Recovery process system developed

Resource Recovery Process System Developed by National Project. Phase I of the national project was carried out from 1973 to 1976 for developing the feasible technology and systems of resource recovery from solid wastes, and the demonstration plant (100 tons/day) for the material - reclamation system in phase II is under construction. The pyrolysis processes which have been developed in phase I of the national project are as follows ... 

In two processes under development as of 1997, the sulfur dioxide stream reacts with reduciag gas over a proprietary catalyst to form elemental sulfur. Both processes have achieved a sulfur recovery of 96% ia a single reactor. Multiple reactor systems are expected to achieve 99+% recovery of the feed sulfur. The direct sulfur recovery process (DSRP), under development at Research Triangle Institute, operates at high temperature and pressure. A similar process being developed at Lawrence Berkeley Laboratory is expected to operate near atmospheric pressure. 

The demand for isoprene for Butyl rubber led to the development of a recovery process for this Cj diolefin. Extractive distillation with acetone was the first process used but it has been replaced with acetonitrile (ACN ). The first step in the process is the fractionation of steam cracker debutanizer bottoms in a conventional two tower system to produce a C5 cut containing 30% isoprene. The first tower rejects C and heavier while the second rejects C4 and lighter materials. 

The reaction of epoxides with C02 affords either CCs or polymers [119], and many reports have been made [120-125] and different active catalysts described [126-130] such as alkyl ammonium-, phosphonium-salts and alkali metal halides, in this respect. The main drawbacks here are the need for a high catalyst concentration, a high pressure (5 MPa of C02), and a temperature ranging from 370 to 400 K. The recovery of the catalysts for reuse is also a key issue, and in order to simplify the recovery process various hybrid systems have been developed, an example being that prepared by coupling 3-(triethoxysilyl)propyltriphenylphosphonium bromide with mesoporous silica [131]. In this case, the reaction was carried out in the absence of solvent, under very mild conditions (1 MPa, 263 K, 1 mol% loading of catalyst, 6h), such that the hybrid catalyst could be recovered and recycled several times. 

The ultimate objective of any disposal form development project is to find an immobilization system which is prepared easily from the waste products of the recovery processes and will not allow hazardous material release during transport, interim storage, normal disposal, and in the event of a credible... 

Efficiency of the MHI Process for Treatment of PCBs. The MHI process was developed for the treatment of chlorinated organics varying from neat PCBs to PCB-contaminated liquids and solid material. The MHI processing system provides a total treatment of PCB and PCB-contaminated material. The process involves the removal of PCBs from contaminated containers, recovery of the usable material, and treatment of recovered PCB using an advanced SCWO process. This process operates at 400 °C and 250 bar with sodium carbonate as a catalyst. The MHI system has a capacity of 4 gal/min and could treat a wide range of PCB concentrations (100 ppm-100 wt.%) [125]. The process efficiency is given in Table 7. 

Although substantial work has been carried out on the recovery of lead from battery residues by electrolytic means, no system has been adopted for large-scale commercial operations. Companies such as Engitech Impianti in Italy and RSR in the USA have patents on electrolytic systems, whilst a European consortium, led by Tecnicas Reunidas in Spain, has developed the chloride-based PLACID and FLINT lead recovery processes. 

Recovery of valuable metals from secondary sources. At the present state of development the more promising metal recovery processes based on SIR systems appear to be in the following applications in terms of both process performance and economic considerations (a) Recovery of metals from dilute solutions, particularly where such solutions are available at low cost (e.g., waste solution from other processes, mine waters, or dump leaching solutions) (b) separation of metals from concentrated solutions obtained by hydrometallurgical processing of complex ores, concentrates, mattes, and scraps and purification of process solutions (such as electrolytes) which may contain a variety of metals that have been only partially recovered in the conventional processing steps (c) separation and purification of met-... 

In the second type of application, the Tomlinson recovery boiler is replaced by a safer and thermally more efficient recovery system, in which the oil produced by thermal treatment is used as plant fuel. This type of process is, in many respects, similar to the Hydropyrolysis Recovery Process developed by the St. Regis Paper Company, USA ( ), the essential difference being the use of a reducing atmosphere in the YTT process. 

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