Injection disposal

Tsang, C.F. and Apps, J.A., Eds., Deep Injection Disposal of Hazardous and Industrial Waste Scientific and Engineering Aspects, Academic Press, New York, 1996. 

Some liquid wastes undergo disposal by injection into the deep subsurface. Underground injection disposal is not allowed for liquid hazardous wastes and sludges that contain 500 mg l-1 or more of arsenic (40 CFR 148.12). The underground injection of many K and other listed arsenic wastes is also not permitted (40 CFR 148.14-148.15). 

For petroleum waste management a deep-well injection disposal process has long been used. This method transfers liquid wastes underground and away from fresh wastewater sources. It is also used to dispose of saltwater in oil fields. 

The sample solutions injected into an ion chromatographic system must be free of particulate matter to avoid plugging of the capillary connecting tubing and the frits at the head of the analytical column. Even samples that appear to be clear may contain unsuspected fine particles. It is more or less standard procedure to filter sample solutions prior to their injection. Disposable membrane filters with a pore diameter of... 

Dusseault, M. B. Bilak, R. A. Bruno, M. Rothenburg, L. Proceedings of the Symposium on Scientific and Engineering Aspects of Deep Injection Disposal of Hazardous and Industrial Wastes Lawrence Berkeley Laboratory, Berkeley, CA, May 10-13, 1994. 

Some deep-well sites have not been without problems. Layers of rock and soil above the disposal sites became contaminated. There are questions about the reliability of geological sites to seal adequately the waste from movement and the potential failme of piping leading to the deposit site. Many sites have not fully resolved effects of potential earthquakes, failures in overpressured sites and other problems. An EPA study reviewed the risks of deep-well injection disposal." ... 

Desulfurize the flue gas. A whole range of processes have been developed to remove SO, from flue gases, such as injection of limestone into the furnace, absorption into wet limestone after the furnace, absorption into aqueous potassium sulfite after the furnace, and many others.However, the byproducts from many of these desulfurization processes cause major disposal problems. 

Water may be injected into the reservoir to supplement oil recovery or to dispose of produced water. In some cases these options may be complementary. Water will generally need to be treated before it can be injected into a reservoir, whether it is cleaned sea water or produced water. Once treated it is injected into the reservoir, often at high pressures. Therefore to design a process flow scheme for water injection one needs specifications of the source water and injected water. 

Gas can be injected into reservoirs to supplement recovery by maintaining reservoir pressure or as a means of disposing of gas which cannot be flared under environmental legislation, and for which no market exists. 

If gas export or disposal is a problem gas re-injection into the reservoir may be an alternative, although this implies additional compression facilities. Gas production may be reduced using well intervention methods similar to those described for reducing water cut, though in this case up-dip wells would be isolated to cut back gas influx. Many of the options discussed under water treatment for multi-layered reservoirs apply equally well to the gas case. 

The control of carbon dioxide emission from burning fossil fuels in power plants or other industries has been suggested as being possible with different methods, of which sequestration (i.e., collecting CO2 and injecting it to the depth of the seas) has been much talked about recently. Besides of the obvious cost and technical difficulties, this would only store, not dispose of, CO2 (although natural processes in the seas eventually can form carbonates, albeit only over very long periods of time). 

In the United States, fibers and injection mol ding are the main appHcations for polypropylene (Table 8), followed by film. In Europe and Japan, injection mol ding appHcations predominate (Table 10). This market area is more likely to decline in economic recession, as consumers postpone purchases of apphances and automobiles. Film appHcations are important in both regions, but fibers are a much less important use for polypropylene in Japan than in other developed regions. The heavy use of polypropylene nonwovens in the manufacture of disposable diapers and similar products, and the wide use of polypropylene carpets in the United States, account for the greater consumption of fibers. 

The sulfur-bearing cap rock, being an enclosed formation, is essentially the equivalent of a pressure vessel. Hot water, pumped into the formation to melt sulfur, must be withdrawn after cooling at approximately the same rate as it is put in, otherwise the pressure in the formation would increase to the point where further water injection would be impossible. Bleedwater weUs, used to extract water from the formations, usually are located on the flanks of the dome away from the mining area where the water temperature is lowest. The water is treated to remove soluble sulfides and other impurities before being discharged to disposal ditches or canals. 

Deep-Well Injection Deep-well injection for the disposal of liquid wastes involves injecting the wastes deep in the ground into permeable rock formation (typically limestone or dolomite) or underground caverns. 

FIG. 25-78 Schematic diagram of an industrial-waste injection well completed in competent sandstone. (From Vreeman, H M, Standard Handbook of Hazardous Waste Treatment and Disposal, McGraw-Hill, 1988.)... 

Applications Deep-well injection has been used principally for liquid wastes that are difficult to treat and dispose of by more conventional methods and for hazardous wastes. Chemical, petrochemical, and pharmaceutical wastes are those most commonly disposed of with this method. The waste may be liquid, gases, or solids. The gases and solids are either dissolved in the liquid or are carried along with the liquid. 

In this design, the inboard labyrinth of the DGS is fed with seal gas that is compatible with the process gas. The outboard labyrinth is injected with an inert gas. With this arrangement, the bearing housing is purged with inert gas, the seal gas leakage is minimized, and the mixture of seal gas and inert gas is vented to a flare or disposal system. Figure 6-21 shows a cross-section of a turboexpander with AMB and DGS. 

Wastewater Deep Well Injection. This is an alternate wastewater disposal procedure and requires some treating prior to injection, such as filtration or pFI adjustment. Permits for this procedure require long lead times. Reference 4 gives prediction methods for refinery wastew ater, generation. 

Liquid waste disposal—evaporation, deep well injection (don t forget filtration and treating), mixing with river or ocean water (don t forget treating)... 

Residuals Produced Liquid injection incinerators produce ash which may require application of a post treatment technology prior to disposal. The byproducts from the emission control devices may also require further treatment prior to disposal. 

Disposal involves the use of postprocess activities that can handle waste, such as deep-well injection and off-site shipment of hazardous materials to waste-management facilities. 

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