Study On New Purification Technology In Biogas By Pressure Swing Adsorption

With the development and utilization of new energy, biogas is a kind of biomass energy, with the properties of high combustion efficiency and low empoison, not only fulfill the growth of energy consumption, it also makes different in environment protection. Due to the advantage of simple operation, low energy consumption and environment friendly, PSA(Pressure Swing Adsorption) is being wildly used. However, there are some problems, such as low adsorptive adsorbent, difficult in setting parameter and less steady in product gas, The key to solve this problems is choose high effective adsorbents, optimize the column structure and operation parameter. This paper refers to purify biogas in PSA, background is to separate the carbon oxide, nitrogen and sulfide from mixture, high specific surface area activated carbon and molecular sieve are test and conclude the operation parameter. Optimization also made in the bottom of column and its plates, the volume of product tank is obtained.Comparison between several kinds of activated carbons, adsorption tests to CO2/N2/CH4are taken, Langmuir adsorption isotherm equation is associated. The same test is taken among molecule sieves. Result shows high specific surface area activated carbon activated carbon, which specific surface area is3325m2/g, and13X molecule sieve is the right adsorbents, the operation temperature is35℃and pressure is0.5Mpa, the desorption of high specific surface area activated carbon activated carbon cost200s and it cost250s to13X molecule sieve.Redesign made in common adsorption column, mixture constructive plates are added in the column bottom, set the operation pressure-0.05Mpa to0.9Mpa to run a completive PSA process, and it cost540s. set the column height3.2m and diameter2.1m, simulating the full process by adsim software, the volume of product tank is614.24L. based on the calculation, scheme drawing of PSA technology is designed.By simulating the PSA technology in biogas purification, the product gas purification shows to be99.32%, recovery is92.12%,7%higher than other PSA technology around the world. Fix cost in this technology is8,082,000yuan,5,000,000profits will be attained in the second year, it shows high economic effectiveness.