我国发展生物质液体燃料的探讨

从我国发展生物质液体燃料的重要性出发，通过对我国生物质液体燃料资源情况以及乙醇作为车用燃料使用的动力性、经济性、使用中的特殊性(对发动机冷起动、气阻、产生液膜的影响)及安全性(乙醇的毒性、对人体、生态的影响，乙醇的安全性、在使用过程中的排放等)进行了较为全面、详细的分析，提出应大力开展生物质液体燃料的基础研宄工作．     

The Role of Biomass in Greenhouse Gas Mitigation

Abstract

Biomass can play a dual role in greenhouse gas mitigation related to the objectives of the UNFCCC, i.e., as an energy source to substitute for fossil fuels and as a carbon store. However, compared to the maintenance and enhancement of carbon sinks and reservoirs, it appears that the use of biomass has so far received less attention as a means of mitigating climate change. Modern biomass options offer significant, cost-effective and perpetual opportunities toward meeting emission reduction targets while providing additional ancillary benefits. Moreover, via the sustainable use of the accumulated carbon, biomass has the potential for resolving some of the critical issues surrounding long-term maintenance of biotic carbon stocks. In the case of Turkey, energy consumption and environmental pollution are increasing rapidly due to its economic growth. As for the energy consumption, in parallel to the demand for heat and electricity, greenhouse gas emissions (GHGs) from energy use increase accordingly. In this regard, biomass and other renewables are becoming an attractive solution to the GHG mitigation for Turkey and other countries throughout the world. Finally, wood products can act as substitutes for more energy-intensive products, can constitute carbon sinks, and can be used as biofuels at the end of their lifetime.     

Stakeholder perspectives on converting forest biomass to energy in Oregon, USA

Within the state of Oregon, USA, there is considerable interest in the possibility of converting forest biomass to energy. A number of studies have assessed the technical feasibility of forest biomass energy, but few have focused on social aspects, an important consideration in projects involving public forests. This study explores the social context of converting forest biomass to energy, using qualitative research methods. Semi-structured interviews were conducted with forty individuals representing nine different stakeholder groups. Information gained through interviews was used to understand stakeholder views on forest biomass energy, including their perspectives on potential barriers and opportunities in Oregon. Findings indicate the most challenging barrier will be access to long-term, consistent supply. A related challenge is the long history of contention between parties over forest products coming from public lands. However, findings also show that there are many areas of common ground between these groups that have historically been at odds, such as agreement on the necessity of restoration treatments in certain forest types, the by-product of which could be used for biomass generation. Potential conflicts still exist, for instance over projects in mixed conifer forests. Development of policies and projects through inclusive, collaborative approaches could alleviate controversies, potentially allowing more activities to move forward. Information provided by this research creates a foundation for discussions as forest biomass energy becomes an increasingly prominent issue in Oregon, the western USA, and other regions of the world.     

Emissions from sawdust biomass and diesel blends fuels

Biomass producer gas presents a very promising alternative fuel to diesel since it is a renewable and clean burning fuel having similar properties to those of diesel. In this outline, a multi-cylinder diesel engine is experimentally optimized for maximum diesel savings, lower emissions, and without any excessive vibration of the engine using sawdust biomass as producer gas. Emission parameters of the double-fuel engine at diverse gas flow rates are contrasted with those of diesel at distinctive load conditions. The study brings out that the greatest diesel reserve happens to be 80% at 8 kW load without any engine issue in dual-fuel mode. Carbon monoxide (CO), hydrocarbon (HC), and carbon dioxide (CO₂) emissions in dual-fuel mode are more contrasted with diesel at all test extents. Smoke opacity and oxide of nitrogen (NO) emission values in dual-fuel mode are less contrasted with diesel.     

生物质燃料的开发利用现状与展望

分析了生物质燃料作为可持续发展的能源利用的前景 ,从固态、液态和气态三种燃料的状态 ,介绍了国内外生物质燃料的利用形式 ,对生物质燃料的商品化和大规模利用进行了展望     

Conversion of carbon dioxide and methane in biomass synthesis gas for liquid fuels production

The premise of this research is to find whether methane (CH₄) and carbon dioxide (CO₂) produced during biomass gasification can be converted to carbon monoxide (CO) and hydrogen (H₂). Simultaneous steam and dry reforming was conducted by selecting three process parameters (temperature, CO₂:CH₄, and CH₄:steam ratios). Experiments were carried out at three levels of temperature (800 °C, 825 °C and 850 °C), CO₂:CH₄ ratio (2:1, 1:1 and 1:2), and CH₄:steam ratio (1:1, 1:2 and 1:3) at a residence time of 3.5 × 10³ g_cat min/cc using a custom mixed gas that resembles biomass synthesis gas, over a commercial catalyst. Experiments were conducted using a Box-Behnken approach to evaluate the effect of the process variables. The average CO and CO₂ selectivities were 68% and 18%, respectively, while the CH₄ and CO₂ conversions were about 65% and 48%, respectively. The results showed optimum conditions for maximum CH₄ conversion was at 800 °C, CO₂:CH₄ ratio and CH₄:steam ratios of 1:1.     

生物质气化工程在村级集中供气系统中的设计

按照生物质燃气物理特性,根据流体力学对输气管道、排水器等进行水力计算,优化设计出自动排水器等各部分结构和尺寸,并在生物质气化集中供气系统工程中得到很好的应用。     

Leveling the playing field of transportation fuels: Accounting for indirect emissions of natural gas

Natural gas transportation fuels are credited in prior studies with greenhouse gas emissions savings relative to petroleum-based fuels and relative to the total emissions of biofuels. These analyses, however, overlook a source of potentially large indirect emissions from natural gas transportation fuels, namely the emissions from incremental coal-fired generation caused by price-induced substitutions away from natural-gas-fired electricity generation. Because coal-fired generation emits substantially more greenhouse gases and criteria air pollutants than natural-gas-fired generation, this indirect coal-use change effect diminishes potential emissions savings from natural gas transportation fuels. Estimates from a parameterized multi-market model suggest the indirect coal-use change effect rivals in magnitude the indirect land-use change effect of biofuels and renders natural gas fuels as carbon intensive as petroleum fuels.     

Parametric techno‐economic studies of coal/biomass co‐gasification for IGCC plants with carbon capture using various coal ranks,fuel‐feeding schemes,and syngas cooling methods

Because of biomass's limited supply (as well as other issues involving its feeding and transportation), pure biomass plants tend to be small, which results in high production and capital costs (per unit power output) compared with much larger coal plants. Thus, it is more economically attractive to co‐gasify biomass with coal. Biomass can also make an existing plant carbon‐neutral or even carbon‐negative if enough carbon dioxide is captured and sequestered (CCS). As a part of a series of studies examining the thermal and economic impact of different design implementations for an integrated gasification combined cycle (IGCC) plant fed with blended coal and biomass, this paper focuses on investigating various parameters, including radiant cooling versus syngas quenching, dry‐fed versus slurry‐fed gasification (particularly in relation to sour‐shift and sweet‐shift carbon capture systems), oxygen‐blown versus air‐blown gasifiers, low‐rank coals versus high‐rank coals, and options for using syngas or alternative fuels in the duct burner for the heat recovery steam generator (HRSG) to achieve the desired steam turbine inlet temperature. Using the commercial software, Thermoflow^®, the case studies were performed on a simulated 250‐MW coal IGCC plant located near New Orleans, Louisiana, and the coal was co‐fed with biomass using ratios ranging from 10% to 30% by weight. Using 2011 dollars as a basis for economic analysis, the results show that syngas coolers are more efficient than quench systems (by 5.5 percentage points), but are also more expensive (by $500/kW and 0.6 cents/kW h). For the feeding system, dry‐fed is more efficient than slurry‐fed (by 2.2–2.5 points) and less expensive (by $200/kW and 0.5 cents/kW h). Sour‐shift CCS is both more efficient (by 3 percentage points) and cheaper (by $600/kW or 1.5 cents/kW h) than sweet‐shift CCS. Higher‐ranked coals are more efficient than lower‐ranked coals (2.8 points without biomass, or 1.5 points with biomass) and have lower capital cost (by $600/kW without using biomass, or $400/kW with biomass). Finally, plants with biomass and low‐rank coal feedstock are both more efficient and have lower costs than those with pure coal: just 10% biomass seems to increase the efficiency by 0.7 points and reduce costs by $400/kW and 0.3 cents/kW h. However, for high‐rank coals, this trend is different: the efficiency decreases by 0.7 points, and the cost of electricity increases by 0.1 cents/kW h, but capital costs still decrease by about $160/kW. Copyright © 2016 John Wiley & Sons, Ltd.     

Catalytic methods in coal processing to syn-gas,carboneous and liquid fuels contributing to sustainable development

The processes of brown coal autothermal carbonization and steam gasification in a fluidized bed of catalytically active materials, catalytic hydrogenation of brown coal and its mixtures with waste polyolefines and sapropelitic coal liquefaction have been studied. The application of fluidized bed of iron-containing materials, which are able to catalyse the volatives oxidation provides the autothermal conditions of coal carbonization without the formation of harmful polycyclic compounds and pyrolysis tars.     

Assessment of low-rank coal and biomass co-pyrolysis system coupled with gasification

To utilize low-rank coal and biomass in a highly efficient and environmental-friendly manner, a co-pyrolysis system coupled with char gasification is investigated. This system has five main units, namely, the drying and mixing, pyrolysis, cooling and separation, combustion, and gasification units, which are simulated by ASPEN plus based on experimental data. Results show that 37% of the pyrolysis char is burned to supply heat for pyrolysis and drying processes based on cascade utilization of heat energy, whereas the rest is sent to a gasifier. The sensitivity analysis is performed to investigate the impacts of steam and O₂ injection on gas composition, gasification temperature, carbon conversion efficiency, heating value of gas during gasification, and gas production efficiency. The fractions of H₂, CH₄, CO, and CO₂ demonstrate diverse variation tendencies with an increasing equivalence ratio and steam-to-char (S/C) ratio. However, carbon conversion efficiency reaches its peak of 99.91% when the equivalence ratio is approximately 4 regardless of S/C ratio. An equivalence ratio of 4 and S/C ratio of 0.15 are used as decent examples to calculate the mass balance and to simulate the overall system. Results show that 1000 kg/h coal and 500 kg/h biomass can produce 285.83 m³/h pyrolysis gas and 2580.78 m³/h gasification gas with low heating values of 8.20 and 9.746 MJ/m³, respectively.     

Meeting energy demand in a developing economy without damaging the environment—A case study in Sabah,Malaysia, from technical,environmental and economic perspectives

The challenges faced by the developing countries are unique in that they need to meet the increasing energy demands for their economic growths at a competitive price without damaging the environments. In this paper, a case study on the electricity demand issue in Sabah, Malaysia, is presented to investigate potential solutions in addressing this current need for a typical developing economy from the technical, economical and environmental perspectives. Sabah, one of the 13 states in Malaysia, is currently experiencing a serious power shortage, especially at the east coast. A 300 MW coal plant is proposed by the electricity utility company. However, the proposal has been rejected in the past several years due to the negative environmental impacts of the plant. In this paper, a number of alternative solutions were evaluated and proposed with respect to the viability of technologies, financial return and minimum environmental impact in terms of GHG emission.     

生物质能的转化和利用技术研究

能源短缺成为影响中国未来发展的主要问题之一。生物质能的应用有助于解决我国能源短缺的问题，同时能够减小化石燃料使用带来的负面影响。文章主要介绍了生物质能的概念、生物质能利用的意义及生物质能的转化和利用技术，而且还提出实际利用过程中需要解决的问题以及未来的发展方向——以生物质为核心的多联产系统。     

生物质能利用技术比较与分析

生物质能的开发利用可同时解决环境污染和能源短缺问题。分析了生物质能源的特点及其利用现状，并对国内外生物质能利用技术进行了分析与比较，为生物质能利用技术的发展提供参考。     

A system performance and economics analysis of IGCC with supercritical steam bottom cycle supplied with varying blends of coal and biomass feedstock

In recent years, Integrated Gasification Combined Cycle Technology (IGCC) has been gaining popularity for use in clean coal power operations with carbon capture and sequestration. Great efforts have been continuously spent on investigating ways to improve the efficiency and further reduce the greenhouse gas emissions of such plants. This study focuses on investigating two approaches to achieve these goals. First, replace the traditional subcritical Rankine cycle portion of the overall plant with a supercritical steam cycle. Second, add biomass as co‐feedstock to reduce carbon footprint as well as SO_x and NO_x emissions. In fact, plants that use biomass alone can be carbon neutral and even become carbon negative if CO₂ is captured. Due to a limited supply of feedstock, biomass plants are usually small, which results in higher capital and production costs. In addition, biomass can only be obtained at specific times in the year, resulting in fairly low capacity factors. Considering these challenges, it is more economically attractive and less technically challenging to co‐gasify biomass wastes with coal. The results show that for supercritical IGCC, the net efficiency increases with increased biomass in all cases. For both subcritical and supercritical cases, the efficiency increases from 0% to 10% (wt.) biomass and decreases thereafter. However, the efficiency of the blended cases always remains higher than that of the pure‐coal baseline cases. The emissions (NO_x, SO_x, and effective CO₂) and the capital costs decrease as biomass ratio (BMR) increases, but the cost of electricity (CoE) increases with BMR due to the high cost of the biomass used. Finally, implementing a supercritical steam cycle is shown to increase the net plant output power by 13% and the thermal efficiency by about 1.6 percentage points (or 4.56%) with a 6.7% reduction in capital cost, and a 3.5% decrease in CoE. Copyright © 2013 John Wiley & Sons, Ltd.     

我国生物质热解液化技术的现状

文章主要阐述了我国生物质热解液化技术的研究现状，包括现有的热裂解液化装置、反应动力学模型、已检测出的不同原料裂解产生的生物油成分及其物理特性分析，提出了生物油精制的必要性和未来需要研究的问题。     

Activity oriented stochastic computer simulation of forest biomass logistics in Greece

An activity oriented stochastic computer simulation model of forest biomass logistics in Greece, based on SLAMSYSTEM simulation language, has been developed. A SLAMSYSTEM simulation network was built to represent forest biomass units flow from felling to storage at a millyard. A simulation experiment with data collected at the Elatia forest region of Drama in North Greece was executed. Several scenarios of the observed and alternative inventory times, interest rates, and operational systems for forwarding, were used to define the effect of inventory time, interest rate, and loss of value due to fibre deterioration and operational systems, on cost per unit per operational stage, and the final cost at the millyard. The model may be used as a prototype Decision Support System for forest biomass logistics in Greece.     

Sustainable energy development and greenhouse gas emissions in an island power system

The objective of this paper was to investigate the options for the sustainable development of the Northern Ireland energy supply system, reducing greenhouse gas emissions. Particular factors which must be considered centre around the isolation of the system, the prospect of a new gaspipeline and electrical interconnector to the rest of the U.K., and the re‐establishment of an electrical interconnector to the Republic of Ireland. The study has relevance for all similar isolated or island systems, which have particular problems because they tend to be relatively small in size, and their isolation means that inter‐connection with their neighbours is either weak or non‐existent. Because of this, they have to carry greater spare capacity than would normally be the case, with consequent efficiency and cost penalties. Copyright © 2000 John Wiley & Sons, Ltd.     

藻类和木质生物质与烟煤掺混燃烧结渣特性

文章利用沉降炉系统开展了河南烟煤与海草和桃木两种生物质的混燃成渣特性实验,对混燃灰的理化性能、矿物质转化过程及其聚集成渣的趋势进行了研究。研究结果表明:藻类生物质海草能够加剧混燃灰渣颗粒的聚集成块趋势,而木本生物质桃木仅造成混燃灰颗粒粒径的略微增长;掺混海草导致混燃灰中的碱金属,Cl和S元素含量增加,灰渣中出现大量低熔点的长石和类长石矿物质,从而增强了灰渣的黏附能力,表现为由包覆引起的成渣机制;掺混桃木的混燃灰因含有较高的Ca和Fe等元素,从而生成了较多的能够抑制低温共熔物形成的钙质硅(铝)酸盐,其提高了混燃灰的熔融温度,并减缓了成渣趋势;藻类生物质中的碱金属,Cl和S等元素除对成渣过程有较大影响外,还会引起冷凝腐蚀等问题,从而对其资源化应用产生负面影响。