Method for detecting free radical ration in coal tar

Abstract

The invention discloses a method for detecting free radical ration in coal tar. The method comprises the steps of removing moisture in the tar in a high speed centrifuging manner, and preserving a tar sample under low temperature or inert atmosphere; adopting a diamagnetism substance to deliquate DPPH(1,1-Diphenyl-2-picrylhydrazyl radical 2,2-Diphenyl-1-(2,4,6-trinitrophenyl) hydrazyl) to prepare a plurality of DPPH standard samples with different free radical concentrations, carrying out EPR (electron paramagnetic resonance) measurement, carrying out secondary integration on an EPR spectrogram, and recording the corresponding secondary integration area; establishing a standard curve according to the free radical contents of the DPPH standard sample with different free radical concentrations and the secondary integration area of the corresponding EPR spectrogram; and filling the tar sample into a pipe, measuring according to the same EPR measuring condition, carrying out secondary integration on the measured EPR spectrogram, and substituting the secondary integration area into the standard curve so as to obtain the free radical content N. The method provided by the invention can exactly measure free radical content in coal tar, meanwhile, the change of the content of the free radical in the coal tar along with the preservation condition is exactly measured, and the method for detecting ration is provided for the research of the free radical in the coal tar and is very simple and easy.

Description

technical field [0001] The invention relates to a method for quantitative detection of free radicals, in particular to a method for quantitative detection of free radicals in coal tar. Background technique [0002] Coal is the main energy source in my country, accounting for about 70% of primary energy for a long time. The pyrolysis of coal refers to the complex process of a series of physical changes and chemical reactions that occur when coal is continuously heated to a higher temperature in the absence of air or in an inert atmosphere. Coal pyrolysis produces semi-coke, tar, and pyrolysis gas. In recent years, due to the shortage of petroleum resources, the production of low-temperature tar by coal pyrolysis has attracted more and more attention. Low-temperature coal tar refers to the tar produced when the pyrolysis temperature is 600°C or below. It is a chemical raw material with high added value. A large amount of paraffin contained in low-temperature coal tar can b...

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Problems solved by technology

[0007] The purpose of the present invention is to overcome the defects of the above-mentioned prior art, such as difficulty in testing tar samples, containing a certain amount of water, low free radical content and instability, etc., find out suitable storage conditions before tar measurement, and provide a coal tar Method for Quantitative Detection of Free Radicals in Medium

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