Dr. Leonid Tartakovsky

Keynote speech title: High-pressure thermo-chemical recuperation – a novel energy conversion process for sustainable propulsion systems

Abstract: Internal combustion engines (ICEs) are a main power plant in transportation and are greatly responsible for fossil fuels consumption, as well as for environment pollution and GHG emission. The utilization of more energy-efficient ICEs together with low-carbon-intensity fuels is, therefore, of great importance. About one-third of fuel energy introduced to ICE is wasted with engine exhaust gases. One of the possible ways of engine's waste heat recovery is by using the energy of the exhaust gases to promote endothermic reactions of fuel reforming. This approach is called Thermo-Chemical Recuperation (TCR). Gaseous hydrogen-rich reforming products have, as a rule, higher heating value and can be burnt more efficiently by approaching the ideal constant-volume combustion of very lean fuel/air mixtures. We suggest focusing on methanol because it is a truly low-carbon-intensity primary fuel, which can be reformed at relatively low temperature (~573K). Methanol can be produced from abundant and widely available sources, such as coal and natural gas, as well as from renewable sources, such as bio-mass.

We go beyond the previous studies in this field by applying direct injection of the reformate gas together with high-pressure steam-reforming process. Secondly, we aim at developing a reformer-ICE set as a part of a series hybrid propulsion system, thus alleviating the acute problems of the reformer's startup and transient behavior. The engine prototype operating in accordance with the described above principles and fed by the separately prepared methanol reforming products was successfully developed and tested. The obtained experimental results show a possibility of engine efficiency improvement up to 70% (higher improvement at lower loads) and dramatic reduction of pollutant emissions, when compared with gasoline. Harmful emissions of the gaseous pollutants CO and NO_x are reduced by 96% and 85%, respectively. Emissions of ultrafine particles are decreased by more than 99%. Ultra-low emissions will make unnecessary an aftertreatment system. The reformer will replace a currently used catalytic converter or a particle filter.