| Hydrogen was one kind of high purity energy. Its burning had no pollution. It can be easily stored and transported. Biomass was the fourth of consumed energy in China. It distributed all over the word. Being one of the methods of hydrogen production from biomass, gasification in supercritical water(SCW) was concerned by researchers at home and abroad because of its superiority. Presently, few research about separation of the products of biomass gasification in supercritical water was reported.Introducing the methods of hydrogen purity in chemical industry, the paper was involved with one of the methods. Based on the thermodynamic model of Perturbed Chain- Statistical Associating Fluid Theory(PC-SAFT) establish the vapor-liquid equilibrium model of hydrogen separation from products of biomass gasification in supercritical water. Using the model, the dates of vapor-liquid equilibrium in high-pressure absorber was caculated. The predicted results show: (1) with increasing pressure the molar fraction of H2 and CO increases, while theirs absorption in liquid phase all increases. It lead to the yeild of hydrogen decreaseing. When choseing the pressure of the absorber, we must balance the purity and the yeild of the hydrogen. (2) the molar fraction of H2 decreases with increasing temperature, while the yeild of hydrogen decreases. So, we also have to balance the purity and the yeild of the hydrogen when Chosing the temperature of the absorber. The pressure impacts the separation is greater than the temperature.(3) There are other factors to effect the separation. This method can not separate CO from H2.
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