TGA/FTIR as a Core Equipment for Delivering Research on Energy System Compound Stability
Lead Research Organisation:
Cranfield University
Department Name: School of Water, Energy and Environment
Abstract
Currently there are large global challenges in the sustainable, reliable generation of energy and power which, through population growth and industrial development, are expected to increase rapidly (IEA; BP, 2018) while there is a need to reduce greenhouse gas emissions and curb climate change (IPCC). To cut emissions, the UK has committed to reduce CO2 emissions relative to 1990 levels by 80% by 2050 (Climate Change Act 2008); recently amended to 'net zero' emissions by 2050.
However, to tackle recent energy and power challenges and meet these CO2 reductions, more needs to be known about specific compounds, as explained below. These compounds include the corrosion-inducing deposits formed by biomass/wastes on the heat exchangers of thermal plant; the stability of these deposits at different temperatures; the impact of power plant gas environment on deposits; the gases that form when these deposits degrade; and the stability of the salts in thermal energy storage systems. All of these areas can be elucidated with the careful application of Thermo-Gravimetric Analysis (TGA; to study the time and temperature at which compounds/mixtures become unstable) and Fourier-Transform Infrared Spectroscopy (FTIR; to study evolved gases).
Each of these research areas involves the use of 'corrosive' or 'dirty' atmospheres for study. The purchased TGA/FTIR will specifically cater to this, with dedicated gas lines to a gas compound and gas detectors for safety. While this equipment will be held within Cranfield's Energy and Power theme, it will provide analytical data to a wide range of researchers based in other themes/centres (including Manufacturing, Aerospace, Water and Transport). These tie in to a range of EPSRC-funded research areas including: Analytical Science, Bioenergy, Carbon Capture and Storage, Combustion Engineering, Energy Storage, Fossil Fuel Power Generation, Materials for Energy Applications, and Materials Engineering - Metals and Alloys.
This equipment will support significant research activities at Cranfield relating to energy and power supply. For example, substituting fossil fuels in thermal power plant with low carbon biomass/wastes brings benefits (crops/wastes use CO2 emitted by the previous combustion cycle). However, there is a wide variety of biomass/waste fuels, dependent upon the global location and time of year, each containing different compounds to conventional fossil fuels (often lower sulphur and higher chlorine levels). Thus, high temperature degradation processes in power plants (e.g. costly heat exchanger fireside corrosion), will vary considerably. Indeed, biomass combustion leads to rapid metal wastage rates and reduced plant life, only offset by lower plant temperatures and so reduced efficiency.
Renewable energy may appear to side-step the challenges of thermal power plant. However, being intermittent, at times little power is produced needing thermal plant to meet demand. When thermal plant 'cycles' from full-load (few renewables) to part-load (plentiful renewables) additional degradation processes occur (fatigue, thermo-mechanical fatigue) as well as part-load being lower efficiency, due to lower operational temperatures. Energy storage systems may 'solve' intermittent renewables, however, a single predominant technology has yet to materialise. Moreover, the requirements for high energy density, repeated charging-discharging cycles, and long-term stability present their own unique challenges. Currently the storage of heat energy using molten salts is under consideration.
Aspects of all of the above challenges are currently being researched at Cranfield University and would benefit from access to this underpinning multi-user equipment. Specifically, projects are underway related to:
*Biomass/waste combustion (and/or co-firing)
*The impacts of altered plant temperature
*The interactions of corrosion and fatigue
*The impact of molten salts on the materials the plant is made from.
However, to tackle recent energy and power challenges and meet these CO2 reductions, more needs to be known about specific compounds, as explained below. These compounds include the corrosion-inducing deposits formed by biomass/wastes on the heat exchangers of thermal plant; the stability of these deposits at different temperatures; the impact of power plant gas environment on deposits; the gases that form when these deposits degrade; and the stability of the salts in thermal energy storage systems. All of these areas can be elucidated with the careful application of Thermo-Gravimetric Analysis (TGA; to study the time and temperature at which compounds/mixtures become unstable) and Fourier-Transform Infrared Spectroscopy (FTIR; to study evolved gases).
Each of these research areas involves the use of 'corrosive' or 'dirty' atmospheres for study. The purchased TGA/FTIR will specifically cater to this, with dedicated gas lines to a gas compound and gas detectors for safety. While this equipment will be held within Cranfield's Energy and Power theme, it will provide analytical data to a wide range of researchers based in other themes/centres (including Manufacturing, Aerospace, Water and Transport). These tie in to a range of EPSRC-funded research areas including: Analytical Science, Bioenergy, Carbon Capture and Storage, Combustion Engineering, Energy Storage, Fossil Fuel Power Generation, Materials for Energy Applications, and Materials Engineering - Metals and Alloys.
This equipment will support significant research activities at Cranfield relating to energy and power supply. For example, substituting fossil fuels in thermal power plant with low carbon biomass/wastes brings benefits (crops/wastes use CO2 emitted by the previous combustion cycle). However, there is a wide variety of biomass/waste fuels, dependent upon the global location and time of year, each containing different compounds to conventional fossil fuels (often lower sulphur and higher chlorine levels). Thus, high temperature degradation processes in power plants (e.g. costly heat exchanger fireside corrosion), will vary considerably. Indeed, biomass combustion leads to rapid metal wastage rates and reduced plant life, only offset by lower plant temperatures and so reduced efficiency.
Renewable energy may appear to side-step the challenges of thermal power plant. However, being intermittent, at times little power is produced needing thermal plant to meet demand. When thermal plant 'cycles' from full-load (few renewables) to part-load (plentiful renewables) additional degradation processes occur (fatigue, thermo-mechanical fatigue) as well as part-load being lower efficiency, due to lower operational temperatures. Energy storage systems may 'solve' intermittent renewables, however, a single predominant technology has yet to materialise. Moreover, the requirements for high energy density, repeated charging-discharging cycles, and long-term stability present their own unique challenges. Currently the storage of heat energy using molten salts is under consideration.
Aspects of all of the above challenges are currently being researched at Cranfield University and would benefit from access to this underpinning multi-user equipment. Specifically, projects are underway related to:
*Biomass/waste combustion (and/or co-firing)
*The impacts of altered plant temperature
*The interactions of corrosion and fatigue
*The impact of molten salts on the materials the plant is made from.
Planned Impact
Research carried out on this combined Thermo-Gravimetric Analysis (TGA) and Fourier-Transform Infrared Spectroscopy (FTIR) system at Cranfield University will have impact by prolonging the lifetimes and clarifying the operational windows of plant for power generation and energy storage. This will assist the UK in meeting its emissions reduction targets, while also retaining a world-leading position in the research and development of systems related to energy and power. Example impacts include:
*Business/industry:
Knowledge gleaned from this project is directly applicable to industry. Power plant operators looking to use novel wastes/biomass fuels (either for firing or co-firing) will have improved confidence in the ability of their systems to withstand the resultant extreme operating conditions. This may result in operating at slightly lower temperatures/pressures (biomass/waste combusting plant is typically 'de-rated' with respect to conventional fossil fuel plant as a result of the increased corrosivity of the deposits/atmosphere generated). This leads to a knock-on impact on operating efficiency; currently such UK biomass plant run at 537 C/137 bar (Steven's Croft) cf. coal plant at 580 C/180 bar (Ratcliffe), dropping efficiency from ~35-38 % for coal to ~30 % for biomass. Research is needed to generate confidence in purchasing and combusting novel fuel mixes (increasing supply security).
In the thermal energy storage sector, a more complete understanding of salt stability will increase investor confidence; a vital step to developing and deploying this technology. Energy storage systems capable of high power density storage and repeated cycling, are key to increasing penetration of renewables into the power generation sector.
Finally, in the aerospace and transportation sectors, new alloy development for improved operation needs confirmation of materials performance under high temperature operating conditions in a range of corrosives gases (and, potentially, deposits).
*The public sector:
Knowledge generated will provide governmental energy policy makers with more options when choosing which power generation methods to encourage. When setting policy, they must consider the cost, supply security and environmental impact. Uptake of this cycle can help lower CO2 emissions (in line with UK legislation e.g. the Climate Change Act and ratification of the Paris Treaty to cut greenhouse gases linked to limiting climate change). Additionally, increasing power generation flexibility both in terms of fuel, such as biomass and wastes, and by deploying energy storage improves the UK's energy portfolio's security. Thus, research possible on this TGA/FTIR system can contribute to the UK Government's Industrial Strategy "Building a Britain Fit for the Future" by producing clean energy to drive growth.
*Environmental:
Benefits will come from (1) the partial de-coupling of power generation from fossil fuels and (2) the further study of materials for energy storage; both immediate and critical global issues. As currently 25% of CO2 emissions come from electricity and heat production (IPCC, 2014), this will lead to improved environmental conditions.
*The general public:
Increasing fuels flexibility for power generation to include biomass (conventionally considered a low carbon fuel as CO2 emitted is assumed to be reabsorbed when the next crop grows) and wastes will increase the uptake of alternative fuel sources. This increases energy security by reducing dependence on a single source, reducing volatility in fuel availability and cost of energy, and thus leading to lower electricity bills.
*Business/industry:
Knowledge gleaned from this project is directly applicable to industry. Power plant operators looking to use novel wastes/biomass fuels (either for firing or co-firing) will have improved confidence in the ability of their systems to withstand the resultant extreme operating conditions. This may result in operating at slightly lower temperatures/pressures (biomass/waste combusting plant is typically 'de-rated' with respect to conventional fossil fuel plant as a result of the increased corrosivity of the deposits/atmosphere generated). This leads to a knock-on impact on operating efficiency; currently such UK biomass plant run at 537 C/137 bar (Steven's Croft) cf. coal plant at 580 C/180 bar (Ratcliffe), dropping efficiency from ~35-38 % for coal to ~30 % for biomass. Research is needed to generate confidence in purchasing and combusting novel fuel mixes (increasing supply security).
In the thermal energy storage sector, a more complete understanding of salt stability will increase investor confidence; a vital step to developing and deploying this technology. Energy storage systems capable of high power density storage and repeated cycling, are key to increasing penetration of renewables into the power generation sector.
Finally, in the aerospace and transportation sectors, new alloy development for improved operation needs confirmation of materials performance under high temperature operating conditions in a range of corrosives gases (and, potentially, deposits).
*The public sector:
Knowledge generated will provide governmental energy policy makers with more options when choosing which power generation methods to encourage. When setting policy, they must consider the cost, supply security and environmental impact. Uptake of this cycle can help lower CO2 emissions (in line with UK legislation e.g. the Climate Change Act and ratification of the Paris Treaty to cut greenhouse gases linked to limiting climate change). Additionally, increasing power generation flexibility both in terms of fuel, such as biomass and wastes, and by deploying energy storage improves the UK's energy portfolio's security. Thus, research possible on this TGA/FTIR system can contribute to the UK Government's Industrial Strategy "Building a Britain Fit for the Future" by producing clean energy to drive growth.
*Environmental:
Benefits will come from (1) the partial de-coupling of power generation from fossil fuels and (2) the further study of materials for energy storage; both immediate and critical global issues. As currently 25% of CO2 emissions come from electricity and heat production (IPCC, 2014), this will lead to improved environmental conditions.
*The general public:
Increasing fuels flexibility for power generation to include biomass (conventionally considered a low carbon fuel as CO2 emitted is assumed to be reabsorbed when the next crop grows) and wastes will increase the uptake of alternative fuel sources. This increases energy security by reducing dependence on a single source, reducing volatility in fuel availability and cost of energy, and thus leading to lower electricity bills.