Steam Reforming and the Production of Hydrogen Gas

Steam Reforming and the Production of Hydrogen Gas

Introduction

Methods to make hydrogen from natural gas are well evolved and account for over 95% of all hydrogen made in the UK and 48% globally. It is foreseen that hydrogen from natural gas can assist as a base to the UK transition to a hydrogen power economy.

 

Production Process

The vapour methane restructuring (SMR) method comprises of the following two steps, as shown in Figure 1.

1. Reformation of Natural Gas The first step of the SMR method engages methane answering with vapour at 750-800°C (1380-1470ºF) to make a synthesis gas (syngas), a blend mainly made up of hydrogen (H2) and carbon monoxide (CO). (Rostrup 2002)

2. Shift ReactionIn the second step, renowned as a water gas move (WGS) answer, the carbon monoxide made in the first answer is answered with vapour over a catalyst to pattern hydrogen and carbon dioxide (CO2). This method happens in two phases, comprising of a high warmth move (HTS) at 350ºC (662ºF) and a reduced warmth move (LTS) at 190-210ºC (374-410ºF).

 

Hydrogen made from the SMR method encompasses little amounts of carbon monoxide, carbon dioxide, and hydrogen sulfide as impurities and, counting on use, may need farther purification. The prime steps for purification include:

• Feedstock purification - This method eliminates venoms, encompassing sulfur (S) and chloride (Cl), to boost the life of the downstream vapour restructuring and other catalysts.

• Product purification - In a fluid absorption scheme, CO2 is removed. The merchandise gas undergoes a methanation step to eliminate residual finds of carbon oxides. Newer SMR plants utilize a force sway absorption (PSA) unit rather than, making 99.99% untainted merchandise hydrogen.

High to ultra-high purity hydrogen may be required for the durable and effective procedure of fuel cells. Impurities are accepted to origin diverse difficulties in ...