1995 Volume 57 Issue 6 Pages 3-10
A direct-injection type diesel engine was remodeled to operate on both diesel fuel and biogas. An apparatus was made to generate synthetic biogas which consists of methane and carbon dioxide. The apparatus supplies biogas, which is premixed with intake air stream, into an intake manifold of the engine. The basic performances of the engine for the operation in dual-fuel mode were investigated. It was found that NOx emission decreased approximately 30 to 70% by use of biogas. The tested engine could operate normally even with the biogas which had 40% methane concentration. However, the specific heat consumption increased by supplying biogas under lower loads. Both engine load and biogas flowrate were key parameters for the effective operation of the engine.