Abstract
The use of waste oils as pyrolysis feedstocks to manufacture high-grade biofuels has prompted researchers to focus on developing renewable energy to overcome the depletion of fossil fuel supplies and the global warming phenomena. Because of their high hydrogen and volatile matter concentration, waste oils are ideal raw materials for the production of biofuels. It is challenging to attain satisfactory results with conventional methods, such as transesterification, gasification, solvent extraction, and hydrotreating due to flaws such as high energy demand, long time, and high operating costs. Catalytic pyrolysis of waste edible oils was employed as a resource for the generation of biodiesel. The application of the catalytic cracking process has the potential to alleviate the existing situation. In this study of catalytic cracking conversion of waste cooking oil to produce different biofuels, grades were investigated using two heterogeneous catalysts. The catalysts were activated montmorillonite (PAMMT) clay and its modified form using a chitosan biopolymer (PAMMT-CH) nanocomposite. The catalysts were identified using infrared spectroscopy, X-ray diffraction patterns, transmittance electron microscopy images, surface area, and thermal stability. The catalysts were tested for their performances using different amounts (0.1-1% by weight) at a temperature assortment of 200-400 °C during a time range of 60-300 min. The experimental studies were carried out in a batch reactor. GC mass spectra were used to investigate the catalytic cracking products. Fractional distillation is used to separate the final products from various reaction conditions. The physicochemical properties of resulting biofuels were profiled by quantifying their densities, viscosities, specific gravities, pour points, flash and fire points, cetane numbers, carbon and ash residues, and sulfur contents. The optimum conditions of the yield product were 300 and 400 °C, catalyst weights of 0.7 and 0.8% w/v, and reaction times of 120 and 180 min concerning the (PAMMT) and (PAMMT-CH) nanocomposite, respectively. The determined properties were located within the limits of the specific standards of ASTM specifications. As a result, the PAMMT nanocomposite produced biofuel comparable to biodiesel according to ASTM specifications, while the PAMMT-CH nanocomposite produced biofuel comparable to biojet.