Future combustion engine power plant - WP4 fuel flexibility: Final report

The objective of WP4 is to increase fuel flexibility of different engine concepts. A number of fuel options, including challenging liquid biofuels and their treatment, as well as gaseous fuels, were explored. LNG was found to be potential solution to oncoming environmental requirements in shipping. The general conception and knowledge of the implementation requirements for the LNG logistic were achieved. Supply chain analysis showed how LNG quality specifications affect an ability to meet future LNG demands in Finland. Alternative upgrading technologies providing sufficient gas quality for the supply to the natural gas grid were explored. The main focus was on operational parameters, upgrading costs and recent developments. Another study on biogas concerned siloxane removal, which is a weak spot for biogas from wastewater and landfills. Knowledge was gained for choosing fit-for-purpose and cost-effective designs for biogas applications in Finland. Method to predict performance of fuels in engine basing just in chemical and physical properties of fuels were explored with two simulation softwares, GT Power and Diesel-RK. However, both of these proved to have limited predictive capability of the combustion process thus making engine testing a necessity. Engine tests with different fuels were utilized for the prediction method. Before the engine tests, pre-treatment methods for difficult fuels were developed to enable their use in engines. Combustion properties of various fuels were studied with special ignition test unit, with a medium-speed and with a high-speed engine. The fuel injection system and engine configurations were modified according to requirements of fuels. Some fuels yielded promising results when engine performance and emissions are considered. Data from engine tests form a base for development of prediction method, but also gives valuable information about the behaviour of various fuels and the engine components. For non-road machinery, diesel-ignited dual fuel ethanol engine was developed. The performance targets were met and the engine can be switched from diesel to diesel-ethanol operation at any load without noticeable change in engine operating point. Depending on speed and load, 20 to 70 % of diesel consumption can be replaced with ethanol. Another study on non-road machinery concluded that 20% FAME biodiesel blend cannot be recommended for the state-of-the art heavy-duty engines without revision of fuel standards.