Oxycoal UK

The research consists of three parallel activities, within three different departments at Imperial College London: Chemical Engineering, Mechanical Engineering and Materials. Chemical Engineering The Chemical Engineering activity will include the validation and demonstration of a scheme for separating CO2 from oxy-combustion effluent gases, utilising a proprietary reaction/separation scheme proposed by Air Products. At present, there are insufficient data to confidently predict the performance of the scheme under industrial conditions and full process design. To this purpose a theoretical, modelling and experimental study will be carried out, involving five steps: 1) the design and commissioning of a laboratory rig suitable for characterisation of the underlying main reaction and mass exchange mechanisms involved, using a well characterised synthetic effluent gas that simulates the actual effluents (but without impurities such as mercury and arsenic); 2) the design and execution of a set of experiments with these synthetic feeds, followed by data analysis and model development; 3) the design and commissioning of a ruggedised reactor/separator rig, suitable for operation in a pilot plant environment, and its validation against the laboratory rig using the same relatively clean synthetic feeds; 4) the commissioning and running of the pilot plant reactor/separator rig at the pilot plant site, utilising the actual effluents produced by the oxy-combustion of pulverised coal; and 5) the analysis of the pilot plant data. This will enable us to: a) assess the separation achieved in practice under various conditions, in terms of purities, recoveries, efficiencies, etc., for CO2 and other main species of interest (such as NOx, SOx, mercury, chlorine); b) to produce a set of quality data suitable for modelling development and estimation of the main mechanisms and parameters involved: c) to produce a set of mathematical models that make use of those data; and d) to assess the ability of the theoretical and numerical models to represent the data obtained, their predictive capabilities over a range of operations, and their potential for use in subsequent process development and design of equipment at a much larger (industrial) scale. Mechanical Engineering The Mechanical Engineering activity will include measuring ignition behaviour of coal dust suspensions in O2/CO2 mixtures representative of oxyfuel power plant conditions using the NIOSH 20 litre ignition test vessel. Tests will be undertaken on the same six coals characterised using different techniques at Nottingham and results will be compared for cross-checking and to identify appropriate fundamental coal property test methods to support future oxyfuel developments. Staff will work closely with industrial staff at RWE to identify novel Reliability, Availability, Maintainability and Operability (RAMO) issues for a range of oxyfuel plant design options and key factors likely to have significant effects on plant performance. They will identify how existing knowledge on coal utilisation science can be applied to analyse and predict RAMO issues, and will specify and undertake any additional fundamental coal characterisation tests that may be possible within the scope of the project and identify and analyse further key fundamental coal utilisation research needs to support RAMO performance prediction and improvement in new oxyfuel plants. Materials The Materials activity will acquire samples of coal, ash and deposits from oxyfuel trials on the E.ON combustion test facility and characterise the microstructures and chemical compositions of these samples, mainly by electron microscopy. This will allow the difference in behaviour of coal minerals and ash between oxyfuel and conventional pulverised coal combustion conditions to be investigated, and the impact of oxyfuel combustion on coal ash properties and boiler deposition to be predicted.