| In this research, the pyrolysis characteristics of camellia oleifera shell and its three main components(cellulose, hemicellulose, Klason lignin) were investigated by TG-FTIR. The effects of temperature and heating rate on the yields, characteristics and energy distribution of solid, gas, liquid products of camellia oleifera shell pyrolysis, were studied by using a fixed bed reactor. The effects of reaction conditions(activation temperature, activation time, water vapor/carbon ratio) on the characteristics of activated carbon prepared from camellia oleifera shell pyrolysis carbon using water vapor activation were studied by using a small rotary activation furnace. The results showed as follows:(1) Camellia oleifera shell was an environmental friendly and renewable energy resources, whose nitrogen and sulfur content was much lower than coal. Its volatile matter, ash and fixed carbon content were 73.52 %, 3.51 %, 22.97 %3respectively. The lignin content of camellia oleifera shell was 32.82%, significantly higher than the other biomass. Above all, camellia oleifera shell had high thermal decomposition and activated carbon preparation research value.(2) The pyrolysis characteristics of camellia oleifera shell and its three main components were investigated by TG-FTIR. The results showed that the pyrolysis process of camellia oleifera shell and its three main components were divided into three stages named drying, fast degradation and slow degradation. Cellulose pyrolyzed at a narrow temperature range of 290~400 Y, and the maximum weight loss rate appeared at 350 Y. The maximum weight loss of hemicellulose focused at 210~370 Y, and the DTG curves of hemicellulose had two obvious weight loss peaks. Klason lignin pyrolyzed at a wider temperature range of 200~600 Y, and the main weight loss of camellia oleifera shell occurred between 200~400 Y. The volatiles of camellia oleifera shell and its three main components pyrolysis included H2O3CO23 CO and CH4, along with kinds of organics, such as aldehydes, acids, ketones, alcohols and phenols.(3) The effects of temperature(300~700 Y) and heating rate(5~30 Y min-1) on the yields, characteristics and energy distribution of solid, gas, liquid products of camellia oleifera shell pyrolysis, were studied by using a fixed bed reactor. The results showed that the yields of solid, gas and liquid products were 28.10 %~53.59 %, 23.06 %~39.79 %, 23.35 %~36.76 %, respectively. With the increase of temperature, the fixed carbon content of biochar increased, and the largest BET surface area was 278.05 m2 g-1 when the pyrolysis temperature was 600 Y. The main components of gas products were CO, CO2, H2 and CH4, along with a small amount of C2H6, C2H4, C3H8, C3H6 or other lightweight carbon hydrocarbon compounds, and the low heating value was 5.85~13.22 MJ Nm-3. Different temperatures and heating rates mainly influenced on the concentration of the main components of liquid product, and the liquid product, with the pH between 2.78~3.56, mainly included acids, phenolic compounds, ketones, aldehydes, esters, and a small amount of alcohols, furan and olefin compounds. Biochar was considered the primary product of camellia shell pyrolysis because it had a higher energy yield, and bio-oil and non-condensable gas contained almost 50% of energy yield when the pyrolysis temperature was >500Y at the pyrolysis heating rate of 20 Y min-1. Therefore, these three types of pyrolysis products as valuable resources should be developed together for utilization. The optimum pyrolysis conditions: the temperature of 600, heating rate of 20 Y min-1. Under this condition, the yields of solid, gas and liquid products were 29.34 %, 32.89 %, 37.77 %, respectively. The BET surface area was 278.05 m2 g-1, and the low heating value of non-condensable gas was 13.21 MJ Nm-3.(4) The effects of activation temperature, activation time and water vapor/carbon ratio on the characteristics of activated carbon prepared from camellia oleifera shell pyrolysis carbon using water vapor activation were studied by using a small rotary activation furnace. The results showed that the optimum activation conditions were the activation temperature of 850 Y, activation time of 1.5h, and water vapor/carbon ratio of 2.0. Under this condition, the iodine adsorption value and BET surface area were 825 mg g-1 and 736 m2 g-1, respectively. Micropores were mainly existed in camellia oleifera shell activated carbon. |
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