Experimental investigation on CO₂ desorption kinetics from MDEA + PZ and comparison with MDEA/MDEA + DEA aqueous solutions with thermo‐gravimetric analysis method

Abstract

The carbon dioxide discharged from fossil fuels combustion products is considered as a major contributor to global warming. The current investigation aimed at CO 2 desorption kinetics in 3.25 mol L -1 methyldiethanolamine (MDEA)-0.1 mol L -1 piperazine (PZ) rich amine aqueous solution with thermo-gravimetric analysis (TGA) method under different heating rates of 2.5, 5, 10, and 20 °C min -1 . The kinetics parameters were determined by comparison of 40 mechanism functions with thermal analysis kinetic method. The average activation energy E was 59.16 kJ mol -1 , preexponential factor A was 5.54 × 10 8 , and the most probable mechanism function was G(α) = [-ln(1 -α)] 3/2 . In addition, the kinetic parameters of CO 2 desorption process from three rich amine aqueous solutions (MDEA, MDEA + diethanolamine(DEA), MDEA + PZ) were compared and the influence of kinetic parameters was further discussed. The desorption rate models of three rich amine aqueous solutions were established and desorption rates were well predicted. The order of desorption rate inferred from desorption rate model was MDEA > MDEA + DEA > MDEA + PZ. The results indicated that TGA combined with thermal analysis kinetics was an effective and quick method with high accuracy, easy operation, and good repeatability for screening absorbents preliminarily in laboratory.

Review and Perspectives of CO2 Absorption by Water- and Amine-Based Nanofluids

“…This section divides the base fluids into two categories (water and amine solutions). The difference between the base liquids will directly affect the absorption effect of CO 2 , and the reported base fluids are listed as follows: (1) water, deionized (DI) water; and (2) amine solutions, MEA, methyldiethanolamine (MDEA), diethanoleamine (DEA), piperazine (PZ), 4-diethylamino-2-butanol (DEAB), 2-amino-2-methyl-1-propanol (AMP), triethylenetetramine (TETA), and MEA–MDEA …”

“…15 This section divides the base fluids into two categories (water and amine solutions). The difference between the base liquids will directly affect the absorption effect of CO 2 , and the reported base fluids are listed as follows: (1) water, deionized (DI) water; 16 and (2) amine solutions, MEA, 17 methyldiethanolamine (MDEA), 18 diethanoleamine (DEA), 19 piperazine (PZ), 20 4-diethylamino-2-butanol (DEAB), 21 2-amino-2-methyl-1-propanol (AMP), 22 triethylenetetramine (TETA), 23 and MEA−MDEA. 24 In addition to the above-mentioned classification according to the type of base fluid, this review also classifies nanoparticles dispersed in a base fluid: (1) non-metallic oxide, SiO 2 25 and graphene oxide (GO); 26 (2) carbon-based adsorbent, carbon nanotubes (CNTs) 27 and multi-walled carbon nanotubes (MWCNTs); 28 (3) metal oxides, alumina (Al 2 O 3 ), 29 zinc oxide (ZnO), 30 magnesium oxide (MgO), 31 and copper oxide (CuO); 32 and (4) magnetic metal oxide, iron oxide (Fe 3 O 4 ) and ferric oxide (Fe 2 O 3 ).…”

Process Intensification of CO2 Desorption

“…Nevertheless, a comprehensive understanding of desorption kinetics is of major importance when selecting a proper solvent for a specific application . Desorption rate is an important aspect in desorption kinetics. , In studies prior to the work of Jamal et al, forward (absorption) and backward (desorption) kinetic rate parameters were assumed to be related . Desorption rate parameters were calculated at conditions identical with those used to determine absorption rate parameters .…”

“…Because of the lower number of hydrogen atoms, the chemical activity of MDEA is lower than that of primary or secondary amines. However, desorption rates are higher as the carbamates formed have a higher metastability . Kierskowka-Pawlak et al developed a simplified pseudo-first-order model for these reversible absorption–desorption reactions.…”

“…This is due to the fact that the absorption activation energy of MDEA was lower than that of the blended MDEA-DEA solvent . The effect on both absorption and desorption kinetics when blending the MDEA solvent with PZ and DEA activators was studied by Shunji et al using the TGA method . Although the activators increased the absorption rate of MDEA, the desorption rates were found to decrease compared to the unblended solvent.…”