China H2 Making System for Sorbitol Production Plant

H2 making systemt for sorbitol production plant
Product Specification

No.DescriptionUnitQty.Remark1PurityVol %99.999%Meet requirement of high purity H2 O2 ≤1PPM N2 ≤3PPM CO ≤1PPM CO2 ≤1PPM CH4 ≤1PPM H20 ≤3PPM 2Flow rateNm3/h220 3TemperatureºC<40 4PressureMpag1.6

Process Diagram
Process Description
This H2 making device is based on natural gas as raw material, and adopts technology of gas making through steam conversion to make coarse hydrogen. Coarse hydrogen go through conversion reaction and PSA purified to obtain the product hydrogen.
Technical Principle
(1)Desulfurization with Natural Gas
Under certain temperature and pressure, the raw gas will saturate through completing olefin hydrogenation reaction with hydrogenation catalyst-Co-Mo, the organic sulfur will be converted to inorganic sulfur at the same time, then reduce the content of organic sulfur and H2S in raw gas to 0.2ppm below under the effect of the desulfurizer- zinc oxide., so as to meet the requirement on sulfur of steam conversion catalyst. The main reaction equation are shown as follows:

RSH+H2→H2S+RH
C4H4S+4H2→H2S+C4H10
H2S + ZnO → ZnS + H2O
(2)Steam Conversion of Hydrocarbons
Steam conversion of hydrocarbons is based on water vapor as oxidizing agent, and then convert hydrocarbons to hydrogen under the effect of nickel catalyst. As it is a heat absorption process, external heat supply is needed. The required heat is supplied by radiation section of reformer through burning fuel gas. As this reaction is strong heat absorption process, increasing amount of vapor and improving temperature is benefit to promote the equilibrium moving to the product direction; at the same time, amount of substance will change before and after this reaction, it is one reaction of volume increased, so pressure increasing can improve the thermal efficiency of remaining steam, low down the production cost, and also increase the utilization of catalyst.
The main reaction equations under nickel catalyst are shown as follows:
CH4 + H2O → CO + 3H2 -Q
CO + H2O →CO2 + H2 + Q
3)Medium-temperature Shift
Reformed gas from reformer contains 13% around CO, the function of conversion is to let CO react with water vapor to form CO2 and H2 under the effect of catalyst, thus to increase the amount of H2 required.
Reaction equation of medium-temperature shift is as follows:
CO + H2O →CO2 + H2 + Q
This is a reversible exothermic reaction, the selection of medium-temperature reaction takes into account the speed and depth of the reaction. Increasing amount of water vapor is benefit for the reaction going ahead toward to right side.
(4) Technical Principle of Pressure Swing Adsorption(PSA)
Technology of pressure swing adsorption had been the main method for separating hydrogen around the world, and also successfully applied in separating and purifying carbon dioxide, nitrogen, oxygen, methane, etc. gas and other industrial gas, it had been more and more widely used.
Adsorption separation of gas mixture is realized in fixed adsorption bed. Fill one or multiple kinds of adsorbents in fixed adsorption bed, after the gas mixture which contains hydrogen going into the fixed adsorption bed under certain pressure, as the difference of gas components in adsorption characteristic, different component will form adsorption enrichment region at different position of adsorption bed, the strongest adsorption component (CO2) will concentrate at the inlet end of adsorption bed, the weakest adsorption component (H2) will concentrate at the outlet end of adsorption bed, the enrichment region of other components will be at the middle part of adsorption bed, thus the hydrogen separation and purification will be realized. It can obtain hydrogen with purity of 99.9%~99.999% through PSA method.
Main Equipment Picture