Review of the state-of-the-art of biogas combustion mechanisms and applications in internal combustion engines

As a kind of renewable biofuel for use in internal combustion engines, biogas has been widely paid attention to recently. In this review, the researches on basic combustion characteristics and chemical kinetics of biogas are summarized, and its applications in internal combustion engines are also discussed. These studies show that the main challenge of the large-scale application of biogas is the instability of its components, which is due to differences in the production process and the raw material species. Detailed chemical kinetics and simplified chemical kinetic models for multiple components of biogas need to be validated. In engine applications, a certain proportion of H2 added to biogas can improve the combustion properties. The application of biogas in dual fuel mode is an attractive way to promote the efficient utilization of biogas. However, further studies on the efficiency and emissions of engines under variable conditions need to be analyzed in detail.