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1.
To address the problem of fossil fuel usage at the Missouri University of Science and Technology campus, using of alternative fuels and renewable energy sources can lower energy consumption and hydrogen use. Biogas, produced by anaerobic digestion of wastewater, organic waste, agricultural waste, industrial waste, and animal by-products is a potential source of renewable energy. In this work, we have discussed the design of combined heat, hydrogen and power (CHHP) system for the campus using local resources. An energy flow and resource availability study is hydrogen recovery, cleaning and energy End-Uses on the university campus from CHHP system. Following the resource assessment study, our team selects Fuel Cell Energy direct fuel cell (DFC) 1500TM unit as a molten carbonate fuel cell. The CHHP system provides the hydrogen for transportation, back-up power and other needs. The research presented in this paper was performed as part of the 2012 Hydrogen Student Design Contest. In conclusion, the CHHP system will be able to reduce fossil fuel usage, greenhouse gas (GHG) emissions and hydrogen generated is used to power different applications on the university campus.  相似文献   

2.
As a carbon-free molecule, ammonia has gained great global interest in being considered a significant future candidate for the transition toward renewable energy. Numerous applications of ammonia as a fuel have been developed for energy generation, heavy transportation, and clean, distributed energy storage. There is a clear global target to achieve a sustainable economy and carbon neutrality. Therefore, most of the research's efforts are concentrated on generating cost-effective renewable energy on a large scale rather than fossil fuels. However, storage and transportation are still roadblocks for these technologies, for example, hydrogen technologies. Ammonia could be replaced as a viable fuel for a clean and sustainable future of global energy. More efforts from governments and scientists can lead to making ammonia a clean energy vector in most energy applications. In this review, ammonia synthesis was assessed, including conventional Haber–Bosch technology. Current hydrogen technologies as the key parameters for ammonia generation are also evaluated. The role of ammonia as a hydrogen-based fuel and generation roadmap are discussed for future utilization of energy mix. Further, ammonia generation processes are addressed in depth, including blue and green ammonia generation. A survey of ammonia synthesis catalytic materials was conducted and the role of catalyst materials in ammonia generation was compared, which showed that the Ru-based catalyst generated the maximum ammonia after 20 h of starting experiment. An end-use plan for using ammonia as a clean energy fuel in vehicles, marines, gas turbines as well as fuel cells, is briefly discussed to recognize the potential applications of ammonia use. The practical and future end-use vision of energy sources is proposed to achieve great benefits at low carbon emissions and costs. This review can provide prospective knowledge of large-scale aspects and environmental considerations of ammonia. Herein, we conclude that ammonia will become the “clean energy carrier link” that will achieve the global energy and economy sustainability targets.  相似文献   

3.
To address the problem of fossil fuel usage at the Missouri University of Science and Technology campus, using of alternative fuels and renewable energy sources can lower energy consumption and hydrogen use. Biogas, produced by anaerobic digestion of wastewater, organic waste, agricultural waste, industrial waste, and animal by-products is a potential source of renewable energy. In this work, we have discussed Hydrogen production and End-Uses from CHHP system for the campus using local resources. Following the resource assessment study, the team selects FuelCell Energy DFC1500™ unit as a molten carbonate fuel cell to study of combined heat, hydrogen and power (CHHP) system based on a molten carbonate fuel cell fed by biogas produced by anaerobic digestion. The CHHP system provides approximately 650 kg/day. The total hydrogen usage 123 kg/day on the university campus including personal transportation applications, backup power applications, portable power applications, and other mobility applications are 56, 16, 29, 17, and 5 respectively. The excess hydrogen could be sold to a gas retailer. In conclusion, the CHHP system will be able to reduce fossil fuel usage, greenhouse gas emissions and hydrogen generated is used to power different applications on the university campus.  相似文献   

4.
An increasingly large percentage of power is being generated from renewable energy sources with intermittent and fluctuating outputs. Therefore there is a growing need for energy storage. With power-to-gas, excess electricity is converted into hydrogen by water electrolysis, which can be stored and, when needed, can be reconverted into electricity with fuel cells. Besides the energy vector for electricity, mobility and heat, hydrogen can be utilized as a raw material for the chemical industry or further be used for the synthesis of various hydrocarbon fuels such as methane.  相似文献   

5.
As the global demand for energy rapidly increases and fossil fuels will be soon exhausted, bio‐energy has become one of the key options for shorter and medium term substitution for fossil fuels and the mitigation of greenhouse gas emissions. Biomass currently supplies 14% of the world's energy needs. Biomass pyrolysis has a long history and substantial future potential—driven by increased interest in renewable energy. This article presents the state‐of‐the‐art of biomass pyrolysis systems, which have been—or are expected to be—commercialized. Performance levels, technological status, market penetration of new technologies and the costs of modern forms of biomass energy are discussed. Advanced methods have been developed in the last two decades for the direct thermal conversion of biomass to liquid fuels, charcoals and various chemicals in higher yields than those obtained by traditional pyrolysis processes. The most important reactor configurations are fluidized beds, rotating cones, vacuum and ablative pyrolysis reactors. Fluidized beds and rotating cones are easier for scaling and possibly more cost effective. Slow pyrolysis is being used for the production of charcoal, which can also be gasified to obtain hydrogen‐rich gas. The short residence time pyrolysis of biomass (flash pyrolysis), at moderate temperatures, is being used to obtain a high yield of liquid products (up to 70% wt), particularly interesting as energetic vectors. Bio‐oil can substitute for fuel oil—or diesel fuel—in many static applications including boilers, furnaces, engines and turbines for electricity generation. While commercial biocrudes can easily substitute for heavy fuel oils, it is necessary to improve the quality in order to consider biocrudes as a replacement for light fuel oils. For transportation fuels, high severity chemical/catalytic processes are needed. An attractive future transportation fuel can be hydrogen, produced by steam reforming of the whole oil, or its carbohydrate‐derived fraction. Pyrolysis gas—containing significant amount of carbon dioxide, along with methane—might be used as a fuel for industrial combustion. Presently, heat applications are most economically competitive, followed by combined heat and power applications; electric applications are generally not competitive. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

6.
The purpose of this study is to assess the political, economic and environmental impacts of producing hydrogen from biomass. Hydrogen is a promising renewable fuel for transportation and domestic applications. Hydrogen is a secondary form of energy that has to be manufactured like electricity. The promise of hydrogen as an energy carrier that can provide pollution-free, carbon-free power and fuels for buildings, industry, and transport makes it a potentially critical player in our energy future. Currently, most hydrogen is derived from non-renewable resources by steam reforming in which fossil fuels, primarily natural gas, but could in principle be generated from renewable resources such as biomass by gasification. Hydrogen production from fossil fuels is not renewable and produces at least the same amount of CO2 as the direct combustion of the fossil fuel. The production of hydrogen from biomass has several advantages compared to that of fossil fuels. The major problem in utilization of hydrogen gas as a fuel is its unavailability in nature and the need for inexpensive production methods. Hydrogen production using steam reforming methane is the most economical method among the current commercial processes. These processes use non-renewable energy sources to produce hydrogen and are not sustainable. It is believed that in the future biomass can become an important sustainable source of hydrogen. Several studies have shown that the cost of producing hydrogen from biomass is strongly dependent on the cost of the feedstock. Biomass, in particular, could be a low-cost option for some countries. Therefore, a cost-effective energy-production process could be achieved in which agricultural wastes and various other biomasses are recycled to produce hydrogen economically. Policy interest in moving towards a hydrogen-based economy is rising, largely because converting hydrogen into useable energy can be more efficient than fossil fuels and has the virtue of only producing water as the by-product of the process. Achieving large-scale changes to develop a sustained hydrogen economy requires a large amount of planning and cooperation at national and international alike levels.  相似文献   

7.
The adoption of new environmentally responsible technologies, as well as, energy efficiency improvements in equipment and processes help to reduce CO2 rate emission into the atmosphere, contributing in delaying the consequences of intensive use of fossil fuels. For more effective actions, it is necessary to make the transition from the fossil-based to the renewable source economy. In this context, hydrogen fuel has a special role as clean vector of energy. Hydrogen has the potential to be decisive in mitigating greenhouse gas emissions, but fossil fuels high profitability due to global energy dependency actually drives the global economy.While renewable energy sources are not worldwide fully established, new technologies should be developed and used for the recovery of energetic streams nowadays wasted, to decarbonize hydrocarbons and to improve systems efficiency creating a path that can help nations and industries in the needed energy economy transition. Hydrogen gas can be generated by various methods from different sources such as coal and water. Currently, almost all of the hydrogen production is for industrial purpose and comes from the Steam Reforming, while the use of hydrogen in fuel cells is only incipient.The article analysis the plasma pyrolysis of hydrocarbons as a decarbonization option to contribute as a step towards hydrogen economy. It presents the Carbon Black and Hydrogen Process (CB&H Process) as an alternative option for hydrogen generation at large scale facility, suitable for supplying large amounts of high-purity carbon in elemental form. CB&H Process refers to a plant with hydrogen thermal plasma reactor able to decompose Hydrocarbons (HC's) into Hydrogen (H2) and Carbon Black (CB), a cleaner technology than its competing processes, capable of generating two products with high added value. Considering the Brazilian context in which more than 80% of the generated electricity comes from renewable sources, the use of electricity as one of the inputs in the process does not compromise the objective of reducing greenhouse gas emissions. It is important to consider that the use of renewable energy to produce two products derived from fossil fuels in a clean way represents integration of technologies into a more efficient system and an arrangement that contributes to the transition from fossil fuels to renewables.The economic viability of the CB&H process as a hydrogen generation unit (centralized) for refining applications also depends on the cost of hydrogen production by competing processes. Steam Methane Reforming (SMR) is a widespread method that produces twice the amount of hydrogen generated by natural gas plasma pyrolysis, but it emits CO2 gas and consumes water, while CB&H process produces solid carbon. For this reason, the paper seeks the carbon production cost by plasma pyrolysis as a breakeven point for large-scale hydrogen generation without water consumption and carbon dioxide emissions.  相似文献   

8.
The majority of energy being used is obtained from fossil fuels, which are not renewable resources and require a longer time to recharge or return to its original capacity. Energy from fossil fuels is cheaper but it faces some challenges compared to renewable energy resources. Thus, one of the most potential candidates to fulfil the energy requirements are renewable resources and the most environmentally friendly fuel is Hydrogen. Hydrogen is a clean and efficient energy carrier and a hydrogen-based economy is now widely regarded as a potential solution for the future of energy security and sustainability. Hydrogen energy became the most significant energy as the current demand gradually starts to increase. It is an important key solution to tackle the global temperature rise. The key important factor of hydrogen production is the hydrogen economy. Hydrogen production technologies are commercially available, while some of these technologies are still under development. Therefore, the global interest in minimising the effects of greenhouse gases as well as other pollutant gases also increases. In order to investigate hydrogen implementation as a fuel or energy carrier, easily obtained broad-spectrum knowledge on a variety of processes is involved as well as their advantages, disadvantages, and potential adjustments in making a process that is fit for future development. Aside from directly using the hydrogen produced from these processes in fuel cells, streams rich with hydrogen can also be utilised in producing ethanol, methanol, gasoline as well as various chemicals of high value. This paper provided a brief summary on the current and developing technologies of hydrogen that are noteworthy.  相似文献   

9.
Fossil fuels possess very useful properties not shared by non-conventional energy sources that have made them popular during the last century but unfortunately they are not renewable. Since the oil crisis of 1973, considerable progress has been made in the search for alternative energy sources. Among the candidates, hydrogen holds a pre-eminent position because of its high energy content, environmental compatibility and ease of storage and distribution. Hydrogen can be produced in a variety of ways. Water electrolysis is one of the most utilized industrial processes for hydrogen production. This article discusses advantages and disadvantages of hydrogen energy. Besides, barriers and challenges to hydrogen economy have been summarized. The current energy situation in Pakistan is presented followed by a road map to hydrogen economy in Pakistan. It is concluded that a combination of fuel cells and a hydrogen infrastructure is a way forward to combat the long-term challenges of climate change and energy security for Pakistan. The hydrogen economy potentially offers the possibility to deliver a range of benefits for the country; however, significant challenges exist and these are unlikely to be overcome without serious efforts.  相似文献   

10.
The ever-increasing energy demand, depleting fossil fuel reserves, and rising temperatures due to greenhouse gas emissions have necessitated the transition towards the generation of green and clean energy through renewable energy sources. Solar energy is one such renewable energy source that has received significant attention owing to its abundance and inexhaustibility. However, solar energy alone cannot replace fossil fuels in the energy portfolio. There exists a need to develop another clean energy source that can potentially act as an alternative to conventional fuels. Hydrogen proves to be an ideal candidate in this domain and can be sustainably generated by water electrolysis by powering the electrolyzer using solar energy. The hydrogen thus synthesized has net zero carbon emissions and is a suitable asset for decarbonizing the environment. This review encompasses the generation of hydrogen using PV-Electrolyzer systems and addresses the challenges associated with the same. Overcoming these drawbacks can ensure a strong position for hydrogen as an alternative fuel in the energy infrastructure. By employing electrolyzers that are fueled by renewable energy and then using that hydrogen to feed a fuel cell, this study aims to clarify the potential and constraints of producing green hydrogen. Since this area of research has not yet been fully investigated, a review article that enables and encourages academics to develop original solutions is urgently needed.  相似文献   

11.
Hydrogen is being considered as a synthetic fuel or energy carrier for the post-fossil fuel era. It has many properties to commend itself: it compliments the nonconventional primary energy sources and presents them to the consumer in a convenient form; it is relatively inexpensive to produce; it can be converted to various energy forms at the consumer end with higher efficiencies than other fuels; it is renewable; and it is the lightest and cleanest fuel. It can be used in every application where fossil fuels are used today, including meeting the energy requirements of human settlements, such as cooking, water and space heating, cooling and refrigeration, lighting, powering farm implements and transportation, and electricity generation. In all these applications, it is superior to conventional fuels and other synthetic alternatives. There are already demonstration projects to show the applications of hydrogen in the domestic and transportation sectors of human settlements.  相似文献   

12.
The efficient use of primary energy sources, which can be used for hydrogen production, is addressed by a consideration of four key measures, which reflect the ability of different sources and processing routes to meet underlying needs and the practical demands of energy on a large scale. The measures considered are carbon dioxide emission reduction, primary energy availability, land use implications and hydrogen production costs. Fourteen pathways to hydrogen are considered involving fossil fuels and nuclear energy as well as the range of renewable sources, and including additional strategies for carbon sequestration.The overall comparison of routes, based on simple figures-of-merit, shows a clear division between those using renewable energies and those associated with the traditional ‘high energy density’ primary sources. Emerging from the work is a clearer view of the implications of following a particular production path, the limitations of certain technologies and the research challenges which must be met in addressing future fuel options and global warming.  相似文献   

13.
14.
Presently majority of the world’s energy demand is met by fossil fuels. These fuels are depleting at an alarming rate. Thus in future, our energy systems will need to be renewable and sustainable, efficient and cost-effective, convenient and safe. Among the various alternative fuels, hydrogen is a long-term renewable and least polluting fuel (produced from renewable energy sources). Its clean burning characteristics help to meet the stringent emission norms. Majority of the work using hydrogen as a fuel is being done in spark ignition engine, however, in this experimental investigation efforts have been made to utilize it in compression ignition engine.  相似文献   

15.
Biohydrogen holds the promise for a substantial contribution to the future renewable energy demands. It seems particularly suitable for relatively small-scale, decentralized systems, integrated with agricultural and industrial activities or waste processing facilities. Biohydrogen is considered as an important key to a sustainable world power supply and is currently being seen as the versatile fuel of the future, with the potential to replace fossil fuels. It has the key prospective to become the ideal means among the range of renewable H2 production technologies presently existing. This review attempts to delineate the prospects and potentials of biohydrogen as renewable energy resource.  相似文献   

16.
Hawaii is committed to replacing imported oil with indigenous, renewable energy resources to enhance the economic and environmental security of the state's citizens. A case study of Hawaii's fuel-energy balance by the end of the 21st century which features two scenarios, a ‘Business-as-Usual’ energy system, based on imported fossil fuels, and a ‘Renewable-Energy’ scenario, based on an alternative energy system consisting entirely of indigenous, renewable energy resources, is presented.

In the year 2100, a projected total energy consumption of approximately 335 million gigajoules would be provided from a hypothetical renewable-energy system of approximately 13 gigawatts-electric of installed capacity. This system would feature methanol-from-biomass to meet liquid fuel requirements for surface transportation, industrial, commercial, and residential sectors; hydrogen via electrolysis in liquid form for air transportation and as a gaseous fuel for industrial purposes; and electricity generated from geothermal, ocean thermal, wind, and photovoltaic sources for all power applications.

A comprehensive economic analysis, including capital costs, operating and maintenance costs, air pollution costs for the total fuel cycle of each energy system, and a local multiplier effect factor of 3·75 per dollar, indicates that between the years of 1987 and 2100 the ‘Business-as-Usual’ scenario will have expended approximately $600 billion (1986 US dollars), and the ‘Renewable-Energy’ scenario will have cost approximately $400 billion. By switching from imported fossil fuels to indigenous, renewable energy resources during this time period, Hawaii's citizens could save approximately $200 billion to help preserve paradise.  相似文献   


17.
Considering the enormous ecological and economic importance of the transport sector the introduction of alternative fuels—together with drastic energy efficiency gains—will be a key to sustainable mobility, nationally as well as globally. However, the future role of alternative fuels cannot be examined from the isolated perspective of the transport sector. Interactions with the energy system as a whole have to be taken into account. This holds both for the issue of availability of energy sources as well as for allocation effects, resulting from the shift of renewable energy from the stationary sector to mobile applications. With emphasis on hydrogen as a transport fuel for private passenger cars, this paper discusses the energy systems impacts of various scenarios introducing hydrogen fueled vehicles in Germany. It identifies clear restrictions to an enhanced growth of clean hydrogen production from renewable energy sources (RES). Furthermore, it points at systems interdependencies that call for a priority use of RES electricity in stationary applications. Whereas hydrogen can play an increasing role in transport after 2030 the most important challenge is to exploit short–mid-term potentials of boosting car efficiency.  相似文献   

18.
Hong Kong is highly vulnerable to energy and economic security due to the heavy dependence on imported fossil fuels. The combustion of fossil fuels also causes serious environmental pollution. Therefore, it is important to explore the opportunities for clean renewable energy for long-term energy supply. Hong Kong has the potential to develop clean renewable hydrogen energy to improve the environmental performance. This paper reviews the recent development of hydrogen production technologies, followed by an overview of the renewable energy sources and a discussion about potential applications for renewable hydrogen production in Hong Kong. The results show that although renewable energy resources cannot entirely satisfy the energy demand in Hong Kong, solar energy, wind power, and biomass are available renewable sources for significant hydrogen production. A system consisting of wind turbines and photovoltaic (PV) panels coupled with electrolyzers is a promising design to produce hydrogen. Biomass, especially organic waste, offers an economical, environmental-friendly way for renewable hydrogen production. The achievable hydrogen energy output would be as much as 40% of the total energy consumption in transportation.  相似文献   

19.
Heavy fossil fuels consumption has raised concerns over the energy security and climate change while hydrogen is regarded as the fuel of future to decarbonize global energy use. Hydrogen is commonly used as feedstocks in chemical industries and has a wide range of energy applications such as vehicle fuel, boiler fuel, and energy storage. However, the development of hydrogen energy in Malaysia is sluggish despite the predefined targets in hydrogen roadmap. This paper aims to study the future directions of hydrogen economy in Malaysia considering a variety of hydrogen applications. The potential approaches for hydrogen production, storage, distribution and application in Malaysia have been reviewed and the challenges of hydrogen economy are discussed. A conceptual framework for the accomplishment of hydrogen economy has been proposed where renewable hydrogen could penetrate Malaysia market in three phases. In the first phase, the market should aim to utilize the hydrogen as feedstock for chemical industries. Once the hydrogen production side is matured in the second phase, hydrogen should be used as fuel in internal combustion engines or burners. In the final phase hydrogen should be used as fuel for automobiles (using fuel cell), fuel-cell combined heat and power (CHP) and as energy storage.  相似文献   

20.
Rising concerns about the dependence of modern energy systems on fossil fuels have raised the requirement for green alternate fuels to pave the roadmap for a sustainable energy future with a carbon-free economy. Massive expectations of hydrogen as an enabler for decarbonization of the energy sector are limited by the lack of required infrastructure, whose implementation is affected by the issues related to the storage and distribution of hydrogen energy. Ammonia is an effective hydrogen energy carrier with a well-established and mature infrastructure for long-distance transportation and distribution. The possibility for green ammonia production from renewable energy sources has made it a suitable green alternate fuel for the decarbonization of the automotive and power generation sectors. In this work, engine characteristics for ammonia combustion in spark ignition engines have been reported with a detailed note on engines fuelled with pure ammonia as well as blends of ammonia with gasoline, hydrogen, and methane. Higher auto-ignition temperature, low flammability, and lower flame speed of ammonia have a detrimental effect on engine characteristics, and it could be addressed either by incorporating engine modifications or by enhancing the fuel quality. Literature shows that the increase in compression ratio from 9.4:1 to 11.5:1 improved the maximum power by 59% and the addition of 10% hydrogen in supercharged conditions improved the indicated efficiency by 37%. Challenges and strategies for the utilization of ammonia as combustible fuel in engines are discussed by considering the need for technical advancements as well as social acceptance. Energy efficiency for green ammonia production is also discussed with a due note on techniques for direct synthesis of ammonia from air and water.  相似文献   

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