Feasibility of blending karanja vegetable oil in petro-diesel and utilization in a direct injection diesel engine

Karanja (Pongamia pinnata) oil, a non-edible high viscosity (27.84 cSt at 40 °C) straight vegetable oil, was blended with conventional diesel in various proportions to evaluate the performance and emission characteristics of a single cylinder direct injection constant speed diesel engine. Diesel and karanja oil fuel blends (5%, 10%, 15%, and 20%) were used to conduct short-term engine performance and emission tests at varying loads (0%, 20%, 40%, 60%, 80%, and 100%). Tests were carried out over the entire range of engine operation and engine performance parameters such as fuel consumption, thermal efficiency, exhaust gas temperature, and exhaust emissions (smoke, CO, CO₂, HC, NO_x, and O₂) were recorded. The brake specific energy consumption (BSEC), brake thermal efficiency (BTE), and exhaust emissions were evaluated to determine the optimum fuel blend. Higher BSEC was observed at full load for neat petro-diesel. A fuel blend of 10% karanja oil (KVO10) showed higher BTE at a 60% load. Similarly, the overall emission characteristics were found to be best for the case of KVO10 over the entire range of engine operation.     

Influence of free fatty acid content of coconut oil on deposit and performance of plant oil pressure stoves

In tropical and subtropical countries, utilization of unprocessed plant oil or used frying oil as household cooking fuel promises to be a competitive alternative to well known fuels like wood and kerosene. However, the use of unprocessed plant oil in plant oil pressure stoves leads to the formation of deposits inside the vaporizer, which have to be removed from time to assure a proper operation of the plant oil pressure stove.Therefore, the objective of this study was to investigate the effect of free fatty acid content of coconut oil on performance and deposit formation in plant oil pressure stoves. Test fuels with different levels of free fatty acid content were prepared by aerating the coconut oil with dry air (5.04 l O₂/kg h) at a temperature of 85 °C. Experiments were performed with the plant oil pressure stove ’Protos’ (BSH Bosch und Siemens Hausgeräte GmbH).As a result, 0.15 g of deposits per kg of consumed oil was found for fresh coconut oil with free fatty acid content of 0.03%, which served as control. Aged oil with a free fatty acid content of 23.1% resulted in 6.48 g deposits per kg of consumed test fuel. Conradson carbon residue CCR of 0.18% was low for control and increased to 0.82% for aged oil. Specific fuel consumption was in a range between 0.284 and 0.304 kg/h without significant differences between the fuels. Performance of the plant oil pressure stove was not affected by the amount of free fatty acids in the plant oil. However, lower heating value decreased from initial 35 MJ/kg for control to 30 MJ/kg for aged fuel, and as consequence power output from plant oil pressure stove decreased. Therefore, plant oils with free fatty acid content below 5%, which is equivalent to an acid value of 10 mg KOH/g, are recommended as fuels for plant oil pressure stoves.     

Exhaust emissions from a diesel powered vehicle fuelled by soybean biodiesel blends (B3-B20) with ethanol as an additive (B20E2-B20E5)

The effects of diesel oil-soybean biodiesel blends on a passenger vehicle exhaust pollutant emissions were investigated. Blends of diesel oil and soybean biodiesel with concentrations of 3% (B3), 5% (B5), 10% (B10) and 20% (B20) were used as fuels. Additionally, the effects of anhydrous ethanol as an additive to B20 fuel blend with concentrations of 2% (B20E2) and 5% (B20E5) were also studied. The emissions tests were carried out following the New European Driving Cycle (NEDC). The results showed that increasing biodiesel concentration in the fuel blend increases carbon dioxide (CO₂) and oxides of nitrogen (NO_X) emissions, while carbon monoxide (CO), hydrocarbons (HC) and particulate matter (PM) emissions are reduced. The addition of anhydrous ethanol to B20 fuel blend proved it can be a strategy to control exhaust NO_X and global warming effects through the reduction of CO₂ concentration. However, it may require fuel injection modifications, as it increases CO, HC and PM emissions.     

Experimental investigation and mathematical modelling of wood combustion in a moving grate boiler

The use of biomass to generate energy offers significant environmental advantages for the reduction in emissions of greenhouse gases. The main objective of this study was to investigate the performance of a small scale biomass heating plant: i.e. combustion characteristics and emissions. An extensive series of experimental tests was carried out at a small scale residential biomass heating plant i.e. wood chip fired boiler. The concentrations of CO, NO_x, particulate matter in the flue gas were measured. In addition, mathematical modelling work using FLIC and FLUENT codes was carried out in order to simulate the overall performance of the wood fired heating system. Results showed that pollutant emissions from the boiler were within the relative emission limits. Mass concentration of CO emission was 550-1600 mg/m³ (10% O₂). NO_x concentration in the flue gas from the wood chips combustion varied slightly between 28 and 60 ppmv. Mass concentration of PM₁₀ in the flue gas was 205 mg/m³ (10% O₂) The modelling results showed that most of the fuel was burnt inside the furnace and little CO was released from the system due to the high flue gas temperature in the furnace. The injection of the secondary air provided adequate mixing and favourable combustion conditions in the over-bed chamber in the wood chips fired boiler. This study has shown that the use of wood heating system result in much lower CO₂ emissions than from a fossil fuel e.g. coal fired heating system.     

Investigation of soybean oil as a diesel fuel extender: Endurance tests

Engine performance and crankcase lubricant viscosity were followed with 1∶2 and 1∶1 fuel mixtures of degummed soybean oil in No. 2 diesel fuel in tests with a John Deere 6-cylinder, 404 cubic in. displacement, direct-injection, turbocharged engine for a total of 600 running hours. A crankcase oil contamination problem resulting in an unacceptable thickening and a potential for gelling did exist with a 50/50 blend or a greater concentration of soybean oil, but it did not occur with the 1∶2 blend. The data accumulated during the initial 600 hr running time indicates that a fuel blend of one-third degummed soybean oil and two-thirds No. 2 diesel (1∶2 blend) may be a suitable fuel for agricultural equipment during periods of diesel fuel shortages or allocations. Additional data are being accumulated and will be analyzed in the future.     

Combustion of low-calorific waste liquids in high temperature air

Waste liquids with low-calorific values are not easy to burn. In this experiment, a furnace with a pair of burners for high-cycled alternate firing was utilized to burn the low-calorific value liquids. In a 1383 K furnace, 1173 K preheated air was achieved via these burners equipped with regenerators. It was observed that the alternate firing with highly preheated air was an effective way to ignite and burn the low-calorific value liquids. The preheated air temperature was higher than the auto-ignition temperature of the flammable mixture of the waste liquids. The combustion gas temperature in the furnace was quite uniform via the high-cycled alternate firing, resulting in a longer residence time of combustion in the furnace as compared to the conventional incinerator. The convective heat transfer in this furnace was higher than that of the conventional incinerator, and more useful energy was extracted from the waste liquids for end users. For the waste liquids with lower heating values of 15.0 MJ/kg (19 wt.% water) and 10.4 MJ/kg (42 wt.% water), it was found that 49% and 10% of the heating values of the waste liquids, respectively, could be used for utility energy. Furthermore, the waste liquid with a lower heating value of 7.1 MJ/kg (45 wt.% water) could burn itself in this furnace without the need of co-firing of any auxiliary fuels. NO_x and CO emissions were lower than 60 ppmv (6% O₂) and 50 ppmv (6% O₂), respectively, for all tests.     

Co-gasification of meat and bone meal with coal in a fluidised bed reactor

After the Bovine Spongiform Encephalopathy illness appeared, the meat and bone meat (MBM) produced from animal residues became an important waste. In spite of being a possible fuel due to its heating value (around 21.4 MJ/kg), an important fraction of the meat and bone meal is being sent to landfills. The aim of this work is to evaluate the co-gasification of low percentages of meat and bone meal with coal in a fluidised bed reactor as a potential waste management alternative. The effect of the bed temperature (800-900 °C), the equivalence ratio (0.25-0.35) and the percentage of MBM in the solid fed (0-1 wt.%) on the co-gasification product yields and properties is evaluated. The results show the addition of 1 wt.% of MBM in a coal gasification process increases the gas and the liquid yield and decreases the solid yield at 900 °C and 0.35 of temperature and equivalence ratio operational conditions. At operational conditions of 900 °C and equivalence ratio of 0.35, the specific yield to gas (y_gas) increases from 3.18 m³(STP)/kg to 4.47 m³(STP)/kg. The gas energy yield decreased 24.1% and the lower heating value of the gas decreases from 3.36 MJ/m³(STP) to 2.16 MJ/m³(STP). The concentration of the main gas components (H₂, CO and CO₂) hardly varies with the addition of MBM, however the light hydrocarbon concentrations decrease and the H₂S concentration increases at the higher temperature (900 °C).     

Co-firing of coal and cattle feedlot biomass (FB) fuels. Part II. Performance results from 30 kWt (100,000) BTU/h laboratory scale boiler burner

The use of cattle manure (referred to as feedlot biomass, FB) as a fuel source has the potential to both solve waste disposal problems and reduce fossil fuel based CO₂ emissions. A co-firing technology is proposed where FB is ground, mixed with coal, and then fired in existing, pulverized coal-fired boiler burner facilities. A research program was undertaken in order to determine (i) fuel characteristics, (ii) combustion characteristics when fired along with coal in a small scale 30-kW_t (100,000 BTU/h) boiler burner facility, and (iii) combustion and fouling characteristics when fired along with coal in a large pilot scale 150-kW_t (500,000 BTU/h) DOE-NETL boiler-burner facility. Part I presented a methodology for fuel collection, fuel characteristics of the FB, its relation to ration fed, and the change in fuel characteristics and volatile oxides due to composting. Part II addresses the pyrolysis characteristics of coal, FB, and blend and presents results on the performance of 90:10 coal:FB (PC) blend as fired in a 30-kW_t boiler-burner unit. The boiler-burner unit is made of steel and lined with a cast ceramic liner for long duration operation and a commercial feeding system is used for firing the coal and the blend. Thermogravimetric analyses (TGA) performed on coal, FB, and 90:10 coal:FB blend reveal that biomass will start releasing gases at 273 °C (523  °F) which is about 100 °C (212 °F) lower than that of coal. The maximum rate of volatile release is about 0.000669 kg/s kg for FB while that of coal is 0.000425 kg/s kg. The experiments revealed that the 90:10 blend burns more completely in the boiler, due to the earlier release of biomass volatiles and higher amount of volatile matter in FB. The NO_x emission for coal was 290 ppm, 0.162 kg/GJ (0.3768 lb/mm BTU) and 260 ppm, 0.1475 kg/GJ (0.343 lb/mm BTU) for the 90:10 blend at 10% excess air. Even though the effective N content of the blend increased by 18%, compared to coal the NO_x emission decreased which is attributed to the higher VM of FB and more N in the form of NH₃. However, due to limited residence time and higher VM, the CO emission increased from 15,582 ppm, 5.29 kg/GJ (12.305 lb/mm BTU) to 22,669 ppm, 7.81 kg/GJ (18.16 lb/mm BTU) when fuel was switched from coal to 90:10 blend. Large scale pilot plant tests performed at the 150-kW_t facility (DOE-NETL) reveal increased falling potential for the blend compared to coal (Part III), emissions were negligible.     

Optimization of the combustion of blends of domestic fuel oil and cottonseed oil in a non-modified domestic boiler

This study characterizes combustion of blends of DFO (domestic fuel-oil) and refined cottonseed oil produced in Burkina Faso at different percentages in a non-modified DFO burner by determining its overall performance (consumption and thermal capacity) and gas emissions (CO, CO₂, O₂, NO, NO_x, SO₂). The physical and chemical characteristics of the different blends confer on each blend the status of a special fuel requiring specific adjustment of the burner. The influence of combustion parameters such as equivalence ratio and fuel pressure is studied. Results show that emissions of CO, NO_x and CO₂ are similar for all fuel blends at the operating point corresponding to 0.86 equivalence ratio and 20 bars fuel pressure. Whatever the fuel pressure is, SO₂ emission is increasing with DFO percentage in blends.Experimental emission results obtained with suitable adjustments for a blend containing 30% cottonseed oil and 70% DFO are compared to the calculated results obtained using a combustion equation based on a global chemical mechanism. The results show that there is a satisfactory match between the calculation and experimental results.     

Cetane number effect on the energetic and exergetic efficiency of a diesel engine fuelled with biodiesel

This study presents the energy, exergy and heat release analysis of a John Deere 4045 T 4.5 L, four-stroke, four-cylinder, turbocharged diesel engine. The engine was run with four different types of fuel: yellow grease methyl ester (YGME); soybean oil methyl ester (SME); and soybean oil methyl ester containing either 0.75 or 1.5 w/w % of the cetane improver 2-ethylhexyl nitrate (SME-0.75%EHN and SME-1.5%EHN, respectively). The engine was tested at 1400 1/min under a full load of 352 Nm. For reliability, the fuels were tested three times, and the mean values were compared using different statistical techniques. The objective in this study was to determine the effect of cetane number and ignition delay on the energy and exergy efficiencies of an internal combustion engine and to compare the results for the types of fuel stated earlier. The average thermal efficiency was approximately 40.5%, and the exergetic efficiency was approximately 37.3%. The mean exergetic efficiencies of the fuels were in the order ψ_SME > ψ_SME-0.75%EHN > ψ_SME-1.5%EHN > ψ_YGME. There were significant differences among the mean values according to Student's t-tests. It is concluded that a lower cetane number, a longer ignition delay period and a higher level of premixed combustion may increase the exergetic efficiency of a diesel engine.     

Oxidation stability of blends of Jatropha biodiesel with diesel

Biodiesel, an ecofriendly and renewable fuel substitute for diesel has been receiving the attention of researchers around the world. Due to heavy import of edible oil, the production of biodiesel from edible oil resources in India is not advisable. Therefore it is necessary to explore non-edible seed oils, like Jatropha curcas (J. curcas) and Pongamia for biodiesel production. The oxidation stability of biodiesel from J. curcas oil (JCO) is very poor and therefore an idea is given to increase the oxidation stability of biodiesel by blending it with petro-diesel. J. curcas biodiesel (JCB), when blended with petro diesel leads to a composition having efficient and improved oxidation stability. The results have shown that blending of JCB with diesel with less than 20% (v/v) would not need any antioxidants but at the same time, need large storage space. Similarly, if the amount of diesel is decreased in the blend, it will require the addition of antioxidant but in lesser amount compared to pure JCB. For the purpose five antioxidants were used namely butylated hydroxytoluene (BHT), tert-butyl hydroquinone (TBHQ), butylated hydroxyanisole (BHA), propyl gallate (PG), and pyrogallol (PY). A B₃₀ blend (30% JCB in the blend of JCB and petro-diesel) has been tested for the same purpose. PY is found to be the best antioxidant among all five antioxidants used. The optimum amount of antioxidant (PY) for pure biodiesel tested for the present experiment is around 100 ppm while it is around 50 ppm for B₃₀ blend to maintain the international specification of oxidation stability.     

Preparation, characterization and mechanical properties of epoxidized soybean oil/clay nanocomposites

New epoxidized soybean oil (ESO)/clay nanocomposites have been prepared with triethylenetetramine (TETA) as a curing agent. The dispersion of the clay layers is investigated by X-ray diffraction (XRD) and transmission electron microscopy (TEM). XRD and TEM data reveal the intercalated structure of ESO/clay nanocomposites has been developed. The thermogravimetric analysis exhibits that the ESO/clay nanocomposites are thermally stable at temperatures lower than 180 °C, with the maximum weight loss rate after 325 °C. The glass transition temperature, T_g, about 7.5 °C measured by differential scanning calorimetry (DSC) and T_g about 20 °C measured by dynamic mechanical study have been obtained. The difference in the T_g between DSC and dynamic measurements may be caused by different heating rate. The nanocomposites with 5-10 wt% clay content possess storage modulus ranging from 2.0×10⁶ to 2.70×10⁶ Pa at 30 °C. The Young's modulus (E) of these materials varies from 1.20 to 3.64 MPa with clay content ranging from 0 to 10 wt%. The ratio of epoxy (ESO) to hydrogen (amino group of TETA) greatly affects dynamic and tensile mechanical properties. At higher amount of TETA, the nanocomposites exhibit stronger tensile and dynamic properties.     

Variations in oxygenated blend composition to meet energy and combustion characteristics very similar to the diesel fuel

By the method of data collation, research into changes in life histories (ignition delay plus time of combustion) of the compounded fuel droplets (diesel fuel-biodiesel fuel (RME)-bioethanol), as well as diesel engine D-144 brake specific fuel consumption rates was performed and obtained results being compared to diesel fuel by an analogous manner.An optimum composition of the multi-component blend B30 + 7.5E demonstrating specific fuel consumption rates and droplet combustion characteristics very similar to diesel fuel was derived. In comparison to B30, a newly derived combustible blend demonstrated fairly improved emissions of exhaust gases. For low load mode: smoke opacity (−10%), NO_X (−2%), CO (−20%), and HC (−12.5%). For average load mode: smoke opacity (−10%), NO_X (−2%), CO (−22%), and HC (−14.5%). For high load mode: smoke opacity (−18%), NO_X (−2%), CO (−22%), and HC (−18%).     

Biodiesel development from high acid value polanga seed oil and performance evaluation in a CI engine

Non-edible filtered high viscous (72 cSt at 40 °C) and high acid value (44 mg KOH/gm) polanga (Calophyllum inophyllum L.) oil based mono esters (biodiesel) produced by triple stage transesterification process and blended with high speed diesel (HSD) were tested for their use as a substitute fuel of diesel in a single cylinder diesel engine. HSD and polanga oil methyl ester (POME) fuel blends (20%, 40%, 60%, 80%, and 100%) were used for conducting the short-term engine performance tests at varying loads (0%, 20%, 40%, 60%, 80%, and 100%). Tests were carried out over entire range of engine operation at varying conditions of speed and load. The brake specific fuel consumption (BSFC) and brake thermal efficiency (BTE) were calculated from the recorded data. The engine performance parameters such as fuel consumption, thermal efficiency, exhaust gas temperature and exhaust emissions (CO, CO₂, HC, NO_x, and O₂) were recorded. The optimum engine operating condition based on lower brake specific fuel consumption and higher brake thermal efficiency was observed at 100% load for neat biodiesel. From emission point of view the neat POME was found to be the best fuel as it showed lesser exhaust emission as compared to HSD.     

Viscosity measurement and modeling of canola oil and its blend with canola stearin in equilibrium with high pressure carbon dioxide

During enzymatic reactions carried out in supercritical CO₂ (SCCO₂) media, CO₂ can expand the liquid reactant mixture, especially lipid-type substances, due to pressure increase and dissolution of CO₂, causing viscosity reduction, and improvement of the diffusion of reactants and products. For better understanding of the transesterification reaction of canola oil and canola stearin in SCCO₂ media, the viscosity of canola oil at 40, 50, 65, and 75 °C and its blend with canola stearin (30 wt%) at 65 °C in equilibrium with high pressure CO₂ was measured up to 12.4 MPa using a rotational rheometer equipped with a high pressure cell. The solubility of CO₂ in canola oil at 40 and 65 °C and its blend with canola stearin at 65 °C was also determined at pressures of up to 20 MPa using a high pressure view cell. The viscosity of canola oil at 40, 50, 65, and 75 °C and its blend with canola stearin at 65 °C decreased exponentially to 87.2, 84.7, 74.8, 66.2, and 74.2% of its value at atmospheric pressure, respectively, with pressure increase up to 12.4 MPa. The viscosity of the samples decreased with an increase in temperature, but the effect of temperature diminished above 10 MPa. The viscosities of CO₂-expanded canola oil and its blend with canola stearin at 65 °C were similar up to 12.4 MPa. The samples exhibited shear-thickening behavior as the flow behavior index reached almost 1.2 at elevated pressures. The mass fraction of CO₂ in canola oil at 40 and 65 °C and its blend with canola stearin at 65 °C reached 24 and 21% at 20 MPa, respectively. The Grunberg and Nissan model was used to correlate the viscosity of CO₂-expanded lipid samples.     

Experimental investigation of diesel engine performance and emission characteristics using jojoba/diesel blend and sunflower oil

Experimental study has been carried out to investigate performance parameters, emissions, cylinder pressure, exhaust gas temperature (T_exhaust) and engine wall temperatures (T_wall) for direct injection diesel engine. Tests were conducted for sunflower oil (S100) and 20% jojoba oil + 80% pure diesel fuel (B20) in comparison to pure diesel fuel with different engine speeds. S100 and B20 were selected for the study because of its being widely used in Egypt and in the world. Also, series of tests are conducted at same previous conditions with different percentage of exhaust gas recirculation (EGR) from 0% to 12% of inlet mass of air fresh charge. Results indicate that S100 or B20 gives lower brake thermal efficiency (η_B), brake power (BP), brake mean effective pressure (BMEP), and higher brake specific fuel consumption (BSFC) due to lower heating value compared to pure diesel fuel. S100 or B20 gives lower NO_X concentration due to lower gas temperature. S100 or B20 gives higher T_wall and T_exhaust due to incomplete combustion inside engine cylinder. S100 or B20 gives higher CO and CO₂ concentrations due to higher carbon/hydrogen ratio. The position of maximum pressure (P_max) change for pure diesel fuel is earlier than for S100 or B20. The results show that S100 or B20 are promising as alternative fuel for diesel engine. The utilization of vegetable oils does not require a significant modification of existing engines. This can be seen as the main advantage of vegetable oils. The main disadvantages of biodiesel fuels are high viscosity, drying with time, thickening in cold conditions, flow and atomization characteristics.     

CO-gasification of pelletized wood residues

A pelletization process was designed which produces cylindrical pellets ∼8 mm in length and 4 mm in diameter. These ones were manufactured using a blend of Pinus Patula and Cypress sawdust and coal in proportions of 0%, 5%, 10%, 20%, and 30% v/v of coal of rank sub-bituminous extracted from the Nechí mine (Amagá-Antioquia). For this procedure, sodium carboxymethyl cellulose (CMC) was used as binder at three different concentrations. The co-gasification experiments were carried out with two kinds of mixtures, the first one was composed of granular coal and pellets of 100% wood and the second one was composed of pulverized wood and granular coal pellets. All samples were co-gasified with steam by using an electrical heated fluidized-bed reactor, operating in batches, at 850 °C. The main components of the gaseous product were H₂, CO, CO₂, CH₄, and N₂ with approximate quantities of 59%, 6.0%, 20%, 5.0%, and 9.0% v/v, respectively, and the higher heating values ranged from between 7.1 and 9.5 MJ/Nm³.     

Comparative evaluation of performance and emission characteristics of jatropha, karanja and polanga based biodiesel as fuel in a tractor engine

Non-edible jatropha (Jatropha curcas), karanja (Pongamia pinnata) and polanga (Calophyllum inophyllum) oil based methyl esters were produced and blended with conventional diesel having sulphur content less than 10 mg/kg. Ten fuel blends (Diesel, B20, B50 and B100) were tested for their use as substitute fuel for a water-cooled three cylinder tractor engine. Test data were generated under full/part throttle position for different engine speeds (1200, 1800 and 2200 rev/min). Change in exhaust emissions (Smoke, CO, HC, NO_x, and PM) were also analyzed for determining the optimum test fuel at various operating conditions. The maximum increase in power is observed for 50% jatropha biodiesel and diesel blend at rated speed. Brake specific fuel consumptions for all the biodiesel blends with diesel increases with blends and decreases with speed. There is a reduction in smoke for all the biodiesel and their blends when compared with diesel. Smoke emission reduces with blends and speeds during full throttle performance test.     

Comparison of solvent performance for CO2 capture from coal-derived flue gas: A pilot scale study

The performance of a proprietary solvent (CAER-B2), an amine-carbonate blend, for the absorption of CO₂ from coal-derived flue gas is evaluated and compared with state-of-the-art 30 wt% monoethanolamine (MEA) under similar experimental conditions in a 0.1 MWth pilot plant. The evaluation was done by comparing the carbon capture efficiency, the overall mass transfer rates, and the energy of regeneration of the solvents. For similar carbon loadings of the solvents in the scrubber, comparable mass transfer rates were obtained. The rich loading obtained for the blend was 0.50 mol CO₂/mol amine compared to 0.44 mol CO₂/mol amine for MEA. The energy of regeneration for the blend was about 10% lower than that of 30 wt% MEA. At optimum conditions, the blend shows promise in reducing the energy penalty associated with using industry standard, MEA, as a solvent for CO₂ capture.     

Generation of highly uniform droplets using asymmetric microchannels fabricated on a single crystal silicon plate: Effect of emulsifier and oil types

Uniform droplets of soybean oil, MCT (medium-chain fatty acid triglyceride) oil and n-tetradecane with a mean diameter of 26-29 μm have been generated using a silicon 24 × 24 mm microchip consisting of 23,489 asymmetric microchannels fabricated by photolitography and deep-reactive ion etching. Each microchannel consisted of a circular 10-μm diameter straight hole with a length of 70 μm and a 50 × 10 μm rectangular microslot with a depth of 30 μm. At the constant oil flux of 10 L m^− 2 h^− 1, the percent of active channels increased with increasing the oil viscosity and ranged from 4% for n-tetradecane to 48% for soybean oil. The size distribution span for SDS (sodium dodecyl sulphate)- and Tween 20 (polyoxyethylene (20) sorbitan monolaurate)-stabilized soybean and MCT oil droplets was 0.21-022. The ability of asymmetric microchannels to generate monodisperse soybean oil droplets at the very low SDS concentration of 0.01 wt.% has been demonstrated. At the SDS concentration below the CMC, the generated droplets tend to attach to the plate surface, whereas at the higher SDS concentration they detach from the plate as soon as they are formed. The agreement between the experimental and CFD (Computational Fluid Dynamics) simulation results was excellent for soybean oil and the poorest for n-tetradecane.