Process for removal of carbon dioxide for use in producing direct reduced iron
US6562103B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 26, 2002 |
| Grant date | May 13, 2003 |
| Priority date | — |
| Expiry date | Aug 26, 2022 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P10/143
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
The present invention relates to a pressure swing adsorption process for direct reduction of iron wherein a portion of spent reducing gas withdrawn from the direct reduction reactor is subjected to a PSA process for the removal of carbon dioxide from the spent reducing gas. An improved CO2-rejection method using an external natural gas purge stream after depressurization and before the product purge step is described. The PSA process comprises an external purge step with a non-absorbable gas, which surprisingly reduces the adsorbent regeneration requirements to maintain the selective adsorption of carbon dioxide from the spent reducing gas. The external natural gas purge results in a cleaner bed before the start of each adsorption cycle. Consequently, significantly more CO2 can be rejected and/or higher hydrogen and CO recoveries can be attained. The external purge stream is fully integrated into the DDRI production scheme.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.