摘要:Calophyllum inophyllum are plants with a propensity of being used as raw materials in liquid fuel production, in an attempt to overcome energy and environmental crisis, due to the use of fossil fuels. However, high viscosity problem of calophyllum inophyllum seed oil has restricted its utilization in internal combustion engines. Therefore, this study was conducted to experimentally upgrade the physical and chemical properties of calophyllum inophyllum seed oil performed using a thermal-catalytic technique at three successive temperatures, which include 400 °C, 500 °C and 600 °C. A natural dolomite catalyst was activated at 500 °C for 2 h and then employed with the reaction time chosen according to the expected temperature. The results show the highest yields of liquid fuel obtained (42.33%), occurred at 500 °C. Meanwhile, gas Chromatography-Mass Spectroscopy (GC-MS) and ASTM standards presented the oil to be mainly composed of 29.43% aliphatic and 38.99% aromatic compounds. In addition, the viscosity of Calophyllum inophyllum seed oil at 40 °C had decreased from 52.48 cSt to 5.73 cSt, and based on GC-MS evaluation, it was seen to significantly contain a hydrocarbon range of C5–C20, and a small fraction greater than C20. The nature of pyhsics shows calophyllum inophyllum seed oil is product similar to conventional diesel fuel which strengthens the possibility of being used as a substitute. Finding of this study has never been carried out experiments with natural dolomite catalysts using two-stage pyrolysis (thermal-catalytic reactors).