淮北煤两级分次萃取物的红外光谱分析

为了揭示煤中可溶组分的存在方式和溶出行为,分别以石油醚和CS2为溶剂对淮北煤进行了按时间段分次取样的两级索氏萃取,并采用FTIR对萃取物进行了定性和定量分析。结果表明,可萃取组分的溶出具有时序性和阶段性特点;萃取物重要基团FTIR吸收峰随时间变化均呈波型曲线规律;石油醚可萃取组分中存在较多较短链的脂肪族组分和两部分特定链长的-OH(-NH)类物质;CS2可萃取物中则有两种特定链长的脂肪族组分和一种特定链长的-OH(-NH)类物质。     

梁家煤镜质组CS2可溶物赋存和溶出规律

为了揭示煤中可溶组分的赋存形式和溶出行为,用溶剂CS2对梁家长焰煤镜质组(LJJY)进行了索氏萃取,对按时间段分批(次)提取萃取物进行了FTIR和GC/MS的定性分析和定量分析.结果表明,LJJY用CS2溶剂进行索氏萃取时,初期萃取速率较快,后期减慢,总萃取率不高;CS2可溶物的溶出过程为:萃取初期溶出的主要是脂肪烃而取代芳烃较少,随反应进行,脂肪烃溶出量越来越少而取代芳烃含量则相对增多,此后溶解的主要是非取代的芳族化合物和含氧化合物;煤变质过程中主要存在着三类反应即芳构化反应、裂解碎化稳定反应和缩合反应.     

童亭煤族组分的溶剂萃取及萃取物分析

采用正己烷、甲醇、丙酮和氯仿4种溶剂对童亭煤经CS2/NMP混合溶剂萃取和反萃取所分离的3个族组分(沥青质组分、精煤和萃余煤组分)进行索氏分级分次萃取,以FTIR和GC为分析测试手段,研究各组分萃取物的结构特征和其中小分子的赋存规律。结果表明:各族组分在不同溶剂中溶解能力差异显著,沥青质组分在正己烷中有很高的萃取率,而精煤则在丙酮中有大量物质被溶出,萃余煤在氯仿中表现出较高的可溶性;各族组分可溶物在溶出行为和组成结构上既有相似性又存在一定的差别;各族组分可溶物中均有小分子化合物存在,且这些GC可检测的小分子主要集中于一定的保留时间区域内;不同族组分中的小分子的赋存形态具有相似性,且这种赋存形态是影响小分子溶出行为的决定性因素。     

两种萃余煤的温和氧化产物的组成分析

分别用二硫化碳 ( CS2 ) /四氢呋喃 (体积比 1∶ 2 )混合溶剂和环己酮对义马煤和美国Pocahontas No.3( P3)标准煤样进行了彻底萃取 ,在 60℃下用 30 %双氧水溶液分别氧化了所得的两种萃余煤 ,用 GC/MS对反应混合物中的水溶液的苯可溶物和水不溶物的 CS2 可溶物进行了分析 .结果表明 :在所得水溶液的苯可溶物中都检测出苯酚 ;在由义马萃余煤氧化所得的水不溶物的CS2 可溶物中检测出多种含氧有机化合物和长链烷烃 ,而在 P3萃余煤氧化所得的水不溶物的 CS2可溶物中只检测到一系列长链烷烃 .     

呼伦贝尔褐煤溶剂萃取及萃余煤的双氧水氧化产物分析

以CS2、乙醇和丙酮作为溶剂,对呼伦贝尔褐煤进行连续萃取,并利用气相色谱/质谱联用(GC/MS)技术对萃取物进行分析。结果表明:CS2萃取物主要由长链脂肪烃和芳烃组成,而这些脂肪烃存在于3种溶剂萃取物中。在40℃条件下,用H2O2溶液采用恒温水浴和超声两种方式氧化萃余煤,超声条件下氧化剧烈,并用FTIR分析了原煤、萃余煤、氧化煤的化学结构的变化。氧化后的水溶物用乙酸乙酯萃取后,用GC/MS检测萃取物,恒温水浴氧化可以检测到30种化合物,而超声氧化只检测到14种,且都是以酯类为主。     

甘肃窑街煤的两级溶剂萃取及萃取物分析

采用正己烷和甲醇两种溶剂对甘肃窑街煤进行索氏分级分次萃取,研究了一定时间段内该煤样萃取率的变化规律,并采用FTIR和GC对各次萃取物进行分析,研究可检测化合物的组成、结构和溶出规律。结果表明：该煤样的两级累积萃取率与累积萃取时间均服从一定的函数关系。小分子化合物的溶出过程符合秦志宏提出的＂前期溶出的主要为游离态小分子,中期开始部分溶出的主要为微孔嵌入态小分子,后期溶出的主要为网络嵌入态小分子＂的溶出规律;小分子化合物的溶出具有连续性、时序性、特殊性等特点。第一级正己烷萃取物中,脂肪族化合物与含羰基、醇、酚、醚等的含氧化合物占据重要地位,芳香族化合物含量较少且主要为单核芳香族化合物,第二级甲醇萃取物中则主要是聚合度较高的芳香族化合物,含氧基团主要为醌基和芳香酮。     

煤焦油制中温沥青的族组分及结构表征

采用溶剂抽提法、元素分析法、傅里叶红外光谱(FTIR)、核磁共振氢谱(1H-NMR)、凝胶渗透色谱法(GPC)对中温煤焦油制备的煤沥青(MCP)和高温煤焦油制备的煤沥青(HCP)组成结构进行研究。研究结果表明:MCP和HCP的平均分子式分别为C_(36.01)H_(34.56)N_(0.35)S_(0.13)O_(2.28),C_(46.90)H_(24.12)N_(0.41)S_(0.23)O_(0.54);软化点分别为77.6℃,86.2℃。MCP的族组成:庚烷可溶物17.34%,庚烷不溶甲苯可溶物66.94%,喹啉不溶物含量为0.95%。HCP的族组成:庚烷可溶物16.86%,庚烷不溶甲苯可溶物39.97%,喹啉不溶物含量为11.89%。与HCP相比,MCP中脂肪侧链、环烷结构较多,芳构化程度较低。采用改进的Brown-Lander模型计算分子平均结构参数,推测出两种煤沥青的平均分子结构。根据研究结果对MCP的利用提出相应的建议。     

全煤阶煤的正己烷分次萃取及萃取物分析

为探索煤中小分子化合物在整个煤阶中的赋存方式及溶出规律,采用正己烷溶剂对年轻褐煤至无烟煤八种煤样进行分次萃取,分析了一定时间段内各煤样萃取率的变化规律,并对各次萃取物进行GC分析.结果表明,煤中小分子化合物的三种赋存形态即游离态、微孔嵌入态及网络嵌入态,在整个煤阶中具有普遍规律性;不同煤阶煤的累积萃取率与累计萃取时间均服从对数函数关系;分次萃取率及总萃取率与碳含量均呈现椅子形曲线关系;正己烷可溶小分子化合物中的Ⅱ型分子最容易析出,Ⅰ型分子次之,Ⅲ型分子最难溶出,且Ⅰ型分子仅在烟煤中才有显现;煤的变质过程基本符合煤的三大变质反应过程即芳构化反应过程、裂解碎化加氢稳定反应过程和缩合反应过程的观点.     

贵州煤焦CS2萃取物的组成分析

用CS2萃取了不同热解温度和升温速率得到的贵州煤焦,并用FTIR和GC/MS分析了煤焦萃取物的组成。结果表明：随着热解温度的升高,快速热解煤焦（GZR）的萃取率逐渐降低,而慢速热解煤焦（GZS）的萃取率减少缓慢,基本保持不变;GZR和GZS萃取物中都含有一定量的芳香族和脂肪族化合物,但GZR950的萃取物中几乎不存在环烷烃和脂肪烃;GZR的CS2萃取物中分别检测到6-12种3-6环的芳烃,GZS的CS2萃取液中没有GC/MS可检测的成分。     

溶剂分级萃取法研究平朔煤的化学组成特征

采用7种不同有机溶剂对平朔煤进行分级萃取,并利用GC／MS测定分析各级萃取物的化合物成分,对其化学组成及结构特征进行了对比研究．结果表明,利用不同溶剂分级萃取的方法可以较有效地对煤中有机化合物族组分起到粗分离的作用．CS2萃取物的主要成分是2环～4环烷基取代芳烃;正已烷萃取物几乎均为长链烷烃;在甲醇萃取物中检测出形式多样的含氧和含氮化合物;在丙酮萃取物中检测出长链烷基环已烷系列;芳烃在苯萃取物中多为2环,而在丙酮萃取物和THF萃取物中则是4环～7环缩合程度较高的芳烃;另外,在煤中首次发现邻二氟苯和氯胺酮．     

鄂尔多斯煤二硫化碳/四氢呋喃萃取物的初步分析

温和条件下用等体积的二硫化碳/四氢呋喃(CS2/THF)混和溶剂萃取鄂尔多斯煤,采用傅立叶变换红外光谱(FTIR)和气相色谱/质谱联用技术(GC/MS)分析了萃取物的化学成分和结构特征。结果表明:经过5次新鲜溶剂萃取,总萃取率为6.6%。第1次萃取物的质量最大,占萃取物总量的68%。各次萃取物的FTIR谱图含有较丰富的官能团信息,推测其中含有脂肪族、芳香族和含杂原子化合物。将5次萃取物分别用GC/MS进行检测,只有第1次萃取物可测,共检测出7种化合物且均为芳香族化合物,其中相对含量较大的3种化合物分别为惹烯、7-丁基-1-己基萘和西蒙内利烯。     

神府东胜煤CS2萃取物组成分析

采用溶剂萃取、色-质联用和色-红联用结合色谱保留值的定性方法，分析研究了神府东胜煤CS2萃取物的化学成分和结构，鉴定出120多种化合物，并对所鉴定出的单个化合物进行了定量分析，讨论了神府东胜煤CS2萃取物化学成分的结构特征．结果表明：萃取物主要由脂肪烃、芳烃和极性化合物三类成分组成．芳烃含量在萃取物中占绝对优势，且主要为1-4环的烷基取代芳烃．脂肪烃除主要成分正构烷烃外，还有少量的类异戊二烯烃和萜烷，极性化合物所占的比例很小，以含氧化合物为主．     

Supercritical extraction of scrap tire with different solvents and the effect of tire oil on the supercritical extraction of coal

Scrap tires are a growing environmental problem because they are not biodegradable. In this investigation, supercritical extraction of scrap tire and co-processing of coal with tire oil were studied. In the first stage, tires were extracted at 400 °C with a number of different solvents. The effects of the hydrocarbon and polar solvents used under the supercritical extraction conditions on the conversion and oil product of tire were determined, and it was observed that all volatile organic material of the scrap tire was converted to the liquid or gas product. In the second stage, coal and supercritical extracted tire oil (SCETO) samples were extracted with different solvents using various tire oil/coal ratios. In general, the use of tire oil generated an improvement for coal conversion. Further, the oil yield was higher than those of coal alone runs. The SCETOs were characterized using spectroscopic (FTIR) and chromatographic analytical techniques (GC–MS). GC–MS, and FTIR results showed that the oils are mainly comprised of alkyl aromatic species. A significant amount of alkyl-substituted phenol compounds was also found to be present in the oils.     

Analysis of the behaviour of pollutant gas emissions during wheat straw/coal cofiring by TG-FTIR

The behaviour of pollutant gas emissions during the firing of wheat straw and coal blends was examined experimentally by using thermogravimetric analysis (TGA). Typical anthracite coal and wheat straw in central China were selected in this study. The ratio of coal to wheat straw by mass was set as 10:90, 15:85, 40:60 and 60:40 and the firing was carried using simulated air with oxygen and nitrogen gases. The emission characteristics of gas pollutants such as HCl, SO₂, CO₂ and NO_x were determined by coupled Fourier transform infrared (FTIR) measurements. The results showed that HCl, SO₂, CO₂ and NO_x emissions were closely related to the volatile combustion and char reacting stages. HCl emission was mainly released during the volatile combustion at the temperature between 220 and 450 °C. The profiles of HCl against temperature exhibit a single-peak, and the HCl peak occurred at 310 °C for all blends no matter what the ratio. The emission profiles of SO₂, and NO_x against temperature had the characteristic of two peaks. The first peak occurred around 320 °C for all blends, and however the second peak shifted towards higher temperatures as the coal content was increased in the blends. The study showed that combining the straw and coal can produce better emission control by reducing the magnitude of the peak releases. The analysis showed that the blended sample with 40% coal and 60% straw by mass produced the lowest levels of HCl, NO_x and SO₂ gas emissions. The CO₂ emission was mainly produced in the char combustion stage and purely increased with the carbon content in the blends.     

胡萝卜中β-胡萝卜素提取工艺的优化研究

采用有机溶剂浸泡法从新鲜胡萝卜中提取β-胡萝卜素,比较不同提取剂的提取效率,确定提取效率较好的提取剂,并优化了提取工艺条件(如提取剂、料液比、提取温度、提取时间等).结果表明,采用丙酮:甲醇(体积比)=7 ∶2的混合溶剂作为提取剂,在料液比(g:mL)为1∶4、提取温度为40℃的条件下提取1h,再用石油醚萃取2次,提取...     

平朔煤CS2萃取物GC/MS分析

采用溶剂萃取和色 -质联用结合色谱保留值的定性方法 ,分析研究了平朔煤 CS2 萃取物的化学组成 ,鉴定出 1 80多种化合物 ,并对鉴定出的单个化合物进行了定量分析 ;讨论了平朔煤CS2 萃取物化学成分的结构特征 .结果表明 :萃取物主要由脂肪烃、芳烃和极性化合物三类成分组成 ;芳烃含量在萃取物中占绝对优势 ,且主要为 2 - 4环的烷基取代芳烃 ;脂肪烃除主要成分正构烷烃外 ,还有少量的类异戊二烯烃和萜烷 ;极性化合物所占的比例很小 ,并首次在煤中发现邻二氯苯 .     

童亭亮煤索氏萃取和超声萃取的GC/MS分析

采用CS<,2>对童亭亮煤进行索氏萃取和超声萃取,用气相色谱/质谱联用仪(GC/MS)对相关萃取物进行分析,结果表明:童亭亮煤的索氏萃取物由正构烷烃和芳烃构成,而超声萃取物还检测到异构烷烃和各类杂原子化合物,并且随着超声萃取时间的增加,所检测到的物质种类更多结构也更复杂;而超声波的空化效应产生的冲击流能促进溶剂和煤样的...     

Viscosities of coal—water—methanol mixtures

A plot of viscosity measurements for coal—water—methanol mixtures vs. percentage methanol in the liquid indicates that the viscosities of both coal—water and coal—alcohol slurries are increased by the addition of the second liquid. The shape of the slurry viscosity curve is very similar, on a greatly exaggerated scale, to the plot of viscosity versus percentage methanol for the pure liquid mixtures. Measurements were made as a part of a test program involving coal—water-methanol fuels. Initial mixtures were 60 wt% Pittsburgh seam coal in liquids composed of varying proportions of water and methanol. Slurries of Montana Rosebud and Texas Lignite coals in water—methanol mixtures also displayed viscosity maxima, but at different fractions of methanol. There was no viscosity peak for 40, 50 or 55% petroleum coke slurries. Slurries of ground glass in water-methanol mixtures were evaluated for comparison and a viscosity maximum was observed, although the peak occurred at a methanol concentration somewhat lower than it occurs in the pure liquid mixture.