Refinery Scheme’s Mass Targeting and Bottom Section Synthesis for Heavy Oil

Abstract

This work evaluates the introduction of heavy oil in a refinery as a first step. The first step will yield an increase in the production of the bottom products (vacuum residue, gas oil and diesel). It will also reduce the production of the light products (gases, LPG and naphtha) from ADU/VDU for oil with API above 20. However, we showed that if the heavy oil is below 20 API, the vacuum residue will be the only increasing product. This also reflects on the unit capital cost. The power and steam required by the refinery should also increase as crude oil becomes heavier due to the high amount of steam used in the delayed coker unit. Nevertheless, the fuel for the fire heaters does not show the expected change as compared to the model.

The report goes to a further step by replacing bottom product processes with gasification and syngas routes. This step results to reduce the total production of fuel. Therefore, the fuel gasification paths MTG, DME (direct and indirect), and FT are more valuable than other gasification paths. All fuel paths showed a similar amount of fuel production, yielding extra production around 100,000 lb/hr compared to the base case. Moreover, the direct path of DME provided the lowest estimated cost compared to other fuel gasification paths. The MTG path and indirect DME path have a similar cost.

The final step is to investigate two challenges related to the gasification cases: water balance and fuel demand. The investigation shows that more than 95% of used water can be recovered by recycling water (both direct and indirect recycling). Furthermore, the study shows that MTG and DME-indirect paths demand less fuel when compared to the base case.