Effect of Pre-oxidation and SO2 Modification on Mercury Removal Performance of High Sulfur Petroleum Coke in Simulated Natural Gas

Abstract

A high sulfur petroleum coke (RPC) was selected as the raw material to make mercury adsorbent used in the simulated natural gas. The effect of pre-oxidation with air at set temperature and set time and sulfurization with 20% SO2 on mercury removal in simulated natural gas was studied. The experiments were carried out on a fixed-bed experimental device. The physicochemical properties of the sorbents were characterized by surface area and porosity analysis, elemental analysis and X-ray photoelectron spectroscopy (XPS). The results show that the mercury removal performance of the sulfur-loaded petroleum coke is greatly improved through carbonthermal reduction reaction. The optimum oxidation temperature of the SO2 activated petroleum coke is 300°C, and the Hg0 removal efficiency decreases with increase of the pre-oxidation time. The three main factors such as non-oxidative sulfur functional groups, carbonyl and ester sulfur functional groups, and pore structure greatly influence the mercury removal characteristics. The pre-oxidation time and temperature play an adjustable role for getting better performance of mercury removal.