An integrated approach for wastewater treatment and algae cultivation: Nutrient removal analysis, biodiesel extraction, and energy and environmental metrics enhancement.

Human urine is rich in nitrogen and phosphorus, and the presence of these elements in wastewater significantly disrupts the biogeochemical cycle. Meanwhile, green algal biomass cultivation is unfeasible without these nutrients. Hence, the present study integrates wastewater treatment and algae cultivation to extract biodiesel and improve its performance through fuel modification. Chlorella vulgaris algae was cultivated in different dilution ratios of water and urine, and the nutrient removal rate was analyzed. Chlorella vulgaris algae biodiesel (CAB) was derived through Bligh and Dyer's method followed by transesterification, and its functional and elemental groups were analyzed. The various volume concentrations of CAB were blended with regular diesel fuel (RDF), and 10% water was added to a 30% CAB blended RDF to evaluate the combustion performance and environmental impacts. The results of the experiments demonstrated that the algae cultivation effectively removed the wastewater nutrients. The functional and elemental groups of CAB are identical to those of RDF. The engine characteristics of test fuels report that the CAB-blend RDF fuel mixtures generate low carbon footprints, whereas negative impacts have been drawn for performance metrics and oxides of nitrogen emissions. The water-emulsified fuel outweighed the unfavorable effects and promoted more efficient and cleaner combustion.

Energy extraction from waste plastics and its optimization study for effective combustion and cleaner exhaust engaging with water and cetane improver: A response surface methodology approach.

This study describes the extraction of energy from waste plastics via the pyrolysis process and its optimization for efficient combustion with cleaner exhaust using water and a cetane enhancer. Water emulsion with cetane improver in waste plastic oil (WPO) was first proposed in this study, and a response surface methodology (RSM) tool was used to optimise the individual parameters. Fourier Transform Infrared (FTIR) spectra were used to characterise the WPO, and ASTM standards were used to evaluate its properties. To enhance the fuel qualities, performance, and emission characteristics, water and Diethyl ether (DEE) were added to WPO. Since the WPO, water, and DEE had their pros and cons on overall engine performance and emissions as a whole, the optimal level of individual parameters was crucial in this field. The process parameters combinations were selected based on the Box-Behnken design, and the experiments were conducted in a stationary diesel engine. The experimental results indicate that the WPO yield rate during the pyrolysis process is 43.93%, and the C-H bonds have the maximum contribution to the WPO yield rate. The result of the optimization indicates that the proposed RSM model is highly robust, and the coefficient of determination is closer to one. The optimal concentrations of WPO, water, and DEE in conventional diesel fuel for efficient and environmentally friendly production are 15.001%, 12.166%, and 2.037%, respectively. The confirmation test indicates that the predicted and experimental values under optimal conditions are in good agreement, and the aggregate demand for fossil fuel has decreased by 28.2%.

Challenges and Opportunities of Low Viscous Biofuel-A Prospective Review.

Under the roof of solid industrialization and accelerated intensification of multiple ranges of mobilization, a huge rise in precious fuel consumption and pollution was observed. Based on the recent hardships of fossil fuels, experts are undoubtedly eager in carrying out their research in renewable environment-friendly fuels. There have been many reviews of works considering the parameters and standards of biodiesel, which is only from various vegetable and seed oils. But very little review work was carried out on only plant-based biofuel. Plant-based fuel has a lower viscosity and higher volatility properties. The target of this review was to make a bridge to overcome these research gaps. This review extensively studies the biological background, production outcome, properties, and reliability of plant-based biofuel and also deeply investigates the feasibility of usage in a diesel engine. From deep investigation it was identified that most of the low viscous fuel had higher brake thermal efficiency (BTE) (2% to 4%) and NOx emission (5% to 10%) than high viscous biodiesel. The formation of hydrocarbon (HC), CO, and smoke emission was similar to high viscous biodiesel. Overall, the low viscous fuel effectively improves the engine behaviors.

Optimization of Bauhinia parviflora biodiesel production for higher yield and its compatibility assessment with water and Di-tert-butyl peroxide emulsion.

The current study aims to attain a higher yield of biodiesel from Bauhinia tree seed wastes through process optimization using response surface methodology (RSM) and assess its compatibility in the diesel engine blended with water and Di-tert-butyl peroxide (DTBP). The Bauhinia parviflora biodiesel (BPB) transesterification originated using a fixed quantity of catalyst, and the transesterification process parameters such as oil-molar ratio (OMR), process temperature (PT), and reaction time (RT) were optimized. Fourier transform infrared spectroscopy (FTIR) and Gas chromatography-mass spectrometry (GC-MS)analysis were applied to characterize and quantify the BPB, and ASTM standards were followed to measure the properties. The prepared BPB (30%) was blended with 10% water and 2% BTBP to enhance the performance and emission characteristics of the BPB in the diesel engine. The optimization result implies that the higher yield of BPB (91.4%) was attained for OMR of 9.2:1, PT of 76 °C, and RT of 67 min. The FTIR report indicates that the carbon-based components are pretty good in the prepared BPB. The GC-MS report indicates that the fatty acids are converted into corresponding methyl esters, and the measured fuel properties are within the prescribed limits. The diesel engine's performance is effectively improved for the BPB blended with water and DTBP. The proposed fuel's overall improvement in hydrocarbon, carbon monoxide, smoke, and oxides of nitrogen emissions is 27.2%, 34.9%, 16.7%, and 11.2%, respectively.

Dataset for the combined effect of cetane improver and water emulsion on energy, environmental and economic values of a diesel engine fueled with lemon peel oil.

The present dataset describes the combined effect of cetane improver and water emulsion on the energy, environmental and economic values of a diesel engine fueled with lemon peel oil (LPO). The LPO was derived from waste lemon peels through a steam distillation process, and the water was blended with LPO using mechanical agitation along with a suitable surfactant. The water concentration in LPO was limited by 20% with an equal interval of 10, and the 2-Ethylhexyl nitrate concentration was limited by 2% on the total volume of the fuel. The fuel properties were measured as per the ASTM standards and the data were presented. The energy, environmental and economic assessments of test fuels were carried out in a four-stroke, naturally aspirated diesel engine fitted with an eddy current dynamometer. The assessments were carried out under different brake mean effective pressure (BMEP) conditions based on the engine load starting from 25% load to full load. The key energy parameters data of the diesel engine such as brake thermal efficiency (BTE), brake specific energy consumption (BSEC), and brake specific fuel consumption (BSFC) were represented for various test fuels under different operating conditions along with a comparison of neat diesel (ND). The raw emissions data such as hydrocarbon (HC), carbon monoxide (CO), and oxides of nitrogen (NOx) derived from the emission analyzer were converted to mass per unit of power, and the data were presented. The cost-benefit analysis data of the proposed fuels was also presented based on the fuel consumption at different engine operating conditions.

Enhancement in combustion, performance, and emission characteristics of a diesel engine fueled with diesel, biodiesel, and its blends by using nanoadditive.

This article presents the results of investigations carried out to evaluate the improvement in combustion, performance, and emission characteristics of a diesel engine fueled with neat petro-diesel (PD), soybean biodiesel (SB), and 50% SB blended PD (PD50SB) by using carbon nanotube (CNT) as an additive. The acid-alkaline-based transesterification process with sodium hydroxide (NaOH) as a catalyst was applied to derive the methyl ester of SB. A mass fraction of 100 ppm CNT nanoparticle was blended with base fuels by using an ultrasonicator and the physiochemical properties were measured based on EN standards. The measured physiochemical properties are in good agreement with standard limits. The experimental evaluations were carried out under varying brake mean effective pressure (BMEP) conditions in a single-cylinder, four-stroke, and natural aspirated research diesel engine at a constant speed of 1500 rpm. The results reveal that the SB and its blend promote shorter ignition delay period (IDP) that is resulting in lower in-cylinder pressure (ICP) and net heat release rate (NHR) compared to PD. The SB and its blend increase the brake specific fuel consumption (BSFC), and reduce the brake specific energy consumption (BSEC) and exhaust gas temperature (EGT), due to lower heating value, and efficient combustion, respectively. As far as the emission characteristics are concerned, the SB and its blend promote lower magnitude of hydrocarbon (HC), carbon monoxide (CO), carbon dioxide (CO2), and smoke emissions compared to PD except for oxides of nitrogen (NOx) emission. The CNT nanoparticle inclusion with base fuels significantly improves the combustion, performance, and emissions level irrespective of engine load conditions.

Multi-response optimization to obtain better performance and emission level in a diesel engine fueled with water-biodiesel emulsion fuel and nanoadditive.

The present study aims to investigate the optimum condition of stationary diesel engine's operating parameters to obtain better performance and emission level, where the diesel engine is fueled with different concentrations of soybean biodiesel (SB), water, and alumina (Al) nanoadditive. Taguchi method coupled with gray relational analysis has been implemented in this study to obtain the optimum concentration of SB, water, and Al nanoparticle, and statistical analysis of variance (ANOVA) is applied to obtain the individual response of operating parameters on overall engine performance and emission level. Various concentration of SB (10%, 20%, and 30%), water (10%, 20%, and 30%), and Al nanoparticle (50 ppm, 100 ppm, and 150 ppm) are mixed with base diesel (BD) by mechanical agitation and followed by an ultra-sonication process. The fuel properties are measured based on EN590 standards, and the experiments are conducted in a single-cylinder, four-stroke, natural aspirated stationary diesel engine based on an L9 orthogonal array fuel combination. From the obtained gray relational co-efficient (GRC) and signal-to-noise (S/N) ratio, the optimum concentration of SB, water, and nanoadditive are identified as 20%, 10%, and 100 ppm, respectively, and a confirmation experiment has also been carried out to confirm the improvements at optimum condition. The ANOVA results imply that water concentration (WC) has the maximum influence on overall diesel engine's performance and emission level followed by nanoparticle and SB concentrations. Overall, it can be concluded that the engine exhibits better performance and greener emissions at optimal condition.

Combustion, performance, and emission analysis of diesel engine fueled with water-biodiesel emulsion fuel and nanoadditive.

The present study is aimed to analyze the combustion, performance, and emission characteristics of water-emulsified soybean biodiesel fueled diesel engine with alumina nanoadditive and the results compared with conventional diesel fuel (BD). Experiments were conducted in a single-cylinder, four-stroke, variable compression ratio, and natural aspirated diesel engine with an eddy current dynamometer at a constant speed of 1500 rpm. Water-soybean biodiesel emulsion fuel was prepared using a mechanical agitator, in which the water concentration was limited to 10%, whereas soybean biodiesel (SB) and surfactant concentrations were 89% and 1% by volume respectively. Alumina (Al) was chosen as a nanoadditive, and the mass fractions of 50 ppm and 100 ppm were blended with emulsion fuel using ultrasonicator and the physicochemical properties were measured. The physicochemical properties of water-emulsified biodiesel and nanoadditive included emulsified biodiesel are at par with EN14214 limits. The in-cylinder pressure (ICP) and net heat release rate (NHR) values of SB are 5.3% and 7.2% lower than BD respectively, whereas the water inclusion significantly increases the ICP and NHR values by 6.9% and 15.9% compared to SB. Brake-specific fuel consumption (BSFC) of SB is higher than BD, and brake-specific energy consumption (BSEC) is lower than BD. An inclusion of 10% water in SB improves the BSFC and BSEC by 4% and 10.6% respectively compared to SB. The Al nanoparticle inclusion in water-emulsified soybean biodiesel further improves the combustion and performance parameters. The exhaust gas temperature (EGT) of sample fuels seems to be lesser than BD due to efficient combustion. As far as the emission characteristics are concerned, the SB promotes lower level of hydrocarbon (HC), carbon monoxide (CO), and smoke emissions with notable increases in oxides of nitrogen (NOx) and carbon dioxide (CO2) emissions. An inclusion of 10% water in SB reduces the NOx, HC, CO, and smoke emission by 21.2%, 16.7%, 16.9%, and 11.8% respectively under peak brake mean effective pressure (BMEP) condition. The addition of Al nanoparticle in biodiesel emulsion fuel further reduce NOx, HC, CO, and smoke emissions and marginally increases the CO2 emission.