Research Of Adsorption Process In Fine Desulfurization With Activated Carbon Fiber

Recently more attention is paid to fine desulfurization technology due to its important role in environment protection and technical gas depuration. Application of traditional fine desulfurization technology to the industry is limited because of its high energy consume, low sulfur removal precision and the exorbitant prices of fine sulfur-removal agent. Consequently, we choose a novel type of carbon material, activated carbon fiber (ACF), as fine desulfurization agent in the experiment, and study its adsorption process under low sulfur dioxide concentration (<0.01%).Currently, in most researches about ACF as desulfurization agent, the concentration of sulfur dioxide is higher than 0.1%. In this paper we did the systematic research of ACF's adsorption ability under low sulfur dioxide concentration.1. Experimental results show that formaldehyde-hydrochloric pararosaniline spectrophotometry is suitable detective method. Its precision, linear range, detection limit and accuracy satisfy the experimental requirement.2. Surface physical and chemical characteristics of ACF are tested, and specific surface, pore-size distribution and surface chemistry reviewed to research the feasibility of ACF as fine desulfurization agent.3. Adsorption process of ACF in fine desulfurization is studied.(1) ACF's adsorbability to low concentration sulfur dioxide (<0.01%) is studied and experiment results show that adsorption capacity of ACF is lower when temperature increases, and concentration of sulfur dioxide decreases.(2) Through breakthrough curves calculating the height of Mass-Transfer-Zone of ACF. The height of MTA calculated is 4~6cm.(3) According to Clausius-Clapeyron equation, the adsorption heat of ACF is calculated. The adsorption heat is 1.37 times of its evaporation heat.(4) Adsorption modes are studied to decide which is suitable to adsorption process of ACF under the experimental conditions. Langmuri mode, BET mode, Freundlich mode and DR equation were calculated and compared. Difference adsorption mode is suitable to different adsorption phase under different concentration.(5) Mass transfer process of ACF is controlled by intraparticle diffusion. Masstransfer coefficient was influenced by concentration of adsorbate. 4. The fine desulfurization efficiency of mixed-packing GAC and ACF in fixed bedis studied. When the packed-height of GAC and that of ACF are in proportion of1: 2, the proportion of desulfurization efficiency to price is larger.