Research on Environmental Protection Treatment for Ex-Service SF₆ Adsorbent

Abstract

SF 6 adsorbents absorb many toxic SF 6 decomposition products, such as SOF 2 , SO 2 F 2 , and H 2 S. Ex-service SF 6 adsorbents that did not undergo environmentally friendly processing will seriously harm the environment. In this work, thermogravimetric analysis and Fourier transform infrared spectroscopy were used to investigate the adsorbates of ex-service SF 6 adsorbents. Adsorbent recycling based on the thermal method was also studied. The vacuum thermal method increased the recycling efficiency of ex-service SF 6 adsorbents to 85%-90%. In addition, the adsorbents recovered through thermal method could be reused in SF 6-gas-insulated equipment. Considering their influence on equipment operation and maintenance, a harmless treatment technology for ex-service SF 6 adsorbents with Ca(OH) 2 was proposed. The adsorption and desorption behaviors of SF 6 adsorbents were predicted via destiny functional theory. The best treatment effect could be obtained when the Ca(OH) 2 amount was equal to 20% of the treatment weight of the adsorbents, and the treatment temperature was maintained at 90 • C. The economic feasibility of the harmless treatment for ex-service SF 6 adsorbents with Ca(OH) 2 was higher than that of the thermal method. INDEX TERMS SF 6 adsorbent, Fourier transform infrared spectroscopy, harmless treatment. II. ANALYSIS OF THE ADSORPTION COMPONENTS OF EX-SERVICE SF 6 ADSORBENTS A. EXPERIMENTAL OBJECT

Adsorption of HF and H2S on α-Al2O3 (0001) Surfaces: A DFT Study

“…However, under the action of an arc, partial discharge, and high temperature, SF 6 gas decomposes to various types of low-fluorine sulfides and then reacts with electrodes, insulating materials, and traces of oxygen or water to produce SOF 2 , SO 2 F 2 , SOF 4 , as well as other decomposition products. − Many scholars , get the decomposition by simulating the discharge. Wei et al − analyzed the adsorption products of ex-service SF 6 adsorbents and studied environmental protection experimental separation technology for the adsorbents, because of the limited experimental conditions, such as getting the variety of different decomposition or simulating the vacuum environment of GIS, etc. Also most decompositions are toxic.…”

Study on Relative Electrical Strength of SF6 Substitute Gas Based on Density Functional Theory

“…Sulfur hexafluoride (SF6) gas is widely used in gas-insulated transmission and distribution equipment such as direct current breakers because of its good insulating properties and arc extinguishing properties [1][2][3][4] SF6 gas also has many shortcomings. For example, in terms of liquefaction temperature, SF6 gas will liquefy in alpine regions, resulting in reduced insulation performance [5].…”