Bilanzierung eines Gesamtprozesses zur Karbonatisierung mineralischer Rohstoffe

Research output: ThesisDoctoral Thesis

Authors

Abstract

The permanent storage of carbon dioxide as carbonates is one of many options to use CO2. Carbonation methods are able to bind carbon dioxide into a solid matrix directly at their point of origin and are therefore a suitable method to reduce carbon dioxide emissions for certain fields of industry. Carbon dioxide reacts in a single- or multistage process with primary or secondary raw materials to solid and stable mixed carbonates. The herewith presented PhD-thesis deals with the topic of balancing a multistage carbonation process in terms of mass and CO2. The thesis aims not only at the optimization of the single process steps, but also at characterizing the produced pure products for their potential application on the market. A process has been developed to gain pure calcium- or magnesiumcarbonates from carbon dioxide and primary (serpentinite) or secondary (ashes and slags) raw materials. The applied method is an indirect carbonation technique implemented in a three step process. For the first step – the dissolution process – hydrochloric acid leaches, in a tempered stirring reactor, the required elements (calcium and/or magnesium) out of the original matrix. In favour of the purity of the final product, all the other metals which have been co-leached out of the matrix of the source rock, need to be eliminated. Step two - the elimination process - is carried out by a simple precipitation reaction with ammonia. During the last step – the carbonation itself – carbon dioxide is brought into the Ca- and Mg- enriched solution to form stable carbonates. Lab scale experiments have provided a sufficient data base to balance the single process steps and generate mass- and CO2-balances for the overall process. These balances will be an innovation to the literature and can build a solid basis for the evaluation of mineral carbonation. The balance results show that the two raw materials serpentinite and incineration ash from residuals of the paper industry are suitable for carbonation regarding the aim of reaching a negative CO2-balance. They are able to bind more CO2, than is emitted during the carbonation process.

Details

Translated title of the contributionBalancing a mineral carbonation process
Original languageGerman
QualificationDr.mont.
Awarding Institution
Supervisors/Advisors
Publication statusPublished - 2020