Aiming at evaluating the effects of natural gas composition on engine operation, the Engine Group of IPT has completed a series of dynamometer tests in a Mercedes Benz M366G gas engine.
Twenty-five gaseous fuel compositions, several specially prepared to extend the available CNG compositions, were engine tested.
The tests were executed to evaluate performance, exhaust emissions and knock-limited spark timing. The experimental results were correlated with methane and Wobbe numbers calculated from the gas composition. The obtained data corroborate the relevance of these parameters to engine operation.
For the tested engine, that uses an open loop fuel system, the data indicate the need to maintain the natural gas specifications in narrow limits if one wants to explore the natural gas low pollutant potential.
This study has subsidized the elaboration of a Brazilian vehicular natural gas specification.