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The present paper briefly elaborates upon the combination of waste palm and waste sunflower oil methyl ester as post-mixed biodiesel blends being injected into a four-stroke compression ignition engine, which is also fueled with inducted bamboo leaf generated producer gas (BLP.gas) that includes gaseous components of CO (carbon monoxide), H 2 (hydrogen), CH 4 (methane), and C x H y (hydrocarbons). The objective of the present research is to evaluate the overall performance, emission, and combustion behavior of a Kirloskar TAF1 modified dual-fuel diesel engine fueled with induced bamboo leaf-derived gaseous fuel at a fixed mass flow rate of 21.69 kg/h and injected mixed biodiesel-diesel blends. Initially, diesel fuel and post-mixed methyl ester were examined in dual-fuel mode with a fixed gas flow rate for different loads. It can be seen from the analysis that brake thermal efficiency got reduced by 4.66% and brake-specific fuel consumption increased by 5.26% for PMOME20 (20% post-mixed oil methyl ester + 80% diesel fuel) + BLP. gas with respect to diesel fuel at extreme loading conditions. Moreover, smoke opacity, carbon monoxide, and unburnt hydrocarbons were reduced by 11.22%, 20.44%, and 10.36%, respectively. On the other hand, oxides of nitrogen were reduced by 19.17% at maximum load for PMOME20 + BLP. gas in dual-fuel operation in contrast to that of petroleum diesel. In light of this, the current research concluded that the use of biodiesel and BLP. gas for dual-operative engines may be regarded as an appropriate option for reducing pollutant environment and petroleum fuel scarcity. • Influence of mixed biodiesel blends with induced bamboo leaf gaseous fuel were investigated. • NOx and smoke opacity showed trade-off curve of 19.11% and 11.22% lower emission for PMOME20+BLP.gas than diesel. • CO 2 emission for PMOME20+BLP.gas was 38.77% higher than diesel at peak load. • PMOME20+BLP.gas at peak load increased In-CP by 6.15% in contrast to diesel. • HRR and ID for PMOME20+BLP.gas decreased by 72.29% and 9.06% in contrast to diesel. [ABSTRACT FROM AUTHOR]

Conventional fossil fuels are being substituted with alternative green fuels because of their greenhouse gas emissions and pollution problems, which pose a severe threat to the environment. Several studies have reported the usage of biodiesel and gaseous fuels in both single and dual-fuel modes. Gaseous fuels such as producer gas, biogas, syngas, and hydrogen produced from renewable biomass could potentially be used along with biodiesel in dual-fuel engines. Still, these are the least investigated in terms of their use as potential energy carriers. This review article encapsulates the viability as well as the impact of various gaseous fuels, including producer gas, biogas, compressed natural gas, liquefied petroleum gas, syngas, and hydrogen, in dual-fuel mode diesel engines with the aim of evaluating the performance, emission, and combustion behavior at various induction as well as operational parameters. Considering emission behaviors of diesel engines fueled with producer gas, biogas, compressed natural gas, and hydrogen, it is found that hydrocarbon and carbon monoxide emissions increase in the range 17.5–31.4% and 11.73–23.6%, respectively. On the contrary, oxide of nitrogen and smoke opacity tend to reduce from 14.3 to 18.2% and 21.4%36.5–63.7%, respectively. Moreover, there is a slight deterioration in performance characteristics for diesel engines fueled with producer gas, biogas, compressed natural gas, and hydrogen in the range of 2.1–8.84% for brake thermal efficiency, and 3.1–7.3% for brake-specific energy consumption. In addition, the combustion characteristics of gaseous fuels is also discussed in detail. Moreover, a SWOT analysis has been carried out with an emphasis on possibilities for usage of gaseous fuels in dual-fuel diesel engines. Finally, the limitations and perspectives of using gaseous fuels are also critically presented. • Key applications of gaseous fuels to dual-fuel engines were critically presented. • Performance and emission of engines running on gaseous fuels were scrutinized. • Engines powered by gaseous fuels could increase global energy consumption. • NOx and greenhouse gas emissions could be remarkably reduced by using gaseous fuels. • SWOT analysis for gaseous fuels was discussed in detail. [ABSTRACT FROM AUTHOR]

Gaseous-liquid fuel combinations of biogas as primary fuel and diesel as pilot fuel were employed to power a compression ignition (CI) engine in this study. The effects of variable input factors such as engine load, compression ratio, and pilot fuel injection advance on the dual-fuel engine's combustion, thermal, and emission performance were investigated. The data acquired during this lab-based testing was used to develop a prognostic model using a Bayesian optimization strategy for hyperparameter optimization and a contemporary ensemble Gaussian process regression (GPR) technique. During model testing, the error analysis revealed that the developed model could predict the experimental data rather correctly, with R2 values ranging from 0.9995 to 0.9999 and MSE values ranging from 0.00018 to 0.1334. The mean absolute error was discovered to be between 0.0091 and 0.3065. Consequently, the developed GPR model can effectively simulate the on-board performance, emission, and combustion characteristics of a diesel-biogas dual-fuel setting. As a consequence, the current work established the GPR model in the existing CI engine meta-modeling framework as a consistent, trustworthy, and robust system analytical approach for diesel-biogas dual fuel mode of operation. • Waste-derived biogas was used to power the diesel engine in dual-fuel mode. • Gaussian process regression was employed to develop a prognostic model. • Bayesian approach was used for hyper parameter optimization for best results. • Used model could predict emission and performance of the engine with 99.9% accuracy. • A precise metamodel framework to simulate the input–output paradigm was developed. [ABSTRACT FROM AUTHOR]

The current study intends to assess the impact of incorporating an oxygenated fuel additive (hydrogen peroxide (H2O2)) into a biodiesel/diesel fuel mix on diesel engine combustion efficiency and instability. The combustion, performance, and emission properties were evaluated using advanced test equipment to offer a full study. The combustion instabilities in terms of cyclic fluctuations were investigated to discover any unusual behavior when H2O2 was added to biodiesel/diesel fuel mixtures. Statistical and continuous wavelet transformations were used to investigate the cyclic fluctuations in peak cylinder pressure and indicated mean effective pressure (IMEP). Diesel, B20 (20%/80% of biodiesel/diesel fuel), B20H5 (20%/5%/75% of biodiesel/H2O2/diesel fuel), and B20H10 (20%/10%/70% of biodiesel/H2O2/diesel fuel) were tested in the study. Experiment results indicated that B20H10 produced the best results. In comparison to B20, B20H10 improved BTE by 6.56% and HRR by 8.5%, while decreasing BSFC by 7.98%, CO and HC emissions by 26.5%, and 6.67%, respectively. Furthermore, the peak pressure and IMEP cyclic changes were also well within permissible ranges. However, it was shown that adding H2O2 to B20 increased NOx emissions. The cyclic variations in the cylinder peak pressure and indicated mean effective pressure were analyzed using statistical methods and continuous wavelet transformation. No abnormality was detected in cyclic variation, thus ruling out any unsafe behavior in introducing test fuel additive to biodiesel blends. In principle, introducing H2O2 into a biodiesel/diesel fuel mix helped improve the engine performance and emissions while having no negative effects on engine life. [ABSTRACT FROM AUTHOR]

[Display omitted] • Biodiesel with a higher degree of unsaturation exhibits poor engine characteristics. • Increasing the degree of unsaturation of biodiesels limits H 2 induction tolerance. • Hydrogen enrichment enhances the performance of slow-burning oils. • Lower biodiesel unsaturation degree and higher H 2 induction reduce carbon emissions. • CO emissions decrease and NOx emissions increase with increasing H 2 induction rate. In this study, a comparison of the behavioural characteristics of CI engine operated under single-fuel mode with biodiesel and dual-fuel mode enriched with hydrogen was conducted. The influence of unsaturation degree on the engine behaviour has been assessed and compared between Grapeseed biodiesel (GSBD) and Wheat Germ biodiesel (WGBD) with Coconut biodiesel (CBD) since CBD has a very low level of unsaturation compared to the other two fuels in the single-fuel mode. In addition, this work also investigates the impact of unsaturation on the H 2 induction, performance, combustion and emission characteristics of a CI engine in dual-fuel operation. The obtained results showed that with the increasing degree of unsaturation, H 2 induction decreases, with CBD tolerating Hydrogen Energy Share (HES) of 13.8 % without knocking, followed by 13.5 % and 12.5 % for GSBD and WGBD, respectively. Comparing the industrial biomass residues alone in dual fuel mode for maximum HES, GSBD-H 2 exhibited superior characteristics with 34 % brake thermal efficiency, 0.22 g/kWh of hydrocarbon, 2.3 g/kWh of carbon monoxide and 35.4 % of smoke opacity as against 32.5 %, 0.31 g/kWh, 3.5 g/kWh and 40.3 % for WGBD, respectively. However, the nitric oxide emissions were slightly higher for GSBD compared to WGBD in both single-fuel and dual-fuel modes. [ABSTRACT FROM AUTHOR]

[Display omitted] • Biodiesel with a higher degree of unsaturation exhibits poor engine characteristics. • Increasing the degree of unsaturation of biodiesels limits H 2 induction tolerance. • Hydrogen enrichment enhances the performance of slow-burning oils. • Lower biodiesel unsaturation degree and higher H 2 induction reduce carbon emissions. • CO emissions decrease and NOx emissions increase with increasing H 2 induction rate. In this study, a comparison of the behavioural characteristics of CI engine operated under single-fuel mode with biodiesel and dual-fuel mode enriched with hydrogen was conducted. The influence of unsaturation degree on the engine behaviour has been assessed and compared between Grapeseed biodiesel (GSBD) and Wheat Germ biodiesel (WGBD) with Coconut biodiesel (CBD) since CBD has a very low level of unsaturation compared to the other two fuels in the single-fuel mode. In addition, this work also investigates the impact of unsaturation on the H 2 induction, performance, combustion and emission characteristics of a CI engine in dual-fuel operation. The obtained results showed that with the increasing degree of unsaturation, H 2 induction decreases, with CBD tolerating Hydrogen Energy Share (HES) of 13.8 % without knocking, followed by 13.5 % and 12.5 % for GSBD and WGBD, respectively. Comparing the industrial biomass residues alone in dual fuel mode for maximum HES, GSBD-H 2 exhibited superior characteristics with 34 % brake thermal efficiency, 0.22 g/kWh of hydrocarbon, 2.3 g/kWh of carbon monoxide and 35.4 % of smoke opacity as against 32.5 %, 0.31 g/kWh, 3.5 g/kWh and 40.3 % for WGBD, respectively. However, the nitric oxide emissions were slightly higher for GSBD compared to WGBD in both single-fuel and dual-fuel modes. [ABSTRACT FROM AUTHOR]