Home Green Energy Revolutionizing Biodiesel: IIT Madras Study Paves the Way for Greener Surfactants

Revolutionizing Biodiesel: IIT Madras Study Paves the Way for Greener Surfactants

Revolutionizing Biodiesel: IIT Madras Study Paves the Way for Greener Surfactants

A new study by researchers at the Indian Institute of Technology (IIT) Madras has found that polyglycerol poly ricinoleate (PGPR) and raw Karanja oil (RKO) can be used as effective and environmentally friendly substitutes for traditional surfactants in biodiesel-water emulsions.

Bullet Point Summary:

  • Renewable surfactants show promise in biodiesel-water emulsions
  • PGPR and raw Karanja oil were found to be effective substitutes for traditional surfactants
  • The use of these surfactants results in reduced engine exhaust emissions.
  • Research conducted by IIT Madras offers insight into the benefits of using emulsion fuels in automotive engines.

Details: Renewable fuel sources are becoming increasingly necessary as the world looks for ways to reduce its dependence on fossil fuels and curb pollution. Compression ignition engines, commonly used in heavy-duty applications, have traditionally run on fossil diesel, but this causes pollution by releasing nitrogen oxides, soot, hydrocarbons, and carbon monoxide.

To find a cleaner alternative, scientists have turned to biodiesel, which is made from non-edible and wastes cooking oil sources and does not contribute to the food versus fuel debate. However, biodiesel-fuelled engines release more nitrogen oxide emissions than fossil diesel and have a lower calorific value, requiring more fuel mass to achieve the same results. To combat these issues, biodiesel must be blended with high specific heat and high latent heat of vaporization fuels or diluents.

One solution is to mix water with biodiesel to improve engine performance and reduce emissions. The temperature in the cylinder of the engine is reduced, which helps mitigate nitrogen oxide emissions. Soot formation is also found to be reduced. However, biodiesel and water do not mix properly, so an emulsifier or surfactant is needed to stabilize the water-in-fuel emulsions.

In this study, researchers at IIT Madras investigated the use of three surfactants in producing stable biodiesel-water emulsions with neat biodiesel as the base fuel and evaluated their effects on engine characteristics. The combination of nonionic Span80-Tween80 was one of the surfactants, along with PGPR and RKO.

It was found that PGPR and Karanja oil were suitable substitutes for Span80-Tween80 as surfactants for biodiesel-water emulsions. They are also relatively cheaper and environmentally friendly. The engine exhaust emissions, such as nitrogen, smoke, and carbon monoxide oxides, were also significantly reduced. These studies can reveal critical insight into the benefits of using emulsion fuels in real-time in automotive engines.

Outcomes:

  • The study found that PGPR and Karanja oil were suitable alternatives to the commonly used mixture of nonionic surfactants, Span80 and Tween80, in producing stable biodiesel-water emulsions.
  • Using these surfactants significantly reduced engine exhaust emissions, including nitrogen oxides, smoke, and carbon monoxide.

Novel surfactants for stable biodiesel-water emulsions to improve performance and reduce exhaust emissions of a light-duty diesel engine

Gowrishankar; Krishnasamy 2022

Full-text link: https://doi.org/10.1016/j.fuel.2022.125562

Help us improve! Select the sentence(s) if helpful, and click on “send feedback” below.

About This Research Work

  • However, the NO x emissions from biodiesel-fuelled engines are higher than from diesel due to the fuel-bound oxygen content, advanced injection timings and a shorter ignition delay.
  • Thus, biodiesel-water emulsions were prepared with 6, 12, and 18 % water by weight of the fuel, using three different surfactants.
  • The effects of variations in water concentration and surfactant type in biodiesel-water emulsions on a light-duty diesel engine’s performance and emission characteristics are investigated with neat biodiesel as a reference fuel.

Research Work

  • A relative comparison of the ignition delay between biodiesel and biodiesel-water emulsions with different surfactants and water concentrations is shown.
  • At rated load, ignition delay with this emulsion increased by 27 % compared to 19 and 16 % for the emulsions prepared with Span.
  • A comparison of the cylinder pressure profiles of biodiesel and biodiesel-water emulsions prepared with different surfactants at water concentrations of 6 and 18 % is shown.
  • The effects of adding water to Karanja biodiesel on engine performance, combustion, and exhaust emissions of a light-duty diesel engine were studied and compared with those obtained with neat Karanja biodiesel as a reference fuel.
  • With an increase in the water concentration, the phasing was further advanced, particularly at full load conditions where the higher in-cylinder temperatures would favor a more intense microexplosion The COV of IMEP for the emulsions was well within 3 %, indicating that the emulsions with higher water concentrations of up to 18 % can be used without any combustion instability The engine performance was significantly improved with emulsions compared to neat biodiesel.
  • Tween80 and PGPR surfactant in emulsions with 18 % water concentration was 69 % with RKO as the surfactant.
Q: What was the purpose of the study conducted by researchers at the Indian Institute of Technology (IIT) Madras?

A: The study aimed to investigate the use of polyglycerol poly ricinoleate (PGPR) and raw Karanja oil (RKO) as effective and environmentally friendly substitutes for traditional surfactants in biodiesel-water emulsions and to evaluate the effects of these surfactants on engine characteristics.

Q: Why is there a need to find a cleaner alternative to fossil diesel in compression ignition engines?

A: Fossil diesel causes pollution by releasing nitrogen oxides, soot, hydrocarbons, and carbon monoxide when used in compression ignition engines. Therefore, there is a need to find a cleaner alternative to reduce dependence on fossil fuels and curb pollution.

Q: How does mixing water with biodiesel improve engine performance and reduce emissions?

A: Mixing water with biodiesel reduces the temperature in the cylinder of the engine, which helps mitigate nitrogen oxide emissions. Soot formation is also reduced by the early vaporization of water inside the fuel droplet, increasing its temperature, and resulting in a phenomenon called microexplosion. This results in smaller fuel fragments, improving air-fuel mixing and reducing the soot formation rate.

Q: What were the three surfactants used in the study?

A: The three surfactants used in the study were the combination of nonionic Span80-Tween80, polyglycerol poly ricinoleate (PGPR), and raw Karanja oil (RKO).

Q: What were the outcomes of the study?

A: The study found that PGPR and Karanja oil were suitable alternatives to the commonly used mixture of nonionic surfactants, Span80 and Tween80, in producing stable biodiesel-water emulsions. Using these surfactants significantly reduced engine exhaust emissions, including nitrogen oxides, smoke, and carbon monoxide.

LEAVE A REPLY

Please enter your comment!
Please enter your name here