Techno-Economic Evaluation of Hydrogen Production via Gasification of Vacuum Residue Integrated with Dry Methane Reforming

Abstract

The continuous rise of global carbon emissions demands the utilization of fossil fuels in a sustainable way. Owing to various forms of emissions, our environment conditions might be affected, necessitating more focus of scientists and researchers to upgrade oil processing to more efficient manner. Gasification is a potential technology that can convert fossil fuels to produce clean and environmentally friendly hydrogen fuel in an economical manner. Therefore, this study analyzed and examined it critically. In this study, two different routes for the produc-tion of high-purity hydrogen from vacuum residue while minimizing the carbon emissions were proposed. The first route (Case I) studied the gasification of heavy vacuum residue (VR) in series with dry methane reforming (DMR). The second route studied the gasification of VR in parallel integration with DMR (Case II). After investigating both processes, a brief comparison was made between the two routes of hydrogen production in terms of their CO2 emissions, en-ergy efficiency, energy consumption, and environmental and economic impacts. In this study, the two vacuum-residue-to-hydrogen (VRTH) processes were simulated using Aspen Plus for a hydrogen production capacity of 50 t/h with 99.9 wt.% purity. The results showed that Case II offered a process energy efficiency of 57.8%, which was slightly higher than that of Case I. The unit cost of the hydrogen product for Case II was USD 15.95 per metric ton of hydrogen, which was almost 9% lower than that of Case I. In terms of the environmental analysis, both cases had comparably low carbon emissions of around 8.3 kg of CO2/kg of hydrogen produced; with such high purity, the hydrogen could be used for production of other products further downstream or for industrial applications.

Conversion of Vacuum Residue from Refinery Waste to Cleaner Fuel: Technical and Economic Assessment

“…The revenue of this project is the selling price of hydrogen and methanol. CAPEX has been converted to the annualized capital charge (ACC) assuming a project life of 30 years and an interest rate of 10% using the relation shown in Equation (11) to determine the total production cost and to perform a cash flow calculation.…”

“…Steam reforming is a highly endothermic reaction requiring a significant amount of energy input. The gasification of heavy residual oil and the steam reforming of natural gas can be integrated in a way that all the energy required for the endothermic reforming reaction is provided by the enthalpy of the hot syngas leaving the gasifier, which will maximize the production of synthesis gas [11]. The syngas produced can be utilized in different ways including burning the synthesis gas to produce electricity as in integrated gasification combined cycle (IGCC) or convert it to hydrogen, methanol, or other Fischer Tropsch (FT) chemicals.…”