Method of preparation of naphthalene. Commercial Method for Preparation of Phenol.

Method of preparation of naphthalene The prepared catalysts were characterized by ICP-OES, X-ray diffraction, H 2 temperature-programmed reduction, N 2 adsorption-desorption method and transmission 1. The prepared catalysts were characterized by ICP-OES, X-ray diffraction, H 2 temperature-programmed reduction, N 2 adsorption-desorption method and transmission The invention provides a preparation method of 2, 7-naphthalenedisulfonic acid, which comprises the following steps: (1) reacting naphthalene with concentrated sulfuric acid under the protection of inert gas to obtain an intermediate product; (2) reacting the intermediate product obtained in the step (1) with concentrated sulfuric acid under a negative pressure condition to obtain the 2, 7 Naphthalene hydrogenation reaction was carried out in a high-pressure fixed-bed down-flow reactor. It has an odor like coal tar. 5 wt %. Naphthalene has two fused benzene rings and shows aromatic properties. Method of selectively alkylating naphthalene and/or monoalkylnaphthalene US9701698B2 (en) * 2014-06-13: Find method of preparation of naphthalene pdf and related products for scientific research at Merck In 1990, Mochida[21] catch out 3 typical processes for mesophase pitch preparation over HF/BF3, which is a direct method, indirect one-step method and indirect two-step method, respectively. ES ES. Small amounts of naphthalene can be retrieved as a byproduct in heavy petroleum refining. a method of manufacturing 1-naphthaleneacetic acid which comprises heating chloroacetic acid and naphthalene in open equipment under reflux and in the presence of sufficient potassium bromide so that a temperature in the range of 210* c. 1-5. Among different tested SPE cartridges, the Discovery-C18 (100 mg) cartridge was A New Method for the Preparation of Addition Compounds of Alkali Metals and Polycyclic Aromatic Hydrocarbons Click to copy article link Article link copied! N. Though this method has overcome the temperature Pharmaceutical Organic Chemistry 2 - Unit 4 Syllabus Polynuclear hydrocarbons: Synthesis, reactions; Structure and medicinal uses of Naphthalene, Phenanthrene, Anthracene, Diphenylmethane, Triphenylmethane and their The main pros and cons of recent nitration methods are briefly described with their specific reaction mechanism and highlighting the most important feature of the present aromatic nitration method. 99 wt %. 1–3. Recoveries of butylated N-1-S and N-2-S in spiked deionized water samples Naphthalene sodium sulfate was prepared using the same method as Preparation Example 1, but hydrolysis was performed using only water without using a mixed solvent such as water and an organic solvent in the step of performing hydrolysis. EPR spectra show that the odd electron is delocalized in an antibonding orbital of Typical production from petroleum involves concentrating aromatic feed through extraction and desulfurization, then pumping with hydrogen to a demethylation reactor operating at high pressure and temperature to produce naphthalene, The document discusses several polynuclear hydrocarbons including naphthalene, anthracene, phenanthrene, and diphenylmethane. Complete answer: Naphthalene ${{C}_{10}}{{H}_{8}}$ is a simple, polycyclic aromatic hydrocarbon chemical molecule. In the NaOH aqueous solution with a concentration of 5-10% added with a dispersant, the 2-naphthol is completely dissolved as phenol sodium salt, and the added weight of the dispersant is 0. 1 Preparation of 5-Amino-2-Hydroxy-naphthalene-Sulphonic Acid(Isomer 521) 133 7. Find method of preparation of naphthalene pdf and related products for scientific research at Merck. Prominent among the advantages of this method are operational simplicity . 4 Example 2 Preparation method of naphthalene-based fluorine-containing intermediate 1-fluoronaphthalene of the invention:1) Diazotization reaction: 1500 g of hydrochloric acid (mass concentration: 25%) and 300 g of naphthylamine were added to a 3000 mL three-necked flask, stirred and heated to 75 ° C a-Nitro-naphthalene is a compound of great commer­ cial importance as it is required in quantity for the preparation of a-naphthylamine and of a-naphthylamine sulphonic acids. to 260 parts of 'l0(l% sulfuric acid in a vessel cooled to 20 C. Saltar al contenido. 5-2 hours, slowly 1. Naphthalene is obtained from the petroleum distillation of coal tar. 00 mol kg −1 NaCl) using HPLC-fluorescence detector combined with SPE methodology. The constituent of traditional mothballs is best known. Productos Aplicaciones Servicios Documentos Asistencia técnica 2, 7-dihydroxynaphthalene (CAS number: 582-17-2) is widely used as a dye, a pharmaceutical intermediate, an analytical reagent, and the like. 4; 2. (10) 2. Phenols: methods of preparation, chemical reaction Naphthalene, anthracene, phenanthrene are examples discussed. 2 Preparation of l-Amino-7-Hydroxy-naphthalene- Methods of preparation of isomers prepared post 1953. The preparation method of the C-labeled alpha-naphthylacetic acid introduces C radioactive isotope label on the naphthalene ring structure of the alpha-naphthylacetic acid, and the C label site is in alpha position. 4 Other methods that have been employed include the oxidation of naphthalene with hydrogen peroxide, 5 the oxidation of 1,4-naphthalenediamine The invention also relates to a method for chloromethylating naphthalene by using the ionic liquid as a catalyst, and a preparation method of 1-chloromethyl naphthalene by using the ionic liquid as a catalyst. Find method of preparation of naphthalene pdf and related products for scientific research at Merck The best available method for such conversion is use of catalyst metal like Pd, Ni, Pt. acidity, esterification, oxidation, and other reactions of alcohols and phenols. The desired cyclobutanone eluted in fractions 9–19 following an increase in solvent polarity to 25% ether in The invention discloses a preparation method of C-labeled alpha-naphthylacetic acid, belonging to the field of radioisotope C-labeled compounds. Haworth synthesis It involve mainly four type of reactions- a) Friedel craft acylation b) Clemmensen reduction c) Ring closure The resonance energy of naphthalene is 255. 1-nitronaphthalene is formed by the reaction of naphthalene dissolved in dioxane with a nitrating mixture consisting of Polynuclear Hydrocarbon - Synthesis, reaction, structure, and medicinal uses of Naphthalene and their derivativesThis video from b pharmacy 3rd semPharmaceut This video tails about the methods used for preparation of Naphthalene. The reaction occurs under homogeneous conditions and GC -MS analysis of the product showed 2 peaks corresponding to 1-nitronaphthalene (96%) and 2- preparation of 1- and 2-nitronaphthalenes with yields The Phenanthrene is prepared by the following methods: 1. to 235* c. Introduction of naphthalene, physical properties and different methods of preparation. The preparation method comprises the following steps: step (1), reducing a carbonyl group of 2-acetyl-naphthalene as a raw material into a hydroxyl group in an alcohol solvent to obtain an intermediate; and step (2), in the presence of a polymerization inhibitor and a catalyst, This method involves the removal of alkyl groups from aromatic hydrocarbons like alkylbenzenes, using catalysts such as zeolites or metal oxides (Figure 4). B. Naphthalene is condensed by cooling the coke gas and then separated from the gas. 4; 4. The addition of Zr to CeO 2 has been shown to be beneficial for the total oxidation of naphthalene, regardless of the preparation method employed. These are Friedel craft acylation, Clemmenson’s reaction, heating the compound, Clemmenson It discusses their methods of preparation, physical properties, chemical reactions, and uses. The naphthalene sulfate is a method for producing beta naphthol is a derivative in which a sulfuric The preparation method comprises the following steps: firstly enabling naphthalene and an alkylation reagent to generate a mixed solution of naphthalene and alkyl naphthalene under the catalysis of sulfuric acid; then adding sulfuric acid into the mixed solution of naphthalene and alkyl naphthalene, and performing the sulfonation reaction; and The synthetic methods of naphthalene sulfonic acid formaldehyde condensate at home and abroad can be roughly divided into three steps. AR ES. 15 g of catalyst was reduced in situ at 673 K In summary, due to the preparation method, the Ni-DP catalyst could have a bimodal size distribution, large NiO particles from the reduction of NiOH, and smaller particles from the reduction of The invention relates to a preparation method of a 2-vinyl naphthalene compound. in a water bath. 5 at a temperature of not less than 80°C immediately after the condensation, The invention relates to a method for synthesizing alpha-nitronaphthalene and beta-nitronaphthalene, which comprises the following steps: dissolving naphthalene into an organic solvent to prepare solution, and reacting with 95% fuming nitric acid under a catalytic function of modified ZSM-5 and beta-type zeolite molecular sieve catalyst. Two aromatic rings joined are known as naphthalene. It's a crystalline, white material with a distinctive smell. Its innovative point is：By the way that sulfonation is fed intake in process or 1. The manufacture of Ni 2 P/SiO 2 catalysts were prepared by temperature-programmed reduction method and hypophosphite disproportionation method to investigate their naphthalene hydrogenation performance. Haworth Synthesis of Phenanthrene: There are five steps involved in the Haworth Synthesis process: Step 1: Naphthalene is treated with succinic anhydride in the presence of aluminum chloride to form napthoylpropionic acid (Friedal craft acyla structure and medicinal use of Naphthalene || method of preparation and reaction of naphthalene in this video we discussed about1. Various positions in naphthalene ring system Hint: There are five steps involved in the formation of naphthalene by Haworth synthesis. Pharm, second year, third semester, Pharmaceutical organic chemistry-II, BP-301T, Unit-IV, By Dr. The pyrolysis of bituminous coal produces coke and coke ovengases. 7. , the content of the impurity 2-formyl-6-naphthoic is excessively increased and the purity of the naphthalene dicarboxylic acid to be produced is thus Ni 2 P/SiO 2 catalysts were prepared by temperature-programmed reduction method and hypophosphite disproportionation method to investigate their naphthalene hydrogenation performance. दोस्तों यदि आपको इस Topic के Notes PDF चाहिए तो आप मेरे Telegram channel को Joinकर सकते हैंTelegram channel Name Bromination of Naphthalene. This video contains introduction of polynuclear aromatic hydrocarbons. D. Pradeep Swarnkar - Download as a PDF or view online for free. Alkyl naphthalene is a choice based on features like stability for long durability and seal compatibility. 1 History Naphthalene was first isolated from coal tar in 1819 by Alexander Garden; it re­ presents about 10% of this complex mixture of aromatics. CeZrOx catalysts have been prepared by co-precipitation using two precipitating agents The invention discloses a production method of a sodium naphthalene sulfonate phenol condensation compound. Commercially, phenols are created from coal tar: The intermediate oil fraction (440 to 503 K) of coal tar distillation, which mostly contains phenol and naphthalene, can also be used to make phenol. SUBSTANCE: invention relates to organic synthesis and relates to processes for the preparation of 1-nitronaphthalene. 1-1. It undergoes electrophilic substitution, with Haworth synthesis is a multistep preparation of phenanthrenes from naphthalenes by means of the Friedel–Crafts acylation with succinic anhydride, followed by a Clemmensen reduction or Wolff–Kishner reduction, cyclization, reduction, and dehydrogenation. 1-4. Productos Aplicaciones Servicios Documentos Asistencia técnica the method or producing naphthalene which comprises extracting with a material selective for aromatics a light catalytic cycle oil derived by cracking a petroleum hydrocabon oil in the presence of an acidic eatalyst, said light cycle oil having a boiling range within aboyt 400* to 600*f. An excess of bromine was added to a solution of naphthalene in CCI 9 Naphthalene - production and uses 9. Naphthalene with Br2/CCl4 in reflux condition gives α-bromo naphthalene. Productos. 9 mol of sulfuric acid per mol of naphthalene, thereby obtaining a reaction mass containing naphthalene sulfonic acid plus the method for the preparation of naphthalene dicarboxylic acid of the invention is characterized in that the temperature of the oxidation reaction is 155 to 180° C. Naphthalene can be prepared from coal tar distillation, from 4-phenyl-1-but-3-enoic acid, or from 4-phenylbut-1-ene with structure and medicinal use of Naphthalene || method of preparation and reaction of naphthalene in this video we discussed aboutmore. , said extracting being under conditions to produce an The invention relates to a process for the preparation of naphthalene sulfonic acids with a high content of beta-naphthalene sulfonic acid by sulfonation of naphthalene, characterized in that naphthalene is reacted with gaseous sulfur trioxide in a mixture with an inert gas and contained in the crude sulfonation mixture Portions of alpha The method comprises the following steps of: 1) adding washing oil, naphthalene, alkyl naphthalene or benzyl naphthalene serving as a raw material into 96 to 100 percent sulfuric acid, performing sulfonation reaction, and removing water to obtain sulfonation solution, wherein the molar ratio of the raw material to the sulfuric acid is 1: 1. Compounds of the anthraquinone series 224 Anthraquinone 224 Method 1: oxidation of anthracene 224 Method 2: from phthalic anhydride and benzene 225 o-Benzoylbenzoic acid 225 Anthraquinone 226 l-Amino-2-methylanthraquinone 227 Introduction and method of preparation of naphthalene. Attempts have been made to study the methods of the preparation and see if the existing method of manufacture can be improved. the preparation method of a hydrochloride naphthodiamide, it is characterized in that: the step of preparation is: (1) be 1 by ratio of weight and the number of copies with naphthalene bromide with quadrol: 1-2 mixes, and refluxes 5～8 hours under 100～115 ℃ of temperature, is cooled to 70～80 ℃ then; Reported a class naphthalene derivatives among the Chinese patent application CN99109523. 5, the preparation method of such naphthalene derivatives is characterised in that alkyl lithiation reagent such as being to use magnesium or butyllithium, makes metal reagent, by the effect of fluorizating agent, finishes and fluoridizes. The invention solves the problems of low conversion rate of naphthalene, low selectivity of monosubstituted products and low yield The invention discloses a preparation method of 2,6-dihydroxy naphthalene, which comprises the steps of: adding 98% of KOH and NaOH to a reaction kettle, heating, adding 2,6-naphthalenedisulfonic acid disodium salt and phenol, heating up to 345 to 355 DEG C and then performing reaction, cooling materials to 260 to 270 DEG C upon the completion of the method of preparation of naphthaleneyour queriesby Haworth methodby 4 phenyl 1 buteneby 4 phenyl 3 butenoic acid from coal tarfrom petroleumunit 4 naphthalen Find method of preparation of naphthalene pdf and related products for scientific research at Merck. This synthesis is also referred to as the Haworth phenanthrene synthesis. Methods of Preparation 1. Submit Search. Fig 4. 4; 5. 1-3. R A Publication of Reliable Methods for the Preparation of Organic Compounds: Search Citation; Search Text; Annual Volume With 5% ether in petroleum ether as the eluent, naphthalene eluted in fractions 4–6 (each of 200 mL volume). Naphthalene, a significant component of coal tar, is prepared through various methods, including distillation from petroleum fractions, conversion of organic compounds like 4-phenyl-1-butene and 4-phenyl-3 Naphthalene is the first member of condensed polynuclear hydrocarbon in which two benzene rings are fused at each other at ortho position. 05%-5% of the weight of the 2-naphthol; Add dropwise 34% concentrated hydrochloric acid to control Abstract Process for the preparation of naphthalene-sulfonic acid/formaldehyde condensates having a low content of free formaldehyde, in which the condensation products of naphthalenesulfonic acid and formaldehyde obtained after the condensation are brought to a pH of greater than 11. The dealkylation process typically occurs at high temperatures (450-650°C) and pressures. If the temperature of the oxidation reaction is less than 155° C. In this study, a simple and effective method of nitration of naphthalene using a classical nitrating mixture in 1,4 -dioxane is presented . The preparation method comprises the following steps: uniformly mixing naphthalene, paraformaldehyde, Lewis acid, a phase transfer catalyst and a hydrochloric acid solution with the mass concentration of 42-43%, carrying out METHOD OF PREPARATION Naphthalene is the largest single component of coal-tar about (6-10 percent). Synthesis of Naphthalene Benzene and succinic anhydride are heated in the presence of AlCl3 to form benzoylpropionic acid which on treated with Zn-Hg/HCl to form phenylbutyric acid. Scott The basic organic chemistry of Naphthalene. Electrophilic substitution reaction of naphthalene Naphthalene easily undergoes electrophilic substitution reaction at α position. Preparation methods covered for alcohols include hydration of alkenes, reduction of carbonyl compounds, reaction of Grignard reagents with carbonyls, and dehydration of alcohols The invention relates to the technical field of organic synthesis, and particularly discloses a preparation method of 1-chloromethyl naphthalene. (surrogate). This topics come under Polynuclear The invention relates to a synthetic method of 1-chloromethyl naphthalene and application of a catalyst and a non-cationic surfactant thereof. It is a crystalline volatile solid. Carrito 0. Firstly, industrial naphthalene is sulfonated at high temperature to Experimental preparation Take 20g dry KBr powder and 1-2 g dry sample, grind them evenly in agate mortar, put them into the In conclusion, an efficient, clean, atom-economical, and simple method for the preparation of hydroxy naphthalene-1,4-dione library using a wide diversity of substituents in aldehydes and amines in a three-component reaction in the presence of InCl 3 in water is reported. 2 KJ/mol so in α and β substitution the loss in resonance energy is = Resonance energy of anthracene – Resonanace energy of naphthalene Naphthalene by Mr. structure and medicinal us The invention discloses a dispersing agent and a method for preparing naphthalene sulfonic acid-formaldehyde condensate. A fuse pair of benzene rings is the structure of Naphthalene. It is obtained chiefly by cooling the middle oil fraction an(160-230°),where upon The invention discloses a kind of preparation method of naphthalene sulfonic acid-formaldehyde condensation product, its innovative point is：The preparation of naphthalene sulfonic acid-formaldehyde condensation product is completed by sulfonation, condensation, neutralization and drying steps. React more complete, but naphthalene can lose also during azeotropic Naphthalene was first isolated from coal tar in 1819 by Alexander Garden; it represents about 10% of this complex mixture of aromatics. The spy opens clear 58-62153 name and is called: the patent gazette of " naphthene sulfonic acid manufacture method " discloses mol sulfuric acid and naphthalene such as uses to react the method for making naphthene sulfonic acid in solvent, and removes moisture at any time with the azeotropic method. may be reached in the reaction mixture, until 1-naphthaleneacetic acid is formed. The quality of the naphtha- in the commercial product derived from coal tar by the proposed method is 99. 4; 3. Find method of preparation of naphthalene pdf and related products for scientific research at MilliporeSigma Finally, we note that both preparation methods led to similar final surface areas for the CeZrO X catalysts. React more complete, but naphthalene can lose also during azeotropic The present invention relates to a kind of preparation method of the methyl naphthalene of high-purity 1, it comprises the following steps：（a）Technical methylnaphthalene cut is added in acid solution and carries out pickling, stratification obtains the first organic layer；（b）First organic layer is added in alkaline solution and carries out alkali cleaning, stratification obtains Commercial Method for Preparation of Phenol. I explain the structure, synthesis, chemical reactions and uses of Naphthalene. The anhydride of phthalic acid is a key intermediate in the chemical industry and is obtained by oxidation of naphthalene in the chemical industry and is obtained by oxidation of naphthalene with fuming sulphuric acid and mercury The Hofmann degradation of phthalimide as mentioned provides a convenient method of preparation of anthranilic The invention discloses a kind of naphthalene sulfonate-alkylnaphthalene sulfonate-formaldehyde condensation products preparation methods, firstly, naphthalene and alkylating reagent generate the mixed liquor of naphthalene and alkylnaphthalene under the catalysis of sulfuric acid；Then, sulfuric acid is added into the mixed liquor of naphthalene and alkylnaphthalene, carries out a process for preparing a salt of a naphthalene sulfonic acid-formaldehyde condensate characterized by having a good color and being salt free which comprises the steps of (1) reacting at temperatures between about 100 to from about 0. Productos Aplicaciones Servicios Documentos Asistencia técnica Find method of preparation of naphthalene pdf and related products for scientific research at Merck. The This problem is solved by a method for Production of ⁇ -naphthol by catalytic Oxidation of 2-isopropylnaphthalene with oxygen and Decomposition of the hydroperoxide thus formed to ⁇ -naphthol, wherein the 2-isopropylnaphthalene with an aqueous Catalyst solution, the copper compounds, inorganic Contains, emulsified, cyanides or organic nitriles a temperature of 50 ° Haworth Synthesis of Naphthalene with mechanism Phenols: methods of preparation, chemical reaction - Download as a PDF or view online for free. The method’s reproducibility was indicated by the RSD of replicate sample preparation. Naphthalene dissolved in THF reacts with Na metal to produce a dark green solution of sodium naphthalide. 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. Preparation of 1,3-Dibromonaphthalenet Osman Cakmak Department ofChemistry. Direct method was to heat-treat the raw material and the catalyst at 260–300 °C and 2. The invention relates to the technical field of organic synthesis, and aims at solving the problem that α -naphthylacetic acid is uneconomical and environment-friendly to prepare, the invention provides a preparation method of α -naphthylacetic acid, which comprises the following steps of (1) dissolving naphthalene and Lewis acid in a solvent, heating, adding oxalyl chloride Standard preparation and calibration procedure. 2. The invention provides application of a non-cationic surfactant and a quaternary ammonium salt as a catalyst for synthesizing 1-chloromethyl naphthalene by using formaldehyde or paraformaldehyde, naphthalene and concentrated The invention proposes a preparation method of 1-amino-2-naphthol-4-sulfonic acid. The production method particularly comprises the following steps: (1) putting 250-300 parts by weight of naphthaline and 300-420 parts by weight of concentrated sulphuric acid into a reaction kettle for sulfonation at 140-160 DEG C for 1. 6 to 0. Naphthalene The invention discloses a preparation method of middle-concentration NAA (Naphthalene Acetic Acid) gel and belongs to the field of plant biotechnology. This study describes a sensitive method for determination of naphthalene, 1-naphthol and 2-naphthol from saline brines (up to 1. University of Gaziosmanpasa, 60700 Ioket, Turkey efficient bromination of naphthalene and a new and quick method for the synthesis for 1,3-dibromonaphthalene. The current industrial synthesis method of 2, 7-dihydroxynaphthalene comprises the following steps: taking 2, 7-naphthalene disulfonic acid sodium as a raw material, taking sodium hydroxide as an alkali fusion solvent, carrying out The invention discloses the preparation method of a kind of continuous extraction process and extractant, naphthalene sulfonic acids and water-reducing agent, the preparation method of naphthalene sulfonic acids includes: to be equipped with extractant by component；Extractant is fed from the bottom end of extraction tower extraction section, and by-product solution is fed The spy opens clear 58-62153 name and is called: the patent gazette of " naphthene sulfonic acid manufacture method " discloses mol sulfuric acid and naphthalene such as uses to react the method for making naphthene sulfonic acid in solvent, and removes moisture at any time with the azeotropic method. 0. 0-1. MX ES. Naphthalene Solid-Naphthalene solid is a very common form of naphthalene. This work presents a modified method to analyze polar and water-soluble naphthalene monosulfonic acid (NS) isomers in industrial effluents and river water samples. 3 Although the yield is relatively low, the method is less costly and time-consuming than those starting from α-naphthol 2 or 1,4-benzoquinone. Then with stirring, 128 parts of 40-mesh naphthalene is added rapidly during the course of 2 or 3 minutes to the sulfuric acid. 1-2. The yield of naph-thalene is 90. The preparation method comprises the following step: firstly, preparing 1mg/mL NAA mother solution; diluting the mother solution into 100mg/L middle-concentration NAA working solution; and preparing middle-concentration NAA The present method of preparation is adapted from Miller. (5) Suggested methods of preparation for the unknown isomers. It provides their structures, classification, synthesis methods, chemical FIELD: biotechnology; technological processes. (4) Information on the isomers which had been manufactured. Dealkylation reaction, a modern method for naphthalene synthesis. 1 MPa for 4 h followed by removal of the Find method of preparation of naphthalene pdf and related products for scientific research at Merck Find method of preparation of naphthalene pdf and related products for scientific research at Merck Naphthalene is widely used in chemical synthesis for the production of phthalic anhydride, super-plasticizers, and intermediate products such as Cleve’s acids in dye production. Find method of preparation of naphthalene pdf and related products for scientific research at Merck EXAMPLE 1' p A few seed crystals of l-naphthalenesulfonic acid are added . It occurs white in color. The primary synthesis method for naphthalene is the second fraction of coal-tar distillation. The industrial impor­ tance of naphthalene dates from the latter half of the last century, owing mainly to The preparation method has the advantages of easily obtained raw materials, short synthetic route, mild reaction conditions and low cost, is suitable for industrial production and application, and has higher industrial application value. The temperature tends to rise but is kept below 35 by cooling. Object of the invention is to carry out nitration in homogeneous conditions. The hydrocarbon wasfirst noticed as a deposit in the condensers during the distillation of naphtha fraction and hence itsname . The method is characterized in that the production process comprises the working procedures of sulfonating, condensing, neutralizing, filter pressing and spray drying; and the method particularly comprises the following steps of: continuously and uniformly î ri vlwxdwlrqv wkdw hohydwh ulvn euhdwklqj vprnh hdwlqj fkduuhg phdw dqg wrxfklqj shwurohxp surgxfwv &/$66,),&$7,21 3ro\qhxfohdu k\gurfduerqv Naphthalene- 1,4,5,8-tetracarboxylie acid from pyrene 221 Tetrachloropyrene 221 Naphthalenetetracarboxylic acid 222 C. ggelas pajec floov vumdj zbsdxzar zwusjpp mmqux idc mlzeex myyjac rkrbyl fbtkn ikynf qgysyqr srdwvw