Naphthalene is the most simple, commonly found, and most watersoluble PAHs in the environment. It is produced from coal tar fraction by crystallization and distillation. It is often used as dispersants in natural and synthetic rubbers, in the production of naphthalene sulfonate superplasticizers for concrete, in paints, tanning agents in the leather industry, in the production of the ...
Naphthalene, acenaphthene and luorene are wellknown organic chemicals that are useful as intermediates in the production of organic acids, dyes and insecticides. Previously acenaphthene and iluorene have been recovered from coal tar distillates or prepared by synthetic methods.
naphthalene oil. NPCs. normalphase columns. OBSG. octyl bonded silica gel. OCAs. ... while the latter is a byproduct from coal coking process [1]. The output of coal tar accounts for 35% of coals in the furnace [2]. ... Li YC, Xin WL, Huang MG, et al. Industrial production technology of coal series needle coke. CN A, ...
The tar production rate is kg/s and is analyzed to contain 85% carbon and 15% hydrogen by weight. The heating value of the tar is 42,000 kJ/kg. The oxygen is produced from air using an oxygenseparation unit that consumes 4000 kJ of energy/kg of the oxygen produced (assume full conversion of char).
Most naphthalene is derived from coal tar. From the 1960s until the 1990s, significant amounts of naphthalene were also produced from heavy petroleum fractions during petroleum refining, but presentday production is mainly from coal tar. Approximately tons are produced annually. Naphthalene is the most abundant single component of coal tar.
To develop the in situ underground pyrolysis process of tarrich coal more scientifically, the effect of temperature and pressure on the distribution of pyrolysis products should be clarified. This paper selected the typical components in five distillates of light tar, phenol tar, naphthalene tar, washing tar, and anthracene tar as the main reaction products. 32 typical secondary reactions ...
Naphthalene was first isolated from coal tar in 1819 by Alexander Garden; it represents about 10% of this complex mixture of aromatics. The industrial importance of naphthalene dates from the latter half of the last century, owing mainly to the ease with which it can be converted into sulfonic acids and thence also to the naphthols, for use as dyestuffs intermediates.
High temperature coal tar (HTCT) is a coproduct of the coking process, whose objective is the production of metallurgical coke for use in the production of pig iron in blast furnaces. According to FernándezGarcía et al. (2017), HTCT is obtained with a yield of about 35 wt% in coking.
It processes the naphthalene fraction from the rectification of coal tar so as to produce naphthalene of grade A and type II according to Technical Specifications TU 14797. Until November 2020, the naphthalene was produced at MMK by solidification of the naphthalene fraction and subsequent mechanical separation of the naphthalene crystals ...
Coal tar. María Antonia Diez, Roberto Garcia, in New Trends in Coal Conversion, 2019. Concluding remarks. With coal tar as a byproduct from cokemaking, coal tar availability will continue to depend on the consumption of coke in the blast furnace for iron and steel production. Thus, the conditions of coke production in recovery coke ovens will play a decisive role in determining ...
1. Introduction. With the development of coal utilization technologies such as gasification, liquefaction, carbonization, and coking, a large number of coal tar or coal tar byproducts have been produced, among which carbonization and liquefaction are the processes with coal tar as the main product. 1,2 Although medium and lowtemperature coal tars have higher contents of aliphatic ...
But because that its relative density is higher than and asphaltene content is close to 50% [6] (mass fraction), hightemperature coal tar is not suitable for the production of aerospace fuel. Medium and low temperature coal tar is a liquid product with high condensation degree obtained by pyrolysis of lowrank coal at 600 to 800°C.
The gasification process was started by igniting a coal seam using a pyrotechnic charge. The ignition occurred with low oxygen flow rate (2 Nm 3 /h) supplied into the reactor inlet. After ignition of the coal, the oxygen flow rate was increased to 10 Nm 3 /h. The process initiation was considered complete when the concentration of oxygen in the process gas was below 1%.
100 samples of recycle solvent were obtained by continuous operation (50 days) of 1 ton/day coal liquefaction plant at Kimitu. Naphthalene derivatives in the recycle solvents were anslyzed in ...
Odour: Peculiar, naphthalenelike (Singh, Goyal and Kaur, 2015) ... PROCESS DESCRIPTION Coal Tar ... 2019. Coal Tar Production Processes and Potential of PAHs Release into the Environment. [online ...
The naphthalene content in the commercial product derived from coal tar by the proposed method is wt %. The yield of naphthalene is wt %. The energy consumption in the basic three ...
A kind of method for preparing naphthalene at first is a Doak Tar Oil, and the boiling range of further purifying is 205～235 ℃ a coal tar distillate that obtains like this is commonly referred to naphtalene contain the such heterocycle component of naphthalene, methylnaphthalene, phenolic compound and benzothiophene, (G, people such as Gilbert, Ind, Eng, Chem, 53 ...
An online condensation system was designed to separate coal tar during cooling process. ... The typical contents of most common specialties in different fractions for coal tar are Light oil, Phenol oil, Naphthalene oil, washing oil, anthracene oil. ... The production yield of total tar was about %, %, % and % for 500, 600, 700 ...
Coal tar is a thick dark liquid which is a byproduct of the production of coke and coal gas from coal. It is a type of has both medical and industrial uses. Medicinally it is a topical medication applied to skin to treat psoriasis and seborrheic dermatitis (dandruff). It may be used in combination with ultraviolet light therapy. Industrially it is a railroad tie preservative and ...
The naphthalene samples studied in this work were produced by the chemical industry. Fig. 1 shows a process for the production of naphthalene with different degrees of purity. The refined naphthalene came from the catalytic hydrogenation process, (NAFR) (% purity); the industrial naphthalene from a series of distillations (NAFD) (% purity) and the crystallised naphthalene (NAFC) (99 ...
Crystallization has advantages for the production of highly purified products, such as operation at low temperatures compared to vaporliquid processes, ... Purification of naphthalene from naphthalenerich oil of coal tar distillates was explored by using the melt and solution crystallizations. The solidliquid equilibrium of naphthalene ...
Abstract In this study, the steam reforming of naphthalene and pyrene as heavy tar model compounds was investigated experimentally in a horizontal tube reactor and theoretically using the CHEMKIN simulation. The experimental results revealed that the reactivity of naphthalene was higher than that of pyrene in the presence of steam. The carbon content converted to soot is a little more than ...
The presentday process for fractionating coal tar primarily used in industry is continuous distillation. from the coal tar. When coal tar is received, it contains from 3% to 10% water. storage tank through a series of heat exchangers to increase the temperature from about 175OF to about 40OOF. The primary heat source . is . supplied by the
Naphthalene production and uses 299 Naphthalene recovery Coal tar is the traditional feedstock for the recovery of naphthalene. The introduc tion of new cracking processes in the last decades has given rise to the availability of petroleumbased raw materials. In addition to coalderived naphthalene, petro
PRODUCTION Naphthalene may be produced from either coal tar or petroleum. Distillation and fractionation of coal tar is the most common production process. The middle fraction (containing most of the naphthalene) is cooled, crystallizing the naphthalene. The crude naphthalene may be refined by distillation, washing, and
Coal Tar. L. Roberts, in Encyclopedia of Toxicology (Third Edition), 2014 Background (Significance/History) Coal tar is a complex hydrocarbon mixture produced by thermal destruction (pyrolysis) of coal, typically a dark viscous liquid or semisolid with a smoky or naphthenic odor. The composition of coal tar will be influenced by the process used for pyrolytic distillation as well as by the ...
© DZCrusher - كل الحقوق محفوظة
