Studies On The Preparation And Adsorption Of Activated Carbon From Spirit Lees

Activated carbon with abundant porous structure and high specific surface area has been used as an important adsorption material, and has been widely used in the food industry, medicine and health, environmental protection and chemical industry etc. In the long term, coal has been dominant in the production of activated carbons. In recent years, biomass resources have been paid more attention to global energy and environment problem. Therefore, the investigations and the development about preparation of activated carbon have become rather active. The abundant spirit lees as fermentation industry byproduct contain rich wood fiber. However, they are the potential environmental pollution materials, because of having so much moisture, with weak acidity, easily rotted its residue. In order to achieve high quality utilization, in our study, spirit lees have been used to make porous functional material, which are the byproducts in the process of solid-state fermentation wine. And they are have an important practical significance in the industry circular economy.In this paper, a series of activated carbons were produced from spirit lees by physical activation, physical-chemical activation and chemical activation. And the parameters, included the carbonization temperature, the activation temperature, the activation strength (time and its ratio) and method, have been investigated. The conditions of controlling structure and properties have been established. Furthermore, the activated carbons in the optimum condition were tested by nitrogen adsorption, and investigated the porous structures of the activated carbons. The morphology of raw material, carbonized material, and activated carbons were all observed by scanning electron microscope. Then, X-ray diffraction analyzed the variation of microcrystalline structure in activated carbons under the different conditions. The results of this paper are as follows:(1) The best carbonization temperature was450℃, and the yield of activated carbons was high in this temperature.(2) The optimum preparation parameters of stream activated carbon were obtained as follows:the flow rate of stream was0.04g/min·gcarbonized material, activation temperature was800℃of the iodine adsorption, the specific surface area and pore volume reached580.9mg/g,371.6m2/g,0.34cm3/g; When activation temperature was850℃, the methylene blue adsorption, the specific surface area and pore volume reached98.7mg/g,323.8m2/g,0.32cm3/g.The optimum preparation parameters of CO2activated carbon were showed as follows:the flow rate of CO2was12mL/min-gcarbonized material, activation temperature was850℃,when the iodine adsorption, the specific surface area and pore volume reached547.8mg/g,313.8m2/g,0.24cm3/g; When activation temperature was950℃, the methylene blue adsorption, the specific surface area and pore volume reached60.5mg/g,337.1m2/g,0.25cm3/g.(3) The ash content of activated carbon was reduced obviously when the charcoal or activated carbon were treated by alkali. When the charcoal was treated by alkali before activation, the iodine adsorption, the methylene blue adsorption, the specific surface area and pore volume reached853.9mg/g,128.4mg/g,553.8m2/g,0.61cm3/g. When activated carbon was treated by alkali after activation, the iodine adsorption, the methylene blue adsorption, the specific surface area and pore volume reached760.0mg/g,162.0mg/g,622.9m2/g,0.67cm3/g.(4) The catalysis activity of KOH was better than physical activation, NaOH, ZnCl2and H3PO4activation. And the optimum preparation parameters of KOH activation were obtained as follows:the KOH/char ratio was1:1, activation temperature was850℃, activation time was1hour, when the iodine adsorption, the methylene blue adsorption, the specific surface area and pore volume reached1206.7mg/g,324.7mg/g,1248m2/g,0.75cm3/g.Generally speaking, the activated carbon with physical activation was characterized by smaller specific surface area and pore volume, lower adsorption performance, but its production process was simple, and its cost was low. So it was suitable for water treatment. Compared with it, the specific surface area and pore volume have been both increased in the activate carbon by physical-chemical activation, and its performance of iodine adsorption and methylene blue adsorption have been improved. The alkali treatment has played an obvious role in pore size distribution, and can be the byproduct of industrial water glass, with the control of the concentration and dosage by alkali treatment. This method can reduce the cost. The activated carbons can be used not only in the wastewater treatment, but also in the denitration and desulfurization. In this chemical activation, the KOH activator’s dosage was less. KOH-activated carbons have been showed the excellent adsorption properties. This method can be used to make high specific surface area activated carbon.