Cold Flow Properties Research Articles

Influence of nano-additives on engine behaviour using diesel-biodiesel blend

Biodiesel, a potential liquid alternative fuel, offers an excellent property such as extend the longevity and clean burning fuel and reduces the greenhouse gas emissions since the trees planed for feedstock of biodiesel absorbs. It also helps to reduce dependency on fossil fuel and helps to economy. Biodiesel offers numerous advantages over conventional diesel, but it has some issues such as its high viscosity, poor cold flow properties, higher nitric oxide (NOx) emissions and poor oxidation stability. Although there are many methods in order to overcome this drawback, addition of nanoparticles in biodiesel has emerged as one of the potential solutions. The nanoparticles improve the thermochemical properties of the fuel. Some studies have been carried out on nano-sized particles in diesel–biodiesel fuel emulsions. The current paper discusses about the effect of nano particles on engines performance and emission parameters and engine life. The paper also discusses about the effect of different size and dosage of nano particles on diesel engine behaviour. The preparation of nanofluid, several characterization methods and enhancing the stability of biodiesel via various techniques are also presented in this paper.

Enhanced the Effects on Improving the Cold Flow Properties and Oxidative Stability of Diesel-Biodiesel Blends by Grafting Antioxidant on Pma Type Pour Point Depressant

Enhanced the Effects on Improving the Cold Flow Properties and Oxidative Stability of Diesel-Biodiesel Blends by Grafting Antioxidant on Pma Type Pour Point Depressant

Synthesis and Evaluation of Bifunctional Polymeric Agent for Improving Cold Flow Properties and Oxidation Stability of Diesel-Biodiesel Blends

Synthesis and Evaluation of Bifunctional Polymeric Agent for Improving Cold Flow Properties and Oxidation Stability of Diesel-Biodiesel Blends

Investigation of Fuel Properties of Tea Seed Oil Biodiesel and Diesel Fuel Mixture

In this study, tea oil methyl ester was obtained from tea seed oil by transesteri-fication method. D100, B100, B50D50 and B20D80 test fuels were obtained by mixing the methyl ester fuel obtained from tea oil with diesel oil at a rate of 50% and 20% volumetrically.Fuel properties were determined by performing the density, kinematic viscosi-ty, cetane number, pH amount, clouding, pouring and freezing point tests, and calorific value, color determination, flash point, cold filter plugging point and copper rod corrosion tests of the test fuels. Considering the test results, it was concluded that the mixtures of B50D50 and B20D80 methyl ester produced from tea oil could be used in diesel en-gines without any modification on the engine and they were alternative fuels to diesel fuel. However, when it is used as B100 fuel, it is not suitable for use on diesel engines in terms of cold flow properties.

An electrical resistivity-based method for measuring semi-clathrate hydrate formation kinetics: Application for cold storage and transport

Tetra-n-butylammonium bromide (TBAB) semi-clathrate hydrate has a large latent heat and suitable phase transition temperatures to be used as a phase change material for cold energy storage and transport. The mass fraction of hydrates in the semi-clathrate hydrate slurry is a key parameter determining the cold carrying capacity and flow properties. We developed a new experimental methodology based on electrical resistivity to quantify the hydrate fraction in semi-clathrate hydrate slurry during hydrate formation. Relationship between electrical resistivity and hydrate fraction of semi-clathrate hydrate slurry was established based on Bruggeman’s effective-medium approximation. After validation, this method was employed to quantitatively investigate the effect of temperature on TBAB hydrate formation from 20 wt% TBAB/water system. As the temperature was lowered from 278.2 K to 274.2 K, the induction time was reduced by 97.8% and the hydrate growth rate was enhanced by over 2.5 times. At 274.2 K and 276.2 K, type A hydrates were preferentially formed followed by a structural transition to type B. At 278.2 K, only type A hydrates were observed. Furthermore, given an appropriate concentration, amino acid L-tryptophan was identified to be a good kinetic promoter for TBAB hydrate formation. The presence of 500 ppm L-tryptophan reduced the induction time by 60% and boost the hydrate growth rate by more than 32%. The electrical resistivity-based method developed in this work has shown simplicity, low cost, high accuracy, and repeatability. It would enable precise investigation of semi-clathrate hydrate kinetics in the future for cold energy applications and beyond.

Comparative analysis of ternary blends of renewable Diesel, diesel and ethanol with diesel

Renewable diesel is the alternative fuel, produced using hydroprocessing. Renewable diesel can replace diesel fuel without any modifications to existing CI engines. Alongwith renewable diesel, ethanol is also environmently friendly with better cold flow properties than diesel. In present work, various blends of diesel, renewable diesel, and ethanol were prepared, which is rarely researched. Physicochemical properties of all blends were investigated to do a comparative analysis with diesel. The percentage of ethanol was kept at 5%, 10% and 15%, renewable diesel at 20%, 30% and 40% and rest was diesel. It was observed that viscosity, density, and calorific value of neat ethanol (1.076 cSt, 764.1 gm/cm3, and 26.8 MJ/kg) was lower compared to diesel (2.42cSt, 837gm/cm3, and 42.57 MJ/kg) and renewable diesel (2.75cSt, 819gm/cm3, and 41.8 MJ/kg). This was overcome with higher proportion of renewable diesel in each blend. Cold filter plugging point of both ethanol (−51 °C) and renewable diesel (−14 °C) helped improve cold flow properties of all blends. There was an improvement in cetane index of various blends because of renewable diesel’s high cetane index (66.3). It is suggested to use ethanol up to 10% and renewable diesel up to 30% as such blends’ have physio-chemical properties at par with diesel.

Innovative approach for co-production of single cell oil (SCO), novel carbon-based solid acid catalyst and SCO-based biodiesel from fallen Dipterocarpus alatus leaves

A new approach for the co-production of SCO, carbon-based solid catalyst and SCO-FAME using Dipterocarpus alatus leaves (DL) was successfully demonstrated. Undetoxified DL hydrolysate (DLH) was converted into SCO by Rhodotorula mucilaginosa KKUSY14, resulting in SCO of 3.11 g/L with SCO yield reaching 0.19 g/g sugar and 24.9 g SCO/kilogram DL. DLS-SO3H and DLHW-SO3H catalysts were effectively prepared from DL solid residue and cell-free fermented DLH waste (DLHW) through direct sulfonation. The catalysts successfully catalyzed the direct transesterification of SCO-rich wet yeast with SCO-FAME yield >87% under optimal condition. The catalysts can be reused up to three cycles with SCO-FAME yield >80%. SCO-FAME yield of >83% was achieved with regenerated catalyst. The SCO-FAME profile consisted of high MUFA and low PUFA contents that improved cetane number, cold flow properties and oxidative stability. The estimated fuel properties of SCO-FAME based on FAME profiles were found to be in accordance with international biodiesel standards. This approach is a promising innovative strategy that could lead towards a green and economical process for biodiesel production. Furthermore, DLHW represents a new carbon material for novel solid acid catalyst preparation.

Biolubricant production via esterification and transesterification processes: Current updates and perspectives

The growing concern and limitations for existing lubricants have driven the need for biolubricants, extensively proposed as the most suitable and sustainable lubricating oils. Biolubricants are generally synthesized from various bio-based sources, including vegetable oils, microbially derived oils, waste cooking oil, etc. They are promising commodities and advantageous to mineral-based analogues due to their exceptional properties like their lubricity, biodegradability, reduced toxicity, and reduced volatility. Yet, their utilization as lubricants is constrained due to their relatively poor cold-flow and thermo-oxidative stability uncertainties even after being chemically modified. Hence, many chemical modification pathways have been reported to overcome this limitation, with the most exploited approaches being esterification and transesterification. This modification pathway enhanced the thermo-oxidative stability and the cold-flow properties of these bio-based oils, increased the yield, and enhanced the quality of the lubricants. With this in mind, this paper reviews up-to-date works conducted in this area and critically report the advancement in esterification and transesterification production of biolubricants. The study further reviews the latest published literature, current updates, and future perspectives related to the synthesis of biolubricants. Also, the review highlights the significant factors that govern the entire reaction process, selection criteria of renewable feedstocks, and the tribological performance of biolubricants.

Biojet fuel production via deoxygenation of crude palm kernel oil using Pt/C as catalyst in a continuous fixed bed reactor

• The production of biojet fuel with low content of oxygenated compounds from crude palm kernel oil was achieved. • The use of continuous fixed-bed reactor provided hight yield and high productivity of biojet fuel. • The cold flow properties of biojet fuel was improved by using HZSM-5 catalyst. This work focused on the conversion of crude palm kernel oil (CPKO) to biojet fuel via deoxygenation reaction in a fixed bed reactor. The catalyst was Pt supported on activated carbon (Pt/C). The investigation involved the effects of various operating parameters such as reaction temperature (350–420 °C), pressure (250 and 500 psi), flow rate of CPKO (0.02 and 0.04 mL/min), flow rate of hydrogen (17.5, 35.0, and 70.0 mL/min), and the amount of catalyst (0.05 and 0.07 g) on the reaction performance and the fuel properties of product. The biojet yield of 58.29%, with the major content of linear alkane in the range of jet fuel (nC8-nC16) of 27.68% and the productivity of 9.32 g product/g catalyst·h were achieved at the optimal operating conditions (420 °C, 500 psi, CPKO flow rate at 0.02 mL/min, hydrogen flow rate at 17.50 mL/min (H 2 -to-CPKO molar ratio of 28.02), and 0.07 g of Pt/C catalyst). The oxygen content was reduced from 18.83% (in CPKO) to 14.96% (in the product). To improve the freezing point of biojet fuel via cracking and aromatization, the catalyst bed was modified by adding HZSM-5 as a catalyst bed adjacent to the bed of Pt/C. The freezing point of product was significantly lowered by 30 °C.

Solid–Liquid Phase Behaviors of Binary Mixtures of Various Partial Acylglycerols by Differential Scanning Calorimetry

AbstractMonoacylglycerol (MAG), diacylglycerol (DAG), and triacylglycerol (TAG) are impurities in biodiesel and a major cause of precipitation. Understanding the behavior of such acylglycerols is essential for predicting biodiesel cold flow properties (CFPs). The previous study on MAG/MAG binary mixtures shows that they tend to solidify by forming molecular compounds. In contrast, TAG/TAG mixtures, which have been studied extensively, are commonly eutectic or monotectic systems, in which each component solidifies separately. The present study focuses on binary mixtures of DAG/DAG and different acylglycerol pairs (MAG/DAG, TAG/MAG, and DAG/TAG), and determination of their solid–liquid phase behavior by differential scanning calorimetry. These mixtures are found to behave as eutectic or monotectic systems with no sign of compound formation. As DAG and TAG have lower contents than MAG in biodiesel and they are unlikely to form molecular compounds with MAG, it is suggested that DAG and TAG have little effect on the biodiesel CFPs.Practical Applications: Biodiesel has attracted much interest because its blending with conventional fossil diesel has become more standard with biofuel mandates. From an energy perspective, the solid–liquid phase behavior of acylglycerols will contribute to building prediction models for biodiesel CFPs.

Optimization of the enzymatic butanolysis of jatropha oil for biodiesel production using Eversa

AbstractThe use of non‐edible oils for energy production is attracting increasing attention, with a particular focus on those oils that can be produced from plants growing in non‐arable areas. Among the possible alternatives, oils with high free fatty acid content, such as jatropha, have shown great potential. The optimization of jatropha oil in the presence of a bio‐based alcohol (butanol) was investigated for the production of biodiesel using a commercial enzyme (Eversa from Novozymes). The optimization was conducted by changing the reaction temperature and the amount of catalyst, with a 6:1 butanol/oil molar ratio, while the reaction time was set to 60 min. The optimal result was found at the highest reaction temperature (42 °C) and the highest catalyst amount (9.79%), with a biodiesel yield of 83%. A second optimization was conducted, allowing the time to run for up to 8 h. Here the final biodiesel produced was in line with the EU14214 standards, fulfilling all the requirements with the exception of the requirement for oxidation stability. In addition to fulfilling most of the EU14214 standards, the cost of this new enzyme is lower than that of other commercial alternatives. Results show that biodiesel produced using butanol as alcohol in the transesterification process improved cold flow properties in terms of cloud point (CP), pour point (PP), and cold filter plugging point (CFPP). © 2021 The Authors. Biofuels, Bioproducts and Biorefining published by Society of Industrial Chemistry and John Wiley & Sons Ltd.

Formate Esters Containing Biodiesel - Diesel Mixed Fuels

The blends of varying proportions of biodiesel (FAME) containing formate esters of glycerol and 93.0 wt.% fatty acid methyl esters, obtained in an interesterification reaction with methyl formate without further purification, and winter diesel fuel, were prepared, analyzed and compared with winter diesel fuel. The obtained results showed that blends comprising up to 20 vol.% of FAME fulfill the requirements of the standard LVS EN 590 concerning such characteristics as cold flow properties, viscosity, density, and carbon residue. The increase of FAME content worsens the cold flow properties; however, the mixed fuel with 20 vol.% or lower FAME content, according to the cloud point and cold filter plugging point values, remains in the same severe climate "Class 0" group as winter fuel. The carbon residue of mixed fuels raises with increasing FAME content, but stay low and do not exceed the limits of standard for mixtures with FAME percentage up to 20 vol.%. The comparison of mixed fuels containing 20 vol.% of FAME and the same amount of neat biodiesel (99.6 wt.% of fatty acid methyl esters) shows that the difference is negligible. The obtained results have indicated a good potential of FAME obtained in the interesterification reaction with methyl formate without further purification as a diesel fuel additive for up to 20 vol.%.

Combination Treatment of Biosurfactant and Copolymer Alkyl acrylate-Vinyl acetate to Improve the Cold Flow Properties of Waxy Gas Oil

One promising bacterial strain (B3), recovered from petroleum-contaminated soil. The isolate was able to produce biosurfactant. Alkyl acrylate–vinyl acetate copolymer was prepared using varying lengths of the alkyl chain. In this study, the effect of copolymer additives along with biosurfactant on the crude oil wax crystallization method has been examined by solid point test and viscosity index measurement for gas oil. The FTIR spectrum analysis of the biosurfactant showed that it was a polymeric molecule. The application of only copolymer having a side- length of the chain of C13 and C22 reduced the solid point of gas oil by 3 and 9 oC respectively. Furthermore, the same copolymer along with biosurfactant decreased the solid point of gas oil by 15 and 21 oC, respectively. Many copolymer additives blended with biosurfactants, it is assumed that it might be used to slow the formation of wax crystals and shape shorter crystals. Because of this shift in crystal form, wax crystals' capacity to intergrow and interlock is substantially reduced. By increasing the length of the alkyl chain and mixing the copolymer and biosurfactant, the viscosity index of gas oil was raised. The blend P3 and P4 additives were also proved to a better viscosity index modifier at all concentrations in gas oil.

Oxidative stability of biodiesel: recent insights

AbstractBiodiesel, the fatty acid methyl ester (FAME) of vegetable and animal oil, is now used extensively worldwide, with blends of up to 7% common. The blending level is still somewhat limited due to a perceived susceptibility of these fuels to oxidation. Oxidation follows a number of pathways, with the primary mechanism being auto‐oxidation, a radical process that results in the production of a range of oxygenated components. These eventually increase the viscosity of the fuel and form deposits detrimental to operation. Further fuel properties are also heavily reliant on the level of oxidation. As such, one of the main challenges in the use of biodiesel is its long‐term instability when stored. Typically synthetic anti‐oxidants have been used to address this issue; however, these systems can also add to the formation of deposits, as well as hazardous emissions, on combustion. Recently, research has focused on novel antioxidant development mainly from plant extracts, although there are a number of other routes for improved performance, including the commercialization of hydrogenated vegetable oil (HVO), a prominent alternative to FAME‐based biodiesel due to its higher stability, straight chain paraffin composition, and better cold flow properties. In this review, the factors that promote this oxidation are presented, including molecular composition, metal contamination, temperature and light exposure, as well as the latest findings on the inclusion of HVO, the current state‐of‐the‐art analytical techniques employed, and the impact of higher pressure injection systems on vehicles that demonstrate deposit formation is not solely due to the unsaturated biodiesel components. © 2021 Society of Chemical Industry and John Wiley & Sons, Ltd

Sustainable production of jojobyl alcohols and cell viability study

AbstractAn innovative biorefinery approach has been applied to evaluate jojoba oil (JO) in high value‐added products. It consists of enzymatic transesterification using short (1‐propanol, 1‐butanol), medium linear (1‐octanol), and branched (2‐ethylhexanol) chain alcohols. The proposed biorefinery approach uses an integrated process for the production of jojobyl alcohol (JA) mixtures (11‐eicosenol, 13‐docosenol and 15‐tetracosenol) as products that can be used in pharmaceutical applications. The remaining fraction of fatty acid alkyl esters (FAAE) has a wide range of industrial uses and could be used as a promising alternative to conventional fuels, as it complies with EN14214, the European Biodiesel Norm. The separation of JA from FAAE was carried out by crystallization using a binary mixture of hexane and diethyl ether. After the separation step, the main properties of FAAE were determined. The results showed that the cold flow properties and oxidation stability of the FAAE fraction, obtained as co‐product during the process, have been improved with respect to transesterified JO. The use of 2‐ethylhexanol as an alcohol in the transesterification reaction increases the amount of the most valuable fraction containing JAs. In vitro cell viability was measured in HEK293T cells using the tetrazolium dye reduction (MTT) assay. The results showed that this oily liquid mixture of JA components (cis‐11‐eicosenol, cis‐13‐docosenol, and cis‐15‐tetracosenol) had a cytotoxic effect at concentrations of 10 and 100 μmol L−1 and no cytotoxic activity at 1 μmol L−1. The concentration of 1 μmol L−1 does not, therefore, modify the cell viability, does not produce toxic effects in the tested cells and could be used as a therapeutic compound. © 2021 Society of Chemical Industry and John Wiley & Sons, Ltd

Improving cold flow properties of palm fatty acid distillate biodiesel through vacuum distillation

Palm fatty acid distillate (PFAD), a by-product of refining process of crude palm oil can be used as a potential feedstock for biodiesel production. However, the application of palm oil-based biodiesel is often hinder by its poor cold flow properties (CFP). Biodiesel fuel with poor CFP may crystallize and result in clogging of fuel lines, filters and injectors that cause engine operability problems. For that, a vacuum distillation method was designed and its feasibility and efficiency in improving the CFP was examined. A total of 13.60wt% of total saturated fatty acid methyl esters were successfully removed from the PFAD biodiesel, resulting in the improvement of the cloud point (CP), cold filter plugging point (CFPP) and pour point (PP) of PFAD biodiesel from 20 °C, 19 °C, and 15 °C to 13 °C, 11 °C, and 9 °C, respectively. It is remarkable that the improved CFPP satisfied the requirements for grade C summer biodiesel for temperate climates in EN 14212 standard. Additionally, Sarin (UFAME) empirical correlation was evaluated and it was found to have a good prediction of CFP for PFAD biodiesel, with lower than 2 °C deviation.

Production, characterization and assessment of reformulated bio-mixture fuel from a mixture of various raw feedstock's and the effect of n-butanol as an additive on bio-mixture blends

The current experimental study focuses on enhancing the characteristics and properties of bio-mix test fuel samples by using an additive such as n-butanol. Raw bio-mix fuel samples were prepared through a method of bio-mix to enhance the quality of biodiesel from the raw mixture of edible and non-edible feedstocks. In this experimental investigation, five test samples were prepared such as BSBW1, BSBW2, BSBW3, BSBW4 and BSBW5 at various blended ratios from the raw mixture of soapnut, borassus flabellifer, waste crude cotton seed oils and transesterified for the formation of bio-mix methyl ester fatty acids. From experimental results, it was observed that BSBW4 and BSBW5 recognized as optimum blends exhibited lower acid value than BSBW1, BSBW2 and BSBW3 blends. The fatty acid compositions of optimum bio-mixed samples were examined by using Gas Chromatography and Mass Spectrometry (GC-MS) to determine the characterization of tested fuels. 10% of the n-butanol additive deployed to the optimal blends BSBW4 and BSBW5 referred to as BSBW4B10 and BSBW5B10 were chosen for further experimental analysis. Experimental test results demonstrated that oxidation stability, cetane number, saturated fatty acid methyl ester, cold flow properties were improved while flash point, viscosity, iodine number, density, free fatty acid and heating value decreased. From this experimental investigation, it was concluded that the method of the n-butanol additive added to the bio-mix fuel samples could enhance the quality of the fuel and met the BIS, ASTM and EN testing procedures and standard limits as compared to all bio-mix and individual fuel samples respectively.

Effect of nanocomposite as pour point depressant on the cold flow properties and crystallization behavior of diesel fuel

The high effective nano-hybrid pour point depressant (PPD) has attracted extensive attention for its potential application in improving the cold flow properties of diesel fuel. In this paper, the nano-hybrid PPD was prepared by melt-blending method using three different alkyl chain lengths (i.e., tetradecyl, hexadecyl, and octodecyl) of n-alkyl methacrylate-maleic anhydride copolymers (R1MC-MA, R1 = C14, C16, C18) and SiO2 nanoparticles. The effect of those nano-hybrid PPDs on the cold filter plugging point (CFPP) and solidifying point (SP) depressing of diesel fuel were studied. Results indicated that nano-hybrid PPD showed much better performance on diesel fuel. The diesel fuel treated with 0.2 wt% C14MC-MA/SiO2 nano-hybrid PPD exhibited the best depression in CFPP and SP by 6 °C and 18 °C, respectively, which higher than that of single C14MC-MA. Viscosity-temperature curves and polarized optical microscopy were conducted to explore the performance mechanism; and results presented that nano-hybrid PPD of C14MC-MA/SiO2 could effectively lower the low-temperature viscosity, and modify the crystallization behavior and crystal morphology of diesel. Therefore, the cold flow properties of diesel were significantly improved.

Physicochemical Properties Enhancement of Biodiesel Synthesis from Various Feedstocks of Waste/Residential Vegetable Oils and Palm Oil

The main aim of the present study was to improve the oxidation stability and cold flow properties of biodiesel produced from waste frying/cooking oil and palm oil. In this work, waste frying/cooking methyl ester (WFME) and palm methyl ester (PME) were prepared using an alkali-catalyzed transesterification process, and the physicochemical properties of the pure biodiesel as well as of binary blends among them were investigated. The results indicated that palm biodiesel and WFME18, produced from a mixture of frying, cooking, sunflower, and corn oils, can be used as antioxidant additives, enhancing biodiesel stability. Additionally, it was found that WFME1 and WFME12 derived from waste residential canola oil can be used as cold flow improvers for enhancing the cold flow properties of palm biodiesel. Moreover, ultra-low sulfur diesel fuel winter (ULSDFW), ultra-low sulfur diesel fuel summer (ULSDFS), kerosene (KF), and benzene (BF) were utilized to enhance the cold flow properties of the samples and meet the requirements of diesel fuel standards. The investigation of the experimental results indicated that blending WFME-PM with a low proportion of petroleum-based fuel (KF and BF) could significantly improve the cold flow properties (CP and PP) as well as oxidation stability of WFME.

Improving the cold flow properties of biodiesel from waste cooking oil by ternary blending with bio‐based alcohols and diesel from direct coal liquefaction

AbstractThe utilization and popularization of biodiesel are always limited by its poor cold flow properties. Both bio‐based alcohol and diesel from direct coal liquefaction (DDCL) has potential to enhance the cold flow properties of biodiesel. In this study, ternary blends of waste cooking oil biodiesel (BWCO) with DDCL and bio‐based ethanol (ET) or 1‐butanol (BT) were conducted to improve the cold flow properties of biodiesel. The pour point (PP), cold filter plugging point (CFPP), and cloud point (CP) of BWCO‐ET, BWCO‐BT, and BWCO‐DDCL binary blends, and BWCO‐ET‐DDCL and BWCO‐BT‐DDCL ternary blends were comparatively assessed. Ternary phase diagrams were also applied to analyze the blending effect of the three components on the cold flow properties of biodiesel. Results showed that both DDCL, ET, and BT can remarkably enhance the cold flow properties of BWCO. When the ternary blends contain 20 vol.% BWCO and less than 40 vol.% ET or BT, DDCL together with ET or BT exerted positive effects on enhancing the low‐temperature flow properties of BWCO, especially on the CP and CFPP. For ternary blends in 20:10:70 blending ratio, BWCO‐BT‐DDCL exhibited the lowest PP, CFPP, and CP of −23, −19, and −17°C, respectively. The crystallization behavior and crystal morphology of blended fuels are also observed via a polarizing optical microscope, and find that DDCL together with BT in biodiesel can effectively retard the aggregation of large crystals and inhibit crystals growth.