The commercial scale production of green hydrogen, through the catalysed electrolysis of water and driven by renewable energy, opens up promising routes for net zero fuels and chemicals. When combined with biogenic or anthropogenic carbon, through Fischer Tropsch synthesis for instance, a variety of premium fuels and chemicals can be manufactured. The main resources needed for the production of power-to-liquids fuels is water, CO (from CO2) and electrical energy. In most power-to-liquid processes, the CO2 is converted to CO via the reverse water-gas-shift (RWGS) reaction. The strongly exothermic methanation reaction is thermodynamically more favoured over the mildly endothermic RWGS reaction at low temperatures, as such minimizing methanation during RWGS becomes a challenge.
The direct electrochemical CO2 reduction reaction over solid catalysts at ambient temperature and atmospheric pressure has emerged as an alternative CO2 utilization and transformation technology. With the combination of renewable energy to drive the overall electrolysis, this could be used for CO provision in the power-to-liquids process.
Fly Ash Modified By Transition Metal Oxides For High Temperature Adsorption Of Contaminants In Off Gas
Mercury is a harmful, highly toxic substance which needs effective control to prevent contamination to humans and the environment. South Africa emits large amounts of mercury especially from coal industries. Techniques to remove mercury on an industrial scale, from coal gas, in an economically viable manner must be explored. In this project two methods of mercury removal namely: the removal of mercury (Hg0) by catalytic conversion to Hg2+ and the adsorption of mercury onto fly ash will be investigated. The two techniques of mercury removal will be assessed on their ability to reduce the overall mercury concentration as well as the overall cost to run the process. The reduction in mercury concentrations will be measured to determine the efficiency of the process. Relationships between the operating conditions (temperature, pressure, pH, catalyst type and unmodified/modified fly ash) and reduction in mercury concentration will be assessed to develop models for use in industrial processes.
Dry Reforming Of Biogas To Produce Hydrogen And Syngas Using A Direct Irradiated Solar Powered Reactor
Dry reforming of biogas (methane) is a viable high-throughput CO2 conversion technology, and possible intermediary step in the utilization of industrial CO2. Biogas can be conveniently produced from sustainable resources such as biomass or municipal waste. The dry reforming process produces a syngas mixture of hydrogen and carbon monoxide, both highly reactive and, in adjusted proportions, a possible feed gas for synthetic fuel synthesis. The reaction is however highly endothermic, requiring a large amount of energy to maintain. Traditional energy sources would offset the carbon deficit, and hence direct solar irradiation is being considered as an alternative. In this project the industrial scale transformation of CO2 and biogas, in a direct solar irradiated reactor, will be considered
