Water Quality Assessment of Large‐scale Bioenergy Cropping Scenarios for the Upper Mississippi and Ohio‐Tennessee River Basins

The Upper Mississippi River Basin and Ohio‐Tennessee River Basin comprise the majority of the United States Corn Belt region, resulting in degraded Mississippi River and Gulf of Mexico water quality. To address the water quality implications of increased biofuel production, biofuel scenarios were tested with a Soil and Water Assessment Tool (SWAT) model revision featuring improved biofuel crop representation. Scenarios included corn stover removal and the inclusion of two perennial bioenergy crops, switchgrass and Miscanthus, grown on marginal lands (slopes >2% and erosion rates >2 t/ha) and nonmarginal lands. The SWAT model estimates show water quality is not very sensitive to stover removal. The perennial bioenergy crops reduce simulated sediment, nitrogen (N), and phosphorus (P) yields by up to 60%. Simulated sediment and P reductions in marginal lands were generally twice that occurring in the nonmarginal lands. The highest unit area reductions of N occurred in the less sloping tile‐drained lands. Productivity showed corn grain yield was independent from stover removal, while yields of the two perennial bioenergy crops were similar in the marginal and nonmarginal lands. The results suggest planning for biofuel production in the Corn Belt could include the removal of stover in productive corn areas, and the planting of perennial bioenergy crops in marginal land and in low‐sloped tile‐drained areas characterized by high N pollution. Editor's note : This paper is part of the featured series on SWAT Applications for Emerging Hydrologic and Water Quality Challenges. See the February 2017 issue for the introduction and background to the series.     

An investigation of engine and fuel system performance in a diesel engine operating on waste cooking oil

Waste cooking oil (WCO) was experimentally examined to determine whether it can be used as an alternative fuel in a 3-cylinder, 4-stroke, direct injection, 48 kW power tractor engine. The test engine was operated under full load conditions using diesel fuel and waste vegetable oil from the 2400 to 1100 rpm and performance values were recorded. Tests were performed in two stages to evaluate the effect of the waste oils on the engine life cycle. When the test engine was operated with diesel fuel and waste cooking oil; engine torque decreased between at ratio of 0.09 % and 3% according to the engine speed. While no significant difference occurs in the diesel fuel tests at the end of 100 hours of operation, an important reduction was observed in the engine torque of the WCO engine between 4.21% and 14.48% according to the engine speed, and an increase in average smoke opacity ratio was also observed. In accordance with the results obtained from the studies, it was determined that the engine performance values of waste cooking oil show similar properties with diesel fuel, but in long-term usage, performance losses increased. In the SEM analysis performed on the fuel system, there were dark deposits at the nozzle tip and stem. According to an EDX analysis at the nozzle tips, the detected elements point to engine oil ash in the combustion chamber and show coking products (C and O). The other elements (Na, S, Ca, P, Cl, and K) point to used WCO.     

新疆第二代生物液体燃料原料潜力评估

我国政府高度重视生物质能的开发,第二代生物液体燃料是一种清洁可再生的生物质能源,较第一代生物质能源更容易获得,因此大力发展第二代生物液体燃料对改善我国能源结构,实现节能减排具有重要意义.本文从年净生物量大、耐干旱、耐盐碱等角度出发,选择出适合新疆发展的棉花、甜高粱及红柳三种第二代生物液体燃料原料植物,并在了解新疆自然条件及国家和新疆政策法规、规划的基础上,预测到2030年三种生物质能源作物生物量,为相关部门制定生物质能源政策提供参考.     

Bio-Energy Systems at the Community Level in the South Pacific: Impacts & Monitoring

Read, Sims and Adams (2001) detailed a case study for bio-energy implementation in a notional small Pacific Island and elaborated a theoretical model for assessing and simulating the socio-economic impacts of a particular bio-energy system designed to produce an exportable liquid fuel along with rural electricity supplies. An important conclusion was that there is no silver-bullet ‘one size fits all’ bio-energy system suited to all situations. Moreover, a system appropriate at one place and time may become obsolete with exogenous technological advance and/or as a community advances down its own development pathway. In order to understand how these issues interact in practice, a selected set of implementation projects is reviewed highlighting scale, capacity, community, technology, governmental policy and the concept of critical mass, as factors that are central to the successful development of the bioenergy sector. Through this evaluation, it is shown that: 1.A significant biomass supply resource base often exists locally in the form of agricultural and forestry residues on which modern bioenergy programmes could be initiated. The use of biomass energy flow charts are an important tool for evaluating the potential of local and national resources. 2. Without an integrated multi-disciplinary, multi-sector and whole-systems approach to the implementation of bioenergy schemes, long term success is likely to remain elusive. 3. There is a requirement at the national level for a coordinated approach with strong policy signals that overcome perverse and practical obstacles.     

Current Practices and Future Opportunities for Policy on Climate Change and Invasive Species

Abstract:  Climate change and invasive species are often treated as important, but independent, issues. Nevertheless, they have strong connections: changes in climate and societal responses to climate change may exacerbate the impacts of invasive species, whereas invasive species may affect the magnitude, rate, and impact of climate change. We argue that the design and implementation of climate-change policy in the United States should specifically consider the implications for invasive species; conversely, invasive-species policy should address consequences for climate change. The development of such policies should be based on (1) characterization of interactions between invasive species and climate change, (2) identification of areas where climate-change policies could negatively affect invasive-species management, and (3) identification of areas where policies could benefit from synergies between climate change and invasive-species management.     

生物质液化燃油的工业适用性及安全性探讨

简要介绍了中国石油安全面临的问题及其对国家经济可持续发展的可能影响;一般生物燃油的用途、物理性能指标、主要元素含量及其与石化轻油、重油同类指标的对比;论述了生物燃油的工业适用性、安全性和环保性;探讨了生物燃油的生产成本、市场销售预测、生产设备造价、产业化开发的经济收益以及农林剩余物资源潜力和产业化开发可能创造的就业机会等问题。     

“污水-微藻-能源”串联技术新进展

水资源危机和能源危机给人类社会的可持续发展带来前所未有的挑战。微藻具有特殊的生理生态功能和突出的优点,是开展污水净化和生物质能源生产的不二选择。文章在简介微藻清除水体氮磷的特点、作用机理及其影响因素、微藻生产生物质能源的优势、油脂积累机制及其影响因素的基础上,提出一种基于微藻为中介以实现污水氮磷去除与生物质能源开发的串联技术体系。该＂污水-微藻-能源＂串联技术体系从微藻自身的生理生态特色出发,将其在污水净化与生物质能源生产上的优势有机结合起来,实现从污水中索要营养物质供微藻生长需要,以低成本、高效开发利用微藻生物质能源,为共同协调解决水资源危机和能源危机提供了新的思路与途径。通过探讨＂污水-微藻-能源＂串联技术体系的核心理念与开发基础,指出串联技术体系必须重视优质微藻品种的选育、光合生物反应器优化、耦合系统的完善以及高附加值胞内物质后续开发等几个关键技术环节。文章最后展望其发展趋势与应用前景。＂污水-微藻-能源＂串联技术体系的开发应用,有望缓解当前社会面临的水环境污染和能源紧缺双层压力,实现社会、经济、资源与环境的可持续发展,具有极其广阔的应用前景。     

固定化酵母重复发酵性能调控

以2.5%海藻酸钠(w/v)、2%氯化钙(w/v)、2%菌体添加量(w/v,细胞干重)包埋固定酿酒酵母,通过增殖活化和批次短周期发酵对固定化粒子的发酵性能进行调控,减缓循环发酵中固定化粒子发酵性能的退化,同时利用扫描电镜(SEM)对固定化粒子的结构和酵母细胞分布情况进行表征.结果表明:调控后,固定化粒子在葡萄糖浓度为80g/L,pH 4.0,35℃的条件下发酵,发酵性能得到明显改善.调控前,连续3批次发酵,平均乙醇生产强度为0.33g/(L·h);调控后,批次发酵周期由72h缩短为24h,连续5批次发酵,平均乙醇生产强度提高至1.22g/(L·h).