Renewable Fuel-Air Optimization Using Zeolite–Fly Ash Hybrid Filters to Enhance Diesel Engine Efficiency

Abstract

The present research explores the enhancement of diesel engine efficiency through the use of an innovative hybrid air filtration system composed of natural zeolite and coal fly ash. The study was designed to improve the combustion process by enriching the intake air with oxygen while simultaneously reducing harmful exhaust emissions. The hybrid materials were subjected to physical activation at 225°C for one hour to enhance their porosity and adsorption capability. Experimental tests were performed on a single-cylinder, four-stroke diesel engine using five composition ratios (Z0F100, Z25F75, Z50F50, Z75F25, and Z100F0) and three filter masses (50 g, 75 g, and 100 g) at rotational speeds of 1500, 2000, and 2500 rpm. Performance parameters, including brake power, brake specific fuel consumption (bsfc), and exhaust opacity, were carefully examined. The results revealed that the physically activated zeolite–fly ash composite effectively improved combustion quality and overall energy efficiency. The most notable enhancement was achieved with the Z50F50 composition at 100 g, yielding a 2.825% increase in brake power and a 7.805% reduction in bsfc. The Z25F75 composition demonstrated the greatest reduction in exhaust opacity, reaching 38.65%. These findings confirm that zeolite–fly ash hybrid filters provide a cost-efficient, sustainable, and environmentally responsible solution for improving engine performance, reducing fuel consumption, and advancing cleaner combustion technologies for modern diesel systems.