Fuel Consumption Reduction and Optimization by Converting a Diesel Bus Fleet Into Diesel-CNG Dual-Fuel System

  • Jean-Pierre Atanas


Transportation is one of the sectors that contribute to greenhouse gases (GHGs) emissions. In recent years, many efforts have been made to reduce carbon footprint, particulate emissions, and cost of operation. Dual fuel technology has proven to be a viable technology since compressed natural gas (CNG) becomes largely available. Nowadays, CNG is the best fuel alternative for the automotive industry, specifically for marine engines, heavy machinery, trucks, and buses for public transportation. This paper describes a novel approach to fuel consumption reduction and the optimization of the cost of operation after dual-fuel CNG-Diesel conversion. Data have been collected from the logistics department and appropriate conversion centers A reduction in CO2, emissions are reported with a reduction in smoke emission and particulate matter (PM) by equipping buses with an active PDF catalyst system whereby NOx, HC, and CO emissions were 10% lower than the limits set by Japan’s current emission standard (JP05). Results were focused on the mixed fuel economy optimization using the best configuration of the CNG ratio map to be loaded in the electronic control unit. Moreover, the range of the buses was increased, hence reducing stall time at pump stations. Finally, the study shows the financial advantages of diesel-engine conversion to the CNG-Diesel dual-fuel engine.Keywords: Engine conversion, Optimization, Fuel economy, CO-carbon Oxide, HC-hydro Carbon, NO-nitrogen oxide