摘 要：
为了探究热解终温对油茶壳热解产物特性的影响,实现油茶壳热解多联产产物的有效利用,该文研究了油茶壳300~700℃热解过程中气、液、固的得率,特性和能量分布规律,讨论了油茶壳热解炭制备活性炭的工艺条件。研究表明,随着热解终温的升高,生物质炭得率下降,不可凝气体得率上升,生物质油得率则呈现先上升后下降的变化趋势。生物质炭的能量产率高达47.21%~81.59%,是油茶壳热解的主要产物,随着热解终温的升高,其固定碳含量增大,比表面积先增加后减小,在600℃达到最高值278 m2/g。油茶壳活性炭制备的最佳工艺条件活化温度850℃,活化时间1.5 h,水蒸气用量与炭的比2.0,此条件下的活性炭得率为37.47%,碘吸附值为825 mg/g,BET比表面积为736 m2/g。该研究为油茶壳热解多联产工艺及产物的综合有效利用提供参考依据。
译 名：
Characteristics of camellia shell pyrolysis products and optimization of preparation parameters of activated carbon
作 者：
Gu Jie;Zhou Jianbin;Ma Huanhuan;Ma Meng;Xing Meiteng;College of Materials Science and Engineering, Nanjing Forestry University;
关键词：
pyrolysis;;temperature;;biomass;;camellia shell;;activated carbon
摘 要：
Biomass is a clean, abundant and renewable energy source with many ecological advantages. Camellia, as one of the most important economic forest resources in China, is a potential biomass source for energy demand. Camellia shell is the primary residue left over from camellia oil production. Currently, the majority of camellia shells haven't been converted into high-quality bio-fuels efficiently. To utilize the camellia shell waste, pyrolysis for poly-generation is a promising technology which converts biomass resource to solid char, liquid oil and biogas. This paper focused on the product yields, characteristics and energy distribution during camellia shell pyrolysis at the temperature ranging from 300 to 700℃, and the reaction of activated carbon prepared from camellia shell pyrolysis used water vapor activation, so as to explore the effects of temperature on the characteristics of camellia shell pyrolysis product, and achieve the comprehensive utilization of products derived from camellia shell pyrolysis based on pyrolytic poly-generation. The pyrolysis of camellia shell and the preparation of activated carbon were carried out with the fixed bed reactor and the small rotary activation furnace, respectively. Gas chromatograph was used to analyze the compositions of non-condensable gas. The surface area of biochar and activated carbon was determined by the surface area and porosity analyzer via nitrogen adsorption at-196°C. The specific surface area was calculated from the adsorption isotherms using the Brunauer-Emmett-Teller(BET) equation. The results showed that with the temperature increasing, biochar yield was declined mainly due to the thermal decomposition of the 3 components(hemicellulose, cellulose, and lignin), which resulted in the increase of non-condensable gas yield. The biochar yield rapidly decreased from 53.59% to 34.12% at 300-400℃, whereas the decrease at the temperature of more than 400℃ was less than 6% because the decomposition of cellulose and hemicellulose was completed. The bio-oil yield achieved the highest at 500℃, which was about 33.75%. Biochar was considered to be the primary product of camellia shell pyrolysis because it had energy yield of 47.21%-81.59%. The sum of energy yield of bio-oil and non-condensable gas reached almost 50% when the pyrolysis temperature was >600℃. Therefore, these 3 types of pyrolysis products as valuable resources should be developed together for utilization. With the increasing of temperature, the fixed carbon percentage of biochar generally increased, while the BET surface area declined after firstly rising, and achieved the highest value of 278 m2/g at 500℃. This increase in temperature also increased the low heating value from 29.92 to 32.40 MJ/kg. The optimum preparation conditions of camellia shell activated carbon were determined as follows: based on yield, the camellia shell activated carbon could be prepared at the activation temperature of 800℃, activation time of 1 h, and water vapor-carbon ratio of 1.0, and the yield achieved 47.79%; based on iodine adsorption value, the camellia shell activated carbon could be prepared at the activation temperature of 850℃, activation time of 1.5 h, and water vapor-carbon ratio of 2.0, and the iodine adsorption value achieved 825 m2/g; based on BET specific surface area, the camellia shell activated carbon could be prepared at the activation temperature of 850℃, activation time of 1.5 h, and water vapor-carbon ratio of 2.0, and the BET specific surface area achieved 736 m2/g. The study of camellia shell pyrolysis based on pyrolytic poly-generation provides a reference for a comprehensive and effective use of the products of camellia shell pyrolysis.
