Valorization of high-salinity effluents for CO2 fixation and hypochlorite generation

Towards the Electrochemical Retention of CO2: Is it Worth it?

“…However, in our project, we are looking for a much simpler process to sequester CO 2 and, here, we are proposing to use brackish solutions which can be obtained easily as the rejection stream of electrodialysis processes, or which can be easily integrated into an electrolysis/electrodialysis cell, because the interest of our research is not to spend a commercial brine but to use electrochemistry in the most environmentally friendly way using waste streams of other processes within the circular economy principles, trying to lead to processes that simultaneously sequester CO 2 and desalinate water. [16] Production of these products was faced in continuous mode, feeding fresh solution continuously to the electrochemical cell. According to Figure 4, production of chlorine, hydrogen and NaOH using electrochemical cells equipped with polymer exchange membranes is as expected.…”

“…This process is the target of many patents [15] but not many reports on its efficiency are found in the literature. [16] As it is known, alkaline hydroxides can be easily produced on the cathode of electrochemical cells when electrolyzing water solutions and this species combines easily with CO 2 to form bicarbonates and carbonates as shown in Equation (1) and (2). [17] CO 2 þ OH À $ HCO À…”

“…In this context, rejection streams from electrodialysis or reverse osmosis treatments can become a suitable electrolyte to produce the NaOH to be used as absorbent and to obtain a highly added value product from the concentrated salts. [16] As with the removal of CO 2 , the removal of chlorides is also a topic of the major significance if another important environmental problem aims to be faced: the salinization of water reservoirs.…”

Effect of [Na+]/[Li+] concentration ratios in brines on lithium carbonate production through membrane electrolysis

“…41 Llanos et al achieved a 93% current efficiency for CO 2 xation with simultaneous hypochlorite production. 42 Mustafa et al recently reviewed the nascent eld of concentrated brine management and CO 2 capture. 43 We recently proposed to take advantage of the hydroxyl anions produced at the cathode of a water electrolyser to adsorb CO 2 as either bicarbonate or carbonate anions and crystallize NaHCO 3 and Li 2 CO 3 , see Fig.…”

“…41 Llanos et al achieved a 93% current efficiency for CO 2 fixation with simultaneous hypochlorite production. 42 Mustafa et al recently reviewed the nascent field of concentrated brine management and CO 2 capture. 43…”