Integrating CO2 utilisation and metal recovery in carbon-intensive industries towards circular economy: process simulation and preliminary results from the CIRECO2 project

Introduction

Carbon-intensive industries in Spain face a competitiveness decline and urgently require disruptive decarbonization solutions. The CIRECO2 project tackles this challenge through an integrated process that combines CO₂ capture and waste valorization, advancing the targets of decarbonization, circular economy and energy transition. The captured CO₂ is valorized through three complementary uses, while metal-bearing wastewater is recycled into catalytic materials within the same facility.

Methods

For the modeling side, a combination of ASPEN software and other softwares for equation solving were used. Each stage of the experimental results was performed in different facilities according to the purpose of the tests. For example, metals from wastewater were precipitated through pH adjustment and recovered using a centrifuge and a vacuum filter. On the other side, catalytic reactions were performed in a semi-continuous and single-path reactor.

Results

Preliminary results will be presented for both the simulation work and the experimental campaign carried out to date. With regard to the simulation, the results might cover the CO₂ absorption and separation section and/or the process separation stages, together with the identification of the critical operating variables throughout the integrated scheme. As for the experimental part, results are presented on metal precipitation under different pH conditions and the characterization of the recovered metals from which the catalysts will be manufactured, along as their utilization as catalysts.

Conclusions

The combination of simulation and early experimental data confirms the technical consistency of the CIRECO2 concept, provides the inputs needed for the next experimental stages, catalyst synthesis and CO₂ methanation testing, and supports the upcoming techno-economic and environmental evaluation of this circular decarbonization pathway.