昭通褐煤“腐植酸的提取——腐黑物的低温热解”的梯级利用特性

Cascade utilization characteristics of Zhaotong lignite “extraction of humic acid from it——low temperature pyrolysis of humin”

以昭通褐煤为原料,通过碱溶酸析法提取腐植酸,探讨各工艺条件下褐煤腐植酸的提取率、腐植酸的品质,并对提完腐植酸后剩余的褐煤腐黑物进行热解气化,以热解产物分布、热解气及焦油的组成为指标,研究其热解气化特性,为开发"腐植酸的提取——腐黑物的低温热解"梯级利用提供基础数据,结果表明:1.5%Na OH、70℃反应温度和3h反应时间、2MPa压力下腐植酸的产率较高,可达到41%以上,得到的腐植酸的总酸性官能团含量可高达6.8mmol/g,其中主要的羧基官能团含量达到4.4mmol/g,腐植酸的灰分产率为14.23%,其对金属元素吸附大小顺序为Al>Si>Fe>Ca>K>Mg。腐黑物(残渣)热解气产率为15.72%,焦油产率为2.29%,热解气中主要的成分有H2、CO、CO2、CH4,其中H2的含量最高可达38.2%,焦油的组分较重且极为复杂,热解半焦的固定碳含量有所提高,热解产物中各组分的含量及比值随热解工艺条件的变化有所改变。

The experiment was carried out with Zhaotong lignite as material.The base-dissolvingacidification method was used to extract humic acid from Zhaotong lignite.The extraction rate andquality of humic acid in different operating conditions were explored.The humin(the residue oflignite)was carried out by pyrolysis and gasification.The yield of gas,the yield of tar,the yield ofchar,the composition of gas and the composition of tar were used as the analysis index to study thepyrolysis and gasification characteristics.The results show that NaOH of1.5%,reaction temperature of70℃,reaction time of3h and reaction pressure of2MPa are the best operating conditions to extracthumic acid and the yield of humic acid could reach41%.The total acidic functional groups content inhumic acid reaches6.8mmol/g.Among it,the carboxyl functional group content achieves4.4mmol/g.The yield of ash in humic acid is14.23%.Humic acid adsorption capacity gradation ofmetal elements is Al>Si>Fe>Ca>K>Mg.The pyrolysis gas yield of humin is15.72%and the tar yield is2.29%.