Modeling the biodiesel production using the wheat straw ash as a catalyst

Wheat straw ash (WSA) was investigated as a new catalyst in biodiesel production from sunflower oil. The characterized by temperature-programmed decomposition, X- ray powder diffraction, Hg porosimetry, N2 physisorption, and scanning electron microscopy - energy dispersive X-ray spectroscopy methods. methanolysis reaction tested the temperature range of 55?65?C, loading 10?20 % oil weight, methanol-to-oil molar ratio 18 : 1?24 1. conditions over WSA were optimized using response surface methodology combination with historical experimental design. optimum process ensuring highest fatty acid methyl esters (FAME) content 98.6 60.3?C, 11.6 (based on weight), 18.3 :1, time 124 min. values statistical criteria, such coefficients determination (R2 = 0.811, R2 0.789, 0.761) mean relative percent deviation (MRPD) value 10.6 (66 data) implied acceptability precision developed model. FAME after 4 h under optimal decreased to 37, 12, 3 %, first, second, third reuse, respectively.