Preliminary Assessment of Synthesis Gas Production via Hybrid Steam Reforming of Methane and Glycerol

Abstract

In this article, hybrid steam reforming (HSR) of desulphurized methane, together with crude glycerol, in existing commercial steam reformers to produce synthesis gas is proposed. The proposed concept consists of a gasifier to produce vapors, gases, and char from crude glycerol, which is coupled with a pre-reformer to further convert the vapors into gases using a steam reforming catalyst. These gases are mixed with methane and subsequently reformed to synthesis gas (CO + H2) in a primary reformer, using a steam reforming catalyst. In the present work, gasification, steam, and hybrid reforming of glycerol are reported. The total product distribution (gas, vapor, and char) of pure and crude glycerol gasification was quantified at different reaction temperatures at very high heating rates (atomization, ∼106 °C/min). With pure and neutralized crude glycerol, no char formation was observed. However, with crude glycerol and pure glycerol doped with KOH, a significant amount of char on carbon basis (∼10%) is produced. The results obtained here show that KOH present in glycerol was responsible for polymerizing higher molecular components formed during thermal degradation. Steam reforming of pure and neutralized crude glycerol was studied at different process conditions in the presence of commercial reforming catalysts. Pure glycerol was easier (in terms of catalyst activity) to reform when compared to neutralized crude glycerol at high temperature (800 °C). The results from the steam reforming of neutralized crude glycerol show that the loss of catalyst activity was due to the presence of organic impurities such as FAMEs, diglycerides, and triglycerides. The proposed HSR concept was demonstrated using 28 wt % pure glycerol and 72 wt % methane (on C1 basis) in a two-stage fixed bed reformer at 800 °C using commercial steam reforming catalyst.