A new recovery process of carbon dioxide from alkaline carbonate solution via electrodialysis

Abstract

Bipolar membrane electrodialysis is applied to CO 2 recovery from alkaline carbonate solution. CO 2 in flue gas is captured by an alkaline hydroxide absorbing solution to form an alkaline carbonate solution. The captured CO 2 is recovered from the alkaline carbonate solution via bipolar membrane electrodialysis, and the alkaline solution is regenerated simultaneously. To reduce the power requirement for CO 2 recovery, this study considers optimal design and operation. Three membrane arrangements were compared, and the results indicate the membrane arrangement comprising a bipolar membrane and cation exchange membrane is the most energy saving. With further optimization of operation conditions, the minimum power requirement for CO 2 recovery was reduced to 2.1 MJ/kg-CO 2 (or 2.1 GJ/t-CO 2 ).

Electrochemical carbon dioxide capture to close the carbon cycle

“…Depending on the charge carriers in the cell, the flow mode (i.e., one-way pass vs. batch mode) and feed concentration, each BPMED process asks for a different cell configuration. While BPM-CEM might be the choice of some researchers for CO 2 recovery from carbonate solutions [105,106], others chose a BPM-AEM [43,92] for the same purpose. That is while novel configurations as BPM-AEM-AEM are also emerging for minimizing BPM fouling when extracting CaCO 3 from seawater [107], see section (3.2.4).…”

Molten catalytic coal gasification with in situ carbon and sulphur capture

“…As in the work by Kamo et al, 28 the alkali hydroxides not only catalyze the steam-coal gasification reaction; they can also capture acid gases, such as HCl, H 2 S, and CO 2 , inside of the gasifier. The alkali hydroxides can be regenerated from these alkali chlorides, sulphides and carbonates outside of the gasifier using cationselective polymer membranes, [29][30][31] such as NafionÒ. Fig.…”

Ion-exchange membranes in chemical synthesis – a review

“…There, BMED can replace such a sorbent thermal decomposition (regeneration) step because acidification of spent solution, with the protons produced by BPM, leads to the release of gaseous CO 2 from the weak carbonic acid and thus allows for sorbent regeneration. This recovery process is attractive due to very low energy consumption -as low as 0.55 kWh kg -1 CO 2 for alkaline carbonates [203][204][205] and around 2−4 kWh kg -1 CO 2 for ammonia [206]. The main obstacle in BMED-based CO 2 desorption is CO 2 gas evolution inside the membrane module compartments, resulting in an increased stack resistance and high energy consumption at high current densities [207].…”