Pure Plant Oil Research Articles

A Review on Atomization and Sprays of Biofuels for IC Engine Applications

Ever increasing energy requirements, environmental concerns and energy security needs are strongly influencing engine researchers to consider renewable biofuels as alternatives to fossil fuels. Spray process being important in IC engine combustion, existing literature on various biofuel sprays is reviewed and summarized. Both experimental and computational research findings are reviewed in a detailed manner for compression ignition (CI) engine sprays and briefly for spark ignition (SI) engine sprays. The physics of basic atomization process of sprays from various injectors is included to highlight the most recent research findings followed by discussion highlighting the effect of physico-chemical properties on spray atomization for both biofuels and fossil fuels. Biodiesel sprays are found to penetrate faster and have narrow spray plume angle and larger droplet sizes compared to diesel. Results of analytical and computational models are shown to be useful in shedding light on the actual process of atomization. However, further studies on understanding primary atomization and the effect of fuel properties on primary atomization are required. As far as secondary atomization is concerned, changes in regimes are observed to occur at higher air-jet velocities for biodiesel compared to those of diesel. Evaporating sprays revealed that the liquid length is longer for biodiesel. Pure plant oil sprays with potential use in CI engines may require alternative injector technology due to slower breakup as compared to diesel. Application of ethanol to gasoline engines may be feasible without any modifications to port fuel injection (PFI) engines. More studies are required on the application of alternative fuels to high pressure sprays used in Gasoline Direct Injection (GDI) engines.

Design and Development of an Efficient Screw Press Expeller for Oil Expression from Jatropha Curcas Seeds: A Computational Flow Dynamics Study of Expeller for Performance Analysis

Diminishing fossil fuel resources, unstable/increasing prices of oil, environmental issues, global warming/climatic shifts, and allied problems have led the world to focus on alternate, environmental friendly, and renewable energy sources. Among many experimental candidates, production of biodiesel from Jatropha curcas L. has gained significant importance. More than 40 countries in the world are evaluating the potential of using this pure plant oil for manufacturing diesel. USEPA’s action sets the 2013 volume at 1.28 billion gallons under the Energy Independence and Security Act of 2007. With this premise, it is imperative to identify innovative technologies to handle Jatropha biomass and its efficient oil extraction for economical biofuel production. This study is aimed to make efficient screw expeller to cater massive Jatropha biomass for its oil extraction. A computational flow dynamics (CFD) simulation is performed to estimate the pressure developed inside the barrel through screw pressing when the fe...

An experimental investigation of a direct burning of crude Jatropha oil (CJO) and pitch in a commercial boiler system

We conducted a test of a direct burning of crude Jatropha oil (CJO) and pitch in a commercial boiler system. The fuel, crude Jatropha oil is not biodiesel which comes from transesterification process of bio oil, but it is pure plant oil like cooking oil. The higher heating value (HHV) of the CJO is 39.3 MJ/kg (9380 kcal/kg) and is lower than that of commercial heating oil, 44.0 MJ/kg. The kinematic viscosity of CJO is 36.2 mm2/s at 40 °C and 8.0 mm2/s at 100 °C. The burner used in the test is a commercial burner for a commercial heating oil and its capacity is 140 kW (120,000 kcal/h).We did a preliminary test whether the combustion is stable or not. The preliminary test was a kind of open air combustion test using the commercial burner with crude Jatropha oil. We found that the combustion can be stable if the crude Jatropha oil temperature is higher than 90 °C. We measured the flue gas concentration by using a gas analyzer. The NOx concentration of crude Jatropha oil is 80 ∼ 100 ppm and CO concentration is nearly 0 ppm at flue gas O2 concentration of 2.5 and 4.5%. We also tested a pitch combustion and the result shows that the NOx concentration of pitch is about 90 ∼ 110 ppm and CO concentration is below 30 ppm at flue gas O2 concentration of 2.5 and 4.5%. As a reference data, combustion of heating oil was conducted. The NOx concentration of heating oil is about 80 ppm which is the lowest value of tested fuels.

A method for measurement of planar liquid volume fraction in dense sprays

A methodology for measurement of planar liquid volume fraction in dense sprays using a combination of Planar Laser-Induced Fluorescence (PLIF) and Particle/Droplet Imaging Analysis (PDIA) is presented in this work. The PLIF images are corrected for loss of signal intensity due to laser sheet scattering, absorption and auto-absorption. The key aspect of this work pertains to simultaneously solving the equations involving the corrected PLIF signal and liquid volume fraction. From this, a quantitative estimate of the planar liquid volume fraction is obtained. The corrected PLIF signal and the corrected planar Mie scattering can be also used together to obtain the Sauter Mean Diameter (SMD) distribution by using data from the PDIA technique at a particular location for calibration. This methodology is applied to non-evaporating sprays of diesel and a more viscous pure plant oil at an injection pressure of 1000bar and a gas pressure of 30bar in a high pressure chamber. These two fuels are selected since their viscosity values are very different with a consequently very different spray structure. The spatial distribution of liquid volume fraction and SMD is obtained for two fuels. The proposed method is validated by comparing liquid volume fraction obtained by the current method with data from PDIA technique.

Common rail diesel tractor engine performance running on pure plant oil

Many studies have been carried out on raw rapeseed oil (PPO) and its performance in a common rail diesel engine. In this study the PPO had characteristics within the DIN V 51605 norm. The engine, model 6068HL481 rated at 103kW and installed in agriculture tractor John Dear 6830, was studied after working for 230h and then for 1000h. Full characteristic of the engine fueled with PPO was obtained for both tests and was then compared with the characteristic of the engine fueled with diesel. A power drop of 12–14% was observed in the engine fueled with PPO as opposed to the one fueled with diesel. The alternate fuel had no impact on the energy efficiency.

Heating of BDE-209 and BDE-47 in plant oil in presence of o,p′-DDT or iron(III) chloride can produce monochloro–polybromo diphenyl ethers

Heating processes of food can alter the concentrations and composition of organohalogen compounds. In this study the fate of two polybrominated diphenyl ether (PBDE) congeners, decabromodiphenyl ether (BDE-209) and 2,2′,4,4′-tetrabromodiphenyl ether (BDE-47) was analyzed when heated in plant oil with and without additional compounds. When the PBDEs were heated in pure plant oil, no transformation was observed. Heating of decabromodiphenyl ether (BDE-209) together with ortho,para′-dichlorodiphenyltrichloroethane (o,p′-DDT) or iron(III) chloride in plant oil resulted in the formation of monochloro–nonabromodiphenyl ethers (Br9Cl-DEs). Almost 10% of the initial amount of BDE-209 was transferred into Br9Cl-DEs. Heating BDE-47 in the presence of iron(III) chloride produced two monochlorinated transformation products which were tentatively identified as 2,2′,4-tribromo-4′-chlorodiphenyl ether (4′-Cl-BDE-17) and 2,4,4′-tribromo-2′-chlorodiphenyl ether (2′-Cl-BDE-28). However, the reactivity was smaller and no Br→Cl exchange was observed with o,p′-DDT. The conditions used in our experiments (200°C; heating 30min–3h) indicate that such reactivity may also occur during cooking of fish, meat and other food samples.

Effect of process conditions on the removal of phospholipids from Jatropha curcas oil during the degumming process

This work aims to study the removal of phospholipids from Jatropha oil through a conventional degumming process combined with ultrafiltration membrane separation in a small-scale batch system. The effect of temperature, amount of acid solution added, and speed of centrifugation during the conventional degumming process were analyzed using response surface methodology (RSM). The optimum operating condition was determined to be at 65°C, with 4wt% acid solution added and a centrifugation speed of 1600rpm. After the degumming process, the phospholipid content of Jatropha oil was reduced from 1200ppm to 60ppm. This was further reduced to less than 20ppm by subjecting the oil to ultrafiltration membrane separation. It was found that the entire process not only decreased the phospholipid content of the oil but also improved its fuel properties, especially its kinematic viscosity and carbon residue. The kinematic viscosity was decreased from 30.02cSt (mm2/s) to 27.20cSt, while the carbon residue was decreased from 7.8% to 4.0%. Aside from the phospholipid content, the other two properties mentioned above were also considered to be important in the use of pure plant oil as a fuel in diesel engines. Future research could investigate the integration and optimization of the conventional degumming process combined with a membrane separation process.

AN EXPERIMENTAL STUDY ON EFFERVESCENT ATOMIZATION OF BIO-OIL FUELS

This paper presents the work on detailed characterization of effervescent spray of Jatropha and Pongamia pure plant oils. The spray characteristics of these biofuels are compared with those of diesel. Both macroscopic and microscopic spray characteristics at different injection pressures and gas-to-liquid ratio (GLR) have been studied. The particle/droplet imaging analysis (PDIA) technique along with direct imaging methods are used for the purpose of spray characterization. Due to their higher viscosity, pure plant oils showed poor atomization compared to diesel and a blend of diesel and pure plant oil at a given GLR. Pure plant oil sprays showed a lower spray cone angle when compared to diesel and blends at lower GLRs. However, the difference is not significant at higher GLRs. Droplet size measurements at 100 mm downstream of the exit orifice showed reduction in Sauter mean diameter (SMD) diameter with increase in GLR. A radial variation in the SMD is observed for the blend and pure plant oils. Pure oils showed a larger variation when compared to the blend. Spray unsteadiness has been characterized based on the image-to-image variation in the mean droplet diameter and fluctuations in the spray cone angle. Results showed that pure plant oil sprays are more unsteady at lower GLRs when compared to diesel and blend. A critical GLR is identified at which the spray becomes steady. The three regimes of spray operation, namely "steady spray," "pulsating spray," and "spray and unbroken liquid jet" are identified in the injection pressure-GLR parameter space for these pure plant oils. Two-phase flow imaging inside the exit orifice shows that for the pure plant oils, the flow is highly transient at low GLRs and the bubbly, slug, and annular two-phase flow regimes are all observed. However, at higher GLRs where the spray is steady, only the annular flow regime is observed.

Toxicological characterization of diesel engine emissions using biodiesel and a closed soot filter

This study was designed to determine the toxicity (oxidative stress, cytotoxicity, genotoxicity) in extracts of combustion aerosols. A typical Euro III heavy truck engine was tested over the European Transient Cycle with three different fuels: conventional diesel EN590, biodiesel EN14214 as B100 and blends with conventional diesel (B5, B10, and B20) and pure plant oil DIN51605 (PPO). In addition application of a (wall flow) diesel particulate filter (DPF) with conventional diesel EN590 was tested. The use of B100 or PPO as a fuel or the DPF reduced particulate matter (PM) mass and numbers over 80%. Similarly, significant reduction in the emission of chemical constituents (EC 90%, (oxy)-PAH 70%) were achieved. No significant changes in nitro-PAH were observed. The use of B100 or PPO led to a NOx increase of about 30%, and no increase for DPF application. The effects of B100, PPO and the DPF on the biological test results vary strongly from positive to negative depending on the biological end point. The oxidative potential, measured via the DTT assay, of the B100 and PPO or DPF emissions is reduced by 95%. The cytotoxicity is increased for B100 by 200%. The measured mutagenicity, using the Ames assay test with TA98 and YG1024 strains of Salmonella typhimurium indicate a dose response for the nitroarene sensitive YG1024 strain for B100 and PPO (fold induction: 1.6). In summary B100 and PPO have good potential for the use as a second generation biofuel resulting in lower PM mass, similar to application of a DPF, but caution should be made due to potential increased toxicity. Besides regulation via mass, the biological reactivity of exhaust emissions of new (bio)fuels and application of new technologies, needs attention. The different responses of different biological tests as well as differences in results between test laboratories underline the need for harmonization of test methods and international cooperation.

CO2-Neutral Fuels and Lubricants Based on Second Generation Oils such as Jatropha

Abstract For the production of raw materials, the generation of energy and for their mobility, the industrialized countries strongly depend on the import of fossil resources. Second generation resources, such as Jatropha, grow on arid soils and produce non-edible oils. Thus, their cultivation does not compete with food production for farmland. Oils of such plants are therefore suggested as sustainable, CO2-neutral and regenerative alternatives to fossil fuels and lubricants. The present work establishes one of the first functional profiles of second generation oils with properties relevant for the use as fuel or lubricants in order to validate the potential for substituting fossil resources. It concentrates on the characterization of oil gained from the Jatropha Curcas plant to be used as fuel and lubricant. Properties were determined such as pour point, flash point, lubricity of diesel-like fuel in high frequency reciprocating rig, high-temperature/high-shear viscosity, and viscosities as function of temperature, extreme pressure behavior, oxidation resistance as well as its toxicity and bio-degradability. These properties are compared to those of currently used plant oils and fossil oils. The fatty acid chain length distribution of Jatropha oil was determined and found to be close to that of palm oil. This qualifies Jatropha oil as a substitute, thus releasing the pressure on the prices of food based oils. First tribological characterizations were carried out and are presented here, showing impressive performance of the as pressed filtered pure Jatropha plant oil. In oil dilution tests carried out on piston-ring/cylinder-liner test rigs, the performance of oils processed from plants such as Jatropha are compared to ester-based, polyalkylene glycol based, and hydrocarbon-based oils. Finally, functional properties of Jatropha were compared to further possible second generation bio-oils and aspects of availability and costs are discussed.

Effect of fatty acid composition of soybean oil on deposit and performance of plant oil pressure stoves

Plant oil as household energy could be a sustainable and locally available alternative for fossil fuel. However, the use of pure plant oil in pressure stoves leads to deposit in the vaporizer. Therefore, objective of this study was to investigate the effect of the degree of unsaturation of plant oils on performance and deposit formation. Soybean oil with an iodine value of 128 g I 2/100 g was used as well as partly hydrogenated soybean oil with an iodine value of 62 g I 2/100 g, hydrogenated soybean oil with an iodine value of 1 g I 2/100 g, and a blend of 50% refined soybean oil and 50% partly hydrogenated soybean oil was confected to obtain an iodine value of 95 g I 2/100 g. In burning trials, the specific fuel consumption, the required frequency of nozzle cleaning and the amount of deposit in the vaporizer were measured. Results showed an exponential increase of deposits in the vaporizer when iodine value of soybean oil was increased: deposits amounted to 0.26 g/kg of consumed fuel for hydrogenated soybean oil and 0.70 g/kg for the original (untreated) soybean oil. However, an increase in the soybean oil iodine value did not affect fuel consumption, which was 0.296 kg/h for hydrogenated soybean oil compared to 0.286 kg/h for original (untreated) soybean oil. Further research is necessary to investigate the chemical reactions in the vaporizer to identify key precursors (factors) and reactions mechanisms that could influence the formation of deposits in plant oil pressure stoves.

Sources of Methyl Ester Yield Reduction in Methanolysis of Recycled Vegetable Oil

AbstractRecycled vegetable oil (RVO) is a relatively cheap raw material for biodiesel production, but biodiesel grade methyl ester yields from RVO were found to be considerably lower than those from pure plant oil. The present paper investigates sources of yield loss during methanolysis of RVOs with free fatty acids (FFA) contents of 0.4–3.3%, and makes suggestions for the improvement of methyl ester yields. Data presented here indicated that yield losses of methyl esters during methanolysis were due to triglyceride and methyl ester hydrolysis and to the dissolution of methyl esters in the glycerol phase. Hydrolysis of triglycerides and methyl esters seemed to be the only side reaction causing yield losses, and the amount of fatty acids from hydrolysis increased with concentration of the potassium hydroxide catalyst. Dissolution of methyl esters in the glycerol phase was probably caused by the detergent effect of potassium salts of fatty acids originating from FFA in the RVO and from triglyceride hydrolysis, and the amount of dissolved methyl esters increased with FFA content of the RVO. The FFA content of the RVO had no effect on hydrolysis, and the amount of triglycerides and methyl esters hydrolysed during methanolysis remained constant with increasing FFA content of the RVO.

Aromatherapy and evidence based practice

In her excellent book, Aromatherapy for Pregnancy and Childbirth, Margaret Fawcett describes aromatherapy as ‘a treatment using pure aromatic plant oils to enhance or restore well-being by stimulating the body's own natural healing processes.’