Pressurized chemical looping methane reforming to syngas for efficient methanol production: Experimental and process simulation study

Abstract

This study investigates the potential of applying pressurized chemical looping reforming (CLR) mechanism for syngas to methanol production process combining of experimental demonstration of methane reforming to syngas and simulation for integration in methanol production. The experimental study was conducted using the internally circulating reactor (ICR) that was specially designed to enable pressurized CLR operation where several experimental cases were completed using a NiO-based oxygen carrier. Up to 4 kW of methane feed was reformed to syngas, achieving high conversion efficiencies and high syngas recovery and purity at pressurized conditions up to 4 bar. Co-feeding H2O or CO2 was found to affect mainly the H2/CO ratio. The simulation study evaluated the potential of integrating the CLR process for large scale methanol production through comprehensive thermodynamic analysis using Aspen plus. The results revealed that CLR-based methanol plant is a highly attractive pathway achieving higher methanol production efficiency outperforming the conventional autothermal reforming (ATR) -based plant by ∼5% efficiency. The main benefits of the CLR-based system is the avoidance of the air separation unit required for ATR plants, and the extra power generation through the gas turbine utilizing the hot exhaust gas of the air reactor. A detailed sensitivity study was also conducted to study the effects of the CLR operating pressure, and the reduced syngas purity caused by possible gas leakage in the ICR, on the overall methanol plant performance.