Unsettled Economic, Environmental, and Health Issues of Ammonia for Automotive Applications

Ammonia has been previously trialed as an automotive fuel; however, it was hardly competitive with fossil fuels in terms of cost, energy density, and practicality. However, due to climate change, those practical and cost-related parameters have finally become secondary deciding factors in fuel selection. Ammonia is safer than most fuels and it offers superior energy densities compared to compressed or liquefied hydrogen. It is believed that ammonia might be an ultimate clean fuel choice and an extension to the emerging hydrogen economy. Unsettled Economic, Environmental, and Health Issues of Ammonia for Automotive Applications examines the major unsettled issues of using ammonia as a clean automotive fuel alternative, including the lack of regulations and standards for automotive applications, technology readiness, safety perception, and presently limited supply. While ammonia as a fuel is still in its infancy, identifying and addressing these challenges early could enable a safe and smooth transition.

Heterogeneous catalyzied FAME synthesis from renewable feedstock

With depleting conventional energy sources there is urgent need to look for alternatives for automotive fuel especially from Non-edible feedstocks. Present work investigates FAME (fatty acids methyl esters) synthesis commonly known as Biodiesel from non-edible feedstock Karanja using heterogeneous catalyst calcium oxide (CaO). Study was investigated considering effects of oil-methanol mole ratio, concentration of catalyst and temperature of reaction. Our results confirm that higher mole ratio was useful to enhance FAME yield. The findings of work confirm that molar ration of 1:8 was optimum for catalyst loading of 2.0% and reaction temperature of 60oC. The maximum yield of FAME was found 92.4%. The work confirms the FAME obtained from Karanja has a potential alternative for petro-based diesel. Novel protocol developed in present work address the issues of downstream processing of biodiesel synthesis and considerable amount of wastewater generated can be avoided.

The Influence of Condensation on the Performance Map of a Fuel Cell Turbocharger Turbine

Exhaust gas of an automotive fuel cell is enriched with water vapour and has a pressure potential which can be utilized by a turbine. The gas expansion in the turbine leads to droplet nucleation and condensation. This results in a release of latent heat and a decrease of the gaseous mass flow which has a considerable influence on the turbine performance. This study aims to numerically investigate the influence of these phenomena on the performance map of the radial turbine of an automotive fuel cell turbocharger. For this purpose, the classical nucleation theory and Young’s droplet growth law are integrated into an Euler-Lagrange approach. The results show an almost linear relation between the pressure ratio and the condensation while the specific aerodynamics of an operating point has only a minor influence. At 80 % relative humidity of the inflow, the investigated turbine showed condensation above a total-to-static pressure ratio of 1.8. Condensation leads to thermal throttling of the turbine and to a temperature increase of the rotor outflow of up to 50 K. Increasing humidity of the inflow increases the power output, but condensation losses reduce the efficiency.