Heterogeneous Calcium Oxide Catalytic Filaments for Three-Dimensional Printing: Preparation, Characterization, and Use in Methyl Ester Production.

This study aimed to investigate heterogeneous catalytic filaments of calcium oxide (CaO) for fused deposition modeling three-dimensional (3D) printers. The CaO catalysts were blended with acrylonitrile butadiene styrene (ABS) plastic to form catalytic filaments. A single-screw filament extruder was used to prepare the filaments, following which their mechanical properties, thermal properties, morphology, catalytic characteristics in biodiesel production, and reusability were evaluated. In accordance with the results, a maximum CaO catalyst content of 15 wt % was recommended to be blended in the ABS pellet. The hardness and compressive strength of these catalytic filaments were shown to be improved. Subsequently, the catalytic filaments with the highest CaO content (15 wt %) were used to produce methyl ester from pretreated sludge palm oil through the transesterification process. To determine the recommended conditions for achieving the highest purity of methyl ester in biodiesel, the process parameters were optimized. A methyl ester purity of 96.58 wt % and a biodiesel yield of 79.7 wt % could be achieved under the recommended conditions of a 9.0:1 methanol to oil molar ratio, 75.0 wt % catalytic filament loading, and 4.0 h reaction time. Furthermore, the reusability of the 15 wt % CaO catalytic filaments was evaluated in a batch process with multiple transesterification cycles. The results indicated that the purity of methyl ester dropped to 95.0 wt % only after the fourth cycle. The method used in this study for preparing and characterizing CaO catalytic filaments can potentially serve as a novel approach for constructing biodiesel reactors using 3D printing technology.

Effects of Blended Diesel-Biodiesel Fuel on Emissions of a Common Rail Direct Injection Diesel Engine with Different Exhaust Gas Recirculation Rates.

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.

Optimization of Oil Extraction from Cocoa Bean Shells Using Three Solvents with Solvent Reusability.

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.

Upgrading Pyrolysis Bio-Oil through Esterification Process and Assessing the Performance and Emissions of Diesel-Biodiesel-Esterified Pyrolysis Bio-Oil Blends in Direct Injection Diesel Engines.

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..

Investigation of free fatty acid reduction from mixed crude palm oil using 3D-printed rotor-stator hydrodynamic cavitation: An experimental study of geometric characteristics of the inner hole.

A continuous esterification process is employed to decrease the free fatty acid (FFA) concentration of FFA-rich mixed crude palm oil. Both optimal and recommended conditions are determined for the esterification reaction conditions and the geometry of the 3D-printed rotor design in the rotor-stator hydrodynamic cavitation reactor. This study is primarily concerned with the effect of the cavitation device configuration, especially the rotor design, on FFA reduction. Instead of conventional spherical or cylindrical drilled holes, a point angle cone-shaped hole is used to create cavities over the rotor surface. These point angles are adjusted to clarify their effect on FFA reduction. The response surface methodology is applied to determine the optimal concentrations of methanol and sulfuric acid, rotor speed, hole diameter and depth, and cone point angle. The recommended conditions are 20.8 wt% methanol, 2.6 wt% sulfuric acid, 3000 rpm, 5 mm hole diameter, 5 mm hole depth, and 110°, respectively. Under this configuration, the FFA content is reduced from 12.014 wt% to around 1 wt%. A maximum yield of 97.34 vol% esterified oil is obtained through a completed phase separation step, and 93.31 vol% pure oil is collected after the cleansing step. The recommended conditions result in reduced chemical usage, cheaper FFA reduction, and lower environmental impact. This creative rotor design effectively improves our understanding of the geometry of the cavitation device, thus enhancing the cavitation effect in industrial operations.

Correction to "Investigating the Effect of a Diesel-Refined Crude Palm Oil Methyl Ester-Hydrous Ethanol Blend on the Performance and Emissions of an Unmodified Direct Injection Diesel Engine".

[This corrects the article DOI: 10.1021/acsomega.2c07537.].

Continuous double-step acid catalyzed esterification production of sludge palm oil using 3D-printed rotational hydrodynamic cavitation reactor.

Sludge palm oil (SPO) with high free fatty acid (FFA) content was processed using a continuous and double-step esterification production process in a rotor-stator-type hydrodynamic cavitation reactor. Three-dimensional printed rotor was made of plastic filament and acted as a major element in minimizing the FFA content in SPO. To evaluate the reduced level of FFAs using both methods, five independent factors were varied: methanol content, sulphuric acid content (H2SO4), hole diameter, hole depth, and rotor speed. The first-step conditions for the esterification process included 60.8 vol% methanol content, 7.2 vol% H2SO4 content, 5.0 mm diameter of the hole, 6.1 mm depth of the hole, and 3000 rpm speed of the rotor. The initial free fatty acid content decreased from 89.16 wt% to 35.00 wt% by the predictive model, while 36.69 wt% FFA level and 94.4 vol% washed first-esterified oil yield were obtained from an actual experiment. In the second-step, 1.0 wt% FFA was achieved under the following conditions: 44.5 vol% methanol content, 3.0 vol% H2SO4 content, 4.6 mm hole diameter, 5.8 mm hole depth, and 3000 rpm rotor speed. The actual experiment produced 0.94 wt% FFA content and 93.9 vol% washed second-esterified oil yield. The entire process required an average electricity of 0.137 kWh/L to reduce the FFA level in the SPO below 1 wt%.

Investigating the Effect of a Diesel-Refined Crude Palm Oil Methyl Ester-Hydrous Ethanol Blend on the Performance and Emissions of an Unmodified Direct Injection Diesel Engine.

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.

Diesel-Biodiesel-Water Fuel Nanoemulsions for Direct Injection and Indirect Injection Diesel Engines: Performance and Emission Characteristics.

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.

Digestibility, Blood Parameters, Rumen Fermentation, Hematology, and Nitrogen Balance of Goats after Receiving Supplemental Coffee Cherry Pulp as a Source of Phytochemical Nutrients.

This research examines the impact of adding dried coffee cherry pulp (CoCP) to goat feed on the digestibility of the feed, rumen fermentation, hematological, and nitrogen balance. A goat feeding experiment employed four male crossbreds (Thai Native × Anglo Nubian) aged 12 months and weighing 21.0 ± 0.2 kg each. The treatment was conceived as a 4 × 4 Latin square with four specific CoCP levels at 0, 100, 200, and 300 g/day. Dry matter intake (DMI), organic matter intake (OMI), and crude protein intake (CPI) were unaffected by the addition of CoCP. However, across treatment groups, there was a linear increase in ether extract intake (EEI) (p < 0.01), neutral detergent fiber intake (NDFI) (p = 0.06), and acid detergent fiber intake (ADFI) (p = 0.04), as well as a quadratic effect on DMI% BW (p = 0.04). The findings showed that rumen temperature, pH, ammonia-nitrogen, or pack cell volume did not change with CoCP supplementation. Total volatile fatty acid showed linear effects on acetate (p = 0.03) and was quadratically affected by propionate concentration (p = 0.02), acetate to propionate ratio (p = 0.01), acetic plus butyric to propionic acid ratio (p = 0.01), and methane estimation (p = 0.01). With increased CoCP supplementation, there was a linear decrease in protozoa count by about 20.2% as the amount of CoCP supplemented increased (p = 0.06). CoCP supplementation in animal feed resulted in a linear decrease in urinary nitrogen (p = 0.02) and a quadratic effect on absorbed nitrogen (p = 0.08) among treatment groups, with greater N utilization values found in goats fed 200 g/d CoCP. In light of this, supplementing CoCP into animal feed may improve animal digestion and rumen fermentation effectiveness while having no effect on feed intake, rumen microbes, or blood metabolites.

Continuous Double-Step Esterification Production of Palm Fatty Acid Distillate Methyl Ester Using Ultrasonic Tubular Reactor.

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.

Effect of Diesel-Palm Fatty Acid Distillate Ethyl Ester-Hydrous Ethanol Blend on the Performance, Emissions, and Long-Term Endurance Test on an Unmodified DI Diesel Engine.

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.

Continuous production of nanoemulsion for skincare product using a 3D-printed rotor-stator hydrodynamic cavitation reactor.

In this study, nanoemulsions for skincare products were continuously produced using a hydrodynamic cavitation reactor (HCR) designed with a rotor and stator. The key component of this research is the utilization of a 3D-printed rotor in a HCR for the production of an oil-in-water nanoemulsion. Response surface methodology was used to determine the process conditions, such as speed of the rotor, flow rate, as well as, Span60, Tween60, and mineral oil concentrations, for generating the optimal droplet size in the nanoemulsion. The results showed that a droplet size of 366.4 nm was achieved under the recommended conditions of rotor speed of 3500 rpm, flow rate of 3.3 L/h, Span60 concentration of 2.36 wt%, Tween60 concentration of 3.00 wt%, and mineral oil concentration of 1.76 wt%. Moreover, the important characteristics for consideration in skincare products, such as polydispersity index, pH, zeta potential, viscosity, stability, and niacin released from formulations, were also assessed. For the niacin release profile of emulsion and nanoemulsion formulations, different methods, such as magnetic stirring, ultrasound, and hydrodynamic cavitation, were compared. The nanoemulsion formulations provided a greater cumulative release from the formulation than the emulsion. Particularly, the nanoemulsion generated using the HCR provided the largest cumulative release from the formulation after 12 h. Therefore, the present study suggests that nanoemulsions can be created by means of hydrodynamic cavitation, which reduces the droplet size, as compared to that generated using other techniques. The satisfactory results of this study indicate that the rotor-stator-type HCR is a potentially cost-effective technology for nanoemulsion production.

Two-stage continuous production process for fatty acid methyl ester from high FFA crude palm oil using rotor-stator hydrocavitation.

Two-stage continuous production process for fatty acid methyl ester (FAME) from crude palm oil was performed using the rotor-stator hydrocavitation reactor. The novel ABS filament printed rotor having spherical holes on the surface of the rotor which is an efficient, fast and cost-effective procedure, was installed in the stainless steel stator of hydrosonic reactor. The 3D printed hydrosonic reactor was used to treat the FFA-rich in MCPO by esterification and followed by transesterification to produce the methyl ester. The optimum conditions of both esterification and transesterification processes were determined using the response surface methodology (RSM). For the 1st step esterification, the conditions of methanol 17.7 vol%, sulfuric acid 2.9 vol%, 3000 rpm rotor speed, hole's diameter and depth 4 and 6 mm, and 25 L/h MCPO, were used for decreasing the FFA from 11.456 to 1.028 wt%. For the 2nd step, transesterification was employed with the optimal condition of 28.6 vol% methanol, 6.2 g/L of potassium hydroxide, 3000 rpm rotor speed, the dimension of the spherical holes on the rotor's surface having diameter of 6.4 mm and 6.2 mm in depth, and esterified oil flow rate 25 L/h, for producing the methyl ester to over 99.163 wt%. Moreover, the purified biodiesel yields and the average energy consumption for the entire two-stage continuous process between hydrosonic and ultrasonic clamp reactors were compared. The results of purified methyl ester clearly indicate that the methyl esters of 99.163 wt% and 97.814 wt% were achieved from hydrosonic and ultrasonic clamp reactors, respectively, under the same optimized conditions. The maximum yields of purified biodiesel were 97.51 vol% and 88.69 vol% using hydrosonic and ultrasonic clamp reactors, respectively. The average energy consumption for the entire continuous two-stage process for both hydrosonic and ultrasonic clamp reactors were 0.049 and 0.056 kW h/L, respectively. For practical industrial processes, stainless steel rotors inside the stator was manufactured by CNC machine, which was also verified under the optimum conditions. The results showed that 1.07 wt% FFA and 99.221 wt% methyl ester of were obtained from first step and second step, respectively.

Continuous acid-catalyzed esterification using a 3D printed rotor-stator hydrodynamic cavitation reactor reduces free fatty acid content in mixed crude palm oil.

Free fatty acid (FFA) content in FFA-rich mixed crude palm oil (MCPO) was reduced through a continuous esterification process. The reaction conditions were optimized, the yield purified esterified oil was determined, and the average total electricity consumption of the entire process was evaluated. The key component of this study was the cost-effective, 3D-printed rotor that was installed in a continuous rotor-stator hydrodynamic reactor. The surface of the rotor was designed with spherical holes where the center-to-center distance between them was fixed. Response surface methodology (RSM) using central composite design (CCD) was employed to analyze the design of experiments (DOE) and optimize FFA-content reduction. The optimized conditions were 17.7 vol% methanol, 2.9 vol% sulfuric acid, a 3000 rpm rotor speed, and surface holes measuring 4 mm in diameter and 6 mm in depth. The experimental results showed that the FFA content in MCPO was reduced from 11.456 to 1.028 wt% upon esterification under these optimal conditions. The maximum yield of esterified oil from the phase separation step was 96.07 vol%, and that of the purified esterified oil was 91.27 vol%. The average total energy consumed by this hydrodynamic cavitation reactor to produce this esterified oil was 0.0264 kW h/L. This 3D printed rotor-stator reactor is a promising, novel reactor technology for producing biodiesel from FFA-rich oils.

Feasibility of Using Diesel-Palm Fatty Acid Distillate Ethyl Ester-Hydrous Ethanol Blend in an Unmodified Direct Injection Diesel Engine: An Assessment of Stability, Fuel Properties, and Emissions.

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.