| Summary: | 碩士 === 國立成功大學 === 環境工程學系 === 88 === This study was not only confirmed with the feasible to reuse the basic impregnated carbon, made from regeneration spent activated carbon, but also dealt with the adsorption characteristics of hydrogen sulfide at different adsorption system. Research works was including physicochemical characteristics of carbon, adsorption capacity and cost-benefit analysis. Used the column and batch adsorption system to investigate the adsorption mechanism and assess the potential of using the batch system to replace the column adsorption system for break through curve preduction.
Result indicated the best-impregnated carbon weight and alkaline solution concentration in this experiment was 37g and 1N, respectively. The nondimension-mass transfer parameter for adsorption column design was included neglect the axial dispersion (Npe>1、δ<1), fluid viscosity effect was small (NSc=0.76), adsorbate affinity was fine (ψ) and neglect the external film resistance (NBi>>1) etc. In this work, we understood the design of column adsorption system was reasonable and advantageous for adsorption. The control parameters of mass transfer of adsorbent and fluid were surface and pore diffusion.
According to the dynamic diffusion model analysis, There were no correlation between effective diffusivity and H2S concentration in a low concentration (low relative pressure= 10-5-10-6). In this research indicated that the intraparticle pore diffusion was one of the major adsorption mechanisms and that had correlation with the pore structure and characteristics
Batch adsorption system with three equilibrium adsorption equations was employed to predict column adsorption result to the impregnated and spent carbon. The low concentrations had the larger predictive error; the others the predict error were approximately 5-44﹪for both using Freundlih and Langmuir equations. But D-R equation had a larger predictive error. it need a further study to investigate the reasons. Compare the experiment and predict adsorption capacity curve, we could know the predict error that was approximately between 10 to 30﹪and the R2 value of all predict curves were greater than 0.995, and whole tendency was found to be very closely. Furthermore, the predictive error of batch system could be decreased by the experimental quality control. Results indicated the batch adsorption system could use to predict the adsorption break through curve for engineering design.
The produce and adsorption efficiency cost of impregnated and spent carbon is $266, $150 dollar-NT/kg; $11, $9(dollar-NT/gH2S/kgAC), respectively. According to the adsorption efficiency cost analysis that indicated the potential of reusing the spent activated carbon by impregnated procedures.
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