The Impact of Hydrogen on a Stationary Gasoline-Based Engine through Multi-Response Optimization: A Desirability Function Approach

Several studies have been conducted on alternatives to fossil fuels in internal combustion engines. In this work, we present an analysis of the optimization of a spark ignition engine (SIE), which operates with a mix of gasoline and hydrogen. Thus, this study tries to enrich the literature about the effect of using hydrogen in SIEs taking into account their performance and environmental issues. The experiments were conducted considering three independent variables: revolutions, the load produced by a dynamometer, and an electrolyte concentration (EC) to produce hydrogen. The effect of these factors was investigated on three response variables that are related to the performance of the engine: torque, hydrocarbon emissions (HC), and power. To achieve this optimization, we employed the design of experiments, the seemingly unrelated regression (SUR), and the desirability function. Once the models were fitted by SUR, the individual desirabilities were calculated and later aggregated into an overall desirability (D), which was optimized using the generalized reduced gradient (GRG) method. The results showed that, with a revolution of 2400 revolutions per minute (RPM), a load of 10 liters per minute (LPM), and an EC of 80 mL/gal, a reduction of approximately 51% of HC emissions was achieved, while the other two response variables demonstrated good performance.