Rational synthesis of microporous carbons for enhanced post-combustion CO₂ capture via non-hydroxide activation of air carbonised biomass

Abstract

Rational combination of a mild activating agent (potassium oxalate) and air carbonised biomass, which is resistant to activation, yields highly microporous carbons with enhanced post-combustion CO2 uptake.

Direct synthesis of organic salt-derived porous carbons for enhanced CO2 and methane storage

“…Volumetric uptake is dependent on the gravimetric storage capacity and the packing density. The volumetric uptake of the PPI-derived carbons (ESI Table S2 †) is very attractive and compares favourably with or outperforms that previously reported for benchmark materialscarbons [33][34][35][36][37][38][39][40][41][42][43][44][45][46] or MOFs. [47][48][49] The best all round performance is for sample PPI-700-2, which achieves CO 2 uptake of 62 g l −1 (35 cm 3 cm −3 ) at 0.15 bar, 196 g l −1 (110 cm 3 cm −3 ) at 1 bar, 401 g l −1 (225 cm 3 cm −3 ) at 5 bar, and 477 g l −1 (267 cm 3 cm −3 ) at 9 bar.…”

“…The CO 2 uptake at 1 bar does not follow the trend in surface area, which once again indicates that carbons must have optimised pores rather than just a high surface area to possess high CO 2 uptake at low pressure. [33][34][35][36][37][38][39][40][41][42][43][44][45][46] The CO 2 uptake of 4.7 mmol g −1 at 1 bar and 25 °C is comparable to the best activated carbons, but the current PPIderived carbons have the advantage of being easy and simple to synthesise, as they only require the carbonisation process and no other chemical compounds than the precursor (PPI). This simpler preparation process yields carbons with better CO 2 uptake at 1 bar (4.1 mmol g −1 to 4.7 mmol g −1 ) compared to that (3.1 mmol g −1 to 3.4 mmol g −1 ) of equivalent PPI-derived carbons wherein acid was used during the washing step post carbonisation.…”

A simple, sustainable route to flexible microporous carbon cloth for energy storage applications

“…negating the use of ZnCl2 and NH4Cl which has to date been considered to be a crucial step in the preparation of ACCs that preserve the flexibility of activated carbon fabric, (ii) not using an additional activating agent, and (iii) use of the less caustic activating agent potassium oxalate (PO), which has previously been shown to give comparable porosity in activated carbons to the more commonly used KOH. [29][30][31] Due to porosity of the resulting ACCs and the sparsity of the literature on the gas uptake capacity of ACCs in general, we explored the CO2 and CH4 uptake of the materials prepared in this work.…”

A simple, sustainable route to flexible microporous carbon cloth for energy storage applications

“…negating the use of ZnCl 2 and NH 4 Cl which has to date been considered to be a crucial step in the preparation of ACCs that preserve the flexibility of activated carbon fabric, (ii) not using an additional activating agent, and (iii) use of the less caustic activating agent potassium oxalate (PO), which has previously been shown to give comparable porosity in activated carbons to the more commonly used KOH. [33][34][35] Due to porosity of the resulting ACCs and the sparsity of the literature on the gas uptake capacity of ACCs in general, we explored the CO 2 and CH 4 uptake of the materials prepared in this work.…”