A CO2 Capture Technology Using Multi-walled Carbon Nanotubes with Polyaspartamide Surfactant

Abstract

Global climate change resulting from the emission of greenhouse gases has become a widespread concern in the recent years. Carbon dioxide alone contributes roughly two-thirds to the enhanced greenhouse effect. Carbon capture and storage (CCS), an approach for mitigating potential global climate change, is widely known as a selected track towards sustainable application of fossil fuels. Technologies to separate and compress CO 2 from power plant flue gases are commercially available. Absorption, using monoethanolamine (MEA), is the most common technology applied to capture CO 2 from flue gas of fossil fuel power plants. However, the efficiency penalty induced by carbon capture within energy conversion systems poses a threat to the economic viability of these systems. The adsorption technology due to the ability to operate at moderate temperature and pressure, the increase of the capacity of CO 2 adsorption and the compliance with the environmental safety are the trickiest in the adsorbent design. The primary objective of this work was to design an adsorbent with ability of adsorbing large quantity CO 2 at efficient energy. A long chain polymer was grafted with a diamine to provide a large CO 2 anchoring site for carbamate formation, covering multiwalled carbon nanotubes (MWNTs) to enhance the surface area and pore volume. Thus, an advanced adsorbent was made after polycondensation of aspartic acid between 190°C-210°C in phosphoric acid medium and the use of dicyclohexylcarbodiimide (DCC) as the coupling agent; this resulted in long chain polysuccinimide (PSI) synthesis. A ethylenediamine (EDA) was grafted to the PSI to give a polyaspartamide (PAA), which, covering the MWNTs, has achieved an adsorbent with 100% EDA incorporation as showed 1 H NMR. The chemical surface of the PAA-MWNTs showed with FTIR analysis the primary amine group and the amide group as CO 2 anchoring sites and biodegradable bonds respectively. As evaluated via BET, the low surface area and pore volume of PAA have increased by 31 and 41 times respectively with the inclusion of MWNTs (8nm). Thus, the surface area, pore volume, and pore size of the synthesized adsorbent (PAA-MWNTs) were 60.4m 2 /g, 0.4cm 3 / respectively. Transmission electron microscope (TEM) analysis and the decrease of graphitized carbon as shown with Raman spectra have shown that the covering of MWNTs by the polymer PAA increased the diameter size from 8nm 2 adsorption using PAA-MWNTs as an adsorbent. The CO 2 th the use of TGA in order to evaluate the CO 2 adsorption capacity of the 2231 adsorbents. The PAA-MWNTs showed a higher CO 2 adsorption capacity of 70gCO 2 /kg compared to PAA, PSI, and MWNTs alone, where the adsorption capacity showed 46.17gCO 2 /kg, 26.90gCO 2 /kg, and 15.20gCO 2 /kg respectively.

Synthesis and evaluation of carbon nanotubes composite adsorbent for CO2 capture: a comparative study of CO2 adsorption capacity of single-walled and multi-walled carbon nanotubes

“…Lee and Park reported that impregnating polyethyleneimine onto MWCNTs increased the CO 2 adsorption capacity of the CNTs by 200% (Lee and Park 2015). In the same vein, Ngoy et al reported that grafting a polyaspartamine surfactant onto MWCNTs could increase the CO 2 adsorption capacity of the material by about 500% (Ngoy et al 2014). In addition, Su et al demonstrated that MWCNT/3-aminopropyltriethoxysilane (APTS) composite adsorbent displayed good CO 2 adsorption performance than the amine-functionalized activated carbon, and the composite material also displayed a lower theoretical energy of regeneration and superior cyclic stability when compared to those of the amine-functionalized activated carbon (Su et al 2011).…”

“…Ngoy et al reported an adsorption capacity of 12.1 mg/g for pure MWCNTs at a temperature and a pressure of 25°C and Table 4). But as the carbon nanotubes used in this study were similar to those used by Ngoy et al (obtained from the same also supplier) it is expected that they will display similar CO 2 adsorption capacities (Ngoy et al 2014). Su et al reported a CO 2 adsorption capacity of 21.5 mg/g for MWCNTs using a mixed gas stream at atmospheric pressure and a temperature of 50°C (Table 4), which is higher than the temperature of this study (Su et al 2011).…”

Superbase‐Added Choline Chloride‐Based Deep Eutectic Solvents for CO2 Capture and Sequestration

“…Apparently, even the presence of superbase is ineffective in inducing CO 2 chemisorption within glycerol via –OH functionalities. We conclude that the presence of ChCl salt has some synergistic effect in this regard as the DES glyceline, constituted of ChCl and glycerol in 1: 2 mole ratio, is able to absorb CO 2 in the presence of these superbases …”

“…However, at ambient conditions, there exist very few liquid hydrocarbon surfactants/liquid polymers, and they are shown to be devoid of enough necessary chemical functionalities to effectively capture and store CO 2 . Further, the CO 2 solubility within liquid surfactants/polymers is attributed to the weak Lewis acid‐base interaction between the electron acceptor CO 2 and electron donor ethoxy (or similar) functionality on the surfactant/polymer . This results in possible physisorption of CO 2 in these media which may not be preferred in certain applications.…”

The Potential of CO2 Capture and Storage Technology in South Africa’s Coal-Fired Thermal Power Plants

“…This technological route produces a flue gas stream that is highly saturated with CO 2 [71][72][73][74][75][76]. This technology also produces flame with an excessively high temperature because, theoretically, if fossil fuel (coal) is burnt in pure oxygen, much heat is produced [77][78][79][80][81][82][83][84][85][86][87][88][89]. The pure oxygen is produced by cryogenics.…”