Review of efficiencies of cogeneration units using internal combustion engines

The most frequently used technology in cogeneration units up to 10 MWe are internal combustion engines and the majority of the models are up to 500 kWe. There are dozens of reciprocating internal combustion engine–based cogeneration unit manufacturers and more than hundred suppliers in the market. In the article, data from supplier technical specifications of 583 units (34 manufacturers) is collected and analyzed. The authors proposed mathematical relations that show dependence of efficiencies on electric power that can be used for initial feasibility studies. Authors also have showed that value of 0.75 for power-to-heat ratio (proposed by EU Directive 2004/8/EC) does not always correspond to current market situation.     

Sustainable farming practices of the Chinese mitten crab (<Emphasis Type="Italic">Eriocheir sinensis)</Emphasis> around Hongze Lake,lower Yangtze River Basin,China

Results of a survey of 156 Chinese mitten crab (Eriocheir sinensis) grow-out farms around Hongze Lake (118.48–118.72°E; 33.36–33.38°N) are reported. Area farmed has remained relatively unchanged but production (59 932 t in 2012) increased steadily over the last 7 years, indicative of the viability and sustainability of the farming system that has gradually replaced intensive Chinese major carp polyculture around Hongze Lake. Results showed that production range was 135–2400 kg ha⁻¹ cycle⁻¹ (mean 1144 ± 34). Crab yields correlated linearly to stocking density and conformed to a normal distribution curve, with 66.7 % of farms yielding 900 kg ha⁻¹ cycle⁻¹ or more. Yield was negatively correlated to pond size and capture size (p < 0.01), and farms with macrophyte coverage rate lower than 30 % of water surface were significantly (p < 0.05) lower than those exceeding 30 %.

Electronic supplementary material

The online version of this article (doi:10.1007/s13280-015-0722-0) contains supplementary material, which is available to authorized users.     

黑龙江省杨树烂皮病气象预报模型的适应性分析

在构建东北地区杨树烂皮病发生发展气象适宜度预报模型的基础上,选取黑龙江省西部地区5个试验点,以1972-1974年当地杨树烂皮病观测记录为标准,对该模型进行局部地区应用试验.结果表明:仅利用当地气象观测站的气象数据进行气象适宜度等级预报的准确率比较低,总体预报准确率仅为38 07％,而对气象要素进行空间插值能把预报准确率提高到72.16％.此研究可为黑龙江省气象部门进行杨树烂皮病的气象适宜度预报提供技术参考.     

Water Transport in Polylactide and Polylactide/Montmorillonite Composites

Polylactide–montmorillonite composites were fabricated by melt-blending followed by compression molding, and water permeability of the composites was studied by both experiments and theoretical models. The water permeation in composites decreases with increasing concentration of montmorillonite. Specifically, at a concentration of 10 wt% of montmorillonite, the water permeation is 34 % less than in the neat polymer. Transmission electron microscopy (TEM) and wide-angle X-ray scattering (WAXS) results show that most of the montmorillonite particles are well-dispersed and randomly exfoliated in the polymer matrix. A fit of theoretical models to the permeation data estimates that montmorillonite platelets are mostly exfoliated in the polymer matrix and oriented randomly, which matches with results from WAXS and TEM.     

Suitability Analysis for Greenway Planning in China: An Example of Chongming Island

Suitability analysis for greenway planning was developed in the Western culture. When applying a suitability analysis to a very different sociocultural context such as China, it is necessary to identify what hinders or promotes it. Through an example of Chongming Island, this article demonstrates how to apply a suitability analysis for greenway planning in China. Furthermore, it argues that obstacles including a lack of data, peculiarity of capability scores within land use and a neglect of scientific group involvement are encountered in the process of applying suitability methods in Chongming or China. Early and sustained attention to such impediments could improve the success of suitability assessment in China. These research results are helpful for the planning and implementation of Chongming greenways.     

冬季燃油节能降耗设备的研制与应用

新疆等西北地区冬季时间长,温度低,由于--35#柴油的价格比0#柴油高,但其燃烧值低于0#柴油,因此考虑用0#柴油代替--35#柴油,以降低钻井成本。回收350℃高温尾气中的热量,进行水罐加热,使水温达到60℃;然后用60℃热水对0#柴油罐进行加热和保温,使油温达到30℃。达到在冬季用0#柴油代替--35#柴油的目的,使尾气回收利用设备不需要另外的能量补给。     

长庆油田采出水处理系统污泥收集及处理

分析长庆油田采出水系统内污泥处理现状,介绍负压排泥和撬装离心脱水组合技术处理污泥的原理、流程及运行情况。该工艺流程在密闭状态下运行,占地少,污泥脱水率稳定,为油田采出水系统污泥处理技术发展和推广应用做了新的尝试。     

浅谈油气开发与环境安全

文章分析了油气能源现状、油气开发与环境的关系、油气开发与环境安全的关系,油气开发中的环境保护对策与环境监理。得出:油气开发既要做到和谐生产,又要保护环境;在油气开发中,对环境有影响的应加大修复力度,采取相应的环境保护措施,确保有效、长效的环境保护目标。     

Solvent extraction for heavy crude oil removal from contaminated soils

A new strategy of heavy crude oil removal from contaminated soils was studied. The hexane-acetone solvent mixture was used to investigate the ability of solvent extraction technique for cleaning up soils under various extraction conditions. The mixtures of hexane and acetone (25 vol%) were demonstrated to be the most effective in removing petroleum hydrocarbons from contaminated soils and approx 90% of saturates, naphthene aromatics, polar aromatics, and 60% of nC₇-asphaltenes were removed. Kinetic experiments demonstrated that the equilibrium was reached in 5 min and the majority of the oil pollutants were removed within 0.5 min. The effect of the ratio between solvent and soil on the extraction efficiency was also studied and results showed that the efficiency would increase following the higher solvent soil ratio. Then the multistage continuous extraction was considered to enhance the removal efficiency of oil pollutants. Three stages crosscurrent and countercurrent solvent extraction with the solvent soil ratio 6:1 removed 97% oil contaminants from soil. Clearly the results showed that the mixed-solvent of hexane and acetone (25 vol%) with character of low-toxic, acceptable cost and high efficiency was promising in solvent extraction to remove heavy oil fractions as well as petroleum hydrocarbons from contaminated soils.     

回收电解锰渣中的可溶性锰

以电解锰渣滤液为实验原料,研究了利用二氧化碳和氨水回收锰渣滤液中可溶性锰的工艺,实验结果表明:当n(氨水):n(可溶性锰)为2.50、二氧化碳曝气流量为50 L/h、曝气时间为5 min、振荡时间为60 min时,可溶性锰回收率达75%以上;对沉淀物进行X射线衍射分析,碳酸锰纯度接近100%。1kg电解锰渣可回收27 mg碳酸锰。