CO2 mineral sequestration integrated with water-gas shift reaction

Ron Zevenhoven, Mikael Virtanen

Research output: Chapter in Book/Conference proceedingConference contributionScientificpeer-review

Abstract

Mineralisation of CO2 using the world’s abundant resources of suitable magnesium-silicate rock offers a large carbon and storage (CCS) potential with documented advantages compared to methods that employ underground CO2 storage. Work in Finland has resulted in what is referred to as “the ÅA route” or “ÅAU process”, which is based on stepwise carbonation of serpentinite rock, containing mainly serpentine (3MgO·2SiO2·2H2O) besides a significant fraction of iron oxides. Magnesium is extracted using ammonium sulphate and converted into magnesium hydroxide (Mg(OH)2), which is carbonated in a pressurised fluidised bed (PFB) reactor at elevated pressure and temperature (~500°C, ~20 bar CO2 pressure).The combined operation of a water-shift reaction and carbonation of Mg(OH)2 is addressed in this paper for (coal) gasification syngas and, in more detail, blast furnace top gas. Water produced during the carbonation step can drive the water-gas shift reaction. HSC (v 5.1.) and Aspen Plus (v.8.2) are used for thermodynamic equilibrium product gas and solid products composition analysis.Optimal process conditions appear to be 400 – 450°C, at a pressure of 40 bar or higher, for acceptable degrees of conversion. This optimum range partly the result of the water-gas shift reaction equilibrium moving to the CO side at higher temperatures, and the increasing intensity of Mg(OH)2 calcination, giving much less reactive MgO instead of the carbonation of Mg(OH)2 to MgCO3. Further work shall address reaction kinetics supported by experiments.
Original languageUndefined/Unknown
Title of host publicationCPOTE 2016 : proceedings of the 4th International Conference on Contemporary Problems of Thermal Engineering, Gliwice – Katowice, Silesia, Poland, 14-16 September 2016
EditorsWojciech Stanek, Paweł Gładysz, Lucyna Czarnowska, Karolina Petela
PublisherThe Silesian University of Technology
Pages919–927
ISBN (Electronic)978-83-61506-36-2
Publication statusPublished - 2016
MoE publication typeA4 Article in a conference publication
EventInternational Conference on Contemporary Problems of Thermal Engineering - 4th International Conference on Contemporary Problems of Thermal Engineering
Duration: 14 Sep 201616 Sep 2016

Conference

ConferenceInternational Conference on Contemporary Problems of Thermal Engineering
Period14/09/1616/09/16

Keywords

  • CCS
  • coal gasification
  • iron- and steelmaking
  • mineral carbonation

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