Design and Manufacture of a Dry HHO (Oxyhydrogen) Electrolysis Module for Emission Reduction in Light Trucks

Abstract

Oxyhydrogen (HHO), a mixture of hydrogen and oxygen generated by water electrolysis, has been examined as a combustion-supporting additive due to its clean-burning characteristics. This study describes the design and fabrication of an HHO generation and supply system for Thaco Towner 750 vehicles. The system employs a dry-type electrolyser, achieving an electrolysis efficiency of 89.8% and a gas production rate of approximately 613.3 ml/min at an operating current of 11 A, ensuring stable gas delivery during engine operation. Engine tests were performed to evaluate the effects of HHO supplementation on exhaust emissions when used with RON95 gasoline. Compared to baseline operation, average reductions of 8.7% in CO, 19.57% in CO₂, and 21.1% in HC were observed. Additional measurements conducted under two idle operating modes showed that, at low idle speed, CO, CO₂, and HC concentrations decreased by 19%, 14%, and 24%, respectively. At high idle speed, emission levels were also reduced, though to a lesser extent, with CO, CO₂, and HC decreasing by 6%, 4%, and 9%. These results indicate that HHO addition leads to measurable changes in exhaust gas composition under idle and high-idle conditions. Further investigations involving fuel consumption, engine performance, and standardized driving cycles are necessary to evaluate its broader impact on emission reduction.