ABSTRACT
The aim of the study was to investigate the exhaust gas emissions and fuel consumption of a common rail direct injection (CRDI) diesel engine using mixed diesel (B10) and biodiesel (B20-B100) fuels. The study's primary objective was to determine the effects of blended diesel-biodiesel fuel on CRDI emissions based on different exhaust gas recirculation (EGR) rates, including carbon monoxide (CO), carbon dioxide (CO2), oxygen (O2), nitrogen oxide (NOx), and hydrocarbon (HC) emissions, smoke opacity, exhaust gas temperature, and fuel consumption. The CRDI experiments involved adjusting the different engine speeds (1400-3000 rpm) and EGR rates (0 and 12.5%), which were analyzed to determine their impact on these parameters for both blended diesel and biodiesel fuels. The results showed that under the conditions of no EGR (0%), the CO and HC emissions and the smoke opacity were lower than those with a 12.5% EGR rate for all fuel types and all cases. With 12.5% EGR rate, the O2 emissions and the EGT of the CRDI diesel engine decreased, which resulted in significantly lower NOx emissions because of EGR into the combustion chamber. For the maximum engine speed of 3000 rpm and with no EGR, the CO and HC emissions and the smoke opacity were lower than those with a 12.5% EGR rate for all fuel types. With a 12.5% EGR rate at 3000 rpm, the O2 emissions and the exhaust gas temperature were reduced by 0.07% and 2.27%, respectively, and the NOx emissions were reduced by 2.54%. However, with EGR, the CO and HC emissions and the smoke opacity increased by 7.70%, 18.61%, and 0.4%, respectively. Furthermore, the fuel consumption of pure biodiesel (B100) at 3000 rpm with a 12.5% EGR rate was reduced by 2.81% compared to that with a 0% EGR rate. Because the temperature in the combustion chamber is high enough for the engine to run, the EGR reuses a portion of the exhaust gases and can help to minimize the quantity of fuel in the combustion chamber. As a suggestion based on these observations, biodiesel fuel should not exceed B80 because the viscosity and density of fuel that are too high may affect the fuel injection system, both the injectors, and the pressure pump, causing the injectors to be unable to work correctly. These findings can contribute to the development of strategies and technologies for reducing emissions and improving fuel efficiency in CRDI diesel engines.
ABSTRACT
Cocoa bean shells from chocolate processing are byproducts of the winnowing process used to remove the shells from the cocoa nibs. The cocoa bean shells have a residual oil content of 11.30 wt % and good nutritional value for animal feed. This study aims to determine the optimal conditions for oil extraction from dried cocoa bean shells using three solvents (hexane, anhydrous ethanol, and hydrous ethanol) while reusing the solvent. The mass ratio of solvent-to-dried cocoa bean shell (2.5-29.5 g/g), stirrer speed (50-550 rpm), and extraction time (0.3-13.7 min) parameters are varied to optimize the oil yield from dried cocoa bean shell using the response surface method. The optimal conditions for hexane were 26.0:1 g/g hexane-to-dried cocoa bean shell ratio, 550 rpm stirrer speed, and 5.2 min extraction time; for anhydrous ethanol, it was 29.5:1 g/g anhydrous ethanol-to-dried cocoa bean shell ratio, 330 rpm stirrer speed, and 7.1 min extraction time; and for hydrous ethanol, it was 27.4 g/g hydrous ethanol-to-dried cocoa bean shell ratio, 550 rpm stirrer speed, and 12.1 min extraction time. The results of oil yields showed that 10.80, 10.50, and 8.90 wt % cocoa bean shell oil yields from the extraction process under optimal conditions using hexane, anhydrous ethanol, and hydrous ethanol, respectively. The high yields of cocoa bean shell oil from hexane and anhydrous ethanol conditions were selected to test the extraction efficiency using reused miscella. Therefore, the extraction efficiency of dried cocoa bean shells with reused miscella using hexane and anhydrous ethanol was examined under optimal conditions to save the amount of solvent and energy. It was found that six cycles of hexane and two cycles of anhydrous ethanol were required to extract oil from cocoa bean shells, with an efficiency of over 80%. The compositions in cocoa bean shell oil from extraction consisted of 99.53% triglycerides, 0.01% free fatty acids, 0.43% diglycerides, and 0.05% monoglycerides for the hexane condition, while the compositions in cocoa bean shell oil were found to be 98.37% triglycerides, 0.53% free fatty acids, 1.02% diglycerides, and 0.08% monoglycerides after being extracted with ethanol. In addition, cocoa bean shell was oil extracted with reused miscella of hexane and anhydrous ethanol solvents to save energy and chemicals during solvent evaporation. This study recommends ethanol over hexane because it is safer for the environment. Both dried and defatted cocoa bean shells could successfully produce feed pellets by using pelletization. The process was achieved by adding 25 wt % water to defatted cocoa bean shells before forming them with a pellet machine.
ABSTRACT
This research aimed to evaluate the performance and emissions of direct injection diesel engines using blends of diesel-biodiesel-esterified pyrolysis bio-oil (D-B-EPB). The pyrolysis process was employed to produce pyrolysis bio-oil (PBO) from solid biomass obtained from fresh palm fruits. Furthermore, a simple and effective esterification process was used to upgrade the PBO. The methyl ester (ME) purity of EPB production was studied to optimize three independent variables: methanol (14.8-65.2 wt %), sulfuric acid (1.6-18.4 wt %), and reaction time (16-84 min) using the response surface methodology. The actual experiment yielded a ME purity of 72.73 wt % under the recommended conditions of 40.3 wt % methanol, 13.0 wt % sulfuric acid, 50 min reaction time, 60 °C reaction temperature, and 300 rpm stirrer speed. Additionally, the stability and phase behaviors of D-B-EPB blends were analyzed by using a ternary phase diagram to determine the potential blending proportion. The results revealed that a fuel blend consisting of 30 wt % diesel, 60 wt % biodiesel, and 10 wt % EPB (D30B60EPB10) met the density and viscosity requirements of diesel standards. This D30B60EPB10 blend was subjected to performance and emission tests in diesel engines at various speeds ranging from 1100 to 2300 rpm and different engine loads of 25, 50, and 75%. In terms of performance analysis, the brake thermal efficiencies of biodiesel and D30B60EPB10 were 7.19 and 3.88% higher than that of diesel, respectively. However, the brake-specific fuel consumption of the D30B60EPB10 blend was 6.60% higher than that of diesel due to its higher density and viscosity and lower heating value compared with that of diesel. In the emission analysis, the D30B60EPB10 blend exhibited performance comparable to diesel while being more environmentally friendly, reducing carbon monoxide, carbon dioxide, nitrogen oxide, and smoke opacity by 8.73, 30.13, 37.55, and 59.75%, respectively. The results of this study suggest that the D-B-EPB blend has the potential to serve as a viable biofuel option, reducing the proportion of diesel in blended fuel and benefiting farmers and rural communities..
ABSTRACT
[This corrects the article DOI: 10.1021/acsomega.2c07537.].
ABSTRACT
In this research, the optimum condition for the production of refined crude palm oil methyl ester from refined crude palm oil was investigated using the response surface method via the transesterification reaction in a batch process. The refined crude palm oil was obtained by vacuum distillation of crude palm oil to extract some of the free fatty acids from the oil, providing nutritional benefits and reducing the chemical consumption of the production process. The purity of methyl ester in the refined crude palm oil methyl ester was studied to adjust four independent variables: methanol content (11-23 vol %), concentration of potassium hydroxide (4-12 g/L), stirrer speed (100-500 rpm), and reaction time (9-45 min). The results showed that methyl ester had a purity of 96.91 wt % when synthesized under optimal conditions of 18.2 vol % methanol, a potassium hydroxide concentration of 10.0 g/L, a stirring speed of 380 rpm, and a reaction time of 36.4 min at 60 °C. Refined crude palm oil methyl ester was blended with diesel and ethanol to study the feasibility of using the diesel-refined crude palm oil methyl ester-hydrous ethanol blend in an unmodified diesel engine. A comparative study of fuel properties, emissions, and performance of the diesel-refined crude palm oil methyl ester-ethanol blend was used to assess the feasibility of fuel blends (D40RM50E10, D30RM60E10, D20RM70E10, and D10RM80E10) in diesel engines at various engine speeds and loads. The results showed that the D40RM50E10 blend provided the closest performance to diesel and was environmentally friendly, as it provided nitrogen oxide and carbon monoxide emissions 32 and 55% lower than those with diesel, respectively. The test results indicated that the diesel-refined crude palm oil methyl ester-hydrous ethanol blend is an attractive alternative fuel in agricultural engines that reduces diesel consumption and benefits farmers and rural communities.
ABSTRACT
An experimental research is assessed to examine the engine performance and exhaust emissions of direct injection (DI) and indirect injection diesel (IDI) engines fueled with petroleum diesel, biodiesel, and nanoemulsion fuel. The nanoemulsion fuel was produced using a hydrodynamic cavitation reactor. These three fuels were used to study the exhaust emissions, brake power, brake specific fuel consumption (BSFC), brake thermal efficiency (BTE), and exhaust gas temperature at engine speeds ranging from 1100, 1400, 1700, 2000, and 2300 rpm with engine loads of 25, 50, and 75%. Furthermore, three fuels were burned in two types of combustion engines such as DI and IDI diesel engines under identical conditions. The finding showed that using DI and IDI engines influenced the magnitude of emissions as well as the performance with different speeds and loads. By comparing the performance of DI and IDI engines at a maximum engine load of 75%, the most concerning parameter among the efficiency of an engine of BTE of diesel, biodiesel, and nanoemulsion fuel from the DI engine was higher at 24.19, 24.83, and 20.76%, respectively, than that of the IDI engine at 2300 rpm engine speed. At the maximum load and speed of engines, the BSFC of diesel, biodiesel, and nanoemulsion fuel in the DI engine were 4.44, 23.73, and 20% lower than in the IDI engine, respectively. Emission results of the DI and IDI engines were analyzed at 75% load and 2300 rpm speed. The results demonstrated that emissions of NO x from nanoemulsion fuel from the IDI engine was significantly reduced by 82.46% when the values were compared to the DI engine. In terms of CO emissions, the IDI engine emits significantly less than the DI diesel engine. The CO emissions of diesel, biodiesel, and nanoemulsion fuel in the IDI engine were 69.02, 28.95, and 48.75% lower than those in the DI engine, respectively. The studies conclude that the emissions from IDI engines clearly show that pollution from exhaust emissions can be reduced to a low level compared to the DI engine. However, when high-performance engines are considered, the DI engine is recommended rather than the IDI engine.
ABSTRACT
Double-step esterification to produce biodiesel from palm fatty acid distillate (PFAD) was performed by utilizing an ultrasound clamp reactor. Six pairs of ultrasonic clamps were attached to the left and right sides of the stainless-steel tube, and each pair was separated 100 mm apart from each other. Therefore, a total of 12 units of ultrasound clamps distributed 4800 W maximum power (12 × 400 W) throughout the continuous reactor by an ultrasonic generator. To optimize each step of the continuous esterification process for producing methyl ester from PFAD, a response surface methodology was used. The final 93.32 wt % methyl ester purity was attained under a double-step esterification process. For the first step, a 3.75:1 molar ratio of methanol to PFAD (46.4 vol % methanol), 6.6 vol % sulfuric acid, and 400 mm length of ultrasound clamp at 25 L/h PFAD flow rate for converting the PFAD to 60.24 wt % methyl ester were recommended. For the second step, the esterification was repeated under a molar ratio of methanol to the first esterified oil of 2.87:1 (61.6 vol % methanol), 5.6 vol % of sulfuric acid, and 400 mm length of ultrasound clamp at 25 L/h esterified oil flow rate. The ultrasonic clamp reactor achieved high yields of esterified oil and the crude biodiesel in a relatively short residence period of 32 s. To determine the product yields of a double-step esterification process, the maximum yields were 103.9 wt % first esterified oil, 107.6% crude biodiesel, and 98 wt % purified biodiesel when calculated on the basis of 100 vol % initial PFAD. The average energy consumed in the production of double-step esterification biodiesel was 0.05796 kWh/L. Therefore, this current approach has a high potential for producing biodiesel with less energy and requires less time to convert the PFAD to a high purity of methyl ester.
ABSTRACT
In this research, the diesel-palm fatty acid distillate ethyl ester-hydrous ethanol, palm fatty acid distillate ethyl ester, and diesel were studied to investigate the gas emissions and performances of the direct injection diesel engine at different engine loads and engine speeds. At all engine speeds and loads, nitrogen oxide emissions from all fuel blends (D50PE40E10, D40PE50E10, and D30PE60E10) were significantly lower than the baseline diesel. At all engine speeds and engine loads, the fuel blends released less carbon dioxide than the baseline diesel, with the exception of the D30PE60E10 blend. Furthermore, D30PE60E10 diesel was used to test wear for 500 h long-term endurance of diesel engine components. The results indicated that biodiesel in fuel blends may reduce engine component wear by forming a thin coating on the metal surface of the engine component. However, after 100 h of continuous operation with D30PE60E10 blend, the engine cannot be restarted because only a part of the fuel pump had many pores on the surface of the plunger, barrel, delivery valve, and valve holder. However, these components may have to be considered to prevent corrosion when this fuel blend was employed.
ABSTRACT
This research focuses on the feasibility of using diesel-palm fatty acid distillate ethyl ester (PFADE)-ethanol in a direct injection diesel engine without any major modifications. Hydrous ethanol was selected for blending in diesel to produce diesohol. The palm fatty acid distillate (PFAD) and PFADE were directly blended in ethanol and diesel. A comparative study of the phase stability in diesel-PFAD-hydrous ethanol and diesel-PFADE-hydrous ethanol was performed with varied blend proportions. The fuel properties, emissions (CO, CO2, NO x , O2, exhaust gas temperature), and fuel consumptions of diesel, PFADE, diesel-PFADE-hydrous ethanol were compared to evaluate the feasibilities of these fuel blends in a diesel engine at the engine speeds 1100, 1400, 1700, 2000, and 2300 rpm. At 2300 rpm, the maximum CO2 emission with 10 wt % hydrous ethanol in the blend was approximately 2%. With regard to fuel consumption, clearly, 20 wt % diesohol gave higher consumption than 10 wt % ethanol at a maximum engine speed of 2300 rpm. The blend D50PE40E10 gave the lowest fuel consumption, while the maximum fuel consumption was with the D10PE70E20 blend. Therefore, both 10 and 20 wt % hydrous ethanol in the diesel fuel are alternatives usable in a diesel engine without modifications.
