Investigation of nanoparticle (Fe3O4) addition to 3rd generation biodiesel (spirulina microalgae)/diesel mixture as an innovative fuel according to different engine variables: An RSM optimization

Abstract

In order to reduce dangerous air pollution and lessen the hazards associated with climate change, biofuels made from vegetable biomass can be utilized as fuel in diesel engines. However, feedstocks and the crop space needed for their cultivation are unavoidable barriers that hinder its adoption and result in a shortage of farmland for increasing food profits. Nevertheless, microalgae are the most reliable and competent biodiesel supply because they are not edible and do not require cropland. Additionally, the addition of nanoparticles has become popular to improve the negative aspects of biodiesel. Based on these, in this study, multi-purpose optimization research was conducted on the addition of iron oxide (Fe3O4) nanoparticles in three different amounts (25, 50, and 75 ppm) to 20 % synthesized spirulina microalgae biodiesel (SSMB)/80 % diesel mixtures. Tests were conducted at three different compression ratios (14.5:1, 15.5:1, and 16.5:1) (CoR) and four different engine loads (25 %, 50 %, 75 %, and 100 %). The response surface methodology (RSM) optimization process was performed with the test results. According to RSM, a desirability coefficient of 0.8299, 15.80:1 CoR, 68 ppm AoN, and 45 % LoE were the ideal conditions. The optimum responses under these circumstances were 421.9653 g/kWh, 19.4014 %, 0.0939 %, 4.0785 %, 73.1716 ppm and 253.0620 ppm for brake-specific fuel consumption (BSFC), brake-thermal efficiency (BTHE), carbon monoxide (CO), carbon dioxide (CO2), hydrocarbon (HC), and nitrogen oxide (NOx), respectively. RSM could be used successfully because the error rates (maximum 6.5 %) when comparing the test results with the RSM optimization outcomes were within reasonable bounds.