禽畜粪便中矿物质组分对其半焦氧化行为的影响

Effect of Mineral Matters on the Oxidation Behavior of Manure Char

低温催化气化工艺可以将禽畜粪便等低品质生物质废物快速地转化为氢或合成气等洁净能源,避免了这些废物的大量积聚对环境造成的危害。使用X射线衍射仪(X-ray diffractometer,XRD)、热重分析(thermogravimetric analyzer,TGA)等分析测试仪器考察禽畜粪便中矿物质组分对其热解半焦特性及其氧化行为的影响。结果表明:选用的禽畜粪便样品中的矿物质组分钙系物质含量较高,特别是鸡粪中含有大量的CaCO3;浓度为5mol/L的HCl及3%HF酸洗处理能够将禽畜粪便中几乎所有的矿物质组分脱除;猪粪半焦氧化行为比较简单,由于CaO的固碳效应,鸡粪半焦的氧化过程较复杂;脱矿物质后禽畜粪便的半焦氧化反应活性明显下降,表明禽畜粪便半焦中的矿物质组分对其氧化过程的催化作用十分显著。

Low quality biomass,especially livestock manure,can be converted quickly by low temperature catalytic gasification process into hydrogen or syn-gas（H2 and CO） and char.The energy from the char combustion was supplied back to the gasification process.The effect of mineral matters on the oxidation behavior of hen and pig manure char was addressed.The content of the minerals（especially Ca） in the manure samples is high and X-ray diffractometer（XRD） results show that the hen manure contains lots of CaCO3,which is converted into CaO during char preparation.Nearly all the mineral matters were removed by 5 mol/L HCl and 3% HF acid washing.The effect of the mineral matters on the pyrolysis behavior of pig manure was small,but the pyrolysis process of hen manure was affected greatly by the presence of CaCO3.The oxidation behavior of pig manure char is very simple,but that of hen manure char is much more complicated due to the CO2 fixation of CaO.The oxidation reactivity of the char from the raw manure is much higher than that of the char prepared from the de-mineralized sample.The difference in the char reactivities should be attributed to the presence of catalytically active inorganic constituents,especially Ca species.