Recovery of different waste vegetable oils for biodiesel production: A pilot experience in Bahia State,Brazil

In Brazil, and mainly in the State of Bahia, crude vegetable oils are widely used in the preparation of food. Street stalls, restaurants and canteens make a great use of palm oil and soybean oil. There is also some use of castor oil, which is widely cultivated in the Sertão Region (within the State of Bahia), and widely applied in industry. This massive use in food preparation leads to a huge amount of waste oil of different types, which needs either to be properly disposed of, or recovered. At the Laboratorio Energia e Gas-LEN (Energy & Gas lab.) of the Universidade Federal da Bahia, a cycle of experiments were carried out to evaluate the recovery of waste oils for biodiesel production. The experiences were carried out on a laboratory scale and, in a semi-industrial pilot plant using waste oils of different qualities. In the transesterification process, applied waste vegetable oils were reacted with methanol with the support of a basic catalyst, such as NaOH or KOH. The conversion rate settled at between 81% and 85% (in weight). The most suitable molar ratio of waste oils to alcohol was 1:6, and the amount of catalyst required was 0.5% (of the weight of the incoming oil), in the case of NaOH, and 1%, in case of KOH.The quality of the biodiesel produced was tested to determine the final product quality. The parameters analyzed were the acid value, kinematic viscosity, monoglycerides, diglycerides, triglycerides, free glycerine, total glycerine, clearness; the conversion yield of the process was also evaluated.     

Methods to empirically estimate direct and indirect rebound effect of energy-saving technological changes in households

Energy efficiency policies have a special importance within carbon emission reduction policies to mitigate the climate change effects. However, potential reductions of energy consumption and, consequently, its resulting emissions, can be offset through the so called “rebound effect”. The concept of “rebound effect” refers to a set of mechanisms whereby the improvement of efficiency reduces the cost of the energy service and this results in the household energy consumption rising and totally or partially negating the reduction achieved by the energy efficiency improvement. This paper provides a methodology to estimate the static direct plus indirect rebound effect of energy efficiency improvements in the use of energy in households. It is based on the combination of econometric estimations of energy demand functions, re-spending modelling and generalised intput-output of energy modelling. It also provides estimations for Catalonia.     

井下运输安全性的灰色综合评判

以平顶山煤业（集团）公司一矿（简称平一矿）为例,运用灰色系统理论,对井下运输系统的安全性进行了灰色综合评判,指出了影响运输安全的人、机、环境各因素中存在的问题,并提出了相应的提高安全性的措施。     

A Multi-Years Analysis of the Energy Balance,Green Gas Emissions,and Production Costs of First and Second Generation Bioethanol

Contemporary reports on the energy and environmental benefits of bioethanol have suggested that the cellulosic ethanol is significantly more efficient. To understand the development potential of energy crops in Taiwan, the present study has assessed the resources and cost inputs for the planning, harvesting, transporting, and storing procedures of the first generation energy crops during 2007–2010 with the perspective of LCA. In addition, a field investigation focusing on rice straw, the largest agricultural waste in Taiwan, has been conducted since 2010 to obtain fundamental data.This study further analyzes the first and second-generation feedstocks from the perspective of LCA based on field investigated data. Taiwan has not yet established an ethanol plant; therefore, this study established production data by simulating the production efficiency of an economical scale using parameters obtained through production trials, and proposed an evaluation model for the energy input, GHG, and production costs of bioethanol in Taiwan. The results of this study were cross-compared with foreign literature to explore the development potential of bioethanol in Taiwan. The results indicate that based on the current cellulosic ethanol technology in Taiwan, regarding the energy balance, GHG, and production costs, is less efficient than that of the first generation bioethanol.     

Effects of introducing energy recovery processes to the municipal solid waste management system in Ulaanbaatar,Mongolia

Currently, most developing countries have not set up municipal solid waste management systems with a view of recovering energy from waste or reducing greenhouse gas emissions. In this article, we have studied the possible effects of introducing three energy recovery processes either as a single or combination approach, refuse derived fuel production,incineration and waste power generation, and methane gas recovery from landfill and power generation in Ulaanbaatar, Mongolia, as a case study. We concluded that incineration process is the most suitable as first introduction of energy recovery. To operate it efficiently,3Rs strategies need to be promoted. And then, RDF production which is made of waste papers and plastics in high level of sorting may be considered as the second step of energy recovery.However, safety control and marketability of RDF will be required at that moment.     

Effects of introducing energy recovery processes to the municipal solid waste management system in Ulaanbaatar,Mongolia

Currently, most developing countries have not set up municipal solid waste management systems with a view of recovering energy from waste or reducing greenhouse gas emissions. In this article, we have studied the possible effects of introducing three energy recovery processes either as a single or combination approach, refuse derived fuel production, incineration and waste power generation, and methane gas recovery from landfill and power generation in Ulaanbaatar, Mongolia, as a case study. We concluded that incineration process is the most suitable as first introduction of energy recovery. To operate it efficiently, 3Rs strategies need to be promoted. And then, RDF production which is made of waste papers and plastics in high level of sorting may be considered as the second step of energy recovery. However, safety control and marketability of RDF will be required at that moment.     

Numerical and experimental investigations on laser melting of stainless steel 316L metal powders

This paper presents numerical and experimental investigations on laser melting of SS grade 316L powder on top of AISI 316L substrate using a pulsed Nd:YAG laser. The objectives of the present study are to understand the effect of process parameters such as laser power, scanning speed and beam size on geometry characteristics of the melt zone and ball formation. We formulated a moving heat source problem and obtained transient temperature solutions using commercial finite element solver. The geometry characteristics of the melt zone are evaluated from the temperature solutions and compared with experimental results. The effect of laser parameters on the geometry, morphology and homogeneity of single track realization was methodically analyzed by utilizing characterization tools such as laser particle size analyzer, macro and microscopic inspection, Scanning Electron Microscope (SEM), X-Ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR). The results presented in this paper are beneficial to realize homogenous layer formation in additive manufacturing processes involving powder melting by laser beam.     

An experimental investigation of fluid flow and combustion characteristics of dual-fuel in a cylindrical combustion chamber

Combustion and fluid flow characteristics of coflowing LPG and kerosene have been investigated experimentally. A cylindrical water cooled combustion chamber was used to investigate the effect of changing the injection location and percentage of liquid fuel during gaseous fuel combustion. It was found that the injection of liquid fuel leads to an increase in the absolute value of maximum positive axial velocity and reduces the absolute value of the maximum negative axial velocity compared to the case of LPG alone. Also, a stable temperature distribution is noticed at axial distance of X/D approximately equal to 2.15 (where X is the axial distance measured from the inlet of diffuser, and D is chamber diameter). This is less than that of gaseous fuel combustion (approximately equal to 2.91). The change of injection location leads to a reduction in values of gas temperatures at X_inj/D=0.15 then it increased to reach maximum values at X_inj/D=0.35 which is approximately the same value for combustion of LPG fuel only. Any further increase in the injection location leads to a reduction in gas temperature, especially at the upstream sections of the combustion chamber. Also, it was found that values of temperature along the combustion chamber were decreased with increasing the percentage of the injected liquid fuel due to incomplete combustion of liquid fuel. Values of combustion chamber efficiency (η) for all percentage of liquid fuel at X_inj/D=0.35 are higher than those for combustion of LPG alone.     

Assessment of renewable energy potential and policy in Turkey – Toward the acquisition period in European Union

This paper aims to assess the renewable energy capacity of Turkey in order to consider main priorities in the energy policy of Turkey. In this paper, renewable energy potential and regulatory conditions are discussed in Turkey in comparison with European Union. The results of the study implemented within the framework of EnviroGRIDS project indicated a promising yet very susceptible future for the implementation of renewable energy power plants in Turkey. The forecasts have shown that the solar power potential utilization is becoming more significant after 2020. The projections for 2050 indicate that electricity consumption from small and medium renewable energy sources including solar and wind will constitute 15% of the total, whereas the solar thermal will constitute around 16%. Geothermal and other renewables will remain around 3%. According to the high demand scenario, in 2050 the share of hydropower in overall electricity generation will be 12%, followed by solar power at 7% and wind power at 3%. Additionally, renewable energy policy and regulations in Turkey and in EU are overviewed in this study. On the contrary to EU, the constant feed-in tariff amount does not consider capital investments of specific energy sources in Turkey that brings disadvantage to the implementation. However, new regulations published and currently applied should be accepted as milestones in acquisition period of Turkey in EU.     

陕北能源开发生态环境补偿对策研究

本文从陕北能源开发入手,通过对生态破坏、经济损失的分析,论述了生态环境补偿的必要性和迫切性,提出了生态环境补偿的依据。从生态学的角度分析了生态的损失补偿是企业产品成本的构成部分,而不应是社会责任承担。阐明了补偿费征收管理办法主要应包括征收范围、征收机构、征收标准、管理使用和罚则等五个方面。