Analysis of a New Liquefaction Combined with Desublimation System for CO2 Separation Based on N2/CO2 Phase Equilibrium

Abstract

Cryogenic CO2 capture is considered as a promising CO2 capture method due to its energy saving and environmental friendliness. The phase equilibrium analysis of CO2-mixtures at low temperature is crucial for the design and operation of a cryogenic system because it plays an important role in analysis of recovery and purity of the captured CO2. After removal of water and toxic gas, the main components in typical boiler gases are N2/CO2. Therefore, this paper evaluates the reliabilities of different cubic equations of state (EOS) and mixing rules for N2/CO2. The results show that Peng-Robinson (PR) and Soave-Redlich-Kwong (SRK) fit the experimental data well, PR combined with the van der Waals (vdW) mixing rule is more accurate than the other models. With temperature decrease, the accuracy of the model improves and the deviation of the N2 vapor fraction is 0.43% at 220 K. Based on the selected calculation model, the thermodynamic properties of N2/CO2 at low temperature are analyzed. According to the results, a new liquefaction combined with a desublimation system is proposed. The total recovery and purity of CO2 production of the new system are satisfactory enough for engineering applications. Additionally, the total energy required by the new system to capture the CO2 is about 3.108 MJ·kgCO2, which appears to be at least 9% lower than desublimation separation when the initial concentration of CO2 is 40%. OPEN ACCESSEnergies 2015, 8 9496

Optimum Expanded Fraction for an Industrial, Collins-Based Nitrogen Liquefaction Cycle

“…A number of improvements have been developed since [ 20 ]. It is of widespread use for pure nitrogen [ 13 , 21 ] and nitrogen mixture [ 22 , 23 , 24 , 25 ] cryogenic processes. Unisim Design R451 uses a modified Peng-Robinson EOS specifically recommended for all components of air in the range of pressure and temperature conditions of this article [ 26 ].…”

Rating and performance of plate fin heat exchanger used for cryogenic separation of CO 2

“…The CO 2 capturing/separation technologies generally used in fossil fuel‐fired thermal power plants are absorption, adsorption, membrane, and cryogenic treatment 3 . In recent years, CO 2 capture by cryogenic treatment has been focused on by many researchers, because it offers the following dual benefits: (i) potential for energy saving and (ii) eco‐friendliness 4 . A heat exchanger (HX) is necessarily used in the cryogenic CO 2 capture process to cool the hot flue gas to a desired low temperature 5 …”

A comparative study of modified Linde and cryogenic cooling for CO 2 separation

“…3 The main merits of the cryogenic CO 2 separation process are (a) high purity CO 2 can be obtained, (b) separated CO 2 either in the form of solid or liquid (which is easier for transport), (c) environmentally friendly compared to other methods, (d) no corrosion potential, (e) has water-saving potential, and (f) simultaneously removes other pollutants (Hg, SO x , NO 2 , HCl, etc). 9 CO 2 separation by the cryogenic method can be done in different ways which include (a) desublimation with the help of packed bed, [10][11][12] (b) liquefaction combined with desublimation, 13 (c) cryogenic liquefaction and separation, 3 and (d) distillation. 14 The desublimation process separates CO 2 as a solid frost at conditions below the sublimation temperature (195 K at 1 bar).…”

“…The CO 2 separation is carried out from the H 2 /CO 2 mixture at a pressure of 15 to 60 bar. 14 Yang et al 13 have conducted a study on CO 2 separation based on new liquefaction combined with a desublimation system. In this study, the CO 2 separation is done at high pressure (20-50 bar).…”

“…They have reported that the energy penalty is around 3.108 MJ/kg CO 2 for 40% of CO 2 on the feed mixture. 13 Adhi et al 19 have conducted a simulation study of an improved cryogenic distillation process for separating CO 2 from natural gas. The study is conducted at high pressure of 48.26 bar.…”