The effect of reaction time and temperature on the aquathermolysis process of heavy crude oil

Hydrothermal upgrading (HTU) performance during aquathermolysis process of heavy crude oil was conducted. All upgrading tests were conducted using a 300-ml autoclave batch reactor at 250 degrees C and 300 degrees C under high pressure for 12, 24, 48, and 72 h in a nitrogen environment. Comprehensive analyses of physical and chemical characteristics of the upgraded oils, including viscosity, elemental composition, SARA fractions as well as Carbon number distribution in saturates of oil samples before and after upgrading, were studied to evaluate the hydrothermal upgrading performance. The results showed that, by increasing the reaction temperatures and times the upgrading performance was improved. The maximum upgrading performance was observed at 300 degrees C and 72 h for in terms of viscosity reduction, increasing the quantity and quality of saturates as a result of thermal decompositions of resin and asphaltenes, and increasing their quantity. In addition, an improvement in upgrading performance can be observed in the increasing of the H/C ratio, removing sulfur and nitrogen due to their desulfurization and denitrogenation. Generally, the obtained data showed that, HTU under studied conditions might be useful for heavy oil pretreatment due to the significant influence on viscosity reduction, heteroatoms removal as well as improving on its the main physical and chemical composition.