Pilot Plant Studies of the CO₂ Capture Performance of Aqueous MEA and Mixed MEA/MDEA Solvents at the University of Regina CO₂ Capture Technology Development Plant and the Boundary Dam CO₂ Capture Demonstration Plant

Abstract

Evaluations of the benefits of using a mixed MEA/MDEA solvent for CO 2 capture in terms of the heat requirement for solvent regeneration, lean and rich loadings, CO 2 production, and solvent stability were performed by comparing the performance of aqueous 5 kmol/m 3 MEA with that of an aqueous 4:1 molar ratio MEA/MDEA blend of 5 kmol/m 3 total amine concentration as a function of the operating time. The tests were performed using two pilot CO 2 capture plants of the International Test Centre for CO 2 Capture (ITC), which provided two different sources and compositions of flue gas. The University of Regina CO 2 plant (UR unit) processes flue gas from the combustion of natural gas while the Boundary Dam CO 2 plant (BD unit) processes flue gas from a coal-fired electric power station. The results show that a huge heat-duty reduction can be achieved by using a mixed MEA/MDEA solution instead of a single MEA solution in an industrial environment of a CO 2 capture plant. However, this benefit is dependent on whether the chemical stability of the solvent can be maintained.

Dynamic simulation of MEA absorption process for CO2 capture from power plants

“…MEA has been blended with amines that are less corrosive and require less steam to regenerate such as MEA/2-amino-2-methyl-1-propanal (AMP) (Dey and Aroonwilas, 2009) and MEA/MDEA (Idem et al, 2006). The additive piperazine (PZ) in MEA solutions was able to accelerate CO 2 absorption and allows use of lower MEA concentrations (Dang and Rochelle, 2003;Dugas and Rochelle, 2011).…”

The effect of CO2-loaded amine solvents on the corrosion of a carbon steel stripper

“…As a result of the faster kinetic reaction of these amines with CO 2 , primary and secondary amines are often preferred industrially. However, the development of multi-component amine mixtures has demonstrated the benefits of using tertiary amines in parallel 4 . The reaction mechanisms of the amines with CO 2 (Reactions 1 and 2) are crucial given that the amine solvents themselves are generally relatively inert, with respect to corrosion.…”

Amine Regeneration Tests on MEA, DEA and MMEA with Respect to Energy Efficiency Study

“…For amine-based post-combustion CO 2 capture (PCCC), close to 70% of the overall energy is distributed during amine regeneration for CO 2 desorption [4]. The heat cost is considered as reboiler heat duty, since the energy required for amine regeneration is supported by hot steam flowing into a reboiler located at the bottom of a regeneration column [5].…”

“…The heat cost is considered as reboiler heat duty, since the energy required for amine regeneration is supported by hot steam flowing into a reboiler located at the bottom of a regeneration column [5]. This heat duty has been an important parameter for design, operation and development of a cost-effective CO 2 absorption-desorption process [4]. According to Rochelle [3], the theoretical minimum energy requirement of CO 2 separation along with the CO 2 compression is estimated to be 0.11 MWh/tonne CO 2 /435.6 kJ/kg CO 2 , which remains a challenge to achieve.…”

“…The last part is very important as the research focus for years. Peer researchers have developed several methods to reduce the part or overall of heat duty [3,4,[6][7][8][9][10][11][12][13][14][15]. Two conventional methods are recommended: solvent improvement and process intensification [2].…”