Optimization of the dual stage procedure of biodiesel synthesis from Neem oil using RSM based Box Behnken design

ABSTRACT

Non-edible Neem oil was abundantly available in India with an estimated current annual production of 100 thousand tons per annum thus making it a strong candidate as a biodiesel feedstock. The major problem of Neem oil is its high free fatty acid (FFA) content (4.2%). The present study comprises of optimization of the dual-stage process of biodiesel synthesis from Neem oil using the Box–Behnken Design. The optimal process variables for esterification was pronounced as alcohol to oil molar ratio of 7.4:1, 0.89 wt% of H₂SO₄ catalyst, reaction temperature of 41°C and reaction duration of 88 minutes yielding Neem oil with optimum FFA value of 1.91% and the predicted FFA value was 1.73%. The optimized Neem Biodiesel yield of 96.39% was achieved with alcohol to oil molar ratio of 7.1:1 and 1.02 wt% of KOH catalyst at a reaction temperature of 41°C in 98 minutes reaction duration. The predicted Biodiesel yield was reported 97.14% at these reaction conditions. These results reveal a reliable forecast of the acid esterification process and alkali transesterification process by response surface methodology. The characteristics of synthesized Biodiesel meet the ASTM D6751 and EN14214 standards thus making it as a suitable power source for Diesel engines.

KEYWORDS:

• Neem oil
• biodiesel
• esterification
• transesterification
• free fatty acid
• response surface methodology
• Box–Behnken design
• stability

Additional information

Notes on contributors

Mayank Chhabra

Mayank Chhabra is serving as Assistant Professor-1 in Mechanical Engineering Department at Amity University, Noida (India). He is pursuing Ph.D from Punjabi University, Patiala (India). His research interests remain focused on Alternative fuels, particularly Biofuels and Internal Combustion Engines.

Balraj Singh Saini

Balraj Singh Saini is serving as Professor in the Mechanical Engineering Department at Punjabi University, Patiala (India). His research interests remain centered on sustainability, particularly in terms of eco-friendly materials and renewable energy resources. During his previous job in automobile R&D, he worked on various design and development projects for on-road and off-road vehicles. On the personal front, he is an amateur astronomer and has been freelancing with national newspapers as a popular science writer.

Gaurav Dwivedi

Gaurav Dwivedi, B.Tech in Mechanical Engineering, M.Tech in Energy System from IIT Roorkee, PhD in the field of Renewable Energy (Biofuel) from IIT Roorkee, India. He has several years of teaching experience in the field of Mechanical Engineering teaching various subjects like IC Engine, Thermodynamics, Fluid Machinery and others. His area of research interest is Bio-diesel, Fuel, Engine Operation, Small hydro Power systems. Currently, he is working as Assistant Professor in the Energy Centre at MANIT Bhopal India.