A Radial Flow Contactor for Ambient Air CO2 Capture

Qian Yu,Wim Brilman

doi:10.3390/app10031080

Abstract

Direct air capture (DAC) of CO2 can address CO2 emissions from distributed sources and produce CO2 from air virtually anywhere that it is needed. In this paper, the performance of a new radial flow reactor (RFR) for CO2 adsorption from ambient air is reported. The reactor uses a supported amine sorbent and is operated in a batch mode of operation or semi-continuously, respectively without or with sorbent circulation. The radial flow reactor, containing 2 kg of the adsorbent, is successfully scaled up from the experimental results obtained with a fixed bed reactor using only 1 g of the adsorbent. In the batch operation mode, the sorbent in the annular space of the RFR is regenerated in situ. With sorbent circulation, the RFR is loaded and unloaded batchwise and only used as an adsorber. A sorbent batch loaded with CO2 is transported to and regenerated in an external (fluid bed) regenerator. The RFR unit is characterized by a low contacting energy (0.7–1.5 GJ/ton-CO2) and a relatively short adsorption time (24–43 min) compared to other DAC processes using the same types of sorbents. The contactor concept is ready for further scale-up and continuous application.

Highlights

The capture of CO2 from ambient air, often called direct air capture (DAC), can address anthropogenic CO2 emissions from distributed sources, which account for between one third and one half of the total CO2 emissions per year [1]
We focus on the process development in the application of CO2 direct air capture in a radial flow reactor (RFR) using a commercial supported amine sorbent, Lewatit® VP OC 1065 (Lewatit) VP OC 1065 (Lewatit), in short: the RFL process (RFR reactor with Lewatit VPOC 1065 as adsorbent)
At this condition, the results showed an overlap of the adsorption rates for the experiments when using 1, 2, and 3 g of sorbent using the fixed-bed reactor

Summary

Introduction

The same system was further developed by Keith et al and was comprised of absorption in an alkaline solution and was coupled to a calcium caustic recovery loop, requiring a temperature of 900 ◦ C during regeneration [9]. Despite its complexity, this optimized and fully engineered system can be regarded as state of the art; it claims to be able to produce CO2 from air at relatively low costs of 94 USD/ton of CO2 [10]

Objectives

Methods

Results

Conclusion