热解温度和时间对生物炭pH值的影响  

Effects of pyrolysis temperature,time and biochar mass ratio on pH value determination for four biochar solutions

作　　者：周强[1,2] 黄代宽 余浪[1,2] 彭芙蓉[1,2] 

机构地区：[1]贵州省环境科学研究设计院,贵阳550081 [2]贵州师范大学,贵阳550001

出　　处：《地球环境学报》2015年第3期195-200,共6页Journal of Earth Environment

基　　金：国家自然科学基金项目(40721002);贵州省科技厅社会发展攻关项目(黔科合SY字(2012)3037)

摘　　要：以稻草、玉米秸秆、木屑、鸡粪为实验原料，分别在不同热解温度（250℃、300℃、350℃、450℃、650℃）和热解时间条件下（30min、60min、90min、120min、180min）制备出生物炭。并在不同生物炭与水的质量比条件下，依据正交实验设计的方案，依次测定了各种生物炭的pH值。结果表明，热解温度是影响各种生物炭pH测定值的关键性因素，生物炭与水的质量比也对pH测定值产生一定的影响，而热解时间的长短并未对生物炭pH测定值产生显著影响。在250~650℃的热解温度条件下，随着温度的升高，四种生物炭的pH值均有不同程度的升高，尤其是在250～350℃这一温度区间，四种生物炭的pH值升高速率最快，此后，随着热解温度的升高，生物炭pH值升高速率逐渐放缓，其中在250~650℃的热解条件下，稻草的pH值升高幅度最大，木屑的pH值升高幅度最小，在350~450℃这一较为理想的热解温度区间范围内所制备的四种生物炭pH值的大小顺序依次为：稻草〉玉米秸秆〉鸡粪〉木屑。Four raw materials, rice straw, hardwood sawdust, corn straw and broiler litter, were prepared in the different pyrolysis temperatures （250 ℃, 300 ℃, 350 %, 450℃, 650℃ ） and pyrolysis time conditions （30 min, 60 min, 90 min, 120 min, 180 min） for biochars respectively. And then, based on the orthogonal experimental designing, the pH value of different biochar to H20 mass ratio was measured. The results showed that, the pyrolysis temperature was the critical factor of influencing pH of various biochar, the mass ratio of biohar to water also had a certain impact on pH value, but the pyrolysis time did not significantly. Commonly, with the increasing of pyrolysis temperature, pH values of four biochar increased in range of 250-650 ℃, especially in the temperature range of 250-350 ℃, the increasing rate was the fastest, and then gradually slowed down. Under the pyrolysis temperature range of 250-650 ℃ for each biochar, rice straw had the widest pH value increase scope, and hardwood sawdust had the narrowest one. Under the same measured conditions, especially for the pyrolysis temperature between 350℃ and 450℃ usually, the order of four biochar was rice straw 〉 corn straw 〉 broiler litter 〉 sawdust of hard wood.

关 键 词：生物炭 PH 热解温度 热解时间 炭水质量比 

分 类 号：TK6[动力工程及工程热物理—生物能] X712[环境科学与工程—环境工程]