畜禽粪便与秸秆混合热解制备生物炭研究

Biochar fertilizer utilization characteristics of mixed pyrolysis of livestock manure and straw

以牛粪和猪粪为原料,玉米芯秸秆为辅料,采用管式反应器制备生物炭,研究热解温度(200、300、400、500℃)和秸秆添加量(20%、40%、60%、80%)对畜禽粪便生物炭产率和理化特性的影响。结果显示,随着热解温度的升高,混合料生物炭产率降低,挥发分含量逐渐降低,而灰分含量、pH、全磷和全钾含量均呈递增趋势,全氮含量呈先增后减趋势;添加秸秆有利于改善畜禽粪便生物炭的pH,调节养分含量;秸秆添加量为20%时,牛粪秸秆混合生物炭的孔隙特性在400℃表现最好,猪粪秸秆混合生物炭的孔隙特性较差。牛粪秸秆混合生物炭相比猪粪秸秆混合生物炭有更好的炭产率、pH和孔隙特性,其较好的孔隙特性有利于其作为吸附剂等使用,猪粪秸秆混合生物炭具有更好的养分特性,可作为磷肥生产辅料或土壤改良剂使用。

Animal manures(cow dung,pig manure)and cornstraw were used to investigate the effects of different temperatures(200,300,400 and 500℃)and different amount of straw(20%,40%,60%,80%)on yields and physicochemical properties of biochar produced in a closed low-oxygen reactor using pyrolysis process.The results showed that biochar yields,volatile content decreased gradually as pyrolysis temperature increased,while ash content,pH and total content of P,K and nutrient contents increased,N content first increased and then decreased.The pore characteristics of cow dung biochar were best at 400℃,while the pore characteristics of pig manure were poor.Adding straw improved pH of biochar and regulated nutrient content.Compared with pig manure biochar,cow dung biochar had better carbon yield,pH and pore characteristics.The nutrient content of cow dung was less than that of pig manure.Cow manure and straw mixed biochar is more suitable for using its pore characteristics as adsorbent and so on.Pig manure and straw mixed biochar is more suitable for using its nutrient characteristics as phosphate fertilizer production auxiliary or soil conditioner.The influence of mixed pyrolysis on the charcoal characteristics needs to be further studied.