Study on adsorption/desorption of typical volatile organic compounds on hydrophobic Y molecular sieve

In recent years, the emission of volatile organic compounds (VOCs) in the coal chemical production process in my country has been increasing, and the air pollution caused by VOCs has become an urgent problem to be solved [1-3]. At present, in the treatment of VOCs, the adsorption method for the treatment of low-concentration organic compound waste gas has a great advantage. With the desorption regeneration and catalytic combustion technology, the industrial application potential is huge [4-6]. Y molecular sieve has no obvious selective adsorption for different VOCs gas, and its equilibrium adsorption capacity is larger than other molecular sieves. Its adsorption characteristics and capacity are most similar to activated carbon, and it has no shortcomings such as difficulty in activated carbon regeneration and flammability. It can be used as an ideal material for VOCs adsorbent[7 ]. There are a large number of hydrophilic Si-OH groups on the surface of conventional Y molecular sieves, which are restricted in the treatment of high-humidity industrial waste gas as adsorbents [8] and need to be hydrophobically modified. The hydrophobic modification of Y molecular sieves at home and abroad mainly focuses on two aspects: dealumination modification and surface hydrophobic modification. The surface hydrophobic modification method is carried out by grafting hydrophobic groups, although it will not affect the internal structure of the molecular sieve, but the long carbon chain will block the pores of the molecular sieve and affect its adsorption performance; and after the adsorption of VOCs is saturated, the hydrophobic Y molecular sieve will desorb and regenerate There are few research reports, so it is of great significance to study the low-temperature regeneration law of hydrophobic adsorbents under the action of microwave [9].

        In this paper, the conventional Y molecular sieve has strong hydrophilicity and poor ability to adsorb VOCs under high humidity conditions. It is modified by gas-phase coating with silicon to prepare hydrophobic Y molecular sieve, and through experiments, it is investigated whether the prepared hydrophobic Y molecular sieve has broad spectrum adsorption The effect of microwave regeneration capacity and regeneration times on the desorption effect of VOCs, and the industrial application prospects of hydrophobic Y molecular sieves are aimed at grasping the various factors and laws that affect microwave regeneration adsorbents, and for the adsorption and removal of VOCs under humid conditions. The development of adsorbents provides a theoretical basis.