Gasoline engines remain a potential source of atmospheric pollution. Dual fuel combustion was under investigation to cope with exposure to pollutants. Investigations on emission parameters and engine performance for a single-cylinder four-stroke petrol engine are carried out using multicriteria decision-making method (MCDM). Bar charts are constructed for three emission parameters in function of engine temperature and fuel consumption for different blends. Fuels were supplied at different engine running speeds. Parameters recorded during the experimental study were the concentrations of carbon monoxide (CO), hydrogen sulfide (H2S), percentages of lower explosive limit (LEL), and combustion duration. The maximum concentration of CO was 339 ppm at 70°C and 4000 rpm. The maximum concentration of H2S (3 ppm), was recorded at 94°C and 4000 rpm. The maximum percentage of LEL recorded was 3% at the majority of temperature and 4000 rpm. Consumption of 25 Cl of (gasoline + HHO) was recorded during the maximum time (50 min). The experiment showed high emissions of CO that can provoke respiratory disorders and explosive gases, factors of explosion at high speeds (4000 rpm), and low temperature (70°C). H2S emissions are very low (0–3 ppm) independently of the engine speeds and temperature. Blending gasoline with HHO shows a reduction in fuel consumption.

The cell voltage in alkaline water electrolysis cells remains high despite the fact that water electrolysis is a cleaner and simpler method of hydrogen production. A multiphysical model for the cell voltage of a single cell electrolyzer was realized based on a combination of current-voltage models, simulation of electrolyzers in intermittent operation (SIMELINT), existing experimental data, and data from the experiment conducted in the course of this work. The equipment used NaOH as supporting electrolyte and stainless steel as electrodes. Different electrolyte concentrations, interelectrode gaps, and electrolyte types were applied and the cell voltages recorded. Concentrations of 60 wt% NaOH produced lowest range of cell voltage (1.15–2.67 V); an interelectrode gap of 0.5 cm also presented the lowest cell voltage (1.14–2.71 V). The distilled water from air conditioning led to a minimum cell voltage (1.18–2.78 V). The water from a factory presented the highest flow rate (12.48 × 10−1cm3/min). It was found that the cell voltage of the alkaline electrolyzer was reduced considerably by reducing the interelectrode gap to 0.5 cm and using electrolytes that produce less bubbles. A maximum error of 1.5% was found between the mathematical model and experimental model, indicating that the model is reliable.