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. 2025 Apr 15;15:12924. doi: 10.1038/s41598-025-92369-y

Enhancing diesel engine performance and emissions with N-Butanol enhanced biodiesel derived from Scenedesmus obliquus algae

Haiter Lenin Allasi 1,✉, Selvam Murugan 2, Harish Kanniah Ananda 2, Dhivya Vairavel 3
PMCID: PMC12000521  PMID: 40234466

Abstract

The main goals of this study were to produce biodiesel from Scenedesmus obliquus algae using n-butanol as a green fuel and to analyse engine performance, combustion characteristics, and emission. Researchers are looking into how N-butanol affects mixes of Scenedesmus obliquus algae used to make biodiesel for use in Common Rail Direct Injection (CRDI) engines. In the studies, different combinations of Scenedesmus obliquus diesel algae were employed: 30 A (Algae), 30 A + 10% N-Butanol, 30 A + 20% N-Butanol, and 30 A + 30% N-Butanol. The pure 100% Diesel (D100) combination was also used. The butanol blends 30 A + 30% N and 30 A + 10% N both exhibit mediocre performance across the board in terms of emissions and combustion. When compared to pure diesel (D100), the ideal addition was 30 A + 20% N - Butanol, which led to a 10.96% gain in brake thermal efficiency and a 7.4% decrease in specific fuel consumption. On the other hand, because of the high concentration of D100 and the noticeable rise in exhaust temperature, there was an increase in nitrogen oxides in the exhaust gases. On the other hand, the exhaust gases concentrations of carbon monoxide and smoke opacity decreased by 19.2%, and 15%, respectively, in contrast to D100. Hydrocarbon emissions, on the other hand, dropped by 8%. The cylinder pressure and heat release rate improved by 8.6% and 36.43%, respectively, according to the combustion characteristic analysis results.

Keywords: CRDI-EGR engine, Engine performances, Emissions, N-Butanol, Scenedesmus obliquus algae

Subject terms: Environmental sciences, Engineering

Introduction

Global consumption of electricity has been estimated to rise by almost 60% by 2035, with daily increases forecast Petroleum and other fossil fuels have been growing scarcer due to increased energy consumer demand; if current developments continue, resources like coal, oil, and natural gas will not run out in approximately 40, 55, or 130 years, respectively (gasoline prices are increasing daily as a result of the rising gasoline use per person. Historically, Energy has been a pivotal role in shaping the today future and the coming year’s .It all started in the industrialization era where the energy sources are used or consumed more. Many studies or researchers have predicted that by 2050 there will be lack of fossil fuels and create energy gap about 80%. There are several alternatives like Renewable sources (Solar, Wind, and Hydro) and other bio fuels. Likewise Term Bio fuels refer are it can be termed as bio-degradable fuel. Where the birth of the bio fuel or became known to world in the late 90’s period. Many studies on the use of biofuel for internal combustion engines have been conducted throughout the last 20 years. Additionally, an estimate of 1.1% was made every year, there is an international rise in the energy consumption of the transportation sector. Renewable energy sources made mostly from biomass are called biofuels. Their feedstock, which consists of crop food that was left over forest residues, urban trash, etc., is the primary source of biomass. The biofuel generated by According to biomass ought to be nontoxic, renewable, and biodegradable. Biofuel is categorized as first, second, or third generation depending on the feedstock’s availability both now and in the future1. This Researches gave birth to the first generation bio fuel which is generated from waste cooking oil. There is a data which says 200 million of gallons of oil is wasted but it wouldn’t help to manage the energy demand. The price of edible oil has grown due to first-generation feedstock, creating problems for food security.

This lead to the development of second generation bio fuel which is generated from non-edible oil plants such as others, as well as animal fats and used cooking oil are examples of second-generation feedstocks”. Due to their sustainability, inedibility, and ability to be produced on barren lands second-generation feedstocks exhibit advantages over first-generation feedstocks. Principal drawbacks of second-generation feedstocks include their high oil content of saturated fatty acids (SFA)2, which works against the transesterification reaction, and the lack of appropriate technology to properly dispose of their waste into the environment. The second-generation fuel also had mixed with several nano particles Zirconium and so on which helped the researchers improve the efficiency and decrease the emission levels3–5. According to algae is a third-generation feedstock that offers numerous benefits over second-generation feedstocks in terms of sustainability and bioenergy6,7. These algae are produced by photosynthesis and CO2 absorption, they have gained interest as a potential source of feedstock for algal biodiesels1,8–14. Triacylglycerols (TAGs), which build up in algal cells, are used to make algal biodiesels, which are renewable alternative fuels. TAGs are made up of three fatty acid residues and glycerol backbones9,11. These fatty acids undergo methyl esterification, and the resulting methyl esters of the fatty acids are utilized to make algae biodiesels15, which are diesel fuels. There are four benefits to using algae biodiesel: Algal farming is not competitive with terrestrial plants for food production because it does not require arable land, and algal biodiesels are sustainable fuels. Firstly, lipids are created by photosynthesis along with Coassimilation16. Secondly, the lipid productivity per unit area is substantially higher than terrestrial plants. Nevertheless, the cost of producing algal biodiesels is considerably greater than that of fossil fuels12,17,18. The productivity of algal lipids has to be increased in order to make biodiesels usable. Molecular breeding has produced a large number of genetically engineered algae with increased lipid output19–21. Random mutagenesis with UV radiation, mutagenic chemicals, or random tag insertion was used to isolate the good algal strain22. The most important necessity for human survival is energy. Humanity’s exclusive reliance on fossil fuels could lead to a severe shortage in the future. According to biofuels derived from bioproducts lessen the need for petroleum oil, have significant positive effects on sustainability, and cut greenhouse gas emissions and pollution. Biodiesel is the most promising type of biofuel. Primarily. The benefits of utilizing biodiesel include its renewable nature, non-toxicity, and biodegradability. It can also be utilized without requiring modifications to current engines due to its qualities comparable to those of diesel fuel and its reduced production of dangerous gas emissions, such as sulphur oxide. According to biodiesel has 78% lower net carbon dioxide emissions over the course of its lifecycle than conventional diesel fuel. Fatty acid methyl esters produced from triglycerides by transesterification with methanol make up biodiesel and other studies have reported that during transesterification, the glycerides in fats or oils react with an alcohol in the presence of a catalyst to form monoesters, which in turn produce free glycerol as a by-product23,24.

A viable substitute for traditional diesel fuel in the search for sustainable energy solutions is biodiesel made from renewable resources. Microalgae are one of the many sources of biodiesel that have attracted a lot of attention because of their high lipid content and quick development rates. Because of its resilience and lipid-rich makeup, the green microalgae species Scenedesmus obliquus stands out as a particularly potential candidate for biodiesel generation. However, the performance and environmental impact of biodiesel as a fuel, in addition to its production efficiency, determine its commercial feasibility22. Fuels for diesel engines, which power a large percentage of industrial and transportation apparatus worldwide, must reduce harmful emissions while simultaneously delivering efficient combustion. Continuous research and innovation are necessary to improve the characteristics of biodiesel and optimize engine performance25,26. The extraction procedure and the addition of additives present a viable path toward enhancing biodiesel quality and engine performance. An efficient solvent for removing lipids from microalgae biomass, such as Scenedesmus obliquus, has been demonstrated to be N-butanol, a four-carbon alcohol. Comparing this extraction approach to traditional extraction procedures, it not only increases lipid output but also has advantages in terms of energy efficiency and environmental sustainability27. It has been discovered that adding n-butanol to biodiesel blends improves the combustion properties, increasing engine efficiency and lowering pollutants. The distinct chemical characteristics of n-butanol, namely its high cetane number and oxygen content, help to overcome major issues with the usage of traditional biodiesel by promoting more complete combustion and reducing particulate matter emissions28,29. This article explores the possibilities of using Scenedesmus obliquus biodiesel extracted with n-butanol as an environmentally friendly diesel engine fuel. We investigate the extraction method, analyse the physicochemical characteristics of the resultant biodiesel, and determine how it affects emissions and engine performance. We want to open the door for a more environmentally friendly and productive future in industry and transportation by utilizing the power of microalgae and cutting-edge extraction methods. The integration of n-butanol with biodiesel derived from Scenedesmus obliquus algae has shown promise in enhancing diesel engine performance and emissions. The production of biodiesel from microalgae, such as Scenedesmus dimorphus and Isochrysis aff. galbana, highlights the efficiency of lipid yields and transesterification reactions30. Incorporating n-butanol as an additive improves combustion and reduces harmful emissions like polycyclic aromatic hydrocarbons (PAHs) and nitrogen oxides (NOx)31,32. Advanced strategies, such as the addition of nano-TiO₂ and post-injection methods, further enhance soot oxidation reactivity and thermal efficiency, making it a viable step towards sustainable fuel innovation33,34.

Cultivation

The cultivation process of Scenedesmus obliquus algae involves several crucial steps to ensure optimal growth and productivity. The advantages of raceway pond systems and tubular photobioreactors are combined in a novel way when using the Boxes photobioreactor system. Photo bioreactor Box Preparation: Cultivation process is to set up the Boxes photobioreactor, which is made up of acrylic boxes with air and pump systems. These elements are essential for preserving the conditions that encourage the growth of algae. Inoculation: The Scenedesmus Obliquus algae seeds are injected into the Boxes photobioreactor to begin the cultivation process. To start the growing process, this entails adding the algal culture to the system. Nutrient Supply: To promote the growth and metabolism of the algal culture, nutrients including nitrogen, phosphorus, and trace elements are given to it. Both biological functions and photosynthesis depend on these nutrients. Carbon Dioxide Supply: The algal culture receives carbon dioxide from the air system of the Boxes photobioreactor. Biomass production and photosynthesis are enhanced by rising CO2 concentrations. Agitation and Mixing: The algal culture is stirred and mixed by internal system pumps. This promotes uniform development by dispersing CO2 and nutrients throughout the culture in an equitable manner. Temperature Control: To keep the ideal temperature range for algae development, the system is cooled as needed. Temperature control keeps algae from overheating and guarantees that they are growing in ideal circumstances. Harvesting: The algal culture is taken out of the Boxes photobioreactor after it achieves the required biomass concentration. There are several different harvesting techniques, including as filtering or centrifugation. Frequent upkeep and tuning of the Boxes photobioreactor are crucial during the cultivation phase, this process shown in Fig. 1. This involves keeping an eye on the pH, temperature, light intensity, and nutrition levels.

Fig. 1.

Fig. 1

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Flow Chart of Algae Biodiesel production method.

Production of biodiesel

A pond is used for cultivating and harvesting algae. The gathered algae are dried and then heated to 102 degrees Celsius. Lipids are removed from dried algae, and 100 cc of dry algae is utilized to make biodiesel. The recovered algae oil is then boiled and combined with methanol and sodium hydroxide. This mixture is agitated at 600 RPM for an hour and kept at 60 °C. After stirring, transfer the mixture to a separate funnel and let it settle for 24 h. During this time, three unique layers arise due to density differences between the liquids: the top layer is biodiesel, the middle layer comprises by-products, and the bottom layer is glycerol. The glycerol is carefully extracted from the separating funnel, allowing the transesterification process to proceed. This procedure further separates mono-, di-, and triglycerides, as well as fatty acids. The residual mixture is poured into another funnel for further separation. The top layer, which contains pure biodiesel, is further purified to eliminate catalysts, residual methanol, glycerol, and soap. To remove these contaminants, the biodiesel is washed continuously with water heated to 80 degrees Celsius. The washing process is repeated up to six times to guarantee complete purification. Following the final washing cycle, the waste products are eliminated, leaving only pure biodiesel. The biodiesel is heated to 100 degrees Celsius to remove any moisture. This final heating stage removes any remaining moisture, leaving high-quality, pure biodiesel ready for usage is shown in Fig. 2 and properties of diesel and biodiesel blends readings is measured by various instruments that readings shown in Table 1. This rigorous procedure, from production to final heating, allows the manufacture of efficient and high-purity biodiesel appropriate for a wide range of applications. To achieve the best results in algae biodiesel production, temperatures, stir speed, and washing cycles must all be carefully monitored.

Fig. 2.

Fig. 2

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Algae Biodiesel production Method.

Table 1.

Fuel properties in comparison to diesel, algae, biodiesel, and biodiesel additives.

Fuel Properties Unit ASTM Standards Diesel A100 A30 A30 + 10% n-Butanol A30 + 20% n-Butanol A30 + 30% n-Butanol

Density

(at 20 °C)

 kg/m3 D1298 822 850 834 845 836 844

Viscosity

(at 40 °C)

 mm2/s D88 3.57 6.58 4.19 4.15 3.58 4.1
Flash Point °C D93 52 96 47 58 52 51
Fire Point °C D93 78 119 71 74 75 75
Calorific Value kJ/kg D240 43,231 41,150 42,468 42,505 42,602 42,851
Cetane Index D613 42 58 49.5 50 47 49
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Experimental setup and procedure

The Fig. 3 shows a single-cylinder, four stroke, naturally aspirated, water-cooled CRDI engine was used for the experiments in the aforementioned study. To load the engine, an eddy current dynamometer was utilized and the specification of Engine is brake power-3.5 kW, Engine cylinder capacity-661 cc, injection pressure-600 bar and injection timing-23o bTDC. In order to help facilitate the data capture of pressure versus crank angle, which could be displayed on a computer via high-speed data acquisition, the combustion characteristics have been collected talking advantage of a piezoelectric pressure transducer in the cylinder head working in tandem with a crank angle sensor. More importantly, a particle size an enzyme analyser was used with the purpose of carrying out the analysis of particle size. J type thermocouples were used to measure the exhaust gas temperature at many different points along the tailpipe. Nitrogen oxide (NOX) and hydrocarbon (HC) emissions were measured an AVL smoke meter to measure the muscle strength of the smoke, and an AVL five gas Analytical instrument for interpreting the smoke. To reach an equilibrium condition, the engine was allowed to warm up for between ten and fifteen minutes at idle load before any testing procedures had been carried out. To make sure the engine had been functioning at its maximum effectiveness, checks were then made on the water supply and lubricating oil levels. To avoid loading mistakes, dynamometer calibrations needed to be carried out. In order to safeguard against interference with the outcomes of the tests, emission measurement instruments were connected to the tailpipe once steady-state conditions had been established in accordance with calibration laws and regulations. Next, various amounts of torque were made available to the engine conditions (0%, 25%,50%,75%,100%) of load in kg (0,3,6,9,12) and the corresponding positive or negative results have been purchased for the examination.

Fig. 3.

Fig. 3

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CRDI engine Experimental setup.

Results and discussions

Combustion behavior

Heat release rate

The primary measure of the fuel’s chemical substance conversion into usable thermal energy is its heat release rate. Chemical energy is transformed into thermal energy, which can be burned as fuel, through a process known as heat release rate. The Heat Release Rate for several samples of D100, A30, A30 + 10% n-Butanol, A30 + 20% n-Butanol, and A30 + 30% n-Butanol is shown in Fig. 4. A30 + 20% n-Butanol was superior to diesel in terms of quality, but it had a delay duration that was nearly identical. This is due to the fact that the n-butanol blend of diesel and algal oil causes diesel to lose its cetane rating, extending the ignition delay time and increasing the amount of fuel that burns during combustion. Therefore, the best way to increase the net heat release rate is to fully oxidize the fuel, which will cause the rate to be greater than D100.

Fig. 4.

Fig. 4

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Crank angle vs. Net heat release.

Cylinder pressure

The quantity of test fuel consumed during the premixed combustion stage determines the engine cylinder pressure. The amount of fuel and air that are supplied and mixed determines how much pressure rises in the cylinder. The engine cylinder’s pressure varies due to the air and fuel mixing and burning. Samples of D100, A30, A30 + 10% n-Butanol, A30 + 20% n-Butanol, and A30 + 30% n-Butanol are shown in Fig. 5 to illustrate the various loading situations. Changes in the in-cylinder pressure in relation to the crank angle for every fuel evaluated under economical load scenarios. A healthy cylinder pressure improves the combustion characteristics and engine performance. A30’s cylinder pressure should be less than A30 + 10% N-Butanol’s. This results in an unequal use of chemical energy and is caused by the fuel’s excessive viscosity and incorrect atomization. The chance of combustion, however, rises when alcohol is added. The cylinder pressure rises in proportion to the increase in combustion rate. There is a slight increase in cylinder pressure in this A30 + 20% Butanol sample when compared to the other samples that contain pure diesel. Its cylinder pressure is higher than that of pure Diesel because of its high oxygen percentage.

Fig. 5.

Fig. 5

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Crank angle vs. Cylinder pressure.

Engine performances

Specific fuel consumption

The Rate at which the brake uses specific fuel consumption is the definition of power output. The Fig. 6 compares the percentage load-related usage of n - butanol and algal oil for the brakes. The outcomes of pure diesel were then contrasted with those of n-butanol and algae. A30 + 20% n-Butanol had the lowest Specific fuel consumption rating, because there is more oxygen present when the ratio of butanol to algal oil is raised, the SFC also increases. Since the engine has more time to perform the combustion process when the compression rate is raised, the effect of the ratio is increased while the SFC is decreased and increased viscosity. As engine load increases, S.F.C. falls for every case, Because of the biodiesel’s higher viscosity and lower calorific value. The value of Specific fuel consumption falls as the fraction of additives rises are comparison to pure diesel, the results indicate an average change in S.F.C. for A30, A30 + 10% n-Butanol, and A30 + 30% n-Butanol.

Fig. 6.

Fig. 6

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Load vs. Specific fuel consumption.

Brake thermal efficiency

Brake thermal efficiency is the quantity of chemical energy in the fuel that is converted into useful energy. The Fig. 7 shows the relationship between load percentage and fuel consumption specific to the different fuel consumption of A30, A30 + 10% n-Butanol, A30 + 20% n-Butanol, and A30 + 30% n-Butanol. Because of the rise in engine cylinder wall temperature, all fuels exhibited a rise in BTE as the load increased. When compared to pure diesel, n-butanol in these A30 + 20% is superior. The engine’s braking thermal efficiency is increased when butanol and algal oil are added to diesel. It is a well-known fact that brake thermal efficiency rises with increasing load. For all blending ratios, butanol blends had a better brake thermal efficiency than algae under all testing circumstances, but a lower brake thermal efficiency than diesel. This is because, of all of them, butanol has the highest enthalpy of vaporization, surpassing even that of diesel. Algal oil also shows this property. Since butanol and algal oil allow air to mix, combustion is enhanced and brake thermal efficiency tends to rise as a result. Because it vaporizes at the highest enthalpy, algae oil has performed better than both fuels.

Fig. 7.

Fig. 7

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Load vs. Brake thermal efficiency.

Emission characteristics

Carbon nonoxides

The primary source of carbon monoxide emissions is insufficient fuel combustion inside the combustion chamber. Variations in CO emissions of all investigated fuel types. The Fig. 8 illustrates how CO emissions rise with increasing load for all fuel situations because shorter combustion times result in incomplete carbon combustion. Additionally, it was noted that pure diesel fuel had the greatest CO emissions value. Because biodiesel contains more oxygen than pure diesel, the CO for A30 + 20% n-Butanol (19.2%) fuel is lower, because of the increased oxygen from the biodiesel and the improved fuel qualities from the n-butanol additions, the CO levels will keep declining. When the injection pressure was increased, the fuel atomized well and the combustion was completed, resulting in a decrease in CO emission for the biofuel additives A30, A30 + 10% n-Butanol, A30 + 20% n-Butanol, and A30 + 30% n-Butanol. However, the reduction in CO emission was less for A30 + 20% n-Butanol than for the other additives.

Fig. 8.

Fig. 8

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Load vs. CO emission.

Hydrocarbon

The Emissions of hydrocarbons (HC) are a sign that the fuel was not entirely burnt. BP’s effect on emissions of greenhouse gases (HC). The fluctuation of HC emissions with load at different fuel injection pressures is depicted in Fig. 9. In addition, sample fuels A30, A30 + 10% n-Butanol, A30 + 20% n-Butanol, and A30 + 30% n-Butanol that were added to mixed biodiesel shown a greater reduction in HC emissions when compared to pure Diesel. Higher oxidation occurred during combustion as a result of the fuel and air combining more perfectly. Due to A30’s high oxygen content, which ensures full combustion and lowers HC emissions, it was found that A30 exhibited fewer HC emissions than diesel. When the biodiesel A30 + 20% n-Butanol blends were tested in engines, the findings revealed that the HC emissions were reduced by 8%.

Fig. 9.

Fig. 9

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Load vs. HC emission.

Nitrogen oxides

The combustion chamber’s high temperature and the quantity of oxygen are the primary causes of the formation of nitrogen oxides. Engine advancement is impeded by nitrogen oxide emissions, which are extremely detrimental to the environment. Temperature and NOx production are inversely correlated with increased combustion quality. The fluctuation in NOX detected for the biodiesel A30, A30 + 10% n-Butanol, A30 + 20% n-Butanol, and A30 + 30% n-Butanol samples is displayed in Fig. 10. NOx is often produced during high-temperature combustion by the reaction of nitrogen and oxygen gases in the presence of air. When compared to pure diesel, biodiesel containing A30, A30 + 10%, A30 + 20%, and A30 + 30% n-butanol all showed reduced NOX emissions. Due to the increased oxygen content and high flame temperature, the mixed blended biodiesel including A30 + 20% n-Butanol showed a lower result (2%) when compared to the other fuel blends at full load conditions. These findings imply that the biofuel that was developed has strong predictive power and may be applied to optimize the system’s NOx (PPM). Adding n-butanol to biodiesel blends reduces NOx emissions as a result of the high oxygen content, leading to complete combustion and a reduction in peak temperatures. Higher oxygen also reduces thermal NOx, produced to a large extent at high temperatures. Introducing exhaust gas recirculation lowers the concentration of oxygen and combustion temperature in a cylinder, thus inhibiting the formation of NOx. This will thereby lower the NOx levels especially when the optimized portion of n-butanol is blended with biodiesel.

Fig. 10.

Fig. 10

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Load vs. NOX emission.

Smoke opacity

The variation in smoke intensity for all tested fuels with respect to different load conditions is shown in Fig. 11. The smoke opacity emission in clean biodiesel was lower than in all measured fuels. Because n-butanol antioxidants combine diesel and biodiesel, even in fuel-rich areas, the oxygen content is accessible, reducing the smoke’s strength. The reason for the decrease in smoke emission of A30 + 20% n-Butanol when correlated with neat base fuel could be related to the higher cetane amount of diesel and the ignition delay period. The smoke opacity of A30, A30 + 10% n-Butanol, A30 + 20% n-Butanol, and A30 + 30% n-Butanol decreased when correlated with neat pure base fuel. It is noteworthy that A30 + 20% n-Butanol produces low smoke emissions in comparison to all other fuels. The engine’s optimal operation extended the dwell time for fuel and air blending, resulting in clean and reliable combustion, which explains the low emissions.

Fig. 11.

Fig. 11

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Load vs. Smoke opacity.

Conclusion

Based on the comprehensive analysis of various performance and emission characteristics observed across different fuel blends (A30, A30 + 10% n-Butanol, A30 + 20% n-Butanol, and A30 + 30% n-Butanol) compared to pure diesel (D100), several key conclusions can be drawn:

  • As engine load increases, BSFC decreases for all fuel blends. A30 + 20% n-Butanol exhibited the lowest BSFC due to improved atomization and increased viscosity, resulting in better fuel efficiency.

  • With increasing load, all fuels showed an increase in BTE. However, n-Butanol blends, particularly A30 + 20% n-Butanol, demonstrated superior BTE compared to both pure diesel and algal oil blends, attributed to better combustion characteristics and higher enthalpy of vaporization.

  • CO emissions decreased with increasing load for all fuel types. Blends containing n-Butanol showed lower CO emissions due to enhanced combustion and increased oxygen content.

  • HC emissions decreased significantly in n-Butanol blends compared to pure diesel, indicating more complete combustion and improved fuel-air mixing.

  • NOx emissions decreased in biodiesel blends with increasing n-Butanol content, attributed to increased oxygen content and improved combustion quality.

  • Smoke emissions were lower in all tested biodiesel blends compared to pure diesel, with A30 + 20% n-Butanol exhibiting the lowest smoke opacity due to enhanced combustion efficiency.

  • A30 + 20% n-Butanol showed a delayed ignition compared to pure diesel, resulting in prolonged combustion and increased heat release rate, indicating efficient utilization of fuel energy.

  • Cylinder pressure increased with the addition of n-Butanol, improving combustion characteristics and engine performance.

In summary, the data indicates that n-Butanol blends, notably A30 + 20% n-Butanol, substantially enhance fuel efficiency, combustion, and emission reduction over pure diesel. These formulations not only improve engine performance but also promote environmental sustainability by lowering harmful emissions, presenting a promising advancement in transportation. This work mainly evaluated performance, combustion characteristics, and emission under standard operating conditions but was not aimed to investigate low-temperature operability of biodiesel blends. Cloud point, pour point, and fuel flow property are very crucial for the cold flow usability assessments in lower temperature condition. All these parameters require further research to ensure the comprehensive evaluation of biodiesel blends from Scenedesmus obliquus and n-butanol, hence confirming their adaptability to different climates and global applications.

Acknowledgements

Not applicable.

Author contributions

HLA: Design and Analysis, SM: Interpretation of data, HKA: Manuscript preparation DV: Result Analysis.

Funding

No Funding support has been provided.

Data availability

The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request.

Declarations

Competing interests

The authors declare no competing interests.

Ethics approval and consent to participate

Not applicable.

Footnotes

Publisher’s note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

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Associated Data

This section collects any data citations, data availability statements, or supplementary materials included in this article.

Data Availability Statement

The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request.

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