Thermodynamic analysis of synthesis of 2,3,3,3-tetrafluoropropene by dehydrochlorination of 2-chloro-1,1,1,2-tetrafluoropropane

The method of density functional theory(DFT) at B3LYP/6-311 + + G(d,p) level was employed to estimate the standard enthalpy of formation ΔfHGmΘ,the standard Gibbs free energy of formation GmΘ,and the isobaric heat capacity Cp,m of some compounds during the synthesis of 2,3,3,3-tetrafluoropropene(HFO-1234yf) by vapor-phase dehydrochlorination of 2-chloro-1,1,1,2-tetrafluoropropane(HCFC-244bb).The heat of reaction ΔrHΘm,the change of Gibbs free energy ΔrGΘm and equilibrium constant lnK respectively as the function of temperature for each independent reaction were calculated.The effects of temperature,pressure and the molar ratio of feed on the chemical equilibrium of reaction were analyzed.The results show that the synthesis of HFO-1234yf by dehydrochlorination of HCFC-244bb is an endothermic reaction,and the ΔfGΘm reduces with the increase of reaction temperature.High temperature,low pressure and the addition of HF and HFC-245cb to feed material are favorable for the formation of HFO-1234yf.