Numerical Investigation of the Effects of Steam Mole Fraction and the Inlet Velocity of Reforming Reactants on an Industrial-Scale Steam Methane Reformer

Chun-Lang Yeh

doi:10.3390/en11082082

Abstract

Steam methane reforming (SMR) is the most common commercial method of industrial hydrogen production. Control of the catalyst tube temperature is a fundamental demand of the reformer design because the tube temperature must be maintained within a range that the catalysts have high activity and the tube has minor damage. In this paper, the transport and chemical reaction in an industrial-scale steam methane reformer are simulated using computational fluid dynamics (CFD). Two factors influencing the reformer temperature, hydrogen yield and stress distribution are discussed: (1) the mole fraction of steam (YH2O) and (2) the inlet velocity of the reforming reactants. The purpose of this paper is to get a better understanding of the flow and thermal development in a reformer and thus, to make it possible to improve the performance and lifetime of a steam reformer. It is found that the lowest temperature at the reforming tube surface occurs when YH2O is 0.5. Hydrogen yield has the highest value when YH2O is 0.5. The wall shear stress at the reforming tube surface is higher at a higher YH2O. The surface temperature of a reforming tube increases with the inlet velocity of the reforming reactants. Finally, the wall shear stress at the reforming tube surface increases with the inlet velocity of the reforming reactants.

Highlights

The environmental impact of greenhouse gas pollutants emitted from the combustion of fossil fuels and the legal regulations against production of air pollutants have increased the necessity for clean combustion
computational fluid dynamics (CFD) researches [1,2,6] of steam methane reformers, the standard k-ε model [13], discrete ordinate (DO)
Radiation model [14] and finite rate/eddy dissipation (FRED) model [15] are adopted for turbulence, radiation and chemical reaction simulations, respectively

Summary

Introduction

The environmental impact of greenhouse gas pollutants emitted from the combustion of fossil fuels and the legal regulations against production of air pollutants have increased the necessity for clean combustion. Hydrogen is an important material for petroleum refineries. It converts crude oil into products with high economic value, e.g., gasoline, jet fuel and diesel. The demand for hydrogen by petroleum refineries has increased due to environmental restrictions and efforts to process heavier components of crude oil. The environmental requirement for low-sulfur-content fuels results in an increasing amount of hydrogen required in hydro-treating processes, and the attempt to process heavier components of crude oil, known as bottom-of-the-barrel processing, increases the demand for hydrogen in hydro-cracking processes [1,2,3]

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