碱液对提取褐煤黄腐酸的影响  

Effect of alkaline solution on extraction of fulvic acid from lignite

作　　者：马力通[1,2,3] 李丽萍 路亚楠 戴博 MA Litong;LI Liping;LU Yanan;DAI Bo(School of Chemistry and Chemical Engineering,Inner Mongolia University of Science and Technology,014010 Baotou,China;Inner Mongolia Engineering Research Center of Comprehensive Utilization of Bio-coal Chemical Industry,014010 Baotou,China;Laboratory of Low Rank Coal Carbon Neutralization,Inner Mongolia University of Science and Technology,014010 Baotou,China)

机构地区：[1]内蒙古科技大学化学与化工学院,内蒙古包头014010 [2]生物煤化工综合利用内蒙古自治区工程研究中心,内蒙古包头014010 [3]内蒙古科技大学低阶煤炭碳中和实验室,内蒙古包头014010

出　　处：《煤炭转化》2023年第5期83-89,共7页Coal Conversion

基　　金：内蒙古自治区科技计划项目(2020GG0158);内蒙古自治区人才开发基金项目(2021年度);内蒙古科技大学基本科研业务费专项资金资助项目(2022年度科研平台创新能力建设项目);中国科学院“西部之光”人才培养引进计划“西部青年学者”项目(2019年度).

摘　　要：为提高褐煤资源的附加值,探索了NaOH,KOH,LiOH,Na_(2)CO_(3),NH_(3)·H_(2)O,Na_(2)SO_(3),NaHCO_(3),Na_(4)P_(2)O_(7)对萃取褐煤黄腐酸结构的影响。采用碱溶酸析法提取褐煤黄腐酸,以不同弱碱性溶剂为萃取剂再经硫酸酸析,通过容量法测定黄腐酸的纯度,并对提取的褐煤黄腐酸进行光谱表征。结果表明:不同碱液提取褐煤黄腐酸的产率不同,但质量浓度相近,其中LiOH提取黄腐酸的产率(质量分数)最高(5.12%);不同碱液提取褐煤黄腐酸的官能团种类相同,但含量不同,Na_(2)CO_(3)提取的褐煤黄腐酸羰基结构最少,NaHCO_(3)做萃取剂时提取的褐煤黄腐酸的芳香度较高、羟基结构较多;不同碱液提取褐煤黄腐酸的E_(4)/E_(6)值明显不同,相对分子质量差距较大,Na_(4)P_(2)O_(7)可提取出相对分子质量为118157的褐煤黄腐酸;Na_(2)SO_(3)是提取褐煤黄腐酸的最佳萃取剂,提取的黄腐酸中苯环结构较少,芳香聚合度较低,纯度高达0.248 g/L。In order to elevate the value of lignite,the effects of NaOH,KOH,LiOH,Na_(2)CO_(3),NH_(3)·H_(2)O,Na_(2)SO_(3),NaHCO_(3) and Na_(4)P_(2)O_(7) extraction on the structure of lignite fulvic acid have been investigated.In this paper,the fulvic acid in lignite was extracted by the alkali-extraction acid-precipitation method,where different weak alkaline solvents were adopted as extractants,followed by acid precipitation using H_(2)SO_(4).The purity of the fulvic acid was determined by volumetric method,and a spectroscopic characterization was performed.It is found that the yield of lignite fulvic acid varies based on the specific alkaline solvent for extraction,however,their concentrations exhibit noteworthy similarity.The highest yield of fulvic acid of 5.12%is achieved when using LiOH for extraction.The functional groups within the lignite fulvic acid extracted from different alkaline solvents are consistent in type,but their proportions differ considerably.Lignite fulvic acid extracted by Na_(2)CO_(3) has the least carbonyl structure,while a higher aromaticity and a enriched hydroxyl structure are achieved when NaHCO_(3) is used for extraction.The E_(4)/E_(6) ratios of lignite fulvic acid extracted from different alkaline solvents are significantly different,accompanied by discernable variations in molecular weight.Na_(4)P_(2)O_(7) can be used to extract lignite fulvic acid,yielding a molecular weight of 118157.Notably,Na_(2)SO_(3) is the best extractant for extracting fulvic acid from lignite,resulting in fulvic acid with less benzene ring structure,fewer aromatic polymerization,and a purity of 0.248 g/L.

关 键 词：褐煤 碱溶酸析法 黄腐酸 紫外-可见光谱 核磁共振氢谱 傅立叶变换红外光谱 

分 类 号：TQ536.1[化学工程—煤化学工程]