Karbon teraktif dengan luas permukaan yang rendah telah dihasilkan daripada biji areca catechu melalui cara pengaktifan fizikal. Biji areca catechu yang mentah telah melalui proses karbonisasi bawah aliran gas nitrogen pada peringkat permulaan. Arang yang diperolehi kemudianya diaktifkan dengan menggunakan gas karbon dioksida. Kedua-dua proses tadi telah dijalankan dalam relau. Pengaruh suhu pengkarbonan, saiz partikel biji areca catechu dan masa pengaktifan terhadap karbon teraktif yang dihasilkan pada suhu pengaktifan yang ditetapkan pada 800°C telah dikaji. Pencirian biji areca catechu, arang dan karbon teraktif telah ditentukan dengan thermogravimetric analisis (TGA), elemental analyzer (EA), Fourier Transform Infrared (FTIR), mikroskop electron imbasan (SEM), dan penjerapan dan nyahjerapan nitrogen untuk mengkaji ciri-ciri fizikal dan ciri-ciri kimia sampel tersebut. Keadaan optimum untuk penyediaan karbon teraktif daripada biji areca catechu adalah pada suhu pengkarbonan 500°C, saiz partikel 125μm dan tempoh pengaktifan selama 2 jam. Luas permukaan dan jumlah isipadu liang bagi karbon teraktif yang dihasilkan pada suhu pengkarbonan 600°C, saiz partikel 125μm dan tempoh pengaktifan selama 1jam masing-masing adalah 0.6795m2/g dan 0.001105 cm3/g. Potensi karbon teraktif telah diuji dengan mencari kapasiti penjerapan warna metilene biru. Daripada keputusan eksperimen, data-data berikut telah dianalisa dengan menggunakan model penjerapan Langmuir dan Freundlich. Data keseimbangan mematuhi model Langmuir dengan nilai R2 bersamaan 0.9954. Kadar kapasiti tertinggi yang diperoleh adalah 52.5mg/g. Model kinetic telah diaplikasikan kepada data dan kadar penjerapan didapati mematuhi tindak balas pseudo pangkat kedua.
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A low surface area of activated carbon was produced from areca catechu nuts by using physical activation. The raw areca catechu nuts were first subjected to carbonization process under the flow of nitrogen gas. The chars obtained were then activated by using carbon dioxide gas. Both processes were done in furnace. The effect of carbonization temperature, particle size of areca catechu nuts and activation time on activated carbon produced at fixed activation temperature of 800°C had been studied. The characterization of areca catechu nuts, selected char and activated carbon were determined by thermogravimetric analysis (TGA), elemental analyzer (EA), Fourier Transform Infrared (FTIR), scanning electron microscopy (SEM), and nitrogen adsorption and desorption analysis to study their physical characteristic and surface chemistry. Optimum condition for preparation of activated carbon from areca catechu nuts was found to be at carbonization temperature of 500°C, particle size of 125μm and activation time of 2 hr. The BET surface area and total pore volume of activated carbon produced from carbonization temperature of 600°C, particle size of 125μm and activation time of 1 hr was 0.6795m2/g and 0.001105 cm3/g respectively. The activated carbon performance was measured by determining the adsorption capacity towards methylene blue dye. From the results of experiments, the data were analyzed by Langmuir and Freundlich models of adsorption. Equilibrium data shows that it fitted well with Langmuir model with R2 value of 0.9954. The maximum methylene blue adsorption was 52.5mg/g. Kinetic model was then applied to the data and rates of adsorption were found to follows pseudo second order kinetics model.
The production of activated carbon from areca catechu nuts by physical activation / Tan Wee Jin