Solvents reactor system

Figure 2-18 Solvents reactor system just before the explosion. Courtesy of Jack M. Jarnagin.

Nuclear Waste. NRC defines high level radioactive waste to include (/) irradiated (spent) reactor fuel (2) Hquid waste resulting from the operation of the first cycle solvent extraction system, and the concentrated wastes from subsequent extraction cycles, in a faciHty for reprocessing irradiated reactor fuel and (3) soHds into which such Hquid wastes have been converted. Approximately 23,000 metric tons of spent nuclear fuel has been stored at commercial nuclear reactors as of 1991. This amount is expected to double by the year 2001. 

Other catalyst systems such as iron V2O5-P2O5 over silica alumina are used for the oxidation. In the Monsanto process (Figure 6-4), n-butane and air are fed to a multitube fixed-bed reactor, which is cooled with molten salt. The catalyst used is a proprietary modified vanadium oxide. The exit gas stream is cooled, and crude maleic anhydride is absorbed then recovered from the solvent in the stripper. Maleic anhydride is further purified using a proprietary solvent purification system. ... 

The reactor system, where the kinetic experiments were carried out can be described as a semi-batch reactor. Only the synthesis gas (H2 and CO) was fed into the reactor continuously during the experiments, while 1-butene and the solvent were in the batch mode. All reactions took place in the liquid phase. The mass balance for an arbitrary component in the gas is given by... 

Sodium hydrosulfite is produced through the Formate process where sodium formate solution, sodium hydroxide, and liquid sulfur dioxide reacted in the presence of a recycled stream of methanol solvent. Other products are sodium sulfite, sodium bicarbonate, and carbon monoxide. In the reactor, sodium hydrosulfite is precipitated to form a slurry of sodium hydrosulfite in the solution of methanol, methyl formate, and other coproducts. The mixture is sent to a pressurized filter system to recover sodium hydrosulfite crystals that are dried in a steam-heated rotary drier before being packaged. Heat supply in this process is highly monitored in order not to decompose sodium hydrosulfite to sulfite. Purging is periodically carried out on the recycle stream, particularly those involving methanol, to avoid excessive buildup of impurities. Also, vaporized methanol from the drying process and liquors from the filtration process are recycled to the solvent recovery system to improve the efficiency of the plant. 

The development of multimode reactors for organic synthesis occurred mainly from already available microwave acid-digestion/solvent-extraction systems. Instruments for this purpose were first designed in the 1980s and with the growing demand for... 

ALMA [Alusuisse maleic anhydride] A process for making maleic anhydride by oxidizing -butane, using a fluid bed reactor and a special organic solvent recovery system. The catalyst contains vanadium and phosphoms on iron oxide. Developed jointly by Alusuisse Italia and ABB Lummus Crest. First licensed to Shin-Daikowa Petrochemical Company, Yokkaichi, Japan, in 1988. The world s largest plant plant was built for Lonza in Ravenna, Italy, in 1994. 

Aeromonas, DNA-based biosensor, 3 807 AeroSizer, 78 150—151 Aerosol containers, 7 781-782 Aerosol dispersions, 7 774-775 Aerosol drug dosage forms, 78 717 Aerosol emulsions, 7 773, 774 Aerosol flow reactors, 77 211-212 Aerosol foams, 7 773, 774 Aerosol packaging, 7 771 Aerosol pastes, 7 775 Aerosols, 7 769-787 8 697 economic aspects, 7 786 filling, 7 785-786 formulation, 7 771-780 product concentrate, 7 772-775 propellants, 7 775-781 U.S. production, 1985-2000, 7 770t Aerosol solutions, 7 772-773 Aerosol solvent extraction system (ASES), 24 17, 18... 

From the industrial point of view, it is advantageous to work with minimal amounts of solvents. This minimises the reactor size and thereby reactor cost. The extreme case is to omit the solvent completely. The use of solvent-free systems is attractive also because solvents can cause many problems (for example fire hazards, environmental problems and high costs). It has been proven possible in many cases to carry out bioconversions in solvent-free mixtures of substrates. Since most substrates are organic compounds, these mixtures behave like systems containing organic solvents and the advantages mentioned... 

Esterification between oleic acid and oleyl alcohol, catalyzed by the Mucor miehei immobihzed hpase in a batch-stirred tank reactor with supercritical carbon dioxide as solvent produced higher reaction rates at supercritical conditions than in the solvent-free system (Knez et al., 1995). 

Extraction System. The flow-through extraction system used in this study is shown in Figure 1. The system is operable up to 400 bar at 200°C. It consists of solvent delivery systems (Fluid 1, Fluid 2, Fluid 3), a flow-through reactor (FR), a set of separator traps (TP1, TP2), and the temperature and pressure control units. The reactor, traps, micrometering valves, and tubing connections are housed in a heated oven. 

A system for the Heck reaction between methyl acrylate and iodobenzene has been developed comprising an imidazolium-functionalized polystyrene monolith, initially for use in batch. This system could be reused six times before any reduction in yield was observed. Accordingly, a continuous-flow reactor system was developed using DMF at 200 °C with a residence time of 3-4 min to achieve full conversion. This system was characterized by very low palladium loadings (0.02 mol%), and ICP-MS of the solution aliquots showed leaching of less than 1 ppm. Attempts at using EtOH as solvent to provide a more environmentally and procedurally benign protocol resulted in maximum yields of 85% [144]. 

Over HBEA zeolites, acetylation of 2-methoxynaphthalene with acetic anhydride leads mainly to l-acetyl-2-methoxynaphthalene. However, the desired product, i.e. 2-acetyl-6-methoxynaphthalene, precursor of Naproxen is obtained at long reaction time by an intermolecular irreversible isomerization process. A very selective production of II (83%) can be obtained by acetylation of 2-methoxynaphthalene over a commercial HBEA zeolite (Si/Al = 15) at 170°C, with nitrobenzene as a solvent. With dealuminated HBEA samples (framework Si/Al ratio between 20 and 40), better results could be expected. Furthermore, preliminary experiments showed that this selective synthesis of 2-methoxynaphthalene can be carried out in a flow reactor system. 

In a second stage the suitability of the reactor system was tested for hydrogenations using supercritical C02 as a solvent. This operating mode required another control strategy, where all the mass flows to the reactor were controlled separately. The pressure was maintained by valve in the exit line. Experiments were carried out using an intermediate from the production of vitamin at F. Hoffmann-La Roche AG. 

Application To produce maleic anhydride from n-butane using a fluid-bed reactor system and an organic solvent for continuous anhydrous product recovery. 

Description Ethylene and comonomer are dissolved in solvent then fed into a reactor. Butene-1, octene-1 or both together can be used as comonomer. The reactor system operates in a solution phase, and, due to inherent low residence time (less than 2 minutes), it offers a tremendous flexibility for grade transitions and significant versatility for meeting product needs of a diverse market. 

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