and EU, respectively. Moreover, attaining the forecasted annual production rate of 227 billion liters of biofuel by most active stakeholders in the biodiesel industry could be easily achieved.This review aims to analyze the performance of biodiesel fuels obtained from UDWO and to demonstrate the suitability of applying these fuels as substitutes to mineral diesel in various industries. Benefits of UDWO as a biodiesel feedstock were as well highlighted.     

The effects of activated Al2O3 on the recycling of light oil from the catalytic pyrolysis of waste printed circuit boards

The effects of employing activated Al₂O₃ during the catalytic pyrolysis of waste printed circuit boards (WPCBs) are investigated, focusing on the recycling of light oil. Variations in the pyrolysis process are studied through analysis of the phase distribution, water content and boiling point fractions of the resulting products. Product composition and carbon number distribution are analyzed using gas chromatography techniques. The use of activated Al₂O₃ increases the light oil fraction and also reduces the quantity of brominated products formed. It was determined that the best yield of light oil and most efficient debromination resulted from catalytic pyrolysis at 600 °C. Applying catalyst-to-feed ratios in the range of 1.0–1.5 also maximizes the yield of light oil. The major oil fraction resulting from catalytic pyrolysis has a boiling point range of 0–250 °C and carbon number range of C6–C9, showing for use as a potential fuel after suitable treatment such as hydrogenation. At a higher catalyst-to-feed ratio of 2.0, activated Al₂O₃ generates a high proportion of light oil fractions containing a significant quantity of chemicals such as phenol (52.67% at 600 °C), although an overall lower yield of oil is obtained. The oil produced in this manner may also be used as a raw material feedstock for the production of various other useful chemicals.     

Flash point of biodiesel/glycerol/alcohol mixtures for safe processing and storage

Mixtures of biodiesel, glycerol, and ethanol/methanol are commonly processed and stored in biodiesel production. In this work, non-ideal models are used to calculate the Flash Points (FPs) of binary and ternary mixtures, using data available from different feedstocks. Despite the fact that biodiesel is considered safer than common diesel fuels, results show a synergistic effect of biodiesel/methanol and biodiesel/ethanol mixtures, resulting in a reduction of the flash point of mixtures to values lower than the ones of pure compounds. Most soluble ternary mixtures were found flammable, the only exception being mixtures with a relatively lower alcohol content (45% mol. ethanol or 42% methanol) at temperature lower than 303 K. Accidental increase in temperature can cause domino effect, due to the higher solubility and the formation of new flammable ternary mixtures.     

炼厂液化石油气(高含烯烃LPG)作为车用燃料的试验研究

炼厂液化石油气成分复杂,主体成分包含大量的烯烃,且含有硫、水及其他杂质.将其直接作为汽车燃料,对车辆以及燃料供给系统均存在不同程度的危害.通过试验研究除杂等精制工艺过程,得到了高含烯烃精制液化石油气,消除了杂质对燃料供给系统和发动机的影响.并研究了高含烯烃液化石油气在车辆上的使用性能.试验表明,高含烯烃液化石油气可使车辆的动力性有所提高,排放性能与标准车用液化石油气接近.由于炼厂液化石油气价格相对较低,因此车辆燃料费用大大降低,得到了包括出租车辆在内的广大用户的认可,具有良好的推广应用前景.     

废弃液晶屏玻璃基板的行星式球磨工艺研究

以废弃液晶屏玻璃基板为原料,研究了球磨方式和球磨时间在球磨过程中对粉料粒径分布的影响。通过对废弃液晶屏玻璃基板的行星式球磨工艺的研究,探讨了球磨方式、球磨时间等因素对球磨效果的影响,以建立玻璃粉体细化的合理球磨方式和工艺参数。     

Experimental study of the characteristics of solid fuel from fry-dried swine excreta

Swine excreta were dried by boiling via immersion in hot oil. In this method, moisture in the excreta is replaced with oil or evaporated by turbulent heat transfer in high-temperature oil. The dried excreta can be used in an incinerator like low-rank coal or solid fuel. Refined waste oil and B–C heavy oil were used for drying. Drying for 8 min at 150 °C reduced the water content of raw excreta from 78.90 wt.% to 1.56 wt.% (refined waste oil) or 1.62 wt.% (B–C heavy oil) and that of digested excreta from 79.58 wt.% to 3.40 wt.% (refined waste oil) or 3.48 wt.% (B–C heavy oil). The low heating values of the raw and digested excreta were 422 kJ/kg and ?2,713 kJ/kg, respectively, before drying and 27,842–28,169 kJ/kg and 14,394–14,905 kJ/kg, respectively, after drying. A heavy metal analysis did not detect Hg, Pb, Cd, As, and Cr in the dried excreta, but Al, Cu, and Zn, which occur in the feed formula, were detected. Thermogravimetric analysis before and after drying revealed that emission of volatiles and combustion of volatiles and fixed carbon occurred at temperatures of 250–500 °C when air was used as the transfer gas.     

A multi-criteria approach to screening alternatives for converting sewage sludge to biodiesel

The search for cheaper feedstock for use in the production of biofuels such as biodiesel has turned attention to various forms of waste products including animal fats, waste oils and now lipids in sludge. With the potential of obtaining sludge at a reduced cost, free, or possibly with incentives, sewage sludge is being investigated as a potential feedstock for biofuel production. For the extraction of oils from the sewage sludge and the subsequent processing, there are various alternatives that should be designed, analyzed, and screened. In developing and screening these alternatives, it is necessary to have a consistent basis for comparing alternatives based on key criteria. While most of the design studies focus on techno-economic criteria, it is also important to include safety metrics in the multi-criteria analysis. In this work, a detailed economic analysis and a safety evaluation are performed on a process involving extraction of triglycerides and fatty acids, pre-treatment of fatty acids (direct conversion to biodiesel), and transesterification of triglycerides to biodiesel. Four solvents, toluene, hexane, methanol and ethanol, are individually used in the extraction process. The resulting triglycerides and fatty acids from each extraction are modeled in the pre-treatment process. ASPEN Plus software is used to simulate the detailed process. Economic analysis is performed using ASPEN ICARUS, and scale-up of a previously analyzed process is used to estimate the cost of the biodiesel portion of the process. A new safety metric (referred to as the Safety Index “SI”) is introduced to enable comparison of the various solvent extraction processes. The SI is based on solvent criteria as well as process conditions. A case study is presented to demonstrate the insights and usefulness of the developed approach. The results of the techno-economic analysis reveal that of the four solvents used for the initial extraction, hexane and toluene were least costly (2.89 and 2.79 $/gal, respectively). Conversely, the safety analysis utilizing the SI reveals that methanol and ethanol are the safer solvent options. The issue of cost/safety tradeoffs is also discussed.     

Optimization of novel pyrazolium ionic liquid catalysts for transesterification of bitter apple oil

In the present study, 4 different functionalized pyrazoliums based on sulfoalkyl-pyrazolium hydrogensulfate and alkylsulfo-alakylpyrazolium hydrogensulfate were explored to catalyze biodiesel production from bitter apple oil (BAO). The results demonstrated that a longer chains catalyst of 2-(4-sulfobutyl) pyrazolium hydrogensulfate (SBPHSO₄) exhibited the highest catalytic activity, which is attributed to its strong acidity. The highest yield of esters was up to 89.5% when the reaction was carried out under the conditions of 5.2 wt% of SBPHSO₄, molar ratio of methanol to BAO of 15:1, 170 °C, and 800 rpm for 6 h. These results demonstrated that ionic liquids offer a promising new type of pyrazolium catalyst for biodiesel production. The use of clean ionic liquids in preparing clean biodiesel could solve the drawbacks associated with using the old conventional catalysts and might be employed as an efficient catalyst for such relevance.     

HMX基钝感传爆药制备技术

为获得性能更佳的钝感传爆药,以奥克托今(HMX)原料为基础,采用溶剂-非溶剂重结晶技术,并辅以超声喷雾工艺制备细化HMX,同时,通过试验方法制备以丙烯酸酯橡胶(ACM)、F2602和Viton A等3种材料为黏结剂的包覆HMX,并分别测试分析其安全性.结果表明:经过细化后,HMX的热稳定性和热敏感性降低,而撞击安定性则...     

Optimization of biodiesel production by alkali-catalyzed transesterification of used frying oil

Biodiesel as an alternative fuel for fossil diesel has many benefits such as reducing regulated air pollutants emissions, reducing greenhouse gases emissions, being renewable, biodegradable and non-toxic. In this study, used frying oil was applied as a low cost feedstock for biodiesel production by alkali-catalyzed transesterification. The design of experiments was performed using a double 5-level-4-factor central composite design coupled with response surface methodology in order to study the effect of factors on the yield of biodiesel and optimizing the reaction conditions. The factors studied were: reaction temperature, molar ratio of methanol to oil, catalyst concentration, reaction time and catalyst type (NaOH and KOH). A quadratic model was suggested for the prediction of the ester yield. The p-value for the model fell below 0.01 (F-value of 27.55). Also, the R² value of the model was 0.8831 which indicates the acceptable accuracy of the model. The optimum conditions were obtained as follows: reaction temperature of 65 °C, methanol to oil molar ratio of 9, NaOH concentration of 0.72% w/w, reaction time of 45 min and NaOH as the more effective catalyst. In these conditions the predicted and observed ester yields were 93.56% and 92.05%, respectively, which experimentally verified the accuracy of the model. The fuel properties of the biodiesel produced under optimum conditions, including density, kinetic viscosity, flash point, cloud and pour points were measured according to ASTM standard methods and found to be within specifications of EN 14214 and ASTM 6751 biodiesel standards.     

Study of high-tech process furnace using inherently safer design strategies (I) temperature distribution model and process effect

High-tech industries, such as those producing semiconductor and TFT-LCD (Thin Film Transistor Liquid Crystal Display), have recently become the most important economic activities in Taiwan. Each of these industries has a complete chain of supply from raw material production, production pre-processing, product manufacturing, to waste handling. Any company in the chain is a critical component, since any accidents of fire, explosion, gas leakage, or power outage would cut off the supply chain, causing inability of continuous operation. In industries of semiconductor and TFT-LCD, great amounts of special gases and chemicals with many machinery equipments are used in the production processes. In cases of accidents or improper installation, this chain of supply, from raw material production, preproduction, product manufacturing, to waste handling materials and equipments may cause severe damages or incidents.This study used the existing model of the horizontal furnace to develop a simulation program. The simulation results were consistent with the existing model, and produced even slightly better results on temperature distribution and temperature sensitivity. The simulation model applied on a vertical furnace could provide data on furnace temperature control for industrial use. Meanwhile, this study also deduced actual temperature control and an ISD strategy, which are consistent with design strategy principles.The validation results on the proposed temperature distribution model suggested that the model can be applied in temperature distribution and sensitivity analysis to obtain adjustment and control models for various heating zones. In the case of a single tool, when processing reduction is 60 pieces, switching off the two heating zones can reduce 44% of power output, for a capacity utilization rate of 93.7% for the entire plant. The application of the proposed temperature control model can reduce power consumption by 121.4 kWh. In addition, with the same number of tools, facilities layouts in two cases have an area difference of 41.4775 m², thus shortening the evacuation time for operators. The experimental results proved that the proposed model has realized the ISD principles of intensification, attenuation, and limitation of effects.     

热采井套损机理及套管强度优化设计

我国稠油资源丰富,然而稠油热采井套管损坏现象普遍存在,且有越来越严重的趋势,提高热采井套管寿命是稠油开采过程中迫切需要解决的问题。分析了热采井套管损坏主要原因,认为高温引起的强度变化、油层出砂亏空、固井质量差、隔热措施不利及套管本身材质问题都有可能引起热采井套管损坏。采用有限元分析软件ANSYS计算了不同隔热措施、不同注汽温度、不同注汽压力、不同套管材料及壁厚条件下套管应力分布规律。计算结果表明,为减少稠油热采井套管损坏,采用隔热措施较好的油管可以明显降低套管上的等效应力,同时在套管柱设计过程中应优选低弹性模量、厚壁套管。提出了VonMises等效应力对比高温屈服强度的校核新方法,为稠油热采井套管强度设计提供依据。     

基于循环经济的煤矿环境评价指标体系

基于循环经济理论和煤矿开采中环境系统的演化规律.从资源循环与资源损失正反两个方面构建了煤矿区环境评估指标体系.指标体系分为目标层、指标类别层和单项指标层3个层次,单项指标层是具体舒化指标.由它直接计算指标类别层的值,进而计算目标层的评估结果.将此指标体系运用到重庆市某县煤矿,对该县近年来煤矿资源开发中环境可持续能力进行了计算和分析,评价结果与实际情况相符,揭示了该县煤矿开发中环境可持续能力提高的关键因素,进一步探讨了煤矿开发中环境能力提高和循环经济理念的实施建议.     

提高铵梯炸药生产安全性的技术途径

本采用粗制TNT代替军工TNT应用于工业炸药中,不仅可减少环境的污染,而且可提高生产安全性。实验证明由粗制TNT制成的炸药,其性能可满足使用要求。