Gaps, barriers and conceptual chasms: theories of technology transfer and energy in buildings

Having shown how much energy might be saved through the use of economically worthwhile measures and technologies, researchers and policy makers then find themselves trying to close the gap between current practice and recognised technical potential. The ensuing process of technology transfer is often seen as a process of overcoming ‘non technical barriers’ which inhibit the realisation of proven technical potential. This familiar approach depends upon a strong conceptual distinction between the social, on the one hand, and the technical, on the other. But does it make sense to talk of technical potential in the abstract? Do people really have technologies ‘transferred’ upon them? Drawing upon ideas from the sociology of science and technology and on recent research funded by Britain's Economic and Social Research Council, this paper unpacks conventional beliefs about the diffusion of energy efficient technologies and suggests an alternative approach which acknowledges the social structuring of technical innovation.     

Scaling-up bio-hydrogen production from food waste: Feasibilities and challenges

Hydrogen has potential as a renewable energy source due to its outstanding clean energy content. The production of hydrogen from food waste by dark fermentation gains attention from researchers across the world as it requires lower energy and chemicals compared to other chemical routes, not to mention that the use of food waste as raw material could help lessen the global waste dumping crisis. Currently, the knowledge of hydrogen production from food waste by dark fermentation is still limited in a laboratory scale. This article intends to provide up-to-date status quo on this technology. Factors affecting production potential, appropriate condition of production, feasibility of scaled-up production and economic value analysis of such technology is summarized and analyzed.     

Microbial hydrogen production by bioconversion of crude glycerol: A review

Hydrogen is a clean source of energy with no harmful byproducts produced during its combustion. Bioconversion of different organic waste materials to hydrogen is a sustainable technology for hydrogen production and it has been investigated by several researchers. Crude glycerol generated during biodiesel manufacturing process can also be used as a feedstock for hydrogen production using microbial processes. The possibility of using crude glycerol as a feedstock for biohydrogen production has been reviewed in this article. A review of recent global biodiesel and crude glycerol production and their future market potential has also been carried out. Similarly, different technical constraints of crude glycerol bioconversion have been elaborately discussed and some strategies for improved hydrogen yield have also been proposed. It has been underlined that use of crude glycerol from biodiesel processing plants for hydrogen production has many advantages over the use of other organic wastes as substrate. Most importantly, it will give direct economic benefit to biodiesel manufacturing industries, which in turn will help in increasing biofuel production and it will partially replace harmful fossil fuels with biofuels. However, different impurities present in crude glycerol are known to inhibit microbial growth. Hence, suitable pretreatment of crude glycerol is recommended for maximum hydrogen yield. Similarly, by using suitable bioreactor system and adopting continuous mode of operation, further investigation of hydrogen production using crude glycerol as a substrate should be undertaken. Furthermore, isolation of more productive strains as well as development of engineered microorganism with enhanced hydrogen production potential is recommended. Strategies for application of co-culture of suitable microorganisms as inoculum for crude glycerol bioconversion and improved hydrogen production have also been proposed.     

Technology up date and new strategies on fuel cells

This paper reports the state of art on fuel cells technology, outlines the most significant results reached all over the world and summarises the strategies developed by researchers and producers to get the commercialisation of these systems. In particular, the authors have examined three potential application fields for fuel cells: (i) stationary power plant for electricity production; (ii) portable power applications; (iii) electric vehicles.

The potential market area for each sector of application has been defined and the research activity necessary to overcome the technical problems that are still open have been detailed. The significant projects of main fuel cells producers are also mentioned.     

Valorization of hydrothermal liquefaction aqueous phase: pathways towards commercial viability

Hydrothermal liquefaction (HTL) is a thermochemical conversion technology that shows promising commercial potential for the production of biocrude oil from wet biomass. However, the inevitable production of the hydrothermal liquefaction aqueous phase (HTL-AP) acts as a double-edged sword: it is considered a waste stream that without additional treatment clouds the future scale-up prospects of HTL technology; on the other hand, it also offers potential as an untapped nutrient and energy resource that could be valorized. As more researchers turn to liquefaction as a means of producing renewable fuel, there is a growing need to better understand HTL-AP from a variety of vantage points. Specifically, the HTL-AP chemical composition, conversion pathways, energy valorization potential, and the interconnection of HTL-AP conversion with biofuel production technology are particularly worthy of investigation. This paper extensively reviews the impact of HTL conditions and the feedstock composition on the energy and elemental distribution of process outputs with specific emphasis on the HTL-AP. Moreover, this paper also compares and contrasts the current state of value-added products separation along with biological (biomass cultivation, anaerobic fermentation, and bioelectrochemical systems) and thermochemical (gasification and HTL) pathways to valorize HTL-AP. Furthermore, life cycle analysis (LCA) and techno-economic assessments (TEA) are performed to appraise the environmental sustainability and economic implications of these different valorization techniques. Finally, perspectives and challenges are presented and the integration approaches of HTL-AP valorization pathways with HTL and biorefining are explored.     

太阳能热发电经济性分析和产业激励政策建议

太阳能热发电作为能够输出稳定优质电力的可再生能源发电形式,已在欧洲、美国等国家和地区快速发展。随着产业链的不断完善、技术水平的逐步提升,太阳能热发电产业有望加速进入规模化发展的新阶段。为促进国内太阳能热发电产业发展,国家能源局于2012年9月委托国家太阳能光热产业技术创新战略联盟会同国家可再生能源中心等单位就太阳能热发电产业发展政策开展研究。通过分析我国太阳能热发电技术现状、产业基础及发展中面临的突出技术和政策问题,发现发电成本高是阻碍太阳能热发电技术在我国产业化推广的最大障碍。鉴于国内尚无商业化太阳能热发电站,同时也不能完全照搬国外的经验模式,研究人员通过采用国际范围内普遍适用的商业化电站投融资模式分析经验,对在中国建设运行一个50 MW槽式太阳能热发电站的经济性和2020年导致成本下降的潜在机遇进行了分析,在假设现行1元/(kW•h) 的光伏上网电价同样适用于太阳能热发电的基础上,提出了扶持太阳能热发电产业发展的短期激励政策建议,同时也对出台商业化太阳能热发电上网电价的可能性以及固定电价形成的方法进行了探讨。     

The current status and perspectives of biofuel production via catalytic cracking of edible and non-edible oils

Biofuel development has gained the attention of researchers in recent years owing to the rate of depletion of fossil fuels. Several processes are currently employed in the conventional production of different biofuels: the production of biodiesel is catalytically performed either through the transesterification of triglycerides using alcohol or the deoxygenative ecofining of triglycerides in a non-alcohol environment; bio-oil is produced by the pyrolysis of biomass; bio-ethanol is produced by the fermentation of sugars obtained from starch or cellulosic based biomass, while bio-gasoline is produced from the catalytic cracking of triglycerides. Owing to the enormous dependency of transport vehicles running on gasoline engines, the development of bio-gasoline may well reduced the dependence of the fuel market on fossil fuels. The present article summarizes recent progresses and future prospects of biofuel production via catalytic cracking technology. This technology can be implemented in current petroleum refineries with minor modifications. However, reactor design and catalyst choice are important issues and have to be addressed before successful implementation of this technology in commercial ventures.     

Downdraft gasification of pellets made of wood,palm-oil residues respective bagasse: Experimental study

The downdraft gasification technology has an increased interest among researchers worldwide due to the possibility to produce mechanical and electrical power from biomass in small-scale to an affordable price. The research is generally focused on improvement of the performance and optimizing of a certain gasifier, on testing different fuels, on increasing the user-friendliness of the gasifier and on finding other uses for the product gas than in an IC-engine, for example liquid fuel production.     

有机朗肯循环的研究进展

有机朗肯循环是一种被认为能有效利用低温热能的技术。科研工作者在不同方面（包括工质、膨胀机、换热器的影响、系统的优化）对有机朗肯循环系统效率的影响进行了大量的研究。本文针对不同热源的工质筛选、膨胀机的特点、系统循环优化以及换热器的影响方面进行了讨论和总结,为有机朗肯循环系统的实际应用提供参考。     

Biofuel cell nanodevices

Looking at the past decades, intense efforts have been made on one of the flourishing technology called biofuel cells with respect to the power or energy crisis prevailing all over the globe. Global researchers are taking part in the development of biofuels cells by exploiting novel characteristics of unconventional materials at atomic and molecule level like nanotubes (carbon nanotubes), nanosheets, nanoparticles, conducting polymers, etc in order to generate effective electricity from the substrates of biological origin via utilizing various biocatalysts. With the advancement in the field of nanotechnology, significant discoveries with respect to the field of biofuel cells have been accomplished. But till date, there has been a significant challenge regarding the performance and efficiency of the biofuels cells. Nowadays, to generate high power, an efficient and skillful approach which consists of the implementation of nano-based materials and conducting polymers with respect to the assembly of the biofuel cells is being considered by many researchers. Bioenergy and biofuels is a potential contestant for alternative fuel and with regard to this nanotechnology is one such significant weapon to synthesize and modify the production of biofuel and bio-energy. It has been assumed that in the near future with such extensive research biofuel cells will take up the economy of a nation in a sustainable way. This review gives the insights of biofuel cells and their types, brief synopsis of applications of the biofuel cells along with the scrutiny of biofuel cells in the market. Significant discussions have been provided in this review relating to the nanomaterials being employed as an electrode in biofuel cells. Certain examples have been mentioned to justify the concept of biofuel cell nanodevices following the ethical considerations of the same.     

A review on sediment microbial fuel cells as a new source of sustainable energy and heavy metal remediation: mechanisms and future prospective

Sediment microbial fuel cells (SMFCs) are different from microbial fuel cells because they are completely anoxic and lack a membrane. SMFCs are a novel technology for the simultaneous production of renewable energy and bioremediation of heavy metals. Recently, SMFCs have attracted the attention of many researchers because of their moderate functioning parameters and ability to use a range of biodegradable substrates like glucose, glutamic acid, river water, cysteine, acetate, and starch. The inocula used in SMFCs include river sediment, marine sediment, and wastewater. For power generation, many exoelectrogens in SMFCs have the ability to transfer electrons from electrodes by using natural electron shuttles. Exoelectrogens use four primary pathways to transfer electrons to the electrodes, including short‐range electron transfer through redox‐active proteins, soluble electron shuttling molecules, long‐range electron transport by conductive pili, and direct interspecies electron transfer. The most dominant mechanism is long‐range electron transfer via conductive pili because pili have metal‐like conductivity. The powering by microbes is an emerging technique for the remediation of heavy metals from sediments. The pathways for transferring electrons in electrotrophs operate in the opposite direction from those in exoelectrogens. To further upgrade SMFC technology, this review targets the prototype, operating factors, working mechanisms, applications, and future perspectives of SMFCs. Copyright © 2017 John Wiley & Sons, Ltd.     

Review on phase change material emulsions and microencapsulated phase change material slurries: Materials, heat transfer studies and applications

Phase change materials (PCM) in the form of slurries have had an increasingly important role as heat transfer fluids and as thermal energy storage media. Although it is a recent technology in the field of thermal energy storage with phase change materials, the volume of literature begins to be significant. This investigation carries out a compilation of information on two latent thermal fluids: PCM emulsions and microencapsulated PCM slurries (mPCM slurries). This review presents tables containing information on the different PCM emulsions and mPCM slurries studied by different researchers, as well as commercially available products. Thermophysical and rheological properties are analyzed, making a special effort to analyze heat transfer phenomena, concluding with the enumeration of application examples available in literature.     

A review on thermo-chemical characteristics of coal/biomass co-firing in industrial furnace

Biomass should be considered as one of the promising sources of energy for mitigating greenhouse gas (GHG) emissions. Co-firing biomass with coal has become a solution for meeting the power crisis as well as to reduce the pollutant emissions. The biomass fuels typically found from woody to grassy and solid recovered fuels depending on its origin and properties. It is suggested that co-firing coal with biomass has a substantial effect on SO_x and NO_x emission level. The ashing process, fly ash quality depends on the conversion technology, capture technology and the properties of the biomass. In order to control the furnace efficiency and production, burnout, optimum injection of biomass sharing with specific information of particle ignition properties are also important. A number of small/laboratory scale and industrial scale experiments have been conducted by different researchers. Different experimental studies performed are reviewed, grouped and summarized based on the fuel processing technology, burnout performance, emission level, environmental aspect, ash information and deposit characteristics, effect of co-firing ratios and adoption of oxy-fuel co-firing. Overall, this paper will highlight existing technologies and emerging trends in co-firing of different types of biomass which will be helpful for future investigations.     

Alternative fuel for gas turbine: Esterified jatropha oil–diesel blend

The oil crisis and the global effort to control the greenhouse effect have forced the researchers to think of various alternative energy sources. This decade has seen increasing importance of chemically treated vegetable oil biodiesel fuels for various applications in heat engines. Post-Kyoto negotiations refer to high level talks attempting to address global warming by limiting greenhouse gas emissions. During Climate Change Conference in Copenhagen the potential topics discussed were carbon capture and storage, biofuels, adaptation financing, technology transfer, sustainable agriculture, emissions targets, tropical forests and rural and transport electrification. Our area of interest is biofuels under which nonedible Jatropha oil due to its properties which are very close to diesel fuel is being explored as an alternative fuel. A lot of research is underway in the use of different biodiesel fuels in Internal Combustion engines, but very limited work has been reported in its use in gas turbines. This paper describes the results of an ongoing development program aimed at determining the technical feasibility of utilizing biodiesel in IS/60 Rovers gas turbine. The test rig is equipped with a dynamometer for turbine loading and AVL exhaust gas analyzer has been used to record emissions. The test results of 2 blends have been reported in this paper. Analyzing the results compared with the base line performance using diesel fuel under normal conditions show encouraging outcomes.     

Potential of photovoltaic systems in countries with high solar irradiation

Renewable energy sources derived principally from solar energy have been gaining ground over the last few years and are now beginning to contribute to the global energy mix. Solar energy in the form of direct electricity conversion (photovoltaics) is already very popular in countries such as the United States, Germany and Japan. The enormous potential of photovoltaic (PV) technology is also obvious and favourable in countries with high irradiation such as the Mediterranean region. The objective of this paper is to review the different up and coming PV technologies, to explore the potential of different PV systems in countries with high solar irradiation and to compare their performance through the assessment of thirteen different types of PV systems that have been installed side by side in Nicosia, Cyprus and Stuttgart, Germany. Finally useful insight into the performance of the PV systems as a function of the meteorological conditions and location will be highlighted.     

Promoting the development of distributed concentrated solar thermal technology in China

Solar energy is increasingly essential to fortify energy security and promote Chinese socio-economic development. The applications of solar thermal energy in China are mainly centralized at low and medium temperature, such as solar water heating, solar cooling and air conditioning, building heating, solar drying and solar power generating. Based on the reality in China, it is presented in this paper that China should promote the distributed concentrated solar thermal (DCST) technology, especially in the industrial field. This technology, which has the potential to reduce the high cost of DCST and overcome the intermittent output of solar energy, is discussed in this paper, as well as how to put DCST technology forward and enlarge scale deployment in China. Finally, it is hoped that suggestions in this paper could be helpful to the researchers, designers and policy-makers who are involving in this field.     

EC FPVI co-ordinated action on ocean energy: A European platform for sharing technical information and research outcomes in wave and tidal energy systems

Energy from the oceans has the potential to make major contributions towards renewable energy targets being adopted by European Governments over the next 10–15 years. To transform this from a possibility into a reality within the time frames requires numerous support frameworks to be implemented which assist research and demonstration programmes and stimulated the sharing of knowledge and resource information between all relevant parties. The EC funded Co-ordinated Action on Ocean Energy puts into place funding and a platform to enables device developers, wave and tidal energy researchers and standards agencies to share knowledge and information which will facilitate the transition of wave and tidal energy from an energy research technology to one approaching commercial competitiveness within the medium-term time frame, 2010–2015.     

利用微藻热化学液化制备生物油的研究进展

微藻是制备生物质液体燃料的良好材料,利用微藻热化学液化制备生物油在环保和能源供应方向都具有非常重要的意义。目前国内外研究者主要采用快速热解液化和直接液化两种热化学转化技术进行以微藻为原料制备生物油的研究。快速热解生产过程在常压下进行,工艺简单、成本低、反应迅速、燃料油收率高、装置容易大型化,是目前最具开发潜力的生物质液化技术之一。但快速热解需要对原料进行干燥和粉碎等预处理,微藻含水率极高,会消耗大量的能量,使快速热解技术在以微藻为原料制备生物油方面受到限制。直接液化技术反应温度较快速热解低,原料无需烘干和粉碎等高耗能预处理过程,且能产生更优质的生物油,将会是微藻热化学液化制备生物油发展的主流方向,极具工业化前景。国内外研究者还尝试利用超临界液化、共液化、热化学催化液化、微波裂解液化等多种新型液化工艺进行微藻热化学液化制备生物油的实验研究。今后的主要研究方向应是将热化学液化原理研究、生产工艺开发、反应器研发、反应条件优化、产品精制等有机地结合起来,进行深入研究。同时应努力节约成本、降低能耗。