ORIGINAL PAPER Utilization of Waste and Under-utilized Pongamia pinnata Seed Oil for Acquiring Maximal Process to Get Ameliorate Yield of Biodiesel Through Response Surface Methodology Tahir Mehmood 1 • Zovia Shaheen 1 • Shoaib Ahmad Malik 2 • Qudsia Tabassam 1 • Faiza Siddique 1 • Lubna Jabeen 1 Received: 5 September 2015 / Accepted: 24 December 2015 Ó Springer Science+Business Media Dordrecht 2015 Abstract The aim of this study was to use the under-uti- lized vegetable seed oil and produce high and better yield of biodiesel. The response surface methodology (RSM) was used, based on central composite rotatable design (CCRD), to optimize four trans-esterification reaction variables for getting high yield: catalyst concentration (CC; 0.25–1.0 %), reaction temperature (RT; 45–65 °C), CH 3 OH-to-oil molar ratio (6:1–12:1) and reaction time (30–90 min). The 2 4 full factorial CCRD design was applied, using four different parameters at five levels, each lead to 30 experiments to produce Pongamia pinnata oil-methyl esters (POMEs). The molar ratio of CH 3 OH to oil and RT were the most signifi- cant (p \ 0.01) factors affecting the yield of POMEs. A linear relationship was recorded between the observed and predicted values (R 2 = 0.9744). Using multiple regression analysis a quadratic polynomial equation was recognized for methyl ester yield (MEY). The quadratic term of CC showed a significant (p \ 0.0001) impact on esters yield. The interaction terms of CH 3 OH to oil molar ratio and CC with reaction time exhibited a ?ve effect on the MEY (p \ 0.05). The optimum reaction conditions for trans-esterification of oils were 6.1 CH 3 OH to oil ratio, 1.0 % CC, 65 °C RT and 1:30 h reaction time, resulting in Pongamia oil MEY of 94.88 %. The RSM was found to be a suitable technique for optimizing trans-esterification process and produced fuel was within the ranges of ASTM D6751 and EN 14214 standards. Keywords Biodiesel Á Underutilized vegetable oil Á Methanolysis Á Optimization of transesterification variables Á Fuel properties Introduction The fast increase in types and volume of waste agricultural biomass, as a result of intensive agriculture in the wake of population growth and improved living standards, is becoming a growing problem as rotten waste agricultural biomass emits many toxic gases and pollutants, hence improper management of waste agricultural biomass is contributing towards drastic climate changes in local air pollution, water and soil contamination. The majority of agrowaste, for example underutilized seed of many plants, have high value compounds which can be used for bene- ficial purpose. The state of the art techniques and process can reduce the costs for waste disposal and would generate the revenue from the sale of the recovered materials and energy. Currently, the energy demand has been a key apprehension for the twenty-first century all over the world. Constantly growing human population, rapid depletion of fossil fuels and rising temperature worldwide leading to the weather alterations are the main reasons for this appre- hension. The tropical world, including a great number of developing countries, has by now sensed the future energy crisis. The developed countries are facing the same con- ditions as they account for high per capita utilization of world energy sources [1]. Additionally, utilization of non- renewable fossil fuel as major energy source is creating a number of problems, for instance universal temperature rise, acid rain, desertification, water contamination, loss of biodiversity, and so many alarming ecological dilemmas [2, 3]. & Tahir Mehmood tahiruosbiochem@yahoo.com 1 Department of Chemistry, University of Sargodha, Sargodha 40100, Pakistan 2 Department of Biochemistry, SMC, University of Sargodha, Sargodha 40100, Pakistan 123 Waste Biomass Valor DOI 10.1007/s12649-015-9472-2