Study On The Preparation Of Polyether Sulfonate By Sulfonation In Rotating Packed Bed

As anionic and non-ionic surfactants,polyether sulfonates have excellent temperature and salt resistance and are widely used in extreme reservoirs during enhanced oil recovery.The synthesis process of polyether sulfonate mainly has liquid phase sulfonation process and gas phase sulfonation process.In this experimental sulfonation system,nonylphenol ethoxylate（NPEO）has the characteristics of high viscosity and high polymerization degree,and in the traditional sulfonation process is prone to the transfer/mixing process and intrinsic reaction mismatch,resulting in oversulfonation and coking problems.Therefore,the reaction mechanism and reaction kinetics of the sulfonation of NPEO and SO₃were investigated in this paper,and on this basis,a process study was carried out on the preparation of polyether sulfonates by sulfonation in the high gravity reactor.The main work and conclusions are as follows:1.The mechanism of the sulfonation reaction between NPEO and SO₃ was revealed.The reaction mechanism for the sulfonation of NPEO by SO₃ was calculated based on DFT theory simulations,showing that the mechanism is a reaction of 1 molecule of NPEO with 2 molecules of SO₃.The free energy barrier（ΔG）for the reaction of NPEO with SO₃ was calculated for different degrees of polymerization,showing that the degree of polymerization has little effect on theΔG of this reaction.The kinetic model for the reaction between SO₃ and NPEO was developed.The kinetic experiments were carried out in a microchannel reactor,showing that the reaction is primary for NPEO and secondary for SO₃.The activation energy of 27.47 k J/mol was obtained and the kinetic equation of the sulfonation reaction was established.2.A new process study on the synthesis of polyether sulfonates by gas-phase SO₃ sulfonation of NPEO in the high gravity reactor was carried out.The SO₃ conversion unit and the experimental high gravity gas phase sulfonation unit were built to investigate the effects of SO₃concentration,reaction temperature,rotation speed and aging time on the performance of polyether sulfonate.Under better conditions,the polyether sulfonate has excellent performance,with oil/water interfacial tension up to 10^-3 m N/m,which meets the requirements of enhanced oil recovery,and the process is efficient without over sulfonation and coking.