-
14751.浮游植物的粒子-一种新的赤潮建模方法
[电力、热力、燃气及水生产和供应业] [2014-08-06]
The authors investigate the hypothesis that phytoplankton blooms can be modeled by treating phytoplankton as discrete particles. A particle-tracking model is inserted into the CE-QUAL-ICM eutrophication model. Phytoplankton are quantified as carbonaceous biomass attached to the particles. Kinetics are adapted from CE-QUAL-ICM. The new model is operated along with existing hydrodynamic and watershed models of the Potomac River estuary. Initial application is to the winter-spring 1994 period. The new model is compared to observations and to a conventional model of the spring diatom bloom. The particle-based model successfully computes a subsurface chlorophyll maximum. The model characteristically displays heterogeneous spatial distribution of chlorophyll with high-amplitude oscillations at the semi-diurnal period. The characteristics and applicability of the particle approach are now established. The model requires optimization of parameter values to improve representation of the observed bloom in the Potomac.
关键词:时间序列分析;藻类;浮游植物;生物质能
-
14752.使用ASPENPLUS模拟高温空气-蒸汽生物质气化的在吸式气化炉
[电力、热力、燃气及水生产和供应业] [2014-08-06]
A comprehensive process model is developed for high temperature air-steam biomass gasification in a downdraft gasifier using the ASPEN PLUS simulator.The simulation results are compared with the experimental data obtained through pilot scale downdraft gasifier.In this study,the model is used to investigate the effects of gasifying agent preheating,equivalence ratio (ER),and steam/biomass (S/B) on producer gas composition,high heating value (HHV),and cold gas efficiency (CGE).Results indicate that H2 and CO contents have increased when gasifying agent preheating is used,while gasifying agent preheating has no effect with H2 and CO at high ER.At high level of S/B,the concentrations of H2 and CO are related with water-gas shift reaction in significant.HHV and CGE depend on the concentrations of H2 and CO in producer gas,which can increase by preheated gasifying agent.However,gasifying agent preheating should apply with waste heat from the process because there is no additional cost of energy price.
关键词:下吸式气化炉; ASPEN PLUS;高温空气 - 蒸汽气化;生物质能
-
14753.使用响应曲面法研究聚乙烯醇(PVA)-Collagen水凝胶的物理特性
[电力、热力、燃气及水生产和供应业] [2014-08-06]
A novel covalent bond cross-linked poly (vinyl alcohol) (PVA)-collagen hydrogel was prepared and the physical properties were studied.The carboxyl groups were introduced into PVA through the reaction with chloroacetic acid.The EDC and NHS were used as cross-linker.The hydrogels were prepared by repeated freezing and thawing.For a better understanding of the influence of the parameters and their interaction,three factors were investigated by a response surface methodology.The physical properties of the hydrogels were analyzed.The results indicated that the response surface models could significantly fit the response values.Moreover,comparing with the single factor,the interactions between factors had more obvious effects to the physical properties of PVA-Collagen hydrogels.After the analysis of factors' influences and investigation of the data and trends,the structure of the hydrogels might be the driving force of the different physical behaviors.
关键词:聚(乙烯醇);胶原蛋白;凝胶;物理性能;生物质能
-
14754.常年提问2012:农民的选择和生物燃料的未来
[电力、热力、燃气及水生产和供应业] [2014-08-06]
The U.S. Renewable Fuel Standard (RFS2) is a strategic response to concerns under the Energy Independence and Security Act (EISA) of 2007 about petroleum fuel supplies and environmental sustainability (EPA 2012). RFS2 regulations mandate specific amounts of renewable fuels to be blended into gasoline and diesel. The renewable fuels also need to emit fewer greenhouse gases than the displaced petroleum. In 2012, the target is for 9of all fuel will be from renewable sources, or a minimum of 15.2 billion gallons of renewable fuel. By 2022, the target is for 36 billion gallons of renewable fuel to be blended into gasoline and diesel and of that amount, 16 billion gallons derived from cellulosic biofuels. While some advanced biofuel will be refined from forest, crop, and urban residues, this paper focuses on the patterns of farmers choices regarding dedicated perennial lignocellulosic energy crops. Throughout this paper we use the term perennial as shorthand for warm season grasses such as those in the genus Panicum or Miscanthus, or short rotation tree crops such as those in the genus Populus or Salix. We focus on choices about these perennial crops because two thirds of the mandated advanced biofuels are expected to be converted at biorefineries from perennials (USDA 2010). RFS2 establishes the goals, but not mechanisms for achieving them. Mechanisms and incentives, however, are embedded in other legislation and programs. For example, the 2008 Farm Bill created the Biomass Crop Assistance Program (BCAP) that is designed to entice farmers to plant and deliver biomass feedstock to biorefineries and electrical plants. The effectiveness of this new program, however, has yet to be fully explored (Aguilar et al. 2011). In 2011, the program received over 40 project area proposals, exceeding the available funding, suggesting increasing adoption, or at least exceeding expectations of policymakers.
关键词:生物燃料;生物质;农业分析;生物能源
-
14755.评价热解油性质和化学的相关的处理和升级并应特别注意管道装运条件
[电力、热力、燃气及水生产和供应业] [2014-08-04]
One factor limiting the development of commercial biomass pyrolysis is challenges related to the transportation of the produced pyrolysis oil. The oil has different chemical and physical properties than crude oil, including more water and oxygen and has lower H/C ratio, higher specific gravity and density, higher acidity, and lower energy content. These differences could limit its ability to be transported by existing petroleum pipelines. Pyrolysis oil can also be treated, normally by catalytic hydrodeoxygenation, and approaches crude oil and petroleum condensates at higher severity levels. This improvement also results in lower liquid yield and high hydrogen consumption. Biomass resources for pyrolysis are expected to become plentiful and widely distributed in the future, mainly through the use of crop residuals and growing of energy crops such as perennial grasses, annual grasses, and woody crops. Crude oil pipelines are less well distributed and, when evaluated on a county level, could access about 18of the total biomass supply. States with high potential include Texas, Oklahoma, California, and Louisiana. In this study, published data on pyrolysis oil was compiled into a data set along with bio-source source material, pyrolysis reactor conditions, and upgrading conditions for comparison to typical crude oils. Data of this type is expected to be useful in understanding the properties and chemistry and shipment of pyrolysis oil to refineries, where it can be further processed to fuel or used as a source of process heat.
关键词:热解油;化学;管道;生物量;化学性质
-
14756.阿斯彭FACE实验中地上生物量和异速生长分析的最终结果
[电力、热力、燃气及水生产和供应业] [2014-08-04]
Our objectives in year 3 were to (1) process fine root samples for DNA fingerprinting (2) complete the data analysis and publish results. During the 2009 field harvest, fine root samples were collected from 6 soil cores from each of 12 treatment rings. After sampling, the soil cores were cut horizontally into 10 cm slices. The fine roots from the 0--10 cm depth were placed on a 1 x 1 mm sieve and rinsed gently with water to separate soil and root material. The root material was placed in plastic bags moistened with water and stored at 4 C until the fresh tissue could be transported to the laboratory. Sample were sorted carefully using forceps and frequent washing to separate the individual fine root fragments. The fine roots of trembling aspen (Populus tremuloides Michx.) were separated from those of other plant species based on morphology and color.
关键词:生物量;植物(植物);DNA测序;森林树木;生物质能
-
14757.生物质在奥运会和吉赛普半岛的生产:更新了日志的残留比率、湿地桩体积与重量比、曲线和供给曲线的选择位置
[电力、热力、燃气及水生产和供应业] [2014-08-04]
iomass residue produced by timber harvest operations is estimated for the Olympic and Kitsap Peninsulas, Washington. Scattered residues were sampled in 53 harvest units and piled residues were completely enumerated in 55 harvest units. Production is based on 2008 and 2009 data and is stratified by forest location, ownership type, harvest intensity, and harvest method. An additional sampling was taken to ascertain the mass of wood present in a pile of biomass: 20 piles of biomass were measured for gross volume, processed into hog fuel, and remeasured for volume; five samples were drawn from each pile and examined for volume, green mass, and bone-dry mass. An equation relating mass of wood in a pile to the gross biomass volume is derived. Finally, the availability and average delivered cost per ton of biomass is calculated for five delivery centers on the Olympic Peninsula.
关键词:生物质残留;湿地;生猪燃料;体积密度;生物质能
-
14758.热解油双层合成气技术的分布式生产
[电力、热力、燃气及水生产和供应业] [2014-08-04]
We have successfully demonstrated a novel reactor technology, based on BASF dual layer monolith catalyst, for miniaturizing the autothermal reforming of pyrolysis oil to syngas, the second and most critical of the three steps for thermochemically converting biomass waste to liquid transportation fuel. The technology was applied to aged as well as fresh samples of pyrolysis oil derived from five different biomass feedstocks, namely switch-grass, sawdust, hardwood/softwood, golden rod and maple. Optimization of process conditions in conjunction with innovative reactor system design enabled the minimization of carbon deposit and control of the H2/CO ratio of the product gas. A comprehensive techno-economic analysis of the integrated process using in part, experimental data from the project, indicates (1) net energy recovery of 49accounting for all losses and external energy input, (2) weight of diesel oil produced as a percent of the biomass to be approx. 14, and (3) for a demonstration size biomass to Fischer-Tropsch liquid plant of approx. 2000 daily barrels of diesel, the price of the diesel produced is approx. $3.30 per gallon, ex. tax. However, the extension of catalyst life is critical to the realization of the projected economics.
关键词:ATR反应器;油热解;合成气;生物质能
-
14759.2014年7月(下半月)电力行业要闻综述
[电力、热力、燃气及水生产和供应业] [2014-08-04]
国家能源局网站7月18日消息,为适应可再生能源发展形势需要,维护风力发电场、光伏电站和电网企业的合法权益,促进电力系统安全优质经济运行,近日,国家能源局和国家工商行政管理总局根据《中华人民共和国电力法》、《中华人民共和国合同法》、《中华人民共和国可再生能源法》等法律法规和国家有关规定,在充分研讨和广泛征求意见的基础上,制定了风力发电场、光伏电站并网调度协议和购售电合同示范文本,并正式印发。
关键词:电力;行业要闻
-
14760.易地催化快速热解技术途径
[电力、热力、燃气及水生产和供应业,化学原料和化学制品制造业] [2014-08-04]
In support of the Bioenergy Technologies Office, the National Renewable Energy Laboratory (NREL) and the Pacific Northwest National Laboratory (PNNL) are undertaking studies of biomass conversion technologies to hydrocarbon fuels to identify barriers and target research toward reducing conversion costs. Process designs and preliminary economic estimates for each of these pathway cases were developed using rigorous modeling tools (Aspen Plus and Chemcad). These analyses incorporated the best information available at the time of development, including data from recent pilot- and bench-scale demonstrations, collaborative industrial and academic partners, and published literature and patents. This technology pathway case investigates converting woody biomass using ex-situ catalytic fast pyrolysis followed by upgrading to gasoline-, diesel-, and jet-range hydrocarbon blendstocks. Technical barriers and key research needs that should be pursued for this pathway to be competitive with petroleum-derived blendstocks have been identified.
关键词:生物质热解;催化剂;化学分析;转换;生物质能