Steam and Pressure Management for the Conversion of Steelworks Arising Gases to H2 with CO2 Capture by Stepwise Technology

Leonie Lucking,Francesco Sebastiani,Marija Sarić,Jebin James,H J A Van Dijk,Jurriaan Boon,Johannis Pieterse,Paul Cobden

doi:10.3390/separations9010020

Leonie Lucking, Francesco Sebastiani + Show 6 more

Open Access

https://doi.org/10.3390/separations9010020

Copy DOI

Abstract

Steel production is a main source of CO2 emissions globally. These emissions must be drastically reduced to meet climate change mitigation goals. STEPWISE is a Sorption Enhanced Reactive Process (SERP) technology that converts steel works arising gases to H2 with simultaneous CO2 capture. The main energy requirements of the process are the high- and low-pressure steam quantities that are needed to rinse and regenerate the adsorbent. In this simulation study, the separation performance of STEPWISE is evaluated over a range of steam and feed pressure inputs by searching those design points where CO2 recovery and purity percentages are equalized. This method is used to facilitate the comparison of different operating regimes. Results highlight the importance of the rinse to purge ratio (R/P) as a design variable. A higher R/P ratio is demonstrated to maintain CO2 recovery and purity of ~95.5%, while total steam consumption and feed carbon loading are reduced by 27% and 20%, respectively. This is achieved without changing other parameters, like cycle time. Additionally, it is demonstrated that the CO2 capture performance can be maintained for varying feed pressure values by tuning the feed carbon loading. Future studies are recommended to focus on the expected role of the feed gas steam content on these findings.

Highlights

Anthropogenic emission of carbon species is projected to disrupt the Earth’s climate over the coming decades
These trends are observed at both S/Ct of 0.8 and 1.1, and it is consistent with previous work on sorption-enhanced water gas shift (SEWGS) optimization [12,24,37]
The diagonal solution lies on a carbon purity (CP) constrained branch

Summary

Introduction

Anthropogenic emission of carbon species is projected to disrupt the Earth’s climate over the coming decades. Carbon Capture and Storage (CCS) is thereby gaining importance as a strategy to prevent carbon emissions from reaching the atmosphere. This is relevant for those industrial sectors that can hardly avoid the use of carbon, like steel making. Gas adsorption is a well-established industrial process for the separation and purification of gases [1,5,6,7,8,9]. A gas species, or adsorbate, is selectively transferred to a solid surface. This gas species is recovered by regenerating the solid material, or sorbent. Regeneration can be achieved by heating the sorbent to higher temperatures or by lowering the adsorbate partial pressures [9,10]

Objectives

Methods

Results

Conclusion