Life Cycle Assessment of a Demonstration Project: Vehicle Use of Hydrogen-Blended Natural Gas

Abstract

Hydrogen is often considered as the way out of the environmental and economical problems associated with the use of fossil fuels. However, one of the main implementation barriers is the missing infrastructure. The introduction of hydrogen-blended compressed natural gas (HCNG) as a fuel for natural gas vehicles could serve as a bridging technology by using the existing natural gas infrastructure for the distribution of hydrogen. The unique conditions on site the large petrochemical complex in Stenungsund, Sweden—a hydrogen surplus and the connection to the natural gas grid—initiated a discussion about demonstrating the vehicle use of HCNG by using an already projected natural gas filling station near the industrial area. The hydrogen surplus used in this context will be replaced by natural gas. The intended aim of this demonstration project is learning in dealing with hydrogen as a fuel for vehicles. The purpose of this thesis is to assess and compare the environmental aspects of using natural gas, HCNG with 15% and 30% hydrogen by volume, and hydrogen as vehicle fuels within the scope of the proposed demonstration project. Life Cycle Assessment is used to analyse and quantify the potential environmental impacts from the use of the considered fuels in two different types of light-duty vehicles with internal combustion engines. The results show that the environmental benefits of performing the demonstration project are limited since there are no overall benefits connected to the use of HCNG and hydrogen compared to the use of natural gas. In general, the results reveal that the potential environmental impact from the fuel supply chain considerably increases towards a hydrogen share of 100% in the fuel. Besides these environmental considerations, however, it has to be taken into account that potential environmental impacts as direct project results cannot be consulted alone, when assessing the demonstration project and deciding whether it should be performed or not. Learning should be maximised and, therefore, the assessment of the demonstration project has to be extended by focusing on the dynamics of technological change, which can be given as a suggestion for further studies