Supervisor: Supervisors: Dr Bill Nimmo and Prof Lin Ma
To achieve the UK’s ambitious target of reducing greenhouse gas emissions by 80% by 2050 without compromising energy security, the UK’s conventional power plants must be operated in a flexible manner in terms of high efficiency, using alternative fuels (e.g. biomass) and integrating technologies for carbon abatement (e.g. Carbon Capture and Storage, CCS). Ultra-supercritical (USC) steam Rankine cycle power generation combined with Circulating Fluidised Bed (CFB) and Fluidized Bed (FB) combustion technology is the most viable alternative to the pulverised coal (PC)-based USC power generation. In addition, operating under USC/FB/CFB conditions has a number of advantages over USC/PC, particularly regarding fuel flexibility.
However, there are still many fundamental research and technical challenges facing the development of this technology. In particular, combustion issues related to safe and stable operation of CFB/FB boilers when burning a variety of solid fuels are not yet fully understood and there is a great need to develop novel materials that will be able to cope with adverse conditions associated with operation.
The specific project areas would include:
To understand how the combustion of a variety of fuels affects Emissions, bed material agglomeration, fouling and corrosion of boiler heat exchanger tubes.
Facilities at the University main campus and at the LCCC will be offered to suitably qualified students for study leading to a PhD in combinations of the following areas.
1. combustion testing at pilot scale (250 kW Fluidised bed),
2. deposition testing and experimentation at pilot plant scale,
3. corrosion testing in lab scale furnaces,
4. fundamental TGA decomposition studies,
5. Biomass characterisation
6. Fluidised bed modelling and CFD studies
Supervisor: Professor Mohamed Pourkashanian, Professor Lin Ma and Dr Kevin Hughes
The combustion of biomass is proposed as a “carbon neutral” alternative to fossil fuel utilisation and even a “carbon negative” technology when combined with Carbon Capture and Storage technologies such as oxyfuel combustion (Bio-CCS). Biomass contains significant amounts of alkali metals, which modify ash melting, slagging, fouling and deposition behaviour within power plant equipment. This project will first investigate thermodynamically the ash melting behaviour of biomass/coal mixtures at oxyfuel conditions. The project will then focus on the chemical kinetic behaviour of alkali salts at oxyfuel conditions using kinetic modelling techniques such as chemkin. Finally the project will couple chemical kinetic models to Computational Fluid Dynamics (CFD) for the prediction of ash deposition inside power plant equipment under bio-CCS conditions.
Supervisor: Professor Mohamed Pourkashanian, Professor Lin Ma and Professor Derek Ingham
Ash related problems such as slagging, fouling, and corrosions on the superheat-exchange tubes are significant problems of coal fired power plant, in particular when firing low grade coals, biomass and under oxyfuel conditions. Increased ash deposition in boilers would reduce system efficiency and also affect safe operation. An advanced ash deposition models will be developed in order to simulate the ash deposition processes that occur during combustion. The new model development will be based on an existing model that has previously been developed at Leeds and will be validated against measurement data. The successful outcome of this research will be very useful for fuel selection and combustion system optimization for future power generation plant.
Supervisor: Professor Mohamed Pourkashanian, Professor Lin Ma, Professor Derek Ingham
Biomass as a renewable fuel is considered to be CO2 neutral. However, firing biomass in power generation plant, either as a sole fuel or for co-firing in both air and oxy-firing conditions, causes a number of complications, such as slagging, fouling, and increased depositions and corrosion on the superheat-exchange tubes. This would reduce both system efficiency and durability. An advanced Computational Fluid Dynamics model will be developed in order to simulate the formation of aerosol, and the process of deposition of fine particles on combustion chamber and heat exchange tube surfaces, that occur during biomass combustion. The model development will be based on an existing model that has previously been developed at Leeds and will be validated against measurement data. The successful outcome of this research will be very useful for biomass fuel selection and combustion system optimization for power generation plant co-firing biomass and coal.