Domínguez A, Blanco C G, Barriocanal C, Alvarez R, Díez M A
Instituto Nacional del Carbón, CSIC, Oviedo, Spain.
J Chromatogr A. 2001 May 18;918(1):135-44. doi: 10.1016/s0021-9673(01)00736-1.
The aim of this study was to determine the volatile products distribution of co-processing of coal with two plastic wastes, low-density polyethylene from agriculture greenhouses and high-density polyethylene from domestic uses, in order to explain the observed decrease in coal fluidity caused by polyethylene waste addition. Polymeric materials, although they are not volatile themselves, may be analysed by gas chromatography through the use of pyrolysis experiments. In this way, a series of pyrolysis tests were performed at 400 and 500 degrees C in a Gray-King oven with each of the two plastic wastes, one high-volatile bituminous coal and blends made up of coal and plastic waste (9:1, w/w, ratio). The pyrolysis temperatures, 400 and 500 degrees C, were selected on the basis of the beginning and the end of the coal plastic stage. The organic products evolved from the oven were collected, dissolved in pyridine and analysed by capillary gas chromatography using a flame ionization detector. The analysis of the primary tars indicated that the amount of n-alkanes is always higher than that of n-alkenes and the formation of the alkenes is favoured by increasing the pyrolysis temperature. However, this effect may be influenced by the size of the hydrocarbon. Thus, the fraction C17-C31 showed a higher increase of n-alkenes/n-alkanes ratio than other fractions. On the other hand, the difference between the experimental and estimated values from tars produced from single components was positive for n-alkanes and n-alkenes, indicating that co-pyrolysis of the two materials enhanced the chemical reactivity during pyrolysis and produced a higher conversion than that from individual components.
本研究的目的是确定煤与两种塑料废料（农业温室用低密度聚乙烯和家用高密度聚乙烯）共处理时的挥发性产物分布，以解释因添加聚乙烯废料而观察到的煤流动性下降现象。聚合材料本身虽不挥发，但可通过热解实验利用气相色谱进行分析。通过这种方式，在格雷 - 金转鼓试验炉中于400℃和500℃对两种塑料废料、一种高挥发烟煤以及由煤和塑料废料组成的混合物（质量比9:1）进行了一系列热解试验。热解温度400℃和500℃是根据煤与塑料共热解阶段的起始和结束温度选定的。从试验炉中逸出的有机产物被收集起来，溶解在吡啶中，并使用火焰离子化检测器通过毛细管气相色谱进行分析。对初级焦油的分析表明，正构烷烃的含量总是高于正构烯烃，且随着热解温度的升高，烯烃的生成更为有利。然而，这种影响可能会受到烃类大小的影响。因此，C17 - C31馏分中正构烯烃/正构烷烃的比值增幅高于其他馏分。另一方面，由单一组分产生的焦油的实验值与估算值之间的差异对于正构烷烃和正构烯烃来说是正值，这表明两种材料的共热解增强了热解过程中的化学反应活性，并且比单一组分产生了更高的转化率。
