Cold Flow Properties Research Articles

Research on combined-pour point depressant of methacrylate-acrylamide copolymers and ethylene-vinyl acetate copolymers for diesel fuel

The combined-pour point depressants (PPDs) have shown potential for the improvement of the cold flow properties of diesel. In this study, free radical polymerization was used to polymerize methacrylate (RMC) and acrylamide (AM) in different molar ratios (1:1, 3:1, 6:1, 9:1, 12:1, 15:1). Methacrylate-acrylamide copolymers (RMC-AM) were synthesized and analyzed through Fourier transform infrared spectroscopy (FTIR), proton nuclear magnetic resonance (1H NMR), and thermogravimetric analysis (TGA) to characterize the copolymers. Through exploring the effect of different chain lengths and different monomer molar ratios on the solid point (SP) and cold filter-plugging point (CFPP) of diesel, C14MC-AM (9:1) showed relatively good performance (ΔSP = 25 °C, ΔCFPP = 10 °C). Then, ethylene–vinyl acetate copolymer (EVA) materials with different VA content were introduced in this study. Diesel treated with 1000 ppm of EVA-2 (VA = 28%) showed relatively good performance (ΔSP = 18 °C, ΔCFPP = 10 °C). C14MC-AM (9:1) was mixed with EVA −2 in different ratios (1:0, 4:1, 2:1, 1:1, 1:2, 1:4, and 0:1, namely, PPDC-1 ~ 7) to produce synergy and improve the cold flow properties of diesel. The ΔSP and ΔCFPP of diesel fuel treated with only 500 ppm PPDC-5 can reach 28 °C and 23 °C, respectively. In addition, the crystallization behavior and crystal morphology of the treated diesel fuel were discussed through differential scanning calorimeter, polarized optical microscope and rheological analysis. The results showed that the combined-PPD made the wax crystals dissolve in the diesel system. The wax crystals became more uniform and denser under the action of AM polar groups.

Effect of Pour Point Depressants Combined with Dispersants on the Cold Flow Properties of Biodiesel‐Diesel Blends

AbstractPoor cold flow property is a major issue that hinders the application of biodiesel‐diesel blends. In this work, a series of methacrylate‐benzyl methacrylate‐N‐vinyl‐2‐pyrrolidone terpolymers (RMC‐MB‐NVP, R = C12, C14, C16, C18) was synthesized and used as the pour point depressants (PPD) for waste cooking oil biodiesel blends. To further improve their depressive effects, dispersants, including Tween (40, 60, and 80), Span (40, 60, and 80), phthalic acid esters (PAE), and fatty alcohol polyoxyethylene ether (FAPE; FAPE 5, FAPE 7, and FAPE 9), were optimized and combined with the C14MC‐MB‐NVP terpolymers. The effects of C14MC‐MB‐NVP terpolymers and combined PPD (PPDC) on the cloud point (CP), cold filter‐plugging point (CFPP), and pour point (PP) of biodiesel blends were studied. Here, results showed that the presence of dispersants can efficiently enhance the solubility and dispersibility of polymeric PPD in biodiesel blends; thus, the PPDC presents better depressive effects. Among them, C16MC‐MB‐NVP (5:1:1) combined with FAPE 7 dispersant at 4:1 mass ratio (PPDC‐FAPE 7) showed the best synergistic effect, and the CP, CFPP, and PP of B20 treated with 2000 ppm PPDC‐FAPE 7 decreased by 4, 10, and 19 °C, respectively. Moreover, differential scanning calorimetry, polarizing optical microscope, and rheological analyses were performed to rationalize the action mechanism of these PPD and dispersants in biodiesel blends.

Effect of poly(ethylene-vinyl acetate) pour point depressant on the cold flow properties and crystallization behavior of soybean biodiesel blends fuel.

Although biodiesel-diesel blends are being widely used in diesel engines, investigations on its cold flow properties and crystallization behavior are still scarce. In this paper, poly(ethylene-vinyl acetate) (PEVA) pour point depressant and petroleum diesel were worked together to enhance the cold flow properties of soybean biodiesel. PEVA presented a better positive effect in reducing the cold filter plugging point (CFPP) of biodiesel blends. B40 treated with 1% PEVA exerted the best cold flow properties, and its CFPP was decreased by -14 °C. In addition, the crystallization behavior was changed variously. The sizes of crystals were decreased as well as the number of crystals was increased notably.

Application of Genetic Algorithm for Increasing the Utilization of Poor-quality Biodiesel through Blending.

Biodiesel is a viable alternative to petroleum diesel. The properties of the biodiesel depend on the feedstock used to produce it. A significant difference in properties exists between different biodiesels. Therefore, standards for biodiesel fuel had been developed considering many factors such as safe handling, corrosion, ignition quality, stability, cold flow property, and performance. For using biodiesel as fuel, the properties of the biodiesel should be within the limits specified in the standard. Unfortunately, biodiesel produced from many feedstocks does not comply with the specifications for all the properties. To utilize biodiesel with poor quality, biodiesels can be blended so that the properties of the blend comply with the specifications. Determining the optimal biodiesel blend ratio experimentally requires a lot of effort particularly when the number of parameters to be optimized is more and when the number of constituent biodiesels in the blend is more. In this work, the application of non-dominated sorting genetic algorithm to predict optimal blends for different scenarios is demonstrated.

Hydrogenated or oxyfunctionalized turpentine: options for automotive fuel components.

Many concerns, such as economic and technical viability and social and ethical aspects, must be considered for a feedstock selection for advanced biofuels. Industrialized countries promote the use of industrial waste or by-products for this purpose. In particular, turpentine has several properties which make it an attractive source for biofuels, including its possible industrial waste origin. Nevertheless, turpentine has shown some disadvantages when blended directly with diesel, especially because it increases the sooting tendency. On the contrary, some derivatives of turpentine can be suitable for diesel blends. Thus, the evaluation of their properties is necessary. In the present work, the properties of hydrogenated and oxyfunctionalized turpentine have been analysed and compared with the purpose of elucidating their benefits and drawbacks in diesel fuel applications, using European standards as a reference. The results show a promising application of both hydroturpentine and oxyturpentine as diesel components. While hydroturpentine significantly improves the diesel cold flow properties, oxyturpentine noticeably reduces the sooting tendency.

Synthesis of Nano-Hybrid Polymethacrylate-Carbon Dots as Pour Point Depressant and Combined with Ethylene-Vinyl Acetate Resin to Improve the Cold Flow Properties of Diesel

Synthesis of Nano-Hybrid Polymethacrylate-Carbon Dots as Pour Point Depressant and Combined with Ethylene-Vinyl Acetate Resin to Improve the Cold Flow Properties of Diesel

Liquid fuel from waste tires: novel refining, advanced characterization and utilization in engines with ethyl levulinate as an additive.

Pyrolysis is a promising thermochemical strategy to convert scrap tires into diesel-like fuels. Crude tire pyrolysis oil (CTPO) was produced in a 10 ton rotating autoclave reactor by thermal depolymerization of the tire polymers. In this work, the prior-reported straightforward and inexpensive strategy of upgrading CTPO using a combination of silica gel (as adsorbent) and petroleum ether (as the solvent) has been scaled up with minimal loss in mass of oil and improved physicochemical characteristics (e.g., lowered acid value, low sulfur content). The upgraded TPO (StTPO) was characterized extensively to better understand their chemical compositions, physicochemical properties, and combustion characteristics. StTPO was mixed with diesel in different volumetric proportions and the blends were studied for performance and emission characteristics in a single-cylinder engine. The use of biomass-derived ethyl levulinate (EL) as a fuel oxygenate improved the cold-flow properties of StTPO–diesel blends as well as lowered the exhaust emissions (e.g., lower NOx). A fuel blend consisting of 50% diesel, 40% StTPO, and 10% EL demonstrated the best fuel properties in the single-cylinder diesel engine.

Evaluation of Biodiesel Produced from Blends of Sunflower Oil and Beef Tallow Through Base Catalysis

The inclination towards climate change and environmental pollution mitigation directs this research toward creating an alternative fuel source to fossil fuel for use in developing tropical countries. This study is designed to investigate biodiesel (alkyl esters) obtained by transesterification of blends of refined sunflower oil and beef tallow using NaOH as catalyst. Triglycerides in the oils reacted with alkanols to produce fatty acid alkyl esters (FAAE) and glyerols as by-product. A pretreatment process of esterification was carried out to remove excess free fatty acids (FFA). Some physical properties such as pour point, cloud point, flash point, density and kinematic viscosity were investigated for the sunflower oil/beef tallow (SO/BT) ratios. The examined physical properties of the methyl esters changed significantly as the beef tallow ratio in the mixture increased in the mixtures. The ratios of 40%SO/60%BT and 60%SO/40%BT exhibited values within standard range of biodiesel and petroleum diesel of ASTM D 6751 and EN 1424. The values of the cold-flow properties of the biodiesel ratios obtained are of convenience for use in tropical regions rather than polar regions.

Pre-hydrogenation stage as a strategy to improve the continuous production of a diesel-like biofuel from palm oil

The continuous production of a diesel-like biofuel from palm oil was evaluated by coupling two reactions stages in series, pre-hydrogenation with a Ni/Al2O3 catalyst at 250 °C and LHSV of 2 h−1, followed by deoxygenation with a sulfided Ni–Mo/Al2O3 at 350–380 °C and LHSV of 1.6–3.3 h-1. The purpose of this process configuration was to improve the selectivity because side reactions on the double bonds, such as polymerization, ring formation and aromatization could be avoided. Both reactions were studied at 3 MPa. In the Ni catalyst, all the metal was in its reduced state and in three different types of cluster. The sulfided Ni–Mo catalyst had mainly sulfided MoSx and Ni-MoSx, but also appreciable amounts of reduced metal species, and the sulfided species were stable up to 500 °C. The pre-hydrogenation enabled the use of higher LHSV without losing conversion nor yield and this means that for a fix throughput, less deoxygenation catalyst can be used. The yield was decreased, at all experimental conditions evaluated, when pre-hydrogenation was not done, due to side reactions on the double bonds. The decarboxylation route was predominant (69.3%) followed by the decarbonylation (11.5%) and the hydrodeoxygenation routes (19.2%). The product had properties similar or superior to those of fossil diesel and biodiesel, with the exception of cold flow properties that were worse than those of fossil diesel but very similar to those of biodiesel.

A Mini Review on the Cold Flow Properties of Biodiesel and its Blends

Biodiesels are renewable fuel that may be produced from various feedstock using different techniques. It is endorsed in some countries of the world as a viable substitute to diesel fuel. While biodiesel possesses numerous benefits, the cold flow properties (CFP) of biodiesel in comparison with petro-diesel are significantly less satisfactory. This is due to the presence of saturated and unsaturated fatty acid esters. The poor CFP of biodiesel subsequently affects performance in cold weather and damages the engine fuel system, as well as chokes the fuel filter, fuel inlet lines, and injector nozzle. Previously, attempts were made to minimize the damaging impact of bad cold flow through the reduction of pour point, cloud point, and the cold filter plugging point of biodiesel. This study is focused on the biodiesel CFP-related mechanisms and highlights the factors that initialize and pace the crystallization process. This review indicates that the CFP of biodiesel fuel can be improved by utilizing different techniques. Winterisation of some biodiesel has been shown to improve CFP significantly. Additives such as polymethyl acrylate improved CFP by 3-9 ° C. However, it is recommended that improvement methods in terms of fuel properties and efficiency should be carefully studied and tested before being implemented in industrial applications as this might impact biodiesel yield, cetane number, etc.

Biofuels from Diethyl Carbonate and Vegetable Oils for Use in Triple Blends with Diesel Fuel: Effect on Performance and Smoke Emissions of a Diesel Engine

The main objective of this work is to contribute to a gradual replacement process of fossil diesel (D) with biofuels composed by diethyl carbonate (DEC) and either sunflower or castor oil, as straight vegetable oils (SVOs). DEC is a very interesting candidate as an oxygenated additive not only because of its low price and renewable nature, but also its favorable fuel properties, such as very low kinematic viscosity, high cetane number, high oxygen content, rich cold flow properties and good miscibility with fossil diesel and vegetable oils. In this work, the more suitable DEC/SVO biofuels are chosen based on kinematic viscosity, according to the European normative. Additionally, the most relevant physical–chemical properties of (bio)fuels such as density, calorific value, cloud point, pour point and cetane number are determined. The influence of DEC on engine performance and exhaust emissions is analyzed by fueling a conventional Diesel engine with the different D/DEC/SVO triple and DEC/SVO double mixtures. The tests results are also compared with commercial diesel. From the results, it is concluded that Diesel engine fueled with the blends studied exhibits an excellent performance in terms of power output, very similar to diesel. Additionally, the use of these blends can remarkably decrease smoke emissions down to 98%, with respect to fossil diesel. The addition of DEC shows a significant improvement in cold flow properties of fuel mixtures in the exchange of a slightly higher brake specific fuel consumption (BSFC) than diesel. Interestingly, the pure biofuels composed by DEC and SVO allow for a suitable engine operation and achieve the lowest emissions, which means these blends can be successfully employed in current engines without adding fossil diesel, i.e., their use entail a 100% renewability.

Co‐processing of rapeseed oil — straight run gas oil mixture: Comparative study of sulfide CoMo/Al2O3-SAPO-11 and NiMo/Al2O3-SAPO-11 catalysts

Co-processing of mixture, containing 30 wt.% of rapeseed oil (RSO) in straight run gas oil (SRGO), was studied over stacked bed sulfide catalytic system containing Mo/Al2O3 as a first layer and CoMo/Al2O3-SAPO-11 or NiMo/Al2O3-SAPO-11 catalyst as the second one. The experiments were performed in a trickle bed reactor at 350−380 °C, 4.0–7.0 MPa, 1.5 h−1 and 1000 Nm3/m3. The hydrodeoxygenation (HDO) of RSO is proceeding over Mo/Al2O3 catalyst mostly through direct HDO route (selectivity > 93 %). The proposed combination of catalysts minimizes the formation of carbon monoxide, that is known as an inhibitor of hydrotreating reactions and can affect the hydroisomerisation/hydrocraking of alkanes over CoMo/Al2O3-SAPO-11 and NiMo/Al2O3-SAPO-11 catalysts. The effects of temperature and pressure on the behavior of Mo/Al2O3-CoMo/Al2O3-SAPO-11 and Mo/Al2O3-NiMo/Al2O3-SAPO-11 systems were studied and the difference in the quality of products were discussed with the emphasis on the cold flow properties. The cloud point of products, obtained in the co-processing of RSO-SRGO mixture over Mo/Al2O3-CoMo/Al2O3-SAP and Mo/Al2O3-NiMo/Al2O3-SAP catalytic systems was decreased to −8 and −13 °C respectively with the temperature increase from 350 to 380 °C. In addition, the hydrogenated products produced over NiMo/Al2O3-SAP were characterized by lower final boiling point values and aromatic content in comparison with that produced over CoMo/Al2O3-SAP catalyst. Unexpectedly, the opposite effect of pressure was observed on the cloud point and the conversion of long chain alkanes, which were produced in hydrodeoxygenation of RSO.

Long Chain Alkylated Ionic Liquids as Pour Point Depressant and Rheology Improver for Crude Oil

Cold flow properties of Iranian crude oil have been investigated by two different imidazolium ionic liquids including 1-dodecyl-3-methylimidazolium reduce the pour point up to bis(trifluoromethanesulfonyl) imide ([C12min](NTf2]) and 1-tetradecyl-3-methylimidazolium bis(trifluoromethanesulfonyl) imide ([C14min](NTf2]). ([C14min](NTf2]) showed high ability to 12°C optimal performance by addition of 2000 ppm. Wax crystallization behaviour of untreated and treated crude oil was monitored using differential scanning calorimetry (DSC) and the polarized optical microscopy (POM). Results from DSC and POM revealed that the presence of both ILs changes the process of crystallization and extends wax precipitation time. Furthermore, rheological behaviour of the crude oil was improved and viscosity was decreased by 73% at 23.5°C and 87% at 15°C by addition of [C14mim][NTf2].

Determination of optimum diesel: jatropha blend for compression ignition diesel engines through fuel properties analysis

The non-edible oil jatropha biodiesel is a diesel blend fuel source for the compression ignition (CI) diesel engines. Hence, the determination of the exact blending ratio of biodiesel to diesel fuel for best engine operation is needed through research. Keeping this in mind, this work investigated various acceptable jatropha biodiesel-diesel blends for diesel engines through fuel properties analysis. In this study, six different volumetric percentages of the biodiesel-diesel fuel samples were prepared. The percentage of the biodiesel was varied from 5 to 30% with a step of 5% by volume. The important properties required for engine operation like cloud and pour point, flash and fire point, density, viscosity and calorific value were measured under standard conditions. The average measured properties of biodiesel-diesel blends were compared with diesel fuel. The possibility of using 100% biodiesel in diesel engines without any modifications is also checked by comparing its properties with diesel fuel. The investigation revealed that the cold flow properties of diesel fuel such as cloud and pour point were improved with jatropha biodiesel blended fuels. Also, the results confirmed the good ignition quality and stability, energy content and atomization property of jatropha biodiesel blended fuels. The diesel and 20% jatropha biodiesel blending (B20) fuels showed an identical pour point temperature of − 3.5 °C. Similarly, B20 fuel has produced only 2.28% lower calorific value and 1.2% higher density as compared to diesel fuel. The other B20 fuel properties such as fire point, viscosity, flash point and cloud point were found within 7.44% to 12.5% higher than the diesel fuel. Hence, the study has recommended the B20 as the optimum blend fuel for CI diesel engines.

Development and Evaluation of Thermodynamic Models for Predicting Cold Flow Properties of Biodiesel

Biodiesel, especially palm oil-based methyl esters (PME), is steadily increasing in consumption in Indonesia and Malaysia as a petroleum diesel substitute. PME has poor cold flow properties due to the presence of saturated bound glycerols. Bound glycerols, such as monoglycerides (MAGs), diglycerides (DAGs), and triglycerides (TAGs), are impurities in biodiesel as a result of incomplete transesterification, and have high melting points. These minor components often solidify even at temperatures higher than the cloud point and thus cause clogging in fuel filters. It is, therefore, essential to predict the solidification temperature for the application of biodiesel, particularly in high blending levels. This study developed and evaluated thermodynamic models for predicting the solidification of biodiesel. Binary and multicomponent mixtures of fatty acid methyl esters (FAMEs) and bound glycerols were prepared as biodiesel models. The solidification temperature was measured by differential scanning calorimetry and the results were compared with the predicted values. It was discovered that most of the binary mixtures of a FAME and a bound glycerol (MAG, DAG, or TAG) behaved as eutectic systems, in which a solid phase consists of a single component. In the case of the eutectic system, the solidification temperature could be estimated by assuming non-ideal liquid solutions, and the modified UNIFAC (Dortmund) model helped calculate the activity coefficient. However, the mixtures of MAG/MAG differed from the eutectic system, suggesting that the solid compounds of different types of MAGs were formed. Thus, the compound formation model was developed, which was successful in predicting the solidification temperatures of biodiesel model fuels that consist of several kinds of FAMEs and MAGs.

Oxyfunctionalized turpentine: Evaluation of properties as automotive fuel

Turpentine from pine trees or from Kraft pulping is a complex mixture of monoterpenes, such as: α-pinene, β-pinene, limonene and myrcene. In this work, β-pinene was reacted with paraformaldehyde to synthesize an oxyfunctionalized turpentine (oxyturpentine) composed mainly by α-pinene, nopol and α-terpineol. This oxyturpentine can be a novel biofuel as far as its properties meet the criteria required by automotive fuel regulations. Binary mixtures of oxyturpentine with a diesel fuel (with no oxygen content) and with a conventional biodiesel have been experimentally characterized following the standard methods for each property (density, kinematic viscosity, lubricity, heating value, volatility, etc.) and the results obtained are critically compared using the limit values of European standards as a reference. Results show that the oxyfunctionalization of turpentine improves some relevant properties for fuel applications, such as lubricity, volatility and sooting tendency (wear scar was reduced around 40% and smoke point was increased more than 300%). With respect to other oxygenated compounds used in fuels blends, such as alcohols and esters, oxyturpentine can reduce the problems of high volatility and low viscosity and lubricity of the former ones and the cold behavior of the latter ones, indicating its suitability as a component of diesel fuels. • Sooting tendency of diesel fuel is notably reduced with oxyturpentine addition. • Reductions in heating value per unit mass are compensated by higher densities. • Cold flow properties are improved upon oxyturpentine blending up to 20%. • Low oxyturpentine contents improve diesel fuel lubricity. • Diesel/oxyturpentine blends up to 20% vol. Meet standard EN 590.

Study on Bio-Diesel as Alternate Fuel Used in I.C. Engines

One of the major incentives for expanding the production and use of bio-fuels worldwide is the potential environmental benefit that can be obtained from replacing petroleum fuels with fuels derived from renewable biomass resources. The use of vegetable oil in diesel engines is one of the available alternatives, but its use in existing vehicles usually requires modification of engine or fuel system components. The increased viscosity, low volatility, and poor cold flow properties of vegetable oils lead to severe engine deposits, injector coking, and piston ring sticking. The paper presents a literature review on vegetable oils as alternative bio-fuel for diesel engines.

Valorization of palm biomass waste into carbon matrices for the immobilization of recombinant Fusarium heterosporum lipase towards palm biodiesel synthesis

Continuous expansion of agriculture for the production of biofuels may be considered a potential source of greenhouse gas (GHG) emissions due to the ever-increasing amount of waste and fossil fuel-dependent materials involved. Agricultural waste utilization through the circular bioeconomy concept offers a pathway to reduce GHG emissions. Palm oil production, for instance, produces palm kernel shells (PKS) and palm oil mill effluents (POME) as wastes in enormous amounts. PKS and POME account for >60% of solid and liquid waste generated from the mill. In this work, the feasibility of a circular palm bioeconomy is explored where waste PKS is directly converted to activated carbons (AC) in a cost-effective one-step technique (550 °C, 10 mL min−1 N2) that departs from the conventional two-step (carbonization and activation) technique. Characterization of the synthesized carbons, PKAC, using Fourier-transform infrared spectroscopy and scanning electron microscopy with energy-dispersive X-ray spectroscopy showed oxygen-rich morphological features that were 2-fold higher than in bituminous coal-derived AC. The <10 μm pore diameters of PKAC were relevant in the immobilization of Aspergillus oryzae whole-cells expressing Fusarium heterosporum lipase (PKAC-FHL). For biodiesel production, the 81.6 IU mg−1 specific activity of PKAC-FHL yielded ≥97.5 wt% fatty acid methyl ester (FAME) from POME. While offering the benefits of environmental remediation through effluent utilization, the produced FAME showed 48.8 Cetane Number and cold-flow properties that conform to ASTM and EN biodiesel requirements. This waste valorization approach, thus, proposes a green framework for the use of POME and PKS in immobilized lipase-catalyzed methanolysis.

Outlook for Direct Use of Sunflower and Castor Oils as Biofuels in Compression Ignition Diesel Engines, Being Part of Diesel/Ethyl Acetate/Straight Vegetable Oil Triple Blends

Today, biofuels are indispensable in the implementation of fossil fuels replacement processes. This study evaluates ethyl acetate (EA) as a solvent of two straight vegetable oils (SVOs), castor oil (CO), and sunflower oil (SO), in order to obtain EA/SVO double blends that can be used directly as biofuels, or along with fossil diesel (D), in the current compression-ignition (C.I.) engines. The interest of EA as oxygenated additive lies not only in its low price and renewable character, but also in its very attractive properties such as low kinematic viscosity, reasonable energy density, high oxygen content, and rich cold flow properties. Revelant fuel properties of EA/SVO double and D/EA/SVO triple blends have been object of study including kinematic viscosity, pour point (PP), cloud point (CP), calorific value (CV), and cetane number (CN). The suitability of using these blends as fuels has been tested by running them on a diesel engine electric generator, analyzing their effect on engine power output, fuel consumption, and smoke emissions. Results obtained indicate that the D/EA/SO and D/EA/CO triple blends, composed by up to 24% and 36% EA, respectively, allow a fossil diesel substitution up to 60–80% providing power values very similar to conventional diesel.In addition, in exchange of a slight fuel consumption, a very notable lessening in the emission of pollutants as well as a better behavior at low temperatures, as compared to diesel, are achieved.

Effect of pH, Temperature, and CO2 Concentration on Growth and Lipid Accumulation of Nannochloropsis sp. MASCC 11

This study determined growth and lipid accumulation in Nannochloropsis sp. MASCC 11 cultivated at different pH, temperatures, and CO2 concentrations in 10-day period. The suitability for biodiesel production was also evaluated based on the fatty acid profiles of microalgae lipid. Nannochloropsis sp. MASCC 11 showed an excellent tolerance to acidic pH (as low as 4.0), high temperatures (at least 40°C), and high CO2 concentrations (5%–15%), which are major stressed conditions in flue gas. The highest algal biomass was acquired at pH of 9.0 (0.44 gL−1), a temperature of 35C (0.63 g L−1), and a CO2 concentration of 5% (2.27gL−1). Maximum lipid production was obtained at pH of 6.0 (108.2 mg L−1), a temperature of 35°C (134.6mgL−1), and a CO2 concentration of 5% (782.7mg L−1). Synthesis of polyunsaturated fatty acids (PUFAs) in biomass was stimulated under high CO2 concentrations, remaining above 80% of total fatty acids, mainly composed of C16:3, C18:2, and C18:3. This led to the algae-based biodiesel having a lower oxidation stability, better cold flow properties, and other parameters such as its kinematic viscosity, cetane number, and specific gravity complied with ASTM or EN 14214 biodiesel specifications. Therefore, the improvement of oxidative stability needs to be considered before Nannochloropsis sp. MASCC 11 lipid can be used for biodiesel production, even if this species can grow well under stressful conditions.