中低温煤焦油重质馏分的化合物组成及表征

Composition and characterization of the heavy fractional compound in medium low temperature coal tar

对中低温煤焦油的综合高效利用有助于提高煤炭作为化工原料的综合利用效能,因而利用联用技术对典型中低温煤焦油重质馏分进行分子表征,可为其后续高效的加工利用提供数据支撑。利用电喷雾电离源(ESI)和大气压光致电离源(APPI)结合傅里叶变换离子回旋共振质谱仪(FT-ICR MS)在分子水平上表征影响典型中低温煤焦油重质馏分加工利用方式的含氮化合物、含氧化合物以及芳烃化合物,探讨含氮和含氧化合物、芳烃类化合物的组成和碳数分布。结果表明,采用正离子电喷雾(+ESI)结合FT-ICR MS共鉴定出N_(1)、N_(2)、N_(1)O_(1)、N_(1)O_(2)、N_(1)O_(3)、N_(2)O_(1)、N_(2)O_(2)、N_(1)O_(1)S_(1)共8种不同分子组成的碱性氮化物;采用负离子(-ESI)模式下FT-ICR MS检测出N_(1)、N_(2)、N_(1)O_(1)、N_(1)O_(2)、N_(1)O_(3)、N_(2)O_(1)、N_(1)O_(1)S_(1)共7类非碱性氮化物,检测出O_(1)、O_(1)S_(1)、O_(2)、O_(2)S_(1)、O_(3)、O 4共6类酸性氧化物;采用APPI正离子模式结合FT-ICR MS检测出4_(1)67种芳烃化合物,其中碱性氮化物相对丰度较高的为N_(1)、N_(1)O_(1)类化合物,而非碱性氮化物相对丰度较高的为N_(1)O_(1)、N_(1)O_(2)类化合物,O_(1)、O_(2)、O_(3)类酸性氧化物具有较高的相对丰度。依据各化合物的等效双键数和碳数分布可推测其分子组成,N_(1)类碱性氮化物母核结构主要为喹啉、吖啶、菲啶、二苯并喹啉和苯并吖啶等2~4环的多芳环结构;N_(1)O_(1)类碱性氮化物的主要母核结构为苯并喹啉、吖啶、菲啶、二苯并喹啉、苯并吖啶、二苯并吖啶同时并有呋喃、氧芴等结构;N_(1)O_(1)、N_(1)O_(2)类非碱性氮化物与碱性氮化物相比,其侧链相对较短,其母核结构为吡咯、吲哚、咔唑并环氧烷、呋喃以及部分苯环结构,氧以羟基、醚基、羰基或酰基形式存在;O_(1)类酸性氧化物种类较多,母核结构主要为萘酚、蒽酚、菲酚、苯并蒽酚、苯并萘酚,还有少量的芘酚;O_(2)类酸性氧化物的种类较少,母核结构主要为萘二酚、蒽二酚、菲二酚,同时也存在羧基官能团的长链烷烃。O_(3)类酸性氧化物的种类介于O_(1)类和O_(2)类之间,母核结构有可能为萘二酚并呋喃、蒽二酚、菲二酚,烷基侧链中含有羟基、醚键或羧基等结构;芳烃化合物主要为烷基侧链较长的2~3环稠环芳烃。

The comprehensive and efficient utilization of medium and low temperature coal tar helped to improve the comprehensive utilization efficiency of coal as a chemical raw material.The compound composition and molecular characterization of the heavy fraction of medium and low temperature coal tar were important data foundations for the efficient processing and utilization of medium and low temperature coal tar.The nitrogen compounds,oxygen compounds and aromatic compounds that affect the processing and utilization of heavy components of typical medium-low temperature coal tar were characterized at molecular level by electrospray ionization source(ESI)and atmospheric pressure photoionization source(APPI)combined with Fourier transform ion cyclotron resonance mass spectrometer(FT-ICR MS).On this basis,the composition and distribution of the above types of compounds were analyzed.The results showed that eight kinds of basic nitrides with different molecular compositions such as N_(1)、N_(2)、N_(1)O_(1)、N_(1)O_(2)、N_(1)O_(3)、N_(2)O_(1)、N_(2)O_(2)、N_(1)O_(1)S_(1)had been identified by positive ion electrospray(ESI)combined with FT-ICR MS.Seven types of non-basic nitrides including N_(1)、N_(2)、N_(1)O_(1)、N_(1)O_(2)、N_(1)O_(3)、N_(2)O_(1)、N_(1)O_(1)S_(1),were detected by FT-ICR MS with negative ion ESI mode,while six types of acid oxides including O_(1)、O_(1)S_(1)、O_(2)、O_(2)S_(1)、O_(3)、O 4 were detected.4_(1)67 aromatic compounds were detected in the positive ion mode of APPI combined with FT-ICR MS.Among them,the basic nitrides of N_(1)and N_(1)O_(1)had higher relative abundance,the higher relative abundance of non-basic nitrides were N_(1)O_(1)and N_(1)O_(2)compounds,and the higher relative abundance of acid oxides were O_(1),O_(2)and O_(3)compounds.According to the equivalent double bond number(DBE)and carbon number distribution of the main compounds,the molecular composition of N_(1)basic nitrides could be inferred.The main nuclear structure of N_(1)basic nitrides were polyaromatic ring with_(2)-4 rings,including quinoline,acridine,phenanthidine,dibenzoquinoline and benzobaadine.The main parent nucleus structures of N_(1)O_(1)alkaline nitrides were benzoquinoline,acridine,phenanthridine,dibenzoquinoline,benzoacridine,and dibenzacridine,which were combined with furan,oxyfluorene,and other structures.Compared with basic nitrides,N_(1)O_(1)and N_(1)O_(2)non basic nitrides had relatively short side chains,and their parent nucleus structures were pyrrole,indole,carbazoepoxane,furan,and some benzene ring structures.Oxygen exists in the form of hydroxyl,ether,carbonyl,or acyl groups.There were many types of O_(1)acidic oxides,and the parent nucleus structure was mainly composed of naphthol,anthracene,phenanthrene,benzo anthracene,benzo naphthol,and a small amount of pyrene phenol.There were fewer types of O_(2)type acidic oxides,and the parent nucleus structure was mainly composed of naphthalene,anthracene,and phenanthrene,as well as long-chain alkanes with carboxyl functional groups.The number of types of O_(3)type acidic oxides was between O_(1)and O_(2)types,and the parent nucleus structure might be naphthalene diphenyl furan,anthracene diphenyl,and phenanthrene diphenyl.The alkyl side chain contained structures such as hydroxyl,ether bonds,or carboxyl groups.Aromatic compounds were mainly_(2)-3 ring polycyclic aromatic hydrocarbons with longer alkyl side chains.