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ДонНТУ >
Портал магистров ДонНТУ
Faculty: Ecology and Chemical Technology
Speciality: Chemical technology of fuel
1.Source and conditions of the resin.
2.Influence of technological factors on yield, composition and properties of the resin.
3.Coal tar as a physical-chemical system.
4.Coal tar as a dispersion system.
5.Technological properties of resins and their evaluation.
6.Theoretical basis of coking coals and the heat produced by batch.
7.Plastical condition and sintering.
8.Changing some properties of coals, with their thermal preparation.
9.Output and coking quality of chemical products.
Currently in the literature there is very little information on the impact of pre-heating the charge at the output and quality of chemical products coking.
The reason for this is poorly understood process of heat production and the lack of data on thermally prepared coking coals in semi-wide.
A topical issue of intensification high temperature pirolysis of coal in the coking batch thermally prepared coal raw material base allows you to expand and improve the quality of coke. The process of thermal coal a substantial impact on the main technological properties of heated coal or charge, which ultimately affects the output and quality control of chemical products coking, in particular coal tar. Therefore, the study of physical-chemical properties of rock in the coal tar thermo preparing coking coal charge is a serious problem.
В настоящее время в литературных источниках очень мало сведений о влиянии предварительного нагрева угольной шихты на физико-химические свойства каменноугольной смолы. Это объясняется недостаточной изученностью пиролизных процессов протекающих в камере коксования, протекающих в камере коксования термически подготовленной шихты в промышленных масштабах. Для изучения влияния предварительного подогрева угольной шихты на выход и свойства каменноугольной смолы в Украине была проведена серия экспериментов на промышленной установке термоподготовки шихты одного из коксохимических заводов. Исследование физико-химических свойств каменноугольных смол, полученных при коксовании предварительно нагретой угольной шихты в промышленных условиях, представляют научную новизну данной работы.
Currently in the literature very little information on the impact of pre-heating the coal charge on the physical-chemical properties of coal tar. This is due to inadequate research pyrolysis processes occur in the chamber coking occurring in the chamber coking thermally prepared charge on an industrial scale. To study the influence of pre-heating the coal charge in the output and the properties of coal tar in Ukraine has been a series of experiments on plant thermal preparing charge of coke plants.
Investigation of physical-chemical properties of coal tar obtained during pre-heating coking coal charge in the industrial conditions of scientific novelty of this work.
Coal tar is a unique, non-unique commodity source of condensed aromatic and heterocyclic compounds, the third volume of production after coking coke and gas. Changes in the quality of the resin may have a negative impact on its consumer properties. Therefore, the results of the research will provide an opportunity to quickly and purposefully to influence the technological properties of coal tar in the coking batch thermal preparing.
Coal tar "born" in the chamber coke oven battery, which is a kind of reactor, which is realized in the complex processes of thermo chemical conversion of organic mass of coal and volatile products of decomposition, the general laws of chemical kinetics and thermodynamics [1].
Thermodynamic more likely is not the process of recovery of phenols to the corresponding hydrocarbons (CRESOLS → toluene, xylenol → xylol) and then turning them into benzene, and the direct conversion of phenols in benzene, without intermediate stages [2].
Theoretically, anything that relates to the coking technology, starting with the brand of the charge, its preparation, design of furnaces, coking conditions to the issuance of coke, and even level of operation of coke batteries and the separation of condensation, has an impact on output, the composition and properties of the resin. The chemical composition of the resin is formed in the coke ovens, and working conditions of office of condensation on it practically does not affect.
In [3, Art. 27-29, 4, Art. 32-36, 5, Art. 34-36] is a list of compounds belonging to the high coking coal tar in appreciable quantities, which determine their practical value in technology for the processing of the resin. These data illustrate the fairness of a well-known fact: coal tar in significant quantities only contains a small number of substances.
There are a number of representations of the resin of high coking coal batch, distinguishing it on grounds of education and use, particularly the chemical composition, the presence of azeotropic and colloidal systems.
Our approach to the characterization of coal tar as a physical-chemical system based on an assessment of the properties of the resin, a manifestation of that in the process of processing determines the solution of practical problems of technology. From this perspective, the most important characteristics of the resin as a physical-chemical system includes dispersion, reactivity and intermolecular interactions of resin compounds, leading to the formation of molecular complexes, and associates, including singular mixtures, eutectics and solid solutions.
Coal tar - a typical system that has all the properties of dispersed systems. Dispersed phase resin in the form of solid, liquid and gaseous dispersed particles distributed in a dispersion medium, which serves as a multi component mixture of organic compounds and their multiple molecular entities, resulting in liquid resin. In studying the electronic structure of dispersed particles (α-and α1 - fraction), coal tar found [6, Art. 29-32] that the concentration of paramagnetic centers (PMTS) in α - fraction than in the corresponding α1 - fractions, characterized by greatly streamlining the structure of the conduction electrons, not permit contribution to the paramagnetic absorption noted that α2 - fraction (α = α1 + α2) is characterized by structures containing unpaired electrons, but do not have sufficiently extensive dual system.
Coal tar delivered to the processing of resin processing plant, is a dehydrated mixture of resins and averaged gas collector and cooling cycles.
According to the existing technical specifications (TU 14-6-171-80) coal tar produced two grades: grade A, 1st and 2nd class - for the production of the electrode pitch, Mark B, 1st class - for the pitch used in the production of pitch coke, 2nd class - for other types of pitch [7]. Cryoscopic and chemical methods for determining small quantities of compounds in coal tar pitch require high labor costs and time, and often not sufficiently accurate. Instead, they use chromatographic methods of analysis [8].
In the process of thermal change of the physical-chemical properties of coals, which affects the process of coking and the quality of coke. Thus, when heating coals occur simultaneously and the following reaction processes:
Out of consideration of chemical process coking coals implies that the heat produced during coking coals crucial speed and temperature to which the hot charcoal.
Pre-heat coal preparation improves their sintering, as well as:
Changing the sintering, the density of the coal loading and other properties of coal in the process of preparation of their heat is described below.
Found that an increase in moisture content of coal from 4.6 to 6.2% accompanied by a slight increase in gas output and some changes in its composition. However, the influence of pre-heating of coal output and composition of chemical products, with coking coals in the factory is still not clear, because so far, in fact there had been no comprehensive and reliable studies of this phenomenon on an industrial scale. On heating of coal initially allocated occluded and adsorbed gases (O2, CO2 and N2), moisture, and then the decomposition products are formed.
The most easily degradable oxygen-containing compounds, therefore, at the beginning of thermal decomposition of coal gas, containing significant quantities of CO2.
Analyzing obtained in laboratory studies experienced data, it can be concluded that the heat produced during coking batch conditions volatile pyrolysis products of some other than when coking raw batch. Studies with several stock shows that the thermal preparation charge slightly softens conditions for pyrolysis of volatile products during coking.
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2. Т.Я. Гоголева, З.И. Шустиков, Химия и технология переработки каменноугольной смолы- М.: Металлургия, 1992. - 256 c.
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6. О.П. Гнилоквас, Г.Ю. Чистова, А.В. Бутакова и др. Опытно-промышленные испытания очистки каменноугольной смолы с присадкой АзНИИ//Кокс и химия. 1987. №5.
7. Б.Н. Житов, Г.Н.Макаров, К.И. Сысков, Коксование термически подготовленных углей. Изд-во «Металлургия», 1971, с.272.
8. Л.И. Мариич, Газовая хроматография в коксохимическом производстве.-М.: Металлургия, 1979. - 192с.