چكيده به لاتين
Carbon dioxide is one of the main pollutants that can cause irreparable damage by climate change, hence solving this problem requires serious attention. currently, chemical absorption by aqueous alkanoamine solutions is the most commonly used commercial method for high-efficiency carbon dioxide separation in the industry. In this study, hybrid solvents have been used to take the advantages of both physical and chemical absorption and corrosion reduction. The selected solvents in this study include sulfolane (SFL), piperazine (PZ) and methyldiethanolamine (MDEA). The experimental range is 20-70°C for temperature and a pressure of 2-8 Bar.The concentrations of hybrid solvents include (10-30 wt%) SFL+(2-8 wt%) PZ+H2O, (10-20wt%) SFL+(10-20 wt%) MDEA+H2O and (1-5 wt%) SFL+(1-5 wt%) MDEA+(1-5 wt%) PZ+H2O in the first, second and third solvent, respectievly. CO2 loading and absorption percentage were obtained in the range of 0.105-0.248 and 22.023-79.21% in SFL-PZ, 0.207-0.375 and 40.843-98.442% in SFL-MDEA and 0.301-0.504 and 19.64-76.29% in SFL+PZ+MDEA solutions, respectively. RSM was used in order to analyze the results. In addition, to find the maximum loading and absorption percentage under optimal conditions numerical optimization was used for each solvent. These values are estimated equal to 0.194 and 54.836% for the SFL-PZ solvent, 0.308 and 72.73% for the SFL-MDEA and 0.431 and 38.50% for SFL-MDEA-PZ solvent, respectively. From the results, carbon dioxide loading in all three solvents has been found to be higher than the aqueous sulfolane solution and less than aqueous amine solutions. In modeling with MATLAB software based on Pitzer model, the concentration of species in the liquid bulk was calculated by the combination of chemical equilibrium, mass balance and charge balance, which has a similar trend to previous studies. By adding VLE equations, it was possible to predict the CO2 loading by the model, calculated relative error between experimental and predicted loading is obtained 4.86% -16.23% in SFL-PZ solvent, 1.41%-15.62% in SFL-MDEA and 8.08% to 22.42% in the solvent SFL-PZ-MDEA.
Keywords: carbon dioxide, absorption, sulfolane, MDEA, piperazine
