Integration of Solid Oxide Fuel Cell in a sugar-ethanol factory: analysis of the efficiency and the environmental profile of the products

The effect of the integration of Solid Oxide Fuel Cell (SOFC) technology in a sugar-ethanol factory on the environmental profile/footprint of the products (sugar, ethanol, electricity) is evaluated. The sugarcane is the primary feedstock and sugar, ethanol and electricity are the main products of the system, where the functional unit is defined as 9.86 ton/h of sugar, 2.195 ton/h of hydrated ethanol (96% w/w) and 847 kWh of electricity. A detailed set of material and energy inputs and outputs was obtained from a local factory and was completed using simulation data by Aspen Plus^®.The environmental impacts (greenhouse gases and air pollution), exergy efficiency and a renewability parameter have been considered as indicators for the comparative assessment with conventional sugar, ethanol and electricity production technologies. The results show that the use of a SOFC technology involves a reduction of greenhouse gas emissions (52-55%) and non-renewable resources (60-64%) when compared with the conventional integrated sugar and ethanol plant. The higher renewability index (0.93) and exergy efficiency (38%) are noticed for the Solid Oxide Fuel Cell technology integrated in the sugar-ethanol factory than conventional sugar-ethanol plant.     

Resource productivity enhancement as means for promoting cleaner production: analysis of co-incineration in cement plants through a life cycle approach

The objective of this paper is to assess the environmental effectiveness of a strategic measure aimed at resource productivity enhancement. The cement industry has been identified as a relevant sector for this global issue, since the related production process enables the use of waste in partial substitution of raw materials and in substitution of traditional fuels. The analysis of the cement production sector in Italy has been here performed, investigating the recovery of energy from waste through co-incineration. In terms of air emissions, the emission performances of cement kilns appear independent from the use of alternative fuels at the percentages usually employed. However, in order to measure the cleanliness of a production system, systematic analysis with global perspective is needed. For this aim, the principles of Life Cycle Assessment (LCA) have been used for a case study analysis of an Italian active plant using an amount of recovered plastics as an alternative fuel resource. The improvement on the investigated process has been quantitatively measured as a way for cleaner production, first in terms of gross energy requirement, and then through an environmental performance comparison with a sector benchmark. The analysis has highlighted the benefits on the global environmental balance for the practice of co-incineration in the cement production process.     

Mercury removals by existing pollutants control devices of four coal-fired power plants in China

The mercury removals by existing pollution control devices in four coal-fired power plants of China were carried out based on a measurement method with the aluminum matrix sorbent.     

超声波-臭氧破解剩余污泥技术的初步研究

剩余污泥的处理与处置是我国和世界面临的重要环境课题.文章初步研究了臭氧、超声波及其组合工艺对剩余污泥的破解作用,考察了反应时间、臭氧流量、超声功率对污泥破解效果的影响.研究表明:臭氧流量为7I/min时破解效果最好,反应40min,SCOD、NH3-N、TN和TP分别比反应前提高了586%、178%、522%和1781...     

浅析我国森林生态效益补偿制度

概述了中国森林生态效益补偿研究的发展历程和总体状况,通过对森林生态效益补偿制度的回顾、补偿现状的描述,综述相关文献分析了森林生态效益补偿制度存在的一些问题,并提出了相应的建议。     

基于未确知测度识别模型在污水处理厂运行效率评价中的应用

污水处理厂运行效率定量评价是当前污水处理行业管理与研究需要解决的问题,运行效率涉及到污水处理水量、水质和污染物的去除率、能耗和药荆消耗等方面诸多项指标。是多指标综合评价问题。文章借助未确知测度识别数学理论．构造了污水处理厂运行效率定量评价模型。并应用于某污水处理厂的运行效率评价,取得了较满意的效果。     

静电旋风水膜除尘系统电晕极优化实验研究*

为了研究电晕极结构对静电旋风水膜除尘系统的影响,采用逐步优化法,对比十字形芒刺电晕极和笼式环形电晕极在不同横向极距、纵向极距、芒刺数下对电场特性的影响。研究结果表明:经优化后,加入芒刺的笼式环形电晕极放电能力优于未加入芒刺的笼式环形电晕极和十字形芒刺电晕极,并在与水膜共同作用时具有较高的除尘效率,其结构参数为:从上至下4层圆环半径依次为107,80,54,28 mm;相邻圆环纵向极距为150 mm,圆环与集尘极的横向极距为90 mm;半径最小圆环上芒刺数为8根,其直径为2 mm,长度为10 mm。优化后的电晕极结构与水膜作用有助于提升静电旋风水膜除尘系统的除尘效率。     

复配型表面活性剂协同无机盐润湿煤尘性能研究*

为有效提高雾化降尘效率,以长焰煤为例,从接触角、表面张力静态试验和粒径测定、喷雾降尘动态试验角度切入,探究不同类型表面活性剂与无机盐的协同关系,进而优选出降尘效果最佳的配比方案。研究结果表明:阴与阴、阴与非、非与非离子复配型表面活性剂与无机盐之间均存在显著协同效应,且通过正交试验可确定协同效果最优的3组配方及其最佳浓度;对比清水,3组配方的平均粒径均有所减小,降尘效率均有大幅提升。综合优选出的最佳配比为质量分数0.08%的仲烷基磺酸钠、0.04%的曲拉通X-100和0.04%的氯化钙复合配制的溶液,该方案的全尘降尘效率为92.55%,比清水提升79.95%;呼尘降尘效率为91.27%,比清水提升82.36%。     

太湖沉积物氮磷吸附/解吸特征分析

通过90组吸附/解吸实验研究了太湖沉积物氮、磷的吸附/解吸等温线特征,同时将平衡点浓度、本底吸附量、吸附效率与间隙水、沉积物中各形态氮、磷进行相关性分析,以期对太湖沉积物的"源"、"汇"情况进行分析.结果表明,在供试的浓度范围内,沉积物氮磷的吸附/解吸等温线呈显著线性关系,全湖氮的平均吸附/解吸平衡点浓度为1.10 m...     

城市绿地系统生态服务效能评价及优化研究——以淮安生态新城为例

通过运用生态服务效能指数的概念,选择5种指标因子(吸收二氧化硫量、吸收热量、蒸腾水量、涵养水源量、滞尘降尘量)构建了淮安生态新城绿地系统生态服务效能评估模型,并运用全排列多边形图示指标法,针对"现状条件"、"概念规划"、"控制性详细规划"、"理想状态"4种情景下的绿地系统进行了生态服务效能评价与预测.结果表明,4种不同的土地利用方式下,绿地系统生态服务效能综合指数分别为0.24、0.56、0.70和0.89,生态服务效能逐步改善.研究结果进一步表明,在"概念规划"和"控制性详细规划"两种情景下,应使城市绿地系统面积大于1200hm2,采用复合式绿地结构并调整林地与草地面积的比例达到7∶3,同时应保证本地植物指数大于70%,研究结果可为生态城市建设提供一定的参考.