BIODIESEL PRODUCTION USING HETEROGENEOUS CATALYST FROM ‘PONKAN’ TANGERINE PEELS (CITRUS RETICULATA BLANCO)
Catalyst, ‘Ponkan’Tangerine, Citrus reticula Blanco, Biodiesel, MSR.
The advance of global energy demand has intensified environmental problems caused by the use of fossil fuels and has been driving the search for and development of greener matrices, which are being used to minimize environmental impacts and human health. This work proposed a sustainable process for the production of biodiesel, an alternative fuel to diesel, with the use of a heterogeneous, green catalyst, called CT, derived from a residual biomass, from the bark of 'Ponkan' mandarin (C. reticulata Blanco). Through d-optimal experimental planning, parameters such as molar methanol/oil ratio, catalyst concentration, temperature and reaction time were evaluated. Initially, three catalyst samples were prepared by calcination of tangerine shells at 4h, CT7 (700 ° C), CT8 (800 ° C) and CT9 (900 ° C), and after preliminary tests, yields (m/m) in biodiesel were 79.77, 77.58 and 77.40 %, respectively. The mass catalyst yield obtained for each temperature (700, 800 and 900 °C) starting from 50 g of bark were 3.76, 1.54 and 0.98%. The catalysts were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM-FEG), X-ray dispersive energy (EDS), CO2 desorption at programmed temperature (CO2-TPD), thermal analysis (TG/DTG) and Hammett basicity test. The quality of biodiesel was evaluated according to the standard procedures established by ASTM (American Society for Testing and Materials) for the kinematic properties of viscosity and density. The XRD patterns of the CT catalyst showed the peaks associated with the characteristic phases of K2CO3 and K2O, both confirmed by FTIR and FRX, which identified large proportions of these oxides. CO2-TPD analysis demonstrated the presence of weak and moderate base sites in the CT catalyst. Good thermal stability was observed through the TG/DTG curves. The reaction parameters during optimization were evaluated by experimental planning via response surface methodology (RSM) through the D-Optimal project. The ideal conditions found were 3 h reaction time, 2.5% p/p catalyst, molar ratio of 15: 1 (methanol: oil) and 60 ° C. For these optimized conditions, the conversion of the reaction by 1HRMN was greater than 87%. A green catalyst obtained from tangerine shells was applied in biodiesel synthesis and presented reuse capacity of up to 5 times.