Showing papers by "Sukhvinder P.S. Badwal published in 2017"

Ammonia as a Renewable Energy Transportation Media

Abstract: Ammonia synthesized using hydrogen from renewable sources offers a vast potential for the storage as well as transportation of renewable energy from regions with high intensity to regions lean in renewable sources Ammonia can be used as an energy vector for an emissionless energy cycle in a variety of ways Ammonia at the point of end use can be converted to hydrogen for fuel cell vehicles or alternatively utilized directly in solid oxide fuel cells, in an internal combustion engine or a gas turbine One ton of ammonia production requires 9–15 MWh of energy However, its conversion back to useful form or direct utilization can lead to substantial energy losses In this paper, we present an overview of the current processes and technologies for ammonia synthesis and its utilization as an energy carrier We have performed an estimation of the round-trip efficiency of different routes for ammonia utilization at the point of end use along with some sensitivity analysis, and we discuss the outcomes resulting

Efficient conversion of CO2 in solid oxide electrolytic cells with Pd doped perovskite cathode on ceria nanofilm interlayer

Abstract: The conversion of CO2 into high energy density fuels and chemicals using electricity generated from renewable sources in High Temperature Solid Oxide Electrolysers is one of the emerging energy storage technologies. By utilising waste heat from industrial processes or solar concentrators or nuclear reactors, HT-SOE devices can reduce the electrical energy input up to 30%. Thus such devices are attractive for utilising CO2 as a renewable energy storage media when coupled with Solar Concentrator Photovoltaic systems. Application of traditional solid oxide fuel cell electrodes such as Ni-YSZ restricts the operation of the electrolyser to using CO2 mixed with reducing gases such as hydrogen or CO to prevent re-oxidation of metallic Ni to NiO in the presence of CO2. Furthermore carbon deposition can occur at high current densities in dry CO2. New redox stable ceramic cathodes (CO2 electrode) are promising alternatives to Ni-YSZ electrodes. In this work, we report electrochemical performance of Palladium (Pd) doped La0.6Sr0.4Co0.2Fe0.8O3−ᵹ (LSCF-Pd) as potential cathode for these devices. Using LSCF-Pd as both anode and cathode, with nanocrystalline thin film doped ceria as an interlayer between the cathode and the electrolyte, current densities in excess of 360 mA cm−2 were obtained at 800 °C in electrolyte supported tubular cells with high CO2 and steam conversion to syngas. The electrochemical performance of the electrode was found to be stable during the 50 h testing of the cell on cyclic load. The cells and reactors used are modular and scalable.

Direct Carbon Fuel Cells

Abstract: Coal is expected to stay as a major source for power production for many more decades despite the emergence of many renewable energy technologies in the overall energy mix. A number of advanced coal-based technologies are under development to reduce the impact of coal-fired power plants on the environment. Among these, direct carbon fuel cells, although at an early stage of research and development, offer a clear path to clean-coal power generation with electric efficiency approaching 70% and combined heat and electricity efficiency close to 90%. They are unique in that they convert solid fuels such as carbon to electricity through its electrochemical oxidation unlike other types of fuel cells that operate on gaseous or liquid fuels. They have small environmental footprint and produce concentrated stream of CO 2 , significantly reducing its capture costs. In this article, a broad overview of the technology, its current status, and potential applications are discussed.

Gasification, DICE, and direct carbon fuel cells for power, fuels, and chemicals production from low rank coals

Abstract: Pulverized fuel (pf) combustion in a boiler for power generation is by far the most common approach for the utilization of low rank coals. The properties of low rank coals (in particular, moisture and alkali content) mean that such an approach is often very inefficient, leading to very high CO2 emissions. Low rank coals, however, are inexpensive, and in some regions represent a significant energy resource. This chapter discusses some of the advanced, high efficiency technologies that are being demonstrated or which are under development, which allow low rank coals to play a role in a low-carbon energy future. The chapter discusses the role of gasification in enabling low rank coals to be used for low emissions power or the production of chemicals, fertilizers, or hydrogen. It also gives an overview of emerging technologies, such as Direct Injection Carbon Engines, and those under development, such as Direct Carbon Fuel Cells.