Experimental Study Of Desulfurization By Rotating Packed Bed And Wet Process

There is always a certain amount of hydrogen sulfide in the natural gas and coke oven gas.Its existence not only does harm to men's health but also corrodes the pressure vessel and pipeline and poisons the catalyst.It can relieve the deficiency of sulfur of China that hydrogen sulfide is gathered together and converted to sulfur elemental.Traditional absorption equipment can be divided into tray towers and packing towers and always has the disadvantage of covering large area,bad mass-transfer efficiency and high energy consumption.In terms of selective absorption,it also has the weakness of long contact time of the liquid and gas and high removal rate of the carbon dioxide.To avoid the shortcomings mentioned above,the RPB was suggested to replace the traditional equipment and combined with 888 method and MDEA method to remove the hydrogen sulfide.At first,the mixed gas of N2,H2 S and CO2 was used as simulated natural gas and the mixed solution of 888 and sodium carbonate was used as the absorption solution.The influences of the revolution of RPB,the flow rate of absorption liquid,the dose of sodium carbonate and temperature on the removal rate of H2 S,overall volumetric mass-transfer coefficient of gas side and selective factor were studied on the experimental platform.The experimental study founds that the removal rate of H2 S and the overall volumetric coefficient of gas side increase with the increase of the revolution of RPB,the liquid flow rate and the dose of sodium carbonate.The influence of the temperature is not notable.For the equipment used in the experiment,the best operating condition is that the revolution of RPB is 1400r/min;the liquid flow rate of absorption solution is 100L/h;the dose of sodium carbonate is 14g/L;the temperature is 40 oC.At the condition mentioned above,the removal rate of hydrogen sulfide reaches up to 99.27%.The removal rate of hydrogen sulfide of selective desulfurization is 1% less than desulfurization.The selective factor first decreases then increases with the increase of the revolution.And it decreases with the increase of liquid flow rate of absorption solution and dose of sodium carbonate.The influence of temperature on selective factor is not notable.Then the mixed gas of N2,H2 S and CO2 was used as simulated natural gas and the MDEA solution was used as the absorption solution.The effects of the revolution of RPB,liquid flow rate of MDEA solution,mass fraction of MDEA and temperature were studied and the experimental results were compared with 888 process.The experimental study founds that the removal rate of hydrogen sulfide and overall volumetric mass-transfer coefficient first increase then decrease with the increase of the revolution of RPB and the mass fraction of MDEA.They increase with the increase of liquid flow rate of MDEA solution and decrease with the increase of the temperature.Compared with 888 process,the reaction rate between the hydrogen sulfide and MDEA is a little slower and the best liquid flow rate of absorption solution is about 1/5 less.The effect of viscosity on reaction rate needs to be taken into account when the mass fraction of MDEA increases.The best operating condition is that the revolution of RPB is 1000r/min;the liquid flow rate of absorption solution is 80L/h;the mass fraction of MDEA is 30wt%;the temperature is 20 oC.At the condition mentioned above,the removal rate of hydrogen sulfide reaches up to 98.92%.The removal rate of hydrogen sulfide of selective desulfurization is 2% less than desulfurization.The selective factor first decreases then increases with the increase of the revolution.And it decreases with the increase of liquid flow rate of absorption solution and mass fraction of MDEA.The influence of temperature on selective factor is not notable.