Delivering the new CCS agenda: Capture Parallel Session

A process systems approach to targeting membrane properties for post-combustion capture – Rahul Anantharaman

Rahul Anantharaman from The Gas Technology Department of SINTEF Energy Research, presented a process systems approach to targeting membrane properties for post-combustion capture. First of all, Rahul introduced the background of developing membranes for CO₂ capture. As he presented, he described three trade-offs that should be considered:

• for membrane properties, the trade-off between permeance and selectivity;
• for specifications, the trade-off between CO₂ product purity and capture ratio;
• for cost, the trade-off between energy and membrane area.

In addition, multi-stage systems are required for post-combustion capture to achieve 95% product purity. However, the complexity of the membrane design increases in the multi-stage process, because identifying the “best” configuration and membrane properties is not straight-forward. The current material development strategies are development and further improvement based on “educated guess” target properties and no systematic benchmarking before development.

Then, he introduced the parametric variation based design method and new paradigm of process design. That is, conduce integrated techno-economic assessment to guide material development and identify target characteristics and guide further development of existing materials. The new proposed method can reduce the development cost and faster the development time and help industry and funding bodies to support best strategies for membrane development. Therefore, the integrated techno-economic assessments can be used to accelerate membrane materials development for cost-effective CO₂ capture and the methodology has received positive feedback. In future, they will extend the methodology to other membrane applications, such as hydrogen, biogas, nature gas, etc.

CO₂ capture in radio frequency heated system – Javier Fernandez Garcia 

Dr Javier Fernandez, lecturer in Chemical Engineering from the University of Leeds, as part of the Capture Panel presented a novel and feasible method for heating rigs by means of radio frequency. The idea for its implementation comes from issues in power supply companies. For instance, stability in the electricity grid, partial gas conversions, high CO₂ emissions, etc. This alternative proposed and developed by Dr Javier offers not only the possibility to save energy but also reduce the idle time in the reactors where the CO₂ capture is carried out. In terms of energy consumption, radio frequency heating (RFH) concept contributes also significantly narrowing the calcium looping cycle up to 21 %.

The experimental setup comprehends a fixed-bed reactor made up with an inconel tube, ceramic tube and coil. The ceramics not only allow working temperatures higher than 900°C but also works a refractory material. In terms of the solid sorbents used for performing the capture of CO₂, CaO-based sorbents were utilized. The author highlighted that CaO/Support sorbents were mainly used considering their low production price, the high durability, sorption capacity and availability. The CO₂ acceptors were synthesized by the Boreskov Institute of Catalysis (Russia) with specific characteristics for attaining a better resistance to sintering. The durability of the as-prepared sorbents in the multicycle capture test was associated with the use of a porous support and the distribution of CaO over the substrate. From this project, it can be concluded that radio frequency heating gives rise to reduce the CO₂ adsorption/desorption cycles by 20% since the temperatures used in the CaO looping process are controlled with accuracy. In addition, it was found that the improvement reached in the control of temperature contributes to diminishing the drastic depletion of capture capacity in CaO by sintering.

Carbon capture with low-temperature amines. Reducing costs by using waste heat and standard containers – Pieter Verberne

Pieter Verberne from CarbonOrO presented a unique technology to capture Carbon Dioxide (CO₂) from gases with low temperature amines which can be implemented for lower cost to ~£25/ton (saving potential up to 50% reduction in OPEX) owing to using waste heat. The technology can be used in production of bio-methane (sustainable equivalent to natural gas), and CO₂. Eindhoven University of Technology and AkzoNobel originally developed CarbonOrO technology. CarbonOrO partners with HOFSTETTER who is the global player in gas treatment systems.

The system contains one absorber and one desorber tank and the amine solution is circulated between the two. In the absorber the amine reacts with CO₂ at about ambient temperature and in the traditional desorber the CO₂ is released ~140oC. CarbonOrO uses unique amine mixture (Lower Critical Solution Temperature –LCST) that releases CO₂ at ~75oC due to an odd chemical effect decompose in two fractions, and the schematic diagram is shown below. Due to the lower temperature requirement, the system can utilize low-grade waste heat from industry thus saving the energy cost and also reduces the CAPEX. Additional saving is possible by considering plastic tanks instead of stainless steel components. CarbonOrO produced containerized units in summer 2018 that can be mass-produced at low cost which has been manufactured after a pilot plant in 2015 following full-scale unit (scaled ~100times from the pilot plant) in summer 2017 with four patented technologies involved.

This blog was co-authored by Julia Barrio Ruiz de Viñaspre, Peng Xie, Hirbod Varasteh, Dhinesh Thanganadar, Sergio Ramirez Solis and Jean-Michel Bellas.