Purifying a gas stream e.g. air comprising N impurities e.g. ethene, comprises selecting one of N impurities as a first impurity, continuously providing a bed made of a zeolite adsorbent material, and recovering a purified gas stream

摘要

The process comprises selecting one of N impurities as a first impurity, continuously providing a bed made of a zeolite adsorbent material comprising X or LSX type zeolite exchanged with cations from barium, calcium, magnesium, strontium or lithium, where the degree of exchange is strictly greater than 0% such that first impurity goes through the remaining N-1 impurities, recovering a purified gas stream, and verifying that, at the outlet of the adsorbent material bed, the content of the first impurity of the purified gas stream is lower than its maximum permissible content. The process comprises selecting one of N impurities as a first impurity, continuously providing a bed made of a zeolite adsorbent material comprising X or LSX type zeolite exchanged with cations from barium, calcium, magnesium, strontium or lithium, where the degree of exchange is strictly greater than 0% such that first impurity goes through the remaining N-1 impurities, recovering a purified gas stream, and verifying that, at the outlet of the adsorbent material bed, the content of the first impurity of the purified gas stream is lower than its maximum permissible content. The operational conditions of the purification process comprise operating ranges specified in the design of the unit in terms of flow, pressure, temperature and composition of gas flow. The content of the first impurity is directly measured: at an outlet of the bed made of adsorbent material; optionally in the bed that is close to an outlet end of the flow gas; or indirectly at a point, where it is concentrated. The method further comprises stopping the purification step before the first impurity reaches its maximum level. The guard bed and the zeolite adsorbent material bed have same nature.