English abstract
In this study, 20 experiments have been conducted to study the mixture of two solvents (DEA
and DMF) with water in order to absorb carbon dioxide gas. Different variables were used
which are five different concentrations, three different temperatures, and three different
pressures. The concentrations were used are (5,10,20, and 25 wt%). The temperatures were
used are 303.15,313.15, and 333.15 K. The pressures were used are 4,6 and 8 bar.
By using equilibrium partial pressure of carbon dioxide to calculate the solubility of CO2 (CO2
mol/solvent mol). Pressure values have been recorded by pressure transmitter for every minute
during the experiment and every experiment takes 4 to 6 hours to reach equilibrium state.
Charts of pressure vs time for each experiment have been provided by the pressure transmitter
which is in the solubility system. The trend was almost same for all experiment that showed
the pressure decreased with time until end of the experiment. As solvent absorb CO2 as much
as it can and its molecules became saturated after a period of time so there is no change in the
pressure at the end of the run.
DOE software has been used to give an experimental plan for performing experiments and to
get a graph of predicted values vs actual values (measured from experiments and calculations)
and three-dimensional charts. Study the relation of solubility with concentration, temperature,
and pressure because experiments were conducted in different values of these parameters. It
has been observed that increasing in pressure results in increasing in solubility. It has been
found that the optimum temperature is 313.15 K and increasing in temperature cause decreasing
in the solubility of CO2. In addition, as concentration of DEA increase the solubility increase.
However, the solubility decreases as DMF concentration increases.
From calculation, the amount of CO2 absorbed by solvent has been found and concentration as
well. The CO2 amount and concentration are increasing until reached equilibrium state.
Regression analysis has been done to do fitting for concentration curve and this implemented
for all the 20 experiments. In addition, some properties have been measured such as refractive
index, viscosity, and density. Correlations of physical properties (density and refractive index)
have been done using sigma plot software which provide correlated equation with its constant
values
