Preparation Of Carbon Adsorbents Biomass Waste And Its Performance Of Deodorizing

As a traditional agricultural country, every year there are a large number of biomass wastes from the main crop straw of rice, corn and wheat in our country. Due to the huge yield, the poor quality and other issues, these biomass wastes are typically processed by incineration or burial. However, in recent years our country has suffered from increasingly serious environmental pollution, the traditional approaches to biomass wastes increase the burden on the environment.In this paper, two high-yield representative biomass wastes?walnut shell and straw? as the raw materials were first selected to prepare the powder of carbon adsorbent. Then the influence of the activator species, activator concentration, the ratio of activator and raw material, carbonization time and temperature on carbon adsorbent deodorizing performance was systematically discussed. Based on results,the best preparation conditions of carbon adsorbent were finally determined. The results showed that the deodorizing effect to the adsorbent prepared by rice straw as raw material was better than that prepared by walnut shells, when the concentration of Zn Cl2 activator was 30%, activation temperature was 550?, liquid feed ratio was3:1, the specific surface area of carbon adsorbent and the adsorption time to H₂S could reach 1104.84 m2·g-1 and 198 min, respectively. The structural analysis showed that there are a large number of pore structures and oxygen-containing functional groups such as-OH,-CH- and-C=O in the surface of straw-based carbon adsorbent,the specific surface area could reach 1104.84 m2·g-1, after adsorption of hydrogen sulfide the surface area and pore volume are significantly decrease, and the elemental sulfur is the mainly form of H₂S.In order to make the carbon adsorbent powder more practical, excellent deodorizing active powder was bonded molding using the adhesive and the structures were analyzed. Research shows when the concentration of the PVB binder was 4%,the mass ratio of straw-based carbon adsorbent to the PVB binder was 1:1 and the forming pressure was 15 MPa, the adsorption of the forming straw carbon to H₂S was optimal, the adsorption time and the strength could reach 70 min and 15N·10-4·m-2, respectively. The results fully meet the requirements of industrial production. But to some extent adsorption performance may be weakened due to the binder blocked the pore structure. Finally, the deodorizer reaction dynamics of carbon adsorbent was discussed based on adsorption time curves of deodorization process. Exponential dynamics model was established, and H₂S adsorption dynamics equation was also obtained in this paper. Surface activation energy is 2245.445J·mol-1, pre-exponential factor is 2.9349.