Process water production

A further improvement in the sustainability of an industrial production process may be achieved by closing the water loops for a number of adjacent industrial production processes. This may be achieved in a so-called eco-industrial area where the primary aim is to arrange industrial production processes in such a way that water, wastes, materials, and energy can be exchanged between the various production processes in an environmentally sustainable and cost effective manner. A shared process water production plant and wastewater treatment plant is then a crucial step. It will, however, be clear that such an approach requires a thorough and detailed study which incorporates not only technical and economical aspects but also legal, organisational and infrastructural aspects as well. 

PERMUTIT Co. (USFilter Corp., Warrendale, PA, US http //www.usfilter.com/water/Business+Centers/Industrial Process Water/ Industrial Process Water Products/pw permutit.htm)... 

Fig. 9.11 Particle Measuring Systems Liquid Volumetric Probe, designed for continuous monitoring of process waters, product liquids and semiconductor chemicals.

Material and product data Data include specifications of feedstock, process water, product and byproducts with composition, instruction on usage and discharge, material safety data sheets, and usable and storage life. Information on quality assurance and quality control of feedstock, process water, products, and byproducts must also be collected. 

Clever M, Jordt F, Knauf R, Rabiger N, Rudebusch M, and Hilker-Scheibel R, Process water production from river water by ultrafiltration and reverse osmosis. Desalination 2000, 131, 325-336. 

Shallow water carbonate (reefs carbonate muds) Reservoir quality governed by diagenetic processes and structural history (fracturing). Prolific production from karstified carbonates. High and early water production possible. Dual porosity systems in fractured carbonates. Dolomites may produce H S. 

After cleavage the reaction mass is a mixture of phenol, acetone, and a variety of other products such as cumylphenols, acetophenone, dimethyl-phenylcarbinol, a-methylstyrene, and hydroxyacetone. It may be neutralised with a sodium phenoxide solution (20) or other suitable base or ion-exchange resins. Process water may be added to facilitate removal of any inorganic salts. The product may then go through a separation and a wash stage, or go direcdy to a distillation tower. 

Caustic Soda. Diaphragm cell caustic is commercially purified by the DH process or the ammonia extraction method offered by PPG and OxyTech (see Fig. 38), essentially involving Hquid—Hquid extraction to reduce the salt and sodium chlorate content (86). Thus 50% caustic comes in contact with ammonia in a countercurrent fashion at 60°C and up to 2500 kPa (25 atm) pressure, the Hquid NH absorbing salt, chlorate, carbonate, water, and some caustic. The overflow from the reactor is stripped of NH, which is then concentrated and returned to the extraction process. The product, about 62% NaOH and devoid of impurities, is stripped free of NH, which is concentrated and recirculated. MetaUic impurities can be reduced to low concentrations by electrolysis employing porous cathodes. The caustic is then freed of Fe, Ni, Pb, and Cu ions, which are deposited on the cathode. 

Secunda discharges no process water effluents. AU. water streams produced are cleaned and reused in the plant. The methane and light hydrocarbons in the product are reformed with steam to generate synthesis gas for recycle (14). Even at this large scale, the cost of producing fuels and chemicals by the Fischer-Tropsch process is dominated by the cost of synthesis gas production. Sasol has estimated that gas production accounts for 58% of total production costs (39). 

Water. Water is often added to processed meat products for a variety of reasons. It is an important carrier of various ionic components that are added to processed meat products. The retention of water during further processing of meat is necessary to obtain a product that is juicy and has higher yields. The amount of water added during the preparation of processed meat products depends on the final properties desired. Water may be added to a meat product as a salt brine or as ice during the comminution step of sausage preparation. 

The toxic nature of mercury and its compounds has caused concern over environmental pollution, and governmental agencies have imposed severe restrictions on release of mercury compounds to waterways and the air (see Mercury). Methods of precipitation and agglomeration of mercurial wastes from process water have been developed. These methods generally depend on the formation of relatively insoluble compounds such as mercury sulfides, oxides, and thiocarbamates. MetaUic mercury is invariably formed as a by-product. The use of coprecipitants, which adsorb mercury on their surfaces facihtating removal, is frequent. 

Water Quality. AH commercial oil shale operations require substantial quantities of water. AH product water is treated for use and operations are permitted as zero-discharge facHities. In the Unocal operation, no accidental releases of surface water have occurred during the last four years of sustained operations from 1986 to 1990. The Unocal Parachute Creek Project compliance monitoring program of ground water, surface water, and process water streams have indicated no adverse water quaHty impacts and no violations of the Colorado Department of Health standards (62). 

When selecting a particular paster adhesive, coating material, and coating process for sohd fiber packaging, the fact that sohd fiberboard lacks the open-flute stmcture (to facihtate exit of moisture from internal phes of paperboard) should be considered. It is generally desirable to minimize the amount of process water added with the adhesive or coating with sohd fiber products. Moisture trapped in the filler phes can result in pin holes or bhsters in the coating and/or warp of the sheet (15). 

A typical process scheme for the direct hydration of propylene is shown ia Figure 2. Turnkey plants based on this technology are available (71,81). The principal difference between the direct and iadirect processes is the much higher pressures needed to react propylene direcdy with water. Products and by-products are also similar, and refining systems are essentially the same. Under some conditions, the high pressures of the direct process can increase the production of propylene polymers. 

These include wastewater cleanup for electroplating (75—78), radioactive processing (79—82), landfill leachate (76,83), and municipal wastewater (84—87) ultrapure water production for electronics-grade (88,89), laboratory-grade (90), and pharmaceutical-grade (91) materials and food processing (qv) (9). 

Fig. 11. Schematic of membrane-based hybrid process for ultrapure water production.

The main contaminant and its concentration ia commercial caprolactam usually is water at <0.1 wt%. Anhydrous caprolactam is produced ia small quantity for use ia anionic polymerisa tion processes. Commercial product of very high purity is required by the users, ie, the fibers and plastics producers, most of whom utilise technologically advanced processes that are sensitive to monomer quality. 

Pharmaceuticals. Pharmaceuticals account for 6% of the Hquid-phase activated carbon consumption (74). Many antibiotics, vitarnins, and steroids are isolated from fermentation broths by adsorption onto carbon foUowed by solvent extraction and distillation (82). Other uses in pharmaceutical production include process water purification and removal of impurities from intravenous solutions prior to packaging (83). 

The recognition in 1940 that deuterium as heavy water [7789-20-0] has nuclear properties that make it a highly desirable moderator and coolant for nuclear reactors (qv) (8,9) fueled by uranium (qv) of natural isotopic composition stimulated the development of industrial processes for the manufacture of heavy water. Between 1940 and 1945 four heavy water production plants were operated by the United States Government, one in Canada at Trail,... 

Product Recovery. Comparison of the electrochemical cell to a chemical reactor shows the electrochemical cell to have two general features that impact product recovery. CeU product is usuaUy Uquid, can be aqueous, and is likely to contain electrolyte. In addition, there is a second product from the counter electrode, even if this is only a gas. Electrolyte conservation and purity are usual requirements. Because product separation from the starting material may be difficult, use of reaction to completion is desirable ceUs would be mn batch or plug flow. The water balance over the whole flow sheet needs to be considered, especiaUy for divided ceUs where membranes transport a number of moles of water per Earaday. At the inception of a proposed electroorganic process, the product recovery and refining should be included in the evaluation to determine tme viabUity. Thus early ceU work needs to be carried out with the preferred electrolyte/solvent and conversion. The economic aspects of product recovery strategies have been discussed (89). Some process flow sheets are also available (61). 

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