Study On Solvent Extraction-Column Chromatography Extracting Crude Phenol From Coal Tar

In northwestern shaanxi province has proven the biggest coal-shenfu dongsheng coalfield in China, the coal is mainly low metamorphic Jurassic coals, which is of good quality, easily accessible, and has high oil content, and has the "natural clean coal" title. In the local has been formed low temperature carbonization industry(semicoke) with considerable scale. Low temperature coal tar is byproducts of low temperature carbonization of coal, its composition is very complicated, which contains more polyphenols (20～30%), phenolic compounds are important chemical raw materials with high added-value. For a long time, because of the lack of understanding of the composition of the coal tar, the valuable resources are practically sold to other provinces or other countries, or directly as a fuel oil use. Nowadays, demonstration projects such as full fractions hydrogenation and delayed coking-hydrogenation of low temperature coal tar are being established in Shanbei region, However, it is harmful for the hydrogenation of fuel oil, for they can increase the hydrogen consumption as well as the carbon residual and other negative effects. Therefore, extracting from low-temperature coal tar polyphenols is one effective way of comprehensive utilization of low-temperature tar.In this paper, taking low temperature coal tar in Shanbei regions as the object of study. Firstly, the basic properties of low temperature coal tar were obtained referring to the analysis methods of petroleum products and coking products. Current, the method of extracting crude phenol from coal tar mainly is the "Acid-base method" in industry, this method is of complicated equipment, high cost, a large amount of water consumption. On the basic characteristics of low temperature coal tar, proposed the coarse extraction method for low temperature coal tar:solvent extraction-column chromatography. According to application requires of the device, doing the following experimental research, which can provide theoretical basis date for the solvent extraction and column chromatography device.According to the corresponding method in the national standard, the content of total phenol in raw material H-tar is30%. Using60-200mesh size of silica gel, the experiment determined silica gel adsorption of phenols with Heptane for extracting agent in different particle sizes, and fitted silica gel adsorption of phenols curve. With the decrease of the particle size of silica gel, adsorption capacity according to the curve changes gradually. Using n-heptane/ethyl acetate as eluting agent for low temperature coal tar by gradient elution, which is good for separation of low temperature coal tar into neutral oil fraction, and rich phenolic fraction, ethyl acetate on phenolics were very selective enrichment. Quality of Neutral oil saturation accounted for56.8%in deasphalting coal tar, hydrocarbon material accounted for75.8%in elution fraction. Through the GC/MS testing analysis, mainly for the C14-C44of alkanes and alkenes, neutral oil fraction can be used as hydrogenation of gasoline, diesel, fuel oil manufacturing raw materials. Rich phenolic fractions accounted for37%in deasphalting coal tar,75.2%of Rich phenolic fractions is phenolic content, which mainly is phenol, methyl phenol, ethyl phenol, naphthol and so on.This research is of certain theoretical guidance significance to the extraction and application of phenolic compounds in low temperature coal tar, it provides theoretical basis data for low temperature coal tar with high added value.