Densities and viscosities of binary systems with N,N-Dimethylaniline and Tetra Ethylene Glycol Dimethyl Ether or N-Methyl-2-Pyrrolidone, as potential solvents for flue gas desulphurization processes

Sulfur oxides are emitted as one of the products in the process of combusting solid fossil fuels in thermal power plants, especially the Kolubara and Kostolac lignites in the Republic of Serbia. In order to reduce the emission level of the indirect Greenhouse gases (GHG) from sta-tionary sources, it is inevitable to implement flue gas desulfurization (FGD) technology. In addi-tion to the classic limestone process, technological procedures based on the physical or chemical absorption of sulfur oxides in the solvent and its thermal regeneration are becoming increasingly common. In order to properly design and optimize the process, it is significant to precisely deter-mine the thermophysical properties of pure components and their mixtures. The paper presents the results of determining the density and viscosity of two binary mix-tures, N,N-Dimethylaniline (N,N-DMA) + Tetra Ethylene Glycol Dimethyl Ether (TEGDME) and N,N-Dimethylaniline (N,N-DMA) + N-methyl-2-pyrrolidone (NMP). Measurements were made using a densitometer Anton Paar DMA 5000 and Stabinger viscometer Anton Paar SVM 3000/G2, at atmospheric pressure. The obtained experimental results are presented as a function of temper-ature and N,N-DMA mole fraction. N,N-DMA belongs to the group of amines, and it has been used as a sorbent for purification of flue gases in processes with thermal regeneration (CANSOLV, Sulphidine and ASARCO pro-cesses). The other two organic solvents are TEGDME and NMP. Special attention was paid to NMP due to its low cost and low viscosity, with its favorable properties, making it competitive as a solvent for FGD. TEGDME is a polar solvent, but it is not selective to SO2 and other gaseous components, so NMP has been suggested as an alternative solution. A regenerative process for SO2 removal, with TEGDME, has already found commercial application (Solinox process). NMP is already industrially used as a solvent in Lurgi's Purisol process, due to its nature for selective desulfurization of flue gases.