Comparative study of ammonia-based clean rail transportation systems for Greater Toronto area

Abstract

Ammonia as a transportation fuel offers a carbon-free, hydrogen rich energy source that emits no greenhouse gases in combustion, and has no global warming potential. Furthermore, it may be produced from any renewable energy resource, and is a strong option for long term sustainability. Ammonia also provides a pathway towards a hydrogen economy, which is the long term goal for environmental sustainability.

This thesis investigates the feasibility of integrating ammonia as a combustion fuel, hydrogen carrier, heat recovery and working fluid, and for indirect engine cooling, within locomotive propulsion systems for nine novel ammonia-based configurations. Thermodynamic, environmental, and economic analyses are conducted for a typical modern diesel-fueled locomotive and the proposed ammonia configurations. The study comparatively assesses potential long term solutions for sustainable, clean rail transportation.

From the modeled results, the proposed systems operating with 50% of required fuel energy replaced by ammonia have a reduction in diesel fuel consumption from 0.211 kg/s to less than 0.10 kg/s. This is associated with a reduction in GHG emissions of more than 8 tonnes CO2eq for a typical daily locomotive duty cycle for commuter operation. Criteria air contaminants are reduced to below upcoming Tier 3 emission levels for NOx and HC emissions, and meet current levels for PM emissions. In total, ten locomotive propulsion systems are investigated including the diesel-fueled locomotive baseline, and the performance gains are considered against economic factors for fuel and equipment costs in a comparative assessment.