The production of activated carbon

The production of activated carbon from coconut shell treated with phosphoric acid (H3PO4) was optimized using the response surface methodology (RSM). Fifteen combinations of the three variables namely; impregnation ratio (1, 1.5, and 2); activation time (10, 20, and 30 min); and activation temperature (400, 450, and 500 °C) were optimized based on the responses evaluated (yield, bulk density, average pore diameter, small pore diameter, and number of pores in a unit area). Pore diameters were directly measured from scanning electron microscope (SEM) images. Individual second-order response surface models were developed and contour plots were generated for the optimization analysis. The optimum range identified for impregnation ratio was from 1.345 to 2, while for the activation time was from 14.9 to 23.9 min. For the activation temperature it was from 394 to 416 °C. The optimum points are 1.725, 19.5 min, and 416 °C, respectively. The models were able to predict well the values of the responses when the optimum variable parameters were validated as proven by the generally acceptable values of the residual percentages. Direct characterization of the pores using the SEM was found to be a good technique to actually see the pores and get actual measurements. Additionally, RSM has also proven to be a good tool in optimization analysis to get not only optimum production condition points but ranges, which are crucial for the flexibility of the production process, as well.

ผลลัพธ์ (แอฟริกา) 1:

Die produksie van geaktiveerde koolstof uit klapper dop behandel met fosforsuur (H3PO4) is geoptimaliseer met behulp van die metode reaksie oppervlak (RSM). Vyftien kombinasies van die drie veranderlikes, naamlik; bevrugting verhouding (1, 1.5, en 2); aktivering tyd (10, 20, en 30 min); en aktivering temperatuur (400, 450, en 500 ° C) is new gebaseer op die antwoorde evalueer (opbrengs, massadigtheid, gemiddelde porie deursnee, klein porie deursnee, en aantal porieë in 'n eenheid area). Porie diameters is direk gemeet vanaf skandeer elektronmikroskoop (SEM) beelde. Individuele tweede-orde reaksie oppervlak modelle is ontwikkel en kontoer plotte is gegenereer vir die optimalisering analise. Die optimum reeks geïdentifiseer vir bevrugting verhouding was 1,345-2, terwyl dit vir die aktivering tyd was 14,9-23,9 min. Vir die aktivering temperatuur was dit 394-416 ° C. Die optimale punte is 1,725, 19.5 min, en 416 ° C onderskeidelik. Die modelle in staat was om goed te voorspel die waardes van die antwoorde wanneer die optimale veranderlike parameters is bekragtig as bewys deur die algemeen aanvaarbare waardes van die oorblywende persentasies. Direkte karakterisering van die porieë met behulp van die SEM Daar is gevind dat 'n goeie tegniek om die porieë eintlik sien en kry werklike metings wees. Daarbenewens het RSM ook bewys dat 'n goeie instrument in optimization analise om nie net optimale produksie toestand punte, maar wissel, wat noodsaaklik is vir die buigsaamheid van die produksie-proses is, asook kry.