CN-117214382-B - Method for rapidly predicting VOCs emission characteristics through benzene series content

Abstract

The invention belongs to the technical field of environmental monitoring of coke oven gas recovery operation areas in coking industry, in particular to a method for rapidly predicting VOCs emission characteristics through benzene content, which is characterized in that the concentration ratio of benzene to toluene is utilized to rapidly infer the VOCs emission characteristics in coking process, the method specifically comprises the steps of determining sampling points, detecting the concentrations of benzene and toluene, respectively carrying out trend analysis by taking the ratio of benzene to toluene and the sum of benzene series concentration and the total concentration of VOCs as ordinate, and predicting and judging the VOCs emission condition of the sampling points of each process of the chemical recovery part of the coking process. Compared with the prior art, the method has the advantages that the concentration ratio of benzene to toluene is particularly utilized by utilizing the concentration of benzene, the VOCs emission characteristic of the coking process can be rapidly estimated, the VOCs emission condition of each process of the chemical recovery part of the coking process can be predicted and judged, and the method has the advantages of simplicity in operation and high efficiency.

Inventors

• ZHENG YOUZHI
• PANG KELIANG
• Meng Xinyang
• WAN CHAORAN

Assignees

• 鞍钢集团北京研究院有限公司

Dates

Publication Date

20260505

Application Date

20230908

Claims (3)

1. 1. A method for rapidly estimating the emission characteristics of VOCs through the content of benzene series is characterized in that the concentration ratio of benzene to toluene is utilized to rapidly estimate the emission characteristics of VOCs in a coking process, and the method specifically comprises the steps of determining and detecting the concentration of benzene and toluene at sampling points, respectively carrying out trend analysis by taking the ratio of benzene to toluene, the sum of the benzene series concentration and the total concentration of VOCs as ordinate, and predicting and judging the emission conditions of VOCs at the sampling points of each process of a chemical recovery part of the coking process; the sampling point is any one or the combination of more than two of a benzene storage tank, a debenzolization procedure, a desulfurization procedure, a tar tank top, an ammonium sulfate procedure and a cold drum procedure; The trend analysis comprises calculation and point location trend graph drawing, wherein the trend graphs are respectively made by taking the serial numbers of all sampling points as the abscissa, taking the ratio of benzene to toluene, the sum of benzene series concentration and the total concentration of VOCs as the ordinate, and the three groups of images are subjected to comparison analysis to obtain the VOCs emission condition of the sampling points of each procedure, which is specifically as follows: (1) The formula of the benzene to toluene ratio is: (equation 1) In the formula (1), R 0 - -the ratio of benzene concentration to toluene concentration, C PhH - -the benzene concentration detected, C PhMe - -the toluene concentration detected; (2) The formula of the total benzene series concentration is: (equation 2) C 1 、C 2 、C 3 - -concentration of benzene series, μg/m 3 (formula 3) (3) The formula for the total concentration of VOCs is: (equation 4) In the formulas (2) and (3), the concentration of C PAMS -57 PAMS gases, the concentration of mug/m 3, C OVOCs -13 aldehyde ketone substances, the concentration of mug/m 3, C TO15 -47 other volatile organic substances and the concentration of mug/m 3 are shown in the specification; The benzene removal process is eliminated because of the uniqueness of the process, when the R 0 value is higher than 1, namely the benzene concentration is higher than the toluene concentration, the benzene concentration and the total concentration of VOCs are higher, and when the R 0 value is lower than 1, namely the benzene concentration is lower than the toluene concentration, the benzene concentration and the total concentration of VOCs are normal, so that the emission characteristics of the VOCs in each process can be judged according to a trend graph of the R 0 value.
2. 2. The method for rapidly predicting the emission characteristics of VOCs according to the content of benzene series, wherein the detection is carried out by the method specified in the standard of measuring tank sample gas chromatography-mass spectrometry of volatile organic compounds in ambient air (HJ 759-2015) and the standard of measuring high performance liquid chromatography of aldehydes and ketones in ambient air (HJ 683-2014).
3. 3. The method for rapidly predicting emission characteristics of VOCs according TO claim 1, wherein the organic matters in the standard adopted in the detection are 117 VOCs which may affect human health and are defined in the environmental protection department's environmental air volatile organic matter monitoring scheme in 2018, which includes 57 volatile organic matters (original PAMS), 13 aldehyde ketones (OVOCs) and 47 other volatile organic matters (part TO 15).

Description

Method for rapidly predicting VOCs emission characteristics through benzene series content Technical Field The invention belongs to the technical field of environmental monitoring of coke oven gas recovery operation areas in the coking industry, and particularly relates to a method for rapidly predicting VOCs emission characteristics through benzene series content. Background VOCs (volatile organic compounds ) refer to organic compounds that participate in atmospheric photochemical reactions. VOCs are not only important precursors of O3 and PM2.5, but also important contaminants that affect human health. The coking industry is one of the very important VOCs industrial emission sources, and the VOCs emission in the coking industry has a series of problems of high concentration, multiple emission sources, various emission types, difficult treatment and the like due to the process specificity. The existing VOCs detection method generally follows 35 organic matters in the standard HJ 644-201 'determination adsorption tube sampling of volatile organic matters in ambient air-thermal desorption/gas chromatography-mass spectrometry' or 24 organic matters specified in the standard HJ 734-2014 'fixed pollution source waste gas determination solid-phase adsorption-thermal desorption/gas chromatography-mass spectrometry of volatile organic matters'. The environmental protection department issued in 2017 a scheme for monitoring Volatile Organic Compounds (VOCs) in the environmental air in the key region in 2018 formally prescribes that VOCs with strong photochemical reaction activity to be detected or possibly affecting human health comprise 117 kinds of alkane, alkene, aromatic hydrocarbon, oxygen-containing volatile organic compounds (OVOCs), halogenated hydrocarbon and the like. Including 57 volatile organics (raw PAMS material), 13 aldehyde ketones (OVOCs) and 47 other volatile organics (part TO15 material). Aromatic hydrocarbons have been the key component of PAMS gas and have been the subject of research. The generation and coexistence mechanism of substances such as benzene, toluene, xylene and ethylbenzene can reveal the generation rule of VOCs. The benzene/toluene/ethylbenzene/xylene ratio (B/T/E/X) is often used to determine the source of benzene series. BTEX sources are complex, fossil fuels, motor vehicle exhaust and certain industrial engineering are their primary sources. The B/T values of benzene and toluene are considered to be important indicators for identifying the contribution of motor vehicle exhaust to hydrocarbons in air. The ratio of meta-para-xylene to ethylbenzene can also be used to estimate the hydrocarbon life in the atmosphere. Pilar et al (1973) propose for the first time that the toluene/benzene concentration ratio can be used to analyze the source of benzene series in air. The ratio of meta-para-xylene to ortho-xylene can also be used to distinguish between emissions characteristics of benzene series from various sources of pollution. The B/T in the benzene series emission of the motor vehicle is about 0.5 (PERRY AND GEE,1995;Brocco et al,1997). The combustion release of the coal, biomass and charcoal in the power station is 1-2. He Qiusheng (2006) the ratio of some machine coke fumes was around 6. The existing detection means require a large amount of experiments and analysis work, so that the timeliness of gas analysis is low, and the VOCs emission condition of each process cannot be responded quickly. Disclosure of Invention The invention aims to provide a method for rapidly estimating the VOCs emission characteristics through the content of benzene series, which overcomes the defects of the prior art, utilizes the concentration of benzene series, particularly utilizes the concentration ratio of benzene to toluene, rapidly estimates the VOCs emission characteristics of a coking process, and predicts and judges the VOCs emission condition of each process of a chemical recovery part of the coking process. Or comparing the trend graph of the ratio of benzene to toluene with the trend graph of the total benzene content and the trend graph of the total VOCs to finish the judgment of the VOCs emission characteristic of the quick analysis chemical recovery part. In order to achieve the above purpose, the present invention is realized by the following technical scheme: A method for rapidly estimating the emission characteristics of VOCs through the content of benzene series is characterized by rapidly estimating the emission characteristics of VOCs in a coking process by utilizing the concentration ratio of benzene to toluene, and specifically comprises the steps of determining sampling points, detecting the concentrations of benzene and toluene, respectively carrying out trend analysis by taking the benzene to toluene ratio, the sum of the benzene series concentrations and the total concentration of VOCs as ordinate, and predicting and judging the emission conditions of VOCs in sampling poin