神府煤新法干馏焦油的性质及组成的研究

本文对神府煤固体热载体新法干馏焦的性质和组成进行了研究。实验结果表明，干馏温度对焦油的产率和性质影响很大，获得焦油的最佳温度为５００－５５０℃。随着干馏温度的增加，焦油的平均分子变大，重组分含量增加。对５００℃焦油〈４２０℃馏分的精细分析结果表明，该馏分主要由酸性组分和中性油组成，碱性组分含量较少。酸性组分主要由苯酚、甲酚和二甲酚组成。中性油主要由脂肪族和芳香族组成，脂肪族中正构烷烃Ｃ１３－Ｃ２５     

焦粉对低阶煤热解焦油气反应行为的影响研究

热解焦油气在输送管路或除尘设备中会发生一定程度的反应,进而影响热解产物的分布和组成,而其中夹带的焦粉粉尘会对焦油气反应产生影响。本研究利用两段流化床热解反应器,考察了不同反应温度下(400-500℃),焦粉对淖毛湖长焰煤热解焦油气反应的影响。结果表明,添加焦粉后,焦油气不仅发生热裂解和热缩聚反应,还会被焦粉作用发生催化裂解反应,焦油产率和沥青含量减小,热解气和积炭产率增加;随着反应温度的升高,焦油气热裂解和热缩聚反应加剧,反应后焦油气较为稳定,不易被焦粉催化,因此,焦粉对焦油产率、沥青含量及热解气产率的影响随温度升高逐渐减弱;而反应温度升高,焦油气催化裂解生成的自由基更容易发生缩聚反应,焦粉对积炭产率的影响变强。此外,焦粉的催化裂解作用使不同反应温度下焦油中杂环化合物含量下降;同时焦粉促进了热解水与焦油气反应,导致不同反应温度下焦油中脂肪烃、芳香烃含量下降,酚类和含氧化合物含量上升。     

污水污泥流化床气化焦油的化学组成分析

以空气为气化剂、并通过GC-MS分析,研究了污水污泥流化床气化时气化温度（650、750和850 ℃）和污泥性质对污泥气化焦油产率及其化学组成的影响。结果表明,污泥气化焦油产率随气化温度的升高而降低,且厌氧消化污泥气化焦油的产率比未消化污泥的低。污泥气化焦油中的化学组成可分为五类：脂肪族化合物、脂环化合物、芳香烃、芳香烃衍生物和杂环化合物。随气化温度的升高,A²/O工艺的未消化污泥气化生成的焦油中脂肪族化合物和脂环化合物的产率均明显降低,芳香烃衍生物的产率则有显著地提高,而芳香烃和杂环化合物的产率均先增加后减少。气化温度为650 ℃时,活性污泥法消化污泥气化焦油中五类有机物的产率均低于未消化污泥的,而A²/O工艺消化污泥气化焦油中芳香烃产率高于未消化污泥的,其他四种有机物的产率则均低于未消化污泥的。     

折流内构件移动床中煤在不同停留时间下的热解行为特性

针对常规移动床煤热解工艺所面临的无法处理粉煤,轻质焦油产率低、焦油品质差等问题,开发了折流内构件移动床热解工艺来调控气固两相的热质传递和热解反应过程。利用多段集气系统可及时地收集煤在不同热解阶段释放出的油气产物,研究了淖毛湖煤在不同温度和停留时间下的热解行为特性和产物品质。结果表明,折流内构件强化了颗粒间的热量和挥发分物质的传递,使其可处理0.4-6.0 mm的粉煤;在热解温度550℃,停留时间为3.0 h时,热解焦油产率达到最高为11.38%(占格金焦油产率的86.87%,质量分数),焦油馏分中低于360℃的轻质组分质量分数为85.0%;随着停留时间的延长,热解气中的H2体积分数从22.1%增加到了35.1%,CO体积分数从8.0%增加到了9.5%;在第一和第二层反应器中的焦油产率随停留时间的延长而增加,在第三和第四层反应器内当停留时间为2.0 h时焦油产率最大;随着床层数的增加,焦油模拟蒸馏馏分中的轻质组分含量增加,焦油脂肪烃化合物含量减小,而单环芳烃和二环芳烃的含量逐渐增加。     

氧化钙催化煤温和气化研究

报道了神木煤在小型流不反应器中,于４５０～７５０℃温度内,用ＣａＯ催化煤温和气化的研究。结果表明：添加ＣａＯ后,气体和半焦产率增加,焦油产率减少;ＣａＯ粒子对煤温和气化生成的焦裂解具有明显催化作用;可以明显增加气相中Ｈ２、ＣＨ４、Ｃ１～Ｃ５产率,降低半焦中Ｈ／Ｃ比,ＣａＯ还具有明显的固硫和固ＣＯ２作用,最后,推测了煤温和气化中ＣａＯ催化裂解多环芳烃侧链的机理。     

低温焦油馏分的组成和统计结构表征

用ＧＣ－ＭＳ研究了代温焦油第４和第５蒸馏馏分的组成和统计平均结构。研究表明,平朔煤低温焦油第４（２３０～２７０℃）和第５（２７０～３４０℃）蒸馏馏分,由脂肪烃类化合物和非脂肪烃类化合物两大类组成。第４和第５馏分的平均分子量分别为２８０．２和２９６．２和２９６．７。第４蒸馏馏分中的非脂肪烃化合物主要由酚类２２．４４％和取代萘酚６２．７３％组成。第５蒸馏馏分中的非脂肪烃化合物主要酚类８．６９％,芳香基     

含氧/蒸汽气氛中煤高温分解产物分布及反应性

在流化床反应器中考察了含氧/水蒸气气氛中煤在850 ℃下的热解特性,包括产物分布特性及生成的半焦与焦油的反应性,研究了温度、过量空气比(Equivalence ratio: ER)和水蒸气/煤比(S/C, 质量比)的影响。结果表明,随热解温度、ER和S/C质量比的增加,气体产率增加,而半焦和焦油产率减少。O₂的加入使CO₂、CO含量明显增加,H₂含量降低。O₂和水蒸气的加入使半焦的比表面积显著增加,半焦气化活性增强,但半焦在900 ℃和 ER 为0.22的条件下出现轻微石墨化,降低了其气化活性。同时,反应气氛中含有O₂和水蒸气对焦油的性质有显著影响,与单纯的N₂气氛相比,O₂和水蒸气的存在使热解焦油中单环芳烃、酮类、酚类、脂肪烃都明显减少,这对于焦油的进一步裂解及重整更加有利。     

生物质与石油焦共气化特性的研究

在内径为50mm,高约950mm的固定床反应器上对生物质与石油焦共气化特性进行了研究。研究了气化模式、石油焦添加比例、添加方式、粒径大小及气化温度对气化效果及焦油量的影响。结果表明,石油焦可以起到催化裂解生物质焦油的作用。随着氧气的体积分数从2%增加到15%时,气体的热值从5.35MJ/m³降低到2.98MJ/m³。在气化温度为700℃时,四种氧气含量下生物质单独气化时焦油产率平均值为6.4%,气体热值为4.31MJ/m³;生物质和石油焦混合气化时焦油产率平均值为2.9%,气体热值为5.19MJ/m³。石油焦的最佳添加比例为1∶1。生物质和石油焦不混掺焦油的产率最大,混掺其次,石油焦提前加入效果最好。随着添加石油焦粒径的增大,石油焦对生物质气化焦油的裂解率逐渐降低。在两种气化模式下,随着气化温度的升高,焦油的产率均逐渐降低。     

外加铁矿石对哈密低阶煤热解特性影响

为探讨铁矿石对哈密低阶煤热解特性影响,采用热重分析仪(thermal gravity analysis/differential thermal gravity,TG/DTG)和实验室固定床反应器(fixed bed)对哈密低阶煤进行热解实验,研究了两种铁矿石对哈密煤热解反应性、热解气和焦油分布规律的影响。利用傅里叶红外光谱(FT-IR)和色谱-质谱分析仪(GC-MS)对焦油中官能团的变化以及焦油中物质组成进行了分析对比。结果表明,当热解温度从室温升高至150℃时,原煤中添加铁矿石的煤样失重速率峰逐渐向高温阶段推移;当热解温度高于450℃时,不同铁矿石对原煤热解的催化作用差异更加明显,且镜铁矿原生矿物质赤铁矿;当两种铁矿石添加量分别为20%时,热解焦油和热解气都能得到较高的收率;对于煤样HM-JT来说,此时焦油产率为7.88%,热解气相产物H_2、CO_2、CH_4、CO产率与未添加镜铁矿的原煤煤样相比分别提高了4.27%、3.76%、4.39%、3.61%。对于煤样HM-CT来说,焦油催化裂解效果一直受到铁矿石添加量的影响。在镜铁矿和赤铁矿添加量分别增加到20%的过程中,煤样热解生成焦油的产率逐渐下降,而轻质焦油产率和轻质焦油分数逐渐增大到6.37%、58.48%、5.34%、56.22%,焦油中氧脱除率分别达到43.16%、36.89%。随着铁矿石的加入,焦油中二甲苯相对含量由4.32%分别降低至3.78%、3.93%,而甲苯相对含量由1.11%升高至1.32%、1.45%;焦油中邻甲酚和二甲酚中分子中的甲基取代基被脱除生成苯酚或甲酚,且镜铁矿对焦油中苯系物和酚类化合物的脱甲基作用强于赤铁矿。     

半焦原位气化气对淖毛湖煤热解焦油产率和品质的影响

本研究采用实验室自制的热解气化一体化反应器,考察了气化合成气对煤热解焦油产率和品质的影响.结果表明,淖毛湖煤热解焦油产率在600℃时达到最大,气化合成气对提高低温(550–600℃)煤焦油的产率更有利,其中,550℃时焦油产率较N2下提高了4.4％.气化合成气气氛下,高温(650–800℃)焦油的产率较N2低,但650...     

A carbanion induced synthesis of highly congested pyrazole and imidazole containing heterocycles

An efficient approach to the synthesis of highly congested di, penta and hexacyclic pyrazoles as well as imidazole fragment containing novel heterocyclic molecule has been developed through a carbanion induced transformation of suitably functionalized 2H-pyran-2-ones, benzo[h]chromene and thiochromeno[4,3-b]pyrans. Due to the presence of fluorescence, we report their prime application metal sensor as off/on switching in ferric ions.     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Selective synthesis of 4,5-dihydroimidazo- and imidazo[1,5-a]quinoxalines via modified Pictet–Spengler reaction

An efficient tandem approach for the selective synthesis of 4,5-dihydroimidazo[1,5-a]quinoxalines 6a–g and imidazo[1,5-a]quinoxalines 7a–h by the reaction of 2-imidazolyl anilines 4a–c with aryl aldehydes 5a–k under mild reaction conditions is described. Introduction of electron releasing alkyl groups in substrates 4a–b was found to be instrumental for the success of the reaction.     

Understanding the Diels-Alder reactivity of 1,2-azaborine analogues

The Diels-Alder reactivity of 1,2-heteroborines (H₄C₄B(H)X, X?=?NH, PH, AsH; O, S, Se) has been computationally explored by means of Density Functional Theory (DFT) calculations. The influence of the HB?=?X fragment on the reactivity of the system has been quantitatively analyzed in detail by means of the so-called Activation Strain Model (ASM) of reactivity. It is found that the interaction between these species and the dienophile is significantly stronger than that computed for their all-carbon isoelectronic counterpart, benzene. In addition, the strain energy plays a key role in the observed reactivity trends. The role of the aromaticity strength of these heteroarenes on the reactivity is also assessed.     

Synthesis of N-substituted carbazolones from α-iodo enaminones via Pd(0)-catalyzed intramolecular coupling under microwave irradiation

A variety of N-aryl and N-alkyl carbazolones were conveniently achieved in good to high yields via Pd₂(dba)₃-mediated intramolecular coupling of N-substituted α-iodo enaminones under microwave irradiation. The Pd(0)-catalyzed cyclization was found to proceed favorably with the more electron-deficient phenyl ring during the reactions involving unsymmetrical N,N-diaryl α-iodo enaminones. This unique property enables the construction of carbazolone skeleton containing nitro substituted benzenoid ring.     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.     

Synthesis of substituted 2,4,5,6-tetrahydrocyclopenta[c]pyrazoles and 2,4,5,6-tetrahydropyrrolo[3,4-c]pyrazoles by intramolecular nitrilimine cycloaddition

Both substituted 2,4,5,6-tetrahydrocyclopenta[c]pyrazoles and 2,4,5,6-tetrahydropyrrolo[3,4-c]pyrazoles have been synthesized by the 3+2 intramolecular dipolar cycloaddition of nitrilimines to alkynes. This cyclization has been extended to more versatile 3-bromo derivatives by the use of alkynylbromides as dipolarophiles.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.