The emission of carbon dioxide into the atmosphere has caused huge concerns around the world, in particular because it is widely believed that the increase in its concentration in the atmosphere is a key driver of climate change. If the current trend in the release of carbon dioxide continues, global temperatures are predicted to increase by more than 4 degrees centigrade, which would be disastrous for the world. With the increase in world population, the energy demand is also increasing. Coal-fired and gas-fired power plants still play a central role in meeting this energy demand for the foreseeable future, even though the share of renewable energy is increasing. These power plants are the largest stationary sources of carbon dioxide. Carbon capture is a technique to capture the carbon dioxide that is emitted in the flue gas from these power plants. This proposal seeks to make a significant improvement in the methods used for carbon capture in order to reduce the total costs. Post-combustion CO2 capture by chemical absorption using solvents (for example, monoethanolamine - MEA) is one of the most mature technologies. The conventional technology uses large packed columns. The cost to build and run the capture plants for power plants is currently very high because: (1) the packed columns are very large in size; (2) the amount of steam consumed to regenerate solvents for recirculation is significant. If we can manage to reduce the size of packed columns and the steam consumption, then the cost of carbon capture will be reduced correspondingly. From our previous studies, we found that mass transfer in the conventional packed columns used for carbon capture is very poor. This proposed research is expected to make very significant improvements in mass transfer. The key idea is to rotate the packed column so that it spins at hundreds of times per minute - a so-called rotating packed bed (RPB). A better mass transfer will be generated inside the RPB due to higher contact area. With an intensified capture process, a higher concentration of solvent can be used (for example 70 wt% MEA) and the quantity of recirculating solvent between intensified absorber and stripper will be reduced to around 40%. Our initial analysis has been published in an international leading journal and it indicates that the packing volume in an RPB will be less than 10% of an equivalent conventional packed column. This proposal will investigate how to design and operate the RPB in order to separate carbon dioxide most efficiently from flue gas. The work will include design of new experimental rigs, experimental study, process modelling and simulation, system integration, scale-up of intensified absorber and stripper, process optimisation, comparison between intensified capture process and conventional capture process from technical, economical and environmental points of view. The research will include an investigation into the optimum flow directions for the solvent and flue gas stream (parallel flow or counter-current) for intensified absorber and the optimum design of packing inside the RPB. The proposal will also compare the whole system performance using process intensification vs using conventional packed column for a CCGT power plant. Based on this, an economic analysis will be carried out to quantify the savings provided by this new process intensification technology.

UK electricity generation still relies around 80% on fossil fuels, with a resulting carbon intensity - the amount of carbon emitted to the atmosphere per unit of electricity generated - ten times higher than the level recommended to avoid dangerous climate change. Half of that electricity currently comes for natural gas and is expected to increase in the next decade as new gas-fired generation is commissioned to replace, along with renewables, old inefficient coal plants built in the 1960s. Over 20GW of gas capacity has been permitted since 2007, equivalent to a quarter of the current installed capacity for electricity generation. Unabated (no carbon capture) gas plants produce six to seven the amount of carbon per unit of electricity compared to the levels recommended for UK electricity generation by 2030. They must be fitted with Carbon Capture and Storage to provide reliable low-carbon energy to fill-in gaps between inflexible nuclear and intermittent wind power generation and a fluctuating electricity demand. Gas CCS R&D is an important emerging field, particularly to address the issue of rapidly increasing additional carbon in shale gas reserves, and many of the concepts and underlying scientific principles are still being 'invented'. Ongoing UK infrastructure investments and energy policy decisions are being made which would benefit from better information on relevant gas CCS technologies, making independent, fundamental studies by academic researchers a high priority. The UK is leading Gas CCS deployment with the retrofit of Peterhead power station, as part of the UK CCS Commercialisation programme at the time of writing. Key engineering challenges remain for the second and third tranche of gas CCS projects to be rolled out in the 2020s and 2030s. Efficient and cost-effective integration of CCS with gas turbines would be enhanced and costs of electricity generation greatly reduced if the carbon dioxide (CO2) concentration in the exhaust were much higher than the typical 3-4% value seen in modern Gas Turbine systems. An innovative solution is to selectively recirculate CO2, upstream of the post-combustion CO2 capture process, from the Gas Turbine exhaust back through the inlet of the engine, thereby greatly increasing CO2 concentration and subsequently reducing the burden on the CCS plant. The main result would be a more cost-effective plant with a significantly reduced visual impact. In order to achieve this concept, 3 main challenges must be overcome, which form the basis of the proposed work: 1. Plant Design and Optimisation. Based on advice from manufacturers and research data, a series of scenarios will be considered for the amount of exhaust recirculation through the engine. This will include results from other parts of the project, such as the engine performance tests. 2. GT-CCS Integration. Experimental testing will show how engines and CCS processes function when the two must work in a symbiotic fashion. This will include the measurement of gas turbine burner performance under operational conditions, engine testing, plus experiments on CCS columns to determine their effectiveness with this recirculated exhaust gas. 3. Scale-up and Intensification. Based on the research data gathered in the previous steps, the project will then publish findings on the viability of this concept, including application of this data to set design rules for future GT-CCS plants. Applying this idea further the project will estimate the impact on the UK's energy mix if these plants were considered economically viable. This project has a strong practical basis, employing a variety of state-of-the-art research facilities from 3 well-established UK Universities. These will include measurement of combustion behaviour under high pressure and temperature conditions, performance testing of GT engine sets with recycled exhaust and fundamental studies of the behaviour of CCS columns.

The emission of carbon dioxide into the atmosphere has caused huge concerns around the world, in particular because it is widely believed that the increase in its concentration in the atmosphere is a key driver of climate change. If the current trend in the release of carbon dioxide continues, global temperatures are predicted to increase by more than 4 degrees centigrade, which would be disastrous for the world. With the increase in world population, the energy demand is also increasing. Coal-fired and gas-fired power plants still play a central role in meeting this energy demand for the foreseeable future, even though the share of renewable energy is increasing. These power plants are the largest stationary sources of carbon dioxide. Carbon capture is a technique to capture the carbon dioxide that is emitted in the flue gas from these power plants. This proposal seeks to make a significant improvement in the methods used for carbon capture in order to reduce the total costs. Post-combustion CO2 capture by chemical absorption using solvents (for example, monoethanolamine - MEA) is one of the most mature technologies. The conventional technology uses large packed columns. The cost to build and run the capture plants for power plants is currently very high because: (1) the packed columns are very large in size; (2) the amount of steam consumed to regenerate solvents for recirculation is significant. If we can manage to reduce the size of packed columns and the steam consumption, then the cost of carbon capture will be reduced correspondingly. From our previous studies, we found that mass transfer in the conventional packed columns used for carbon capture is very poor. This proposed research is expected to make very significant improvements in mass transfer. The key idea is to rotate the packed column so that it spins at hundreds of times per minute - a so-called rotating packed bed (RPB). A better mass transfer will be generated inside the RPB due to higher contact area. With an intensified capture process, a higher concentration of solvent can be used (for example 70 wt% MEA) and the quantity of recirculating solvent between intensified absorber and stripper will be reduced to around 40%. Our initial analysis has been published in an international leading journal and it indicates that the packing volume in an RPB will be less than 10% of an equivalent conventional packed column. This proposal will investigate how to design and operate the RPB in order to separate carbon dioxide most efficiently from flue gas. The work will include design of new experimental rigs, experimental study, process modelling and simulation, system integration, scale-up of intensified absorber and stripper, process optimisation, comparison between intensified capture process and conventional capture process from technical, economical and environmental points of view. The research will include an investigation into the optimum flow directions for the solvent and flue gas stream (parallel flow or counter-current) for intensified absorber and the optimum design of packing inside the RPB. The proposal will also compare the whole system performance using process intensification vs using conventional packed column for a CCGT power plant. Based on this, an economic analysis will be carried out to quantify the savings provided by this new process intensification technology.

It is accepted that UK energy networks face a number of unprecedented challenges in the upcoming decades. These challenges include the threat to the security of energy supply due to declining indigenous fossil fuel reserves, increased reliance on imported fossil fuel (78% of coal and 50% of natural gas are imported, it is predicted that gas import will be over 80% in 2020), and planned retirement of ageing generation capacity over the next decade (approximately 20GW or 25% of the existing generation capacity); decarbonising electricity generation to achieve the goal of 80% reduction in CO2 emissions by 2050; and coping with the future increases in electricity demand from electrification of transportation and space heating. To address these great challenges, it is recognized that the UK energy networks, must change, strategically and the existing regulatory arrangements should be examined to check if they are fit for the purpose of future energy network operations. To ensure that power supply closely matches demand, the amount of electricity generated must be well controlled and managed. If the balance between supply and demand is broken and the difference exceeds a critical level, the power system may fail and cause a regional blackout. The UK is especially vulnerable in terms of network stability as it has a relatively isolated small island power network. Currently, 80% of our electricity is generated from fossil fuel (coal or gas) with the load balancing function mainly managed through fossil fuel peaking generation plants that respond to load changes. The mix of electricity generation in the UK will change dramatically with a large reduction in the use of coal and gas and an increase in the clean variable, intermittent renewable energy generators. The inherent energy storage capability that we currently enjoy due to our dependence on fossil fuel power generation will then be greatly reduced by 2030. Solutions are needed to address the network challenges that will occur due to a decrease in the implicit energy storage available with the planned reduction in fossil fuel power generation and the integration of large amounts of unpredictable intermittent renewable sources. Energy storage can provide manifold values in i) help meeting of peaky large scale electrical loads, ii) providing time varying energy charge management, iii) allowing renewable power generation to be stored to alleviate intermittence, iv) improving power quality/reliability, v) meeting remote load needs, vi) storage for management of distributed power generation, etc. This proposed research programme will focus on the challenging technical and economic issues faced by integrating large grid scale energy storage with the energy network.