Potential of fueling spark-ignition engines with syngas or syngas blends for power generation in rural electrification: A short review and S.W.O.T. analysis

Biomass gasification represents one of the most attractive solutions in rural electrification projects. It enables energy recovery from agricultural waste or forest resources in rural areas isolated from the grid. The use of the syngas produced by gasification in spark-ignition engines offers the local population a simple, available, and low-cost technology to meet their electrical energy needs. However, the loss of engine performance when fueled with syngas, compared to gasoline operation, has prompted researchers to study the mixing of syngas with other types of fuel to overcome its low heating value. This article, therefore, presents a review of the use of syngas in spark-ignition engines, either fully, or in a mixture as the pilot fuel or as an additive. A S.W.O.T. analysis is then conducted based on the results of the review with a focus on applications in rural electrification. The study highlights the contribution of syngas enrichment to the improvement of the quantity and quality of electrical energy produced. When syngas is used as an additive, its impact is not directly energetic but rather on the en-gine's lifetime, which is extended thanks to more stable operation and faster combustion. The review also shows that the use of syngas blends affects the quantity of pollutants in the engine's exhaust gas: CO, NOx and HC are reduced when syngas is enriched. However, CO and CO2 emissions may increase when syngas is used as an additive due to the presence of these gases in the input. In the context of rural electrification, the use of syngas blends may improve the sustainability of the project through a better quality of service and a longer lifetime of the facility. However, a higher level of competence is required for people in charge of the site to control the production processes and the fuel-mixing. Finally, this study indicates the need for more research to explore the use of other fuels such as alcohol in the blend or the use of syngas blends in compression ignition engines.