Environmental and energy valuation of waste-derived Cymbopogon Martinii Methyl Ester combined with multi-walled carbon (MWCNTs) additives in hydrogen-enriched dual fuel engine

Abstract

This study uses a Capparis Spinosa Methyl Ester or Cymbopogon Martinii Methyl Ester (CMME25) and hydrogen dual fuel engine using multi-walled multi-additive nanotubes (MWCNT). In this experiment, a single-cylinder diesel engine was used. Through the intake manifold, hydrogen is introduced at predetermined flow rates of 5 and 10 lpm. The enriched hydrogen MWCNT of 50 and 100 ppm is combined with the CMME25 fuel. Results from the first round of experiments showed that combustion characteristics and performance were improved by hydrogen enrichment. The addition of hydrogen in the CMME25 fuel blend exhibited better performance (BTE (2.52% higher at 5 lpm and 4.52% higher at 10 lpm), BSFC (1.8% lower at 5 lpm and 2.2% lower at 10 lpm), and increased combustion parameters with lower ignition delay and combustion duration and lower emission gases (CO (8.3% at 5 lpm and 13.4% at 10 lpm), HC (7.2% at 5 lpm and 13.1% at 10 lpm), smoke (4.27% at 5 lpm and 9.06% at 10 lpm)) except NOx emission (4.82% at 5 lpm and 8.16% at 10 lpm) when compared with CMME25 without hydrogen addition. The second phase discussed the effect of multi-walled nanotubes (MWCNTs) blended with CMME25 fuel enriched with hydrogen of 10 lpm. The addition of multi-walled nanotubes in the CMME25 fuel blend revealed that higher BTE and lower BSFC were observed. MWCNT nanoparticles operate as catalysts to accelerate combustion. Minimising ignition delay and HRR advances peak HRR. Hydrogen increased the hydrogen-carbon ratio, improved air/fuel mixing, and shortened combustion, reducing CO emissions. MWCNTs decreased HC emissions by catalysing fuel oxidation and combustion. NOx emission was 6.3 and 12.8% lower for MWCNT 50 and 100 ppm, respectively. Smoke emissions decreased by 8.1 and 14.22% for MWCNT 50 and 100 ppm. Nanoparticles improved fuel droplet evaporation, thermal conductivity, and smoke emission.