Effect of rare earth addition on Cu-Fe/AC adsorbents for phosphine adsorption from yellow phosphorous tail gas

Phosphine (PH₃) is a highly toxic air pollutant, commonly produced in phosphorous chemical industry. But it has received less research attention due to its handling difficultly. CO is the main content of the phosphorous chemical industry tail gas, the concentration of which is always more than 80 vol.%, and it can be the feed gas to produce various valuable products such as formate, oxalate, and methanol and so on. But, PH₃ is one of the important barriers, which is harmful to the following chemical process. In order to make use of the tail gas, PH₃ should be removed firstly, and CO should be covered in the whole purified procedure at the same time. In this work, the modified activated carbon (MAC) was used as the adsorbent to separate PH₃ from the mixture tail gas. Series of MAC adsorbents were prepared for the adsorption of PH₃, which loaded Cu-Fe and Ce (La), or separately. The PH₃ adsorption capacities, chemical and physical properties of MAC were all investigated. The results showed that over 99% PH₃ adsorption efficiency was achieved when used MAC adsorbents. The removal efficiency and PH₃ adsorption capacity of the Cu-Fe-Ce/AC (20:1:0.4) were both much higher than those modified activated carbons. The maximum PH₃ adsorption capacity was 71 mg of PH₃/g of MAC on the Cu-Fe-Ce/AC, which were much higher than literature data using CuO only for adsorbing hydride gases.