Experimental Study On The Separation Of FCC Dry Gas Via Hydrate Formation And Preliminary Exploration On The Hydrate Reactor

Separating of the mixture gas by forming hydrate is a novel separation technology,compared with the traditional separation technology,it has a distinct advantage and broad application prospects.This paper aims to separate FCC dry gas by this technology,recycling of high value-added ethylene component from FCC dry gas.For this purpose,make a lot of basic research.The main works are briefly described as follows:(1)To determine the hydrate formation conditions of FCC dry gas and ethylene with the thermostatic pressure search method experiments were carried out in deionized water,polyethylene benzene sulfonic acid sodium(PSS),isooctyl glucoside(APG),sodium lignosulphonate(So-Li)four different systems.The experimental results show that: three kinds of surfactants on ethylene and FCC dry gas hydrate formation conditions have minimal impact,have no obvious inhibitory effect.(2)Three kinds of surfactants systems gas-liquid interface properties were determined by hanging drop method.The experimental results show that the gas-liquid interfacial tension and adsorption free energy of three kinds of surfactant systems were lower than deionized water system,it show that the surfactant can promote the dissolution of gas in the working liquid and promote the formation of hydrate.Compared with other surfactant systems,APG system has better promotion effect.(3)Experimental determination of the ethylene hydrate formation kinetics in deionized water,PSS,APG,So-Li four different systems,the effects of temperature,pressure,types of surfactants and concentration in aqueous solution on ethylene gas hydrate formation rate and storage capacity were systematically studied.The experimental results show that: ethylene hydrate has more formation rate and storage capacity under the APG system,the other two surfactants have weaker promoting.(4)With the presence of APG,FCC dry gas hydrate phase equilibrium separation and formation kinetics experimental were performed on intermittent separation device,the effects of temperature,pressure,gas-liquid ratio and APG concentration in aqueous solution on the hydrate formation rate and separation efficiency were systematically investigated.The experimental results show that the presence of APG can enhance the formation rate of ethylene hydrate and have better separation efficiency than pure water system.Under the condition of 281.15 K,3.5 MPa,300 gas-liquid ratio,0.2 wt% concentration,the C2H4 recovery can be increased to 77.80 % and gas storage to 165 in the single stage phase equilibrium separation process,separation efficiency significantly.(5)Establish a new type I hydrate dynamic model for FCC dry gas by combining with Chen-Guo hydrate model,obtain the model parameter values k and q through the regression experiment data.Combined with micro model to calculate the separation experiment results,model calculation value and experimental value has a good congruency,show that predictive model is good.(6)Using Fluent software to simulate the type of orifice plate hydration reactor internal flow field,successfully set up the continuous separation experiment device base on the venturi tube suction hydration reactor.