Residuals expanded

Savoskin M.V., Yaroshenko A.P., Mysyk R.D., Shologon V.I., Khripunov S.V. Synthesis of expandable residual graphite nitrate stabilized with glacial acetic acid. Proceedings of the International Conference on Carbon 2003 Oviedo, Spain. P. 188-189. 

Secondary alcohols (C q—for surfactant iatermediates are produced by hydrolysis of secondary alkyl borate or boroxiae esters formed when paraffin hydrocarbons are air-oxidized ia the presence of boric acid [10043-35-3] (19,20). Union Carbide Corporation operated a plant ia the United States from 1964 until 1977. A plant built by Nippon Shokubai (Japan Catalytic Chemical) ia 1972 ia Kawasaki, Japan was expanded to 30,000 t/yr capacity ia 1980 (20). The process has been operated iadustriaHy ia the USSR siace 1959 (21). Also, predominantiy primary alcohols are produced ia large volumes ia the USSR by reduction of fatty acids, or their methyl esters, from permanganate-catalyzed air oxidation of paraffin hydrocarbons (22). The paraffin oxidation is carried out ia the temperature range 150—180°C at a paraffin conversion generally below 20% to a mixture of trialkyl borate, (RO)2B, and trialkyl boroxiae, (ROBO). Unconverted paraffin is separated from the product mixture by flash distillation. After hydrolysis of residual borate esters, the boric acid is recovered for recycle and the alcohols are purified by washing and distillation (19,20). 

Essentially all of the methane [74-82-8] is removed ia the demethanizer overhead gas product. High recovery of ethane and heavier components as demethanizer bottoms products is commonplace. The work that is generated by expanding the gas ia the turboexpander is utilized to compress the residue gas from the demethanizer after it is warmed by heat exchange with the inlet gas. Recompression and deUvery to a natural gas pipeline is performed downstream of the plant. A propane recovery of 99% can be expected when ethane recoveries are ia excess of 65%. 

The rich oil from the absorber is expanded through a hydrauHc turbiae for power recovery. The fluid from the turbiae is flashed ia the rich-oil flash tank to 2.1 MPa (300 psi) and —32°C. The flash vapor is compressed until it equals the inlet pressure before it is recycled to the inlet. The oil phase from the flash passes through another heat exchanger and to the rich-oil deethanizer. The ethane-rich overhead gas produced from the deethanizer is compressed and used for produciag petrochemicals or is added to the residue-gas stream. 

Minimills and other EAF plants ate expanding iato flat-roUed steel products which, by some estimates, requite 50—75% low residual scrap or alternative raw material. Up to 16 million t of new capacity are expected to be added ia the United States between 1994 and 2000 (18). Developments ia other parts of the world also impact scrap use and supply. Possible scrap deficiencies of several million tons have been projected for EAFs ia East Asia and ia parts of Europe. This puts additional strains on the total scrap supply, particularly low residual scrap (19,20). The question of adequate supply of low residual scrap is always a controversial one. Some analysts see serious global shortages ia the first decade of the twenty-first century others are convinced that the scrap iadustry has the capabiUty to produce scrap ia the quantities and quaUty to meet foreseeable demand. This uncertainty ia combination with high scrap prices has led to iacreased use of scrap alternatives where the latter is price competitive with premium scrap. Use of pig iroa has iacreased ia EAF plants and mote capacity is being iastaHed for DRI and HBI outside the United States. 

The need to obtain greater recoveries of the C9, C3, and C4S in natural gas has resulted in the expanded use of low-temperature processing of these streams. The majority of the natural gas processing at low temperatures to recover light hydrocarbons is now accomphshed using the turboexpander cycle. Feed gas is normally available from 1 to 10 MPa. The gas is first dehydrated to a dew point of 200 K and lower. After dehydration the feed is cooled with cold residue gas. Liquid produced at this point is separated before entering the expander and sent to the condensate stabilizer. The gas from the separator is... 

Blade and disk residual life eurves showing the pereent of life eonsumed per unit time versus expander inlet temperature shall be provided. 

Gas emerges from each expander cooled to -61°C (-77°F). Additional heat exchangers lower the temperature to -84°C (-120°F), at which point all the LNG is removed for delivery. Residue gas, now under reduced pressure, is passed along to the nitrogen rejection unit (NRU) where inert nitrogen is separated and vented into the atmosphere. Helium is also recovered in the NRU. The remaining residue gas is 90% methane. 

For analytieal purposes, eonsider that the mass earrier in the expander with higher temperature and lower pressure eould be thought of as an ideal gas. Beeause exhaust gas pressure and temperature are nearly unehangeable onee seleeted (unless the effieieney degrades), its residual enthalpy may be assumed eonstant. The expander operating eondition mainly depends on the inlet parameters, and the power developed by an expander may be ealeulated from the equation ... 

It has been proposed that rapidly eooling the expander with steam eombined with flue gas would leave tlie expander free of deposits. This suggestion is unlikely to work witli multi-stage expanders beeause eatalyst residue is likely to remain in the spaee between the disks. Moreover, there is a eoneern that this type of eooling eould eause loealized eooling in the expander and partial deformation of eomponents. 

The gas is routed through heat exchangers where it is cooled by the residue gas, and condensed liquids are recovered in a cold separator at appro.ximately -90°F. These liquids are injected into the de-methanizer at a level where the temperature is approximately -90°F. The gas is (hen expanded (its pressure is decreased from inlet pressure to 22.3 psig) through an expansion valve or a turboexpander. The turboexpander Lises the energy removed from the gas due to the pressure drop to drive a compressor, which helps recompress the gas to sales pressure. The cold gas f-)50°F) then enters the de-methanizer column at a pressure and temperature condition where most of the ethanes-plus Lire in the liquid state. 

More recently the thermal decompn of single large ciysts of AP has been studied on a hot-stage microscope. It was found that the low temp decompn started on a cryst face as a dark spot which rapidly expanded into a hole which then spread thruout the cryst. The ciysts were not consumed, but a residue of finely powd AP was always left (Ref 45)... 

A finely powdered solid sample of an osmium oxide (which melts at 40. °C and boils at 130.°C) with a mass of 1.509 g is placed into a cylinder with a movable piston that can expand against the atmospheric pressure of 745 Torr. Assume that the amount of residual air initially present in the cylinder is negligible. When the sample is heated to 200.°C, it is completely vaporized and the volume of the cylinder expands by 235 mL. What is the molar mass of the oxide Assuming that the oxide is OsOv, find the value of x. 

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