The growth of the global hydrogen market demands more efficient industrial processes for its production. Hydrogen can be produced from renewable or nuclear sources, using electricity as an intermediate energy carrier. However, industrially is produced mainly by steam reforming of methane or other hydrocarbons and also by gasification of coal and oil refining residues. Methane steam reforming (MSR) is being used for decades, despite the severe operating conditions (high temperatures and pressures) and low-energy efficiency, which challenges the development of more efficient and reliable processes. The present chapter provides an overview of hydrogen production via MSR, purification processes and procedures for enhancing the hydrogen production. Sorption-enhanced and membrane-enhanced reactors, considering selective CO₂ sorption removal from the reaction bulk and selective hydrogen membrane permeation are, respectively, addressed. Particular attention was paid to the recently proposed hybrid sorption-enhanced membrane reactor (HSEMR), in which sorption and permeation processes occur inside the reforming reactor. This technology allows lower operating temperatures, produces hydrogen with higher purity and exhibits higher reaction conversions than sorption or membrane reactors. The major contributions in this field are reviewed and the advantages and drawback of each approach are discussed in detail.

Chapter Contents:

• Abstract
• 13.1 Introduction
• 13.2 Hydrogen production via methane steam reforming and purification
• 13.2.1 Methane steam reforming process
• 13.2.2 Methane steam reforming kinetic model
• 13.2.3 PSA principles (hydrogen purification)
• 13.3 Enhanced methane steam reforming processes
• 13.3.1 Sorption-enhanced reactor
• 13.3.2 Membrane-enhanced reactor
• 13.3.3 Hybrid sorption-enhanced membrane reactor
• 13.3.3.1 Hybrid sorption-enhanced membrane reactor with a fluidized bed
• 13.3.3.2 CO2/H2 active membrane piston reactor with CO2 adsorption (CHAMP-SORB)
• 13.3.3.3 Modelling the hybrid sorption-membrane reactor
• 13.4 Conclusions
• Nomenclature
• References

Inspec keywords: chemical reactors; coal gasification; renewable energy sources; steam reforming; sorption; membranes; hydrogen production; oil refining

Other keywords: HSEMR; nuclear sources; global hydrogen market; oil refining residues; renewable sources; MSR; coal gasification; industrial process; hydrogen production; multifunctional hybrid sorption-enhanced membrane reactor; hydrocarbons; intermediate energy carrier; methane steam reforming

Subjects: Fuel processing industry; Chemical industry; Industrial processes