Thermodynamic analysis of in-situ hydrogen from hot compressed water for heavy oil upgrading. (22nd October 2019)

• Record Type: Journal Article
• Authors: Hosseinpour, Morteza; Hajialirezaei, Amir Hossein; Soltani, M.; Nathwani, Jatin
• Is Part Of: International journal of hydrogen energy. Volume 44:Number 51(2019)
• Page Start: 27671
• Page End: 27684
• Publication Date: 2019-10-22
• Subjects: Hot compressed water (HCW) -- Heavy oil -- Partial oxidation -- Aspen Plus® -- Thermodynamic analysis; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2019.08.223
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: Due to many benefits of heavy oil upgrading in the green medium of hot compressed water (HCW), the present study considers the thermodynamic analysis of in-situ hydrogen created by partial oxidation of light hydrocarbons (HC) in HCW. The aim is seeking the upgrading condition where light hydrocarbons create hydrogen (H2 ) and carbon monoxide (CO) assisted by partial oxidation of light hydrocarbons. The formed CO collaborates in in-situ active hydrogen through water gas shift reaction (CO+H2 O↔H2 +CO2 ) which is more effective than external hydrogen for hydrogenation of heavy oil in HCW. Applying the powerful capability of Aspen Plus®, i.e., sensitivity analysis, the effect of significant parameters, such as temperature, pressure (water density), water to oil ratio, and oxygen (O2 ) to oil ratio are studied comprehensively in order to maximize the amount of active hydrogen. The results indicate that higher temperatures and the amount of water (H2 O/heavy oil) are two favorable factors to increase the contribution of active hydrogen, while the pressure is not a determinant factor at supercritical condition (P ≥ 25 MPa). The formation of methane is also decreased at high temperature which is desired for upgrading system. The higher amount of water implies more quantity of O2 since partial oxidation affords the enthalpy of auto-thermal reforming of HO. Hence there should be a compromise in the selected ratios of H2 O/HC and O2 /HC in HCW upgrading system. A set of experiments are conducted in order to compare the simulation and experimental results. Although the experimental results are established on kinetic data which also reflect the physical effect of HCW during HO upgrading, however, the thermodynamic study provides valued information, in agreement with experiments, that improves our understanding of HO upgrading in HCW with less coke. Graphical abstract: Image 1 Highlights: Hydrogen (H2 ) production from hot compressed water (HCW) via partial oxidation of heavy oil was modeled by Aspen Plus software. A sensitivity analysis was conducted to study the effect of the main operating parameters aimed to the H2 production. Experiments were conducted in order to track the results of simulation. The most thermodynamic favorable operating conditions for upgrading heavy oil in HCW were identified.