Towards negative CO2 emissions: energy and multiphase flow studies

点击翻译按钮获取中文摘要

Five sub-projects are proposed, each of which can contribute directly or indirectly to greater efficiency and reduced greenhouse gas emissions. Research will be conducted on pressure swing capture of CO2 by cyclic calcination/carbonation of dry sorbents (e.g. dolomite), applicable to chemical looping systems. The focus will be on combining inexpensive sorbents with preventioin or reduction in loss of reactivity upon repeated cycling. Rapid depressurization, periodic prolonged carbonization, pre-treatment and magnesium sorbents will be tested, in some cases for >1000 cycles. One issue encounterd with chemical looping and other energy systems is variation in particle density as reactions proceed. We will undertake an experimental and computational fluid dynamics study of particle segregation in gas- and liquid-fluidized beds to determine the mechanisms of segregation and to develop improved predictive methods. Earlier work has indicated that a significant cause of the abject failure of current empiical and semi-empirical methods of predicting particle entrainment from gas-fluidized beds may be the influence of electrostatic charges on the escaping particles and those left behind in the bed. We will investigate electrostatic charges on entrained particles and their influence. Our application of a "travelling fluidized bed" to investigate the perfomance and accuracy of a number of modern measurement techniques will be completed by close statistical analysis of the data obtained so far at five Canadian universities, and by sending the unit, accompanied by a graduate student, to facilities in the US and UK where there are unique instrumental capabilities. A comprehensive database will also be established and made available for testing of CFD codes. Finally, our work on coupling of complementary hydrogenation and dehydrogenation processes on either side of a permselective membranes, across which hydrogen and heat are transferred, will be extended. This will involve an experimental proof-of-concept study, as well as further modelling where the fixed bed on one or both sides is replaced by a fluidized bed. Each of these five sub-projects will contribute to the training of highly qualified personnel.