Production and Characterization of Activated Carbon from Waste Tire by H_3PO_4 Treatment for Ethylene Adsorbent Used in Active Packaging

摘要

Pyrolysis is one form of energy recovery process which has the potential to generate oil, gas and char products. The char becomes an attractive by-product, with applications including production of activated carbons, which is useful as a ethylene sorbent for climacteric fruit packaging. In this work, activated carbon prepared from waste tire, produced as a by product of the bio-diesel extraction industry was prepared via chemical treatment with phosphoric acid (H_3PO_4) at three different char: H_3PO_4 ratios (1:1, 1:2 and 1:3) under fixed bed pyrolysis at 400, 500 and 600°C for 30 minutes in nitrogen (N_2) flow rate of 1000 mL/min and heating rate of 20°C/min. Result shows that char pyrolyzed at 800°C contained high fixed carbon and low volatile content favorable for subsequent activation process compared to other cases. (data not show here) Under the experimental conditions investigated, impregnation ratio of 1:2 were found to be suitable for producing high-surface area activated carbon. It was shown that H_3PO_4 did work effectively as dehydration reagent at approximately 600°C. The obtained carbons were characterized by nitrogen adsorption-desorption isotherms at -196°C. The surface area of activated carbons, which were determined by application of the Brunauer-Emmett-Teller (BET) and t-plot methods, were achieved as high as 833.50 m~2/g. The chemically activated carbons were found to be mainly type II carbons and high adsorption property (Methylene blue adsorption = 622 mg/g and Iodine number = 899 mg/g).