Linings glass

Modular glass components are employed in solvent recovery applications where the use of glass ensiures product purity. 

The brewing industry was responsible for the development of the first large scale glassed steel equipment. It was the result of the need to impose consistency of the quality of the beer. This took place in the early 1800s. Between that time and the start of the Second World War there were no notable developments in glassed steel composites. 

With the advent of war the need developed for critical chemicals that were often corrosive and sticky. This sparked development programs to find materials to meet these needs. It was during this time that the importance of characteristics other than corrosion resistance of the composite were recognized, specifically thermal loading and mechanical stressing. Since that time, continued research efforts have culminated in a glassed steel product that is one of the major materials of construction used by the chemical processing industry. 

There are three main areas of application where glass-lined equipment is 

Those involving highly corrosive acids and bases Those involving high-purity processes where cleanliness is important for the ability to clean as well as to minimize the risk of metal contamination 

For polymerization reactions to prevent polymers from sticking on vessels 

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This process yields satisfactory monomer, either as crystals or in solution, but it also produces unwanted sulfates and waste streams. The reaction was usually mn in glass-lined equipment at 90—100°C with a residence time of 1 h. Long residence time and high reaction temperatures increase the selectivity to impurities, especially polymers and acrylic acid, which controls the properties of subsequent polymer products. 

Acryflc acid, alcohol, and the catalyst, eg, sulfuric acid, together with the recycle streams are fed to the glass-lined ester reactor fitted with an external reboiler and a distillation column. Acrylate ester, excess alcohol, and water of esterification are taken overhead from the distillation column. The process is operated to give only traces of acryflc acid in the distillate. The bulk of the organic distillate is sent to the wash column for removal of alcohol and acryflc acid a portion is returned to the top of the distillation column. If required, some base may be added during the washing operation to remove traces of acryflc acid. 

Rhenium hexafluoride [10049-17-9J, ReF, is a pale yeUow soHd at 0°C, but a Hquid at ambient temperature. In the presence of moisture it hydroly2es rapidly forming HF, Re02, and HRe04 (see Rheniumand rhenium compounds). It is not safe to store ReF in a glass trap or glass-lined container. Leaks in the system can initiate hydrolysis and produce HF. The pressure buildup causes the system to burst and an explosion may result. 

A solution of sodium cyanide [143-33-9] (ca 25%) in water is heated to 65—70°C in a stainless steel reaction vessel. An aqueous solution of sodium chloroacetate [3926-62-3] is then added slowly with stirring. The temperature must not exceed 90°C. Stirring is maintained at this temperature for one hour. Particular care must be taken to ensure that the hydrogen cyanide, which is formed continuously in small amounts, is trapped and neutrali2ed. The solution of sodium cyanoacetate [1071 -36-9] is concentrated by evaporation under vacuum and then transferred to a glass-lined reaction vessel for hydrolysis of the cyano group and esterification. The alcohol and mineral acid (weight ratio 1 2 to 1 3) are introduced in such a manner that the temperature does not rise above 60—80°C. For each mole of ester, ca 1.2 moles of alcohol are added. 

AH mercury compounds should be stored in amber botties or otherwise protected from light. In manufacture, glass-lined equipment is preferred, although stainless steel may be used. Stainless steel may cause some discoloration at high temperatures if concentrated acetic acid is used. 

Mercuric Sulfate. Mercuric s Af2iX.e.[7783-35-9] HgSO, is a colorless compound soluble ia acidic solutions, but decomposed by water to form the yellow water-iasoluble basic sulfate, HgSO 2HgO. Mercuric sulfate is prepared by reaction of a freshly prepared and washed wet filter cake of yellow mercuric oxide with sulfuric acid ia glass or glass-lined vessels. The product is used as a catalyst and with sodium chloride as an extractant of gold and silver from roasted pyrites. 

Commercially, sulfonation is carried out by the classic method with sulfuric acid. Modem reactors are glass-lined older equipment was made from cast iron or coated with enamel Processes often use chlorosulfonic acid or sulfur trioxide to minimi2e the need of excess sulfuric acid. Improved analytical methods have contributed to the success of process optimi2ation (9—12). 

Storage. Phenol is shipped in dmms, tank tmcks, and tank cars. It is loaded and shipped at elevated temperatures as a bulk Hquid. In storage, phenol may acquire a yeUow, pink, or brown discoloration which makes it unusable for some purposes. The discoloration is promoted by the action of water, light, air, and catalysts, eg, traces of iron or copper. When stored as a solid in the original dmm or in nickel, glass-lined, or tanks lined with baked phenolic resin, phenol remains colorless for a number of weeks. 

Glass-lined reactor systems ate used occasionally for halogenated resins to prevent corrosion of the reactor components. Copper and brass fitting should be avoided due to the significant induence on resin cute characteristics. 

Flame-Retardant Resins. Flame-retardant resins are formulated to conform to fire safety specifications developed for constmction as well as marine and electrical appHcations. Resins produced from halogenated intermediates (Table 5) are usually processed at lower temperatures (180°C) to prevent excessive discoloration. Dibromoneopentyl glycol [3296-90-0] (DBNPG) also requires glass-lined equipment due to its corrosive nature. Tetrabromophthahc anhydride (TBPA) and chlorendic anhydride (8) are formulated with ethylene glycols to maximize fiame-retardant properties reaction cycle times are about 12 h. Resins are also produced commercially by the in situ bromination of polyester resins derived from tetrahydrophthahc anhydride... 

The reaction is facilitated by elevated temperature necessitating pressure-capable, glass-lined reactors and exotic metallurgy for fittings to withstand the severely corrosive conditions. PAG product having 10—12% Al as AI2O2 can be produced. 

Processes for Sulfation of Fatty Alcohols with GISO H. Lauryl alcohol is batch sulfated by gradual addition of CISO H to lauryl alcohol in a glass-lined stirred reactor over about a 2.5-h period at a temperature of 26—32°C. Gaseous HCl is expelled, aided by a slow continuous N2... 

Conoco operated a stirred tank Pfaudler glass-lined reactor for the batch SO sulfonation of detergent alkylate. The plant utilized over-the-fence SO converter gas (8% SO ia dry air) having h batch cycles (264). AHied Chemical Company provided details for batch SO sulfonation (265,266)... 

Shipment and Storage. Sulfur dichloride, if kept dry, is noncorrosive at ambient temperatures, thus carbon steel and Hon can be used Hi the constmction of tanks, piping, and dmms. However, when water or humidity is present, materials resistant to hydrochloric acid must be used, eg, glass-lined pipe. Teflon, titanium, HasteUoy C, or possibly a chemically resistant, glass-reiaforced polyester. Threaded pipe joHits should be assembled with Teflon tape. Hoses should be constmcted with a Teflon inner lining with the outer tube constmcted of Neoprene or braided 316 stainless steel protected by an adequate thickness of Teflon. Sulfur dichloride should be stored away from heat and away from dHect rays of the sum. Toluene and sulfur dichloride react exothermically when catalyzed by Hon or ferric chloride. Safety precautions should be foUowed when such a mixture is present (165). 

In a batch process (176), a glass-lined jacketed iron vessel is charged with either sulfur monochloride or sulfur dichloride and about 1% of antimony trichloride as a catalyst. Chlorine is introduced into the reactor near the bottom. Liquid oleum is added to the reactor at such a rate that the temperature of the reaction mass is held at ca 25°C by the use of cooling water in the jacket. 

Ma.nufa.cture. The preparation of sulfuryl chloride is carried out by feeding dry sulfur dioxide and chlorine into a water-cooled glass-lined steel vessel containing a catalyst, eg, activated charcoal. Alternatively, chlorine is passed into Hquefted sulfur dioxide at ca 0°C in the presence of a dissolved catalyst, eg, camphor, a terpene hydrocarbon, an ether, or an ester. The sulfuryl chloride is purified by distillation the commercial product is typically 99 wt % pure, as measured by ASTM distillation method D850. 

Sulfurchlorination of unsaturated compounds or mercaptans is normally carried out at atmospheric pressure in a glass-lined reaction vessel because of the potential to Hberate HCl during the reaction. The sulfurchlorination vessel is equipped with a cooling jacket or coils (very exothermic reaction), a nitrogen or dry air sparging system, an overhead condenser, and a caustic or bleach scmbber. If one of the reactants (olefin or mercaptan) is alow boiling material, ie, isobutylene, a glass-lined pressure vessel is recommended. 

Halide Displacement. Hahde displacement is a method used to prepare thiols that are not readily available by normal means. It requires a two-phase, water—organic system, that can be quite corrosive. Normally, this type of reaction, a classic Sj 2 type, is undertaken in HasteUoy or glass-lined... 

Processes that are essentially modifications of laboratory methods and that allow operation on a larger scale are used for commercial preparation of vinyhdene chloride polymers. The intended use dictates the polymer characteristics and, to some extent, the method of manufacture. Emulsion polymerization and suspension polymerization are the preferred industrial processes. Either process is carried out in a closed, stirred reactor, which should be glass-lined and jacketed for heating and cooling. The reactor must be purged of oxygen, and the water and monomer must be free of metallic impurities to prevent an adverse effect on the thermal stabiUty of the polymer. 

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