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.     

生活污泥干化与生活垃圾协同焚烧研究分析

我国城市化的快速发展导致城市人口的迅速膨胀,城市生活污水产生量也迅速增加,在污水处理过程中自然而然的产生了大量的污泥。据不完全统计,每年一座中等城市产生的污泥量大约在25~30万t。本文通过对生活污泥干化的研究与生活垃圾协同焚烧的研究,有助于形成积极的公众舆论和认同,为垃圾协同污泥焚烧技术在全国的推广实施提供便利。     

有机垃圾热解生物碳的研究进展

生物碳是有机垃圾热解的产物。生物碳具有多孔性、高比表面积、高度芳香化结构,充当土壤活性调理剂能增加土壤微生物吸附性能,保水、保肥,促进作物生长,同时还具有贮碳功能。综述了近年来有机垃圾热解及热解生物碳的研究进展,着重介绍了生物碳的形成条件、特征结构、在土壤中的生物与非生物氧化过程,以及对全球气候变化和土壤环境效益等研究动态。展望了有机垃圾热解生物碳技术用于城镇有机垃圾处理的发展前景,提出应重点加强的几个研究方向:1)实现不同混合垃圾制取相似结构的生物碳;2)垃圾热解过程中污染物的控制;3)有机垃圾生物碳的土壤环境行为与环境效益。     

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.     

Glycerine from biodiesel: The perfect diesel fuel

Glycerine supply currently exceeds its demand by a significant margin as it is formed as by-product in biodiesel production. Different routes for its utilisation are currently being looked into, especially ones that would allow its use as a fuel addition. However these routes are not as energy efficient as its direct combustion.Previously glycerine and other very low cetane number calorific liquids were thought impossible to be used as fuels in compression ignition engines. We have developed a combustion cycle that permits the utilisation of glycerine as a fuel in a compression ignition engine without the need for pilot fuels or cetane improving additives. The paper discusses the results of glycerine combustion in standard unmodified Lister-Petter and Deutz compression ignition engines.     

Distributed generation by energy from waste technology: A life cycle perspective

Municipal Solid Waste in general and its organic fraction in particular is a potential renewable and non-seasonal resource. In this work, a life cycle assessment has been performed to evaluate the environmental impacts of two future scenarios using biogas produced from the organic fraction of municipal solid waste (OFMSW) to supply energy to a group of dwellings, respectively comprising distributed generation using solid oxide fuel cell (SOFC) micro-CHP systems and condensing boilers. The London Borough of Greenwich is taken as the reference case study. The system is designed to assess how much energy demand can be met and what is the best way to use the digestible waste for distributed energy purposes.The system is compared with two alternative scenarios fuelled by natural gas: a reference scenario, where the electricity is supplied by the grid and the heat is supplied from condensing boilers, and a fuel cell micro-CHP system. The results show that, although OFMSW alone can only supply between 1% and 4% of the total energy demand of the Borough, a saving of ∼130 tonnes of CO₂ eq per year per dwelling equipped with micro-CHP is still achievable compared with the reference scenario. This is primarily due to the surplus electricity produced by the fuel cell when the micro-CHP unit is operated to meet the heat demand. Use of biogas to produce heat only is therefore a less desirable option compared with combined heat and power production. Further investigation is required to identify locally available feedstock other than OFMSW in order to increase the proportion of energy demand that can be met in this way.     

一种新型垃圾焚烧发电废水浓液的处理工艺技术

垃圾发电涉及烟气、废水、炉渣及飞灰的三废处理,如何在全厂工艺中合理消纳废水、这涉及各类设备新材料的应用以及结合生产中各种工艺的相互穿插应用,以便在工艺中的各环节,消纳废水。我国垃圾发电行业起步晚,各工艺独立且单一,本文以项目实例,在烟气处理工艺中,采用新型旋转雾化器,引入废水的浓液作为旋转雾化器冷却水,达到烟气处理与废水浓液处理两种工艺交叉,一起重叠处理,在烟气中蒸发,与常规垃圾电厂将浓液泵入石灰浆溶液中再达到旋转雾化器相比,开辟了一条有效的路径。     

Occupant injury severity from lateral collisions: A literature review

Problem

Side impacts are a serious automotive injury problem; they represent about 30% of all fatalities for passenger vehicle occupants. This literature review focuses on occupant injuries resulting from real lateral collisions. It emphasizes the interaction between injury patterns and crash factors, taking into account type of injuries and their severity. It highlights what is known on the subject and suggests further studies.

Method

We reviewed papers identified by searches in two electronic databases for the 1996-2009 publication period, and in specific journals and conference proceedings.

Results

Studies on the Primary Direction of Force (PDOF) have revealed that fatal crashes occur most frequently when the PDOF is at 3 or 9 o'clock. The risk of serious injury is two to three times higher for the near-side occupant than for the far-side occupant. Head injuries predominate in oblique impacts and thoracic injuries in perpendicular ones. A few results are also reported on side airbag protection.

Conclusions

This literature review presents an overall picture of the injuries caused by lateral collisions, though each of the papers or articles examined focuses mostly on some particular aspect of the problem. The incidence of specific injuries depends on the data source used. Very few population-based analyses of lateral collision injuries were found.

Impact on industry

New studies are needed to evaluate new protective devices (e.g., lateral airbags, inflatable curtains). Without interfering with their care duties, Emergency Medical Technicians could be systematically trained to observe the collision's specific characteristics and to report all their relevant observations to the emergency physicians to increase the likelihood of prompt diagnosis and proper care.     

生活垃圾焚烧发电项目环境影响评价要点研究

本文立足于生活垃圾焚烧发电项目要求,从多个角度详细介绍了项目环境影响评价的要点,包括污染源评价、选址要求等,并介绍了支持保障策略,希望能够为未来生活垃圾焚烧发电提供理论支持。     

Graduated driver licensing: review of evaluation results since 2002

Unintentional injury from motor-vehicle crashes is the number one cause of death among teenagers in the United States. Increasingly, jurisdictions have adopted three-stage graduated driver licensing (GDL) systems for young novice drivers. Since a previous review of U.S. GDL evaluation results, many more U.S. states and Canadian provinces have implemented GDL and/or had enough time pass that additional evaluation results are now available. Twenty-one studies of GDL within 14 individual jurisdictions, and six studies of GDL in the U.S. nationwide, were collected, reviewed, and summarized. Positive results (usually crash reductions) of varying degrees were reported from nearly all the studies. Given differences in approaches, study goals, methods, and analyses, the results are surprisingly consistent. Overall, GDL programs have reduced the youngest drivers' crash risk by roughly 20 to 40%. Research on teen driving and comprehensive GDL enhancements could further reduce teen drivers' motor-vehicle crashes, injuries, and fatalities. IMPACT ON INDUSTRY: Policy-makers, as well as the motor vehicle, insurance, and other industries have been involved in teen driving safety and could enhance and coordinate their roles.     

Abatement of ammonia and amines from waste gases: a summary

The technologies that allow the abatement of ammonia and amines from waste gases are briefly described. Advantages and drawbacks of thermal and catalytic oxidation processes, condensation, adsorption on solids, scrubbing and biofiltration are discussed.     

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 process industries resilience: Risk-based with a network approach

Risk management can be defined as coordinated activities to conduct and control an organization with consideration of risk. Recently, risk management strategies have been developed to change the approach to hazards and risks. Resilience as a safety management theory considers the technical and social aspects of systems simultaneously. Resilience in process industries, as a socio-technical system, has four aspects of early detection, error-tolerant design, flexibility, and recoverability. Meanwhile, process industries' resilience has three phases: avoidance, survival, and recovery, determining the transition between normal state, process upset event, and catastrophic event. There may be various technical and social failures such as regulatory and human or organizational items that can lead to upset or catastrophic events. In the avoidance phase, the upset event is predicted, and thus, the system remains in a normal state. For the survival phase, the system state is assumed to be an upset process event, and the system tries to survive through the unhealthy process conditions or remains in the same state, probably with low performance. In the recovery phase, the system is supposed to be catastrophic, and the emergency barriers are prioritized to show the severity of the consequences and response time, leading to a resumption of a normal state. Therefore, a resilience-based network can be designed for process industries to show its inherent dynamic transition in nature. In this study, network data envelopment analysis (DEA), as a mathematical model, is used to evaluate the relative efficiency of the process industries regarding a network transition approach based on the system's internal structure. First, a resilience-based network is designed to consist of three states of normal, upset, and catastrophic events. Then, the efficiency of each industrial department, which is defined as decision-making units (DMUs), is evaluated using network DEA. As a case study, a refinery that is considered a critical process industry is assessed. Using the proposed model shows the efficient and inefficient DMUs in each of three states of normal, upset, and catastrophic events of the process and the projection onto efficient frontiers. Besides calculating the network efficiency, the performance of each state is extracted to precisely differentiate between DMUs. The results of this study, which is one of the fewest cases in the area of performance evaluation of process industries with a network approach, indicated a robust viewpoint for monitoring and assessment of risks.     

Remediation procedure used for contaminated soil and underground water: A case study from the chemical industry

This is a case study of contamination by a non-aqueous phase liquid (NAPL) that leaked from a chemical plant. The remediation procedure adopted for the initial phase of the plume migration was a plastic diaphragm wall coupled with a series of water extraction wells designed to avoid environmental impact on the surrounding ecosystems. Monitoring has shown that the containment is successful, and additional measures that contribute to accelerating remediation have been adopted. The authors wished to investigate how remediation might be further enhanced. The use of in situ aeration coupled with a system of soil vapor extraction (AS/SVE) has been chosen, since the remediation of sites with characteristics similar to those in this study, if based exclusively on dissolved-phase control, would take several decades to be completed. The transport of contaminant plumes has been simulated by using an analytical model to evaluate the effectiveness of the natural attenuation of the contaminant. The results of the simulation have confirmed the limited effectiveness of the natural attenuation of the contaminant, as well as the effective increase of remediation that would occur if the AS/SVE system is applied. A sensitivity analysis that included several combinations of increments of parameters that correspond to the decay rate of the source and the dissolved plume has simulated what might happen if the AS/SVE system is implemented.     

废弃火药在工业炸药中的再利用研究进展

介绍了废弃发射药及固体推进剂在工业炸药中的资源化利用技术,概述了含火药的粉状炸药、浆状炸药、乳化炸药、铵油炸药及灌注型炸药的爆轰性能,分析了各类炸药的工艺生产、使用及安全环保等特点。粉碎后的火药颗粒(Φ≤5 mm)可用于制备粉状炸药,也可利用现有的工业炸药生产工艺,将火药作为敏化剂加入浆状炸药、乳化炸药/乳化基质中,或将大颗粒火药直接与铵油炸药混合。这些方法工艺简单,且火药的加入有利于提高炸药的爆轰性能。尤其是含火药颗粒的灌注炸药生产工艺更简单、安全性更高,避免了火药粉碎工艺,废弃火药的再利用率高,而且炸药的爆轰性能优良,爆速大于6000 m/s,用作震源药柱或露天炸药等具有良好的应用前景。国内已成功地将废弃发射药再利用于工业炸药中,取得了良好的效益。借鉴国内外的研究成果,结合工业炸药的发展趋势,目前应重点进行废弃复合固体推进剂的应用研究。     

生活垃圾焚烧发电厂烟尘中重金属沉降对土壤环境影响分析

本文以一日处理生活垃圾2250t的生活垃圾焚烧发电厂为例,根据其重金属的排放量,预测重金属随大气扩散、迁移,最终通过自然降水和自然沉降进入土壤后,对土壤环境的影响。结果表明,项目建成后的20年内,大气评价范围内土壤中重金属的累计值满足《土壤环境质量建设用地土壤污染风险管控标准(试行)》 (GB36600-2018)表1中第二类用地筛选值要求。