Abatement


ABATES-LOWERALIPHATIC AMINES] (Vol 2)  [c.644]

If regulations governing specific emission limit VOC concentrations to the low ppm range then, of course, vapor fractions such as those illustrated by the above tabulation will not be acceptable. It may, however, still be justified to consider VOC condensation as a precursor to a final abatement device such as an adsorption bed. Removing most of the solvent from a vent stream by condensation, can drastically reduce the size and cost of a downstream cleanup system.  [c.254]

Regardless of the techniques used to purify the KA oil, several waste streams are generated during the overall oxidation—separation processes and must be disposed of. The spent oxidation gas stream must be scmbbed to remove residual cyclohexane, but afterwards will stiU contain CO, CO2, and volatile hydrocarbons (especially propane, butane, and pentane). This gas stream is either burned and the energy recovered, or it is catalyticaHy abated.  [c.241]

Applications. Both industrial emissions reduction and indoor air-poUution abatement uses will grow. For example, the development of adsorbents with higher capacity for removal of radon from humid air could allow the development of a one-bed, delay-for-decay system in which radon adsorbs, decays to lead, and is precipitated onto the adsorbent.  [c.287]

Since SO2 and NO2 are criteria pollutants, their emissions are regulated. In addition, for the purposes of abating acid deposition in the United States, the 1990 Clean Air Act Amendments require that nationwide SO2 and NO emissions be reduced by approximately 10 million and 2 million t/yr, respectively, by the year 2000. Reasons for these reductions are based on concerns which include acidification of lakes and streams, acidification of poorly buffered soils, and acid damage to materials. An additional major concern is that acid deposition is contributing to the die-back of forests at high elevations in the eastern United States and in Europe.  [c.378]

Pollution Abatement and Conservation of Energy Review for Munitions Plant Modemi tion, TR 2210, PTA, Dover, N.J., 1976.  [c.29]

Prilling and Granulation. Worldwide, prilling is the most widely used method of sohdifying urea, but the use of granulation is increasing rapidly. In prilling, molten urea that is almost anhydrous is forced through spray heads or spinner buckets at the top of a tower to produce droplets that fall through a countercurrent stream of air in which they soHdify to form prills. Urea prilling requires taller towers than ammonium nitrate prilling in order to achieve comparable particle size. The height of towers ranges from 21 to 52 m. The temperature and rate of flow of air also affect the size and quaUty of prills. Urea prilling is an economical method for finishing, but the prills have low strength and are generally too small for use in blending with granular materials such as diammonium phosphate. Also, the prilling operation is a serious polluter, the abatement of which is costly because of the large volume of dust-laden air that must be treated. For these reasons there is a strong trend toward granulation of urea.  [c.220]

The abatement of fluorine emissions and disposal of by-product calcium sulfate from phosphoric acid plants are environmental concerns.  [c.226]

Ore flotation processes treat millions of tons of minerals per year, and since these are associated with mining activity they appear to be associated with physical damage to the environment. However, these technologies have a long history of practice and associated environmental control procedures. Specially lined tailings ponds, turbidity, and toxic chemical abatement approaches designed to eliminate environmental damage, as well as revegetation of old mining sites tailings ponds, dams, and dikes, are widespread practices. Furthermore, the flotation process is a technology well estabUshed in sewage treatment and water purification, and it can be used for the removal of harmful ions from effluents. Therefore it is safe and the flotation industry is self-regulating.  [c.54]

Oxides of nitrogen, NO, can also form. These are generally at low levels and too low an oxidation state to consider water scmbbing. A basic reagent picks up the NO2, but not the lower oxidation states the principal oxide is usually NO, not NO2. Generally, control of NO is achieved by control of the combustion process to minimize NO, ie, avoidance of high temperatures in combination with high oxidant concentrations, and if abatement is required, various approaches specific to NO have been employed. Examples are NH injection and catalytic abatement (43).  [c.58]

The uses of lead are many and varied. U.S. consumption is summarized in Table 6. Some of the main uses are in the manufacture of storage batteries, ammunition, nuclear and x-ray shielding devices, cable covering, ceramic glazes, and noise control materials (see Noise POLLUTION AND ABATEMENT METHODS). Lead is also used in bearings (see Bearing materials), in brass and bronze (see Copper alloys), in casting metals, for pipes, traps, and bends, and in some solders (see Solders and brazing alloys).  [c.53]

The average dust loading in rotary kilns is 10% of the kiln feed or approximately 20 kg/t of lime, allowing for a ratio of limestone to lime of 2 on a weight basis. Primary collection of particulates is accompHshed with multiple cyclones that entrap about 85% of the dust loading. A secondary system is necessary to abate most of the remaining dust. Of the secondary systems in use, the baghouse is the predominant type, followed by the wet scmbber, electrostatic precipitator, and gravel bed filter (see Airpollution control methods).  [c.172]

Sewage Treatment. In the abatement of stream poUution, wastewater from sewage plants must meet stringent standards that increasingly require chemical treatment, usually including lime. Lime treatment precipitates phosphates and most heavy metals. It also aids clarification by coagulating a high percentage of soHd and dissolved organic compounds, thereby reducing biological oxygen demand (BOD). When lime raises the pH to 11—12, most bacteria and vimses are destroyed, as weU as odor. The high pH also helps to volatilize ammonia, a nitrogen-plant nutrient (26).  [c.178]

Eig. 1. Monopressure process using catalytic NO abatement, where BEW = boiler feed water, CH = high level compression, CM = medium level compression, CW = cooling water, and D = makeup driver, EX = expander, and E = filter.  [c.40]

Fig. 2. Dual-pressure process using extended absorption for NO abatement. RC = refrigerated cooling see Figure 1 for other definitions. Fig. 2. Dual-pressure process using extended absorption for NO abatement. RC = refrigerated cooling see Figure 1 for other definitions.
The design of nitric absorption columns is a specialized process requiring the individual tailoring of each tray for its cooling requirements and the gas volumes needed for oxidation of the nitric oxide. A good summary of absorber design aspects is available (52). Modem processes use columns having bubble cap or sieve trays. Capacities of around 1800 t/d HNO have been achieved in a single column. Columns are up to 6 m in diameter, 80 m high, and contain as many as 30—50 trays. Discounting NO abatement requirements, the economic optimum for absorber efficiency results in tail gas NO concentrations of ca 1500—2500 ppmv. For abatement reasons single absorption columns reach tail gas NO compositions of ca 200 ppmv. The need to make processes more efficient and to meet environmental regulations has led to new advances in understanding absorption chemistry. One such development is the High Efficiency Absorption (HEA) technology developed by Rhc ne Poulenc. The specifics of this technology are not well known, but it can reduce the size of an absorber column by up to 35% (53). HEA is reported (54) to be appHcable in regions in which the gas-phase concentration of NO is low (<8000 ppm) and the rate-limiting step for nitric acid formation is typically the gas-phase oxidation of NO. By direcdy oxidizing nitrous acid in the hquid phase to nitric acid, the usual decomposition of nitrous acid into nitric oxide and acid is circumvented and the large oxidation volumes needed to regenerate NO2 from NO are greatly reduced.  [c.43]

NO Abatement. Source performance standards for nitric acid plants in the United States were introduced by the U.S. EPA in 1971 (55). These imposed a discharge limit of 1.5 kg of NO as equivalent nitrogen dioxide per 1000 kg of contained nitric acid, which corresponds to about 200—230  [c.43]

Extended absorption uses an additional column to oxidize and react the nitrogen oxides with water to form acid. Bubble cap trays hold their Hquid seal on shutdown and are therefore preferred for minimizing NO abatement problems during start-up and shutdown. Low partial pressures of nitrogen oxides lead to low rates of oxidation and a need for large amounts of gas-phase holdup. Extended absorption requires relatively few trays but large oxidation volumes, and often employs refrigeration to promote the oxidation process and minimize column size. This method of abatement is most effective for high pressure absorption in which abatement to less than 200 ppmv NO can be achieved in a single column. In general, medium pressure plants use two absorption columns to achieve concentrations of ca 500 ppmv NO. Cold tail gases are reheated by heat exchange with hot process gas to increase power recovery in the expander.  [c.43]

Selective catalytic abatement uses a catalyst and ammonia fuel to selectively reduce nitrogen oxides in preference to combustion with the much higher levels of oxygen in the tail gas. This method can operate over a wide range of pressures but requires temperatures to be 210—410°C. Eor effective abatement, a slight excess of ammonia is used, leaving 5—20 ppmv in the treated tail gas. Higher concentrations of ammonia present a potential safety hazard that has to be avoided by the use of good process controls. Ammonia at low temperatures can form ammonium nitrate and nitrite, which might accumulate in downstream equipment and pose an explosion hazard upon being heated. Base metal oxides (titanium and vanadium) are commonly used as the catalysts, although platinum, palladium, or zeoHtes may also be used. The catalysts are usually shaped as honeycombs or flat parallel plates. The treated tail gases are also reheated for improved expander energy recovery.  [c.43]

Nonselective abatement uses a catalyst and fuel (gaseous hydrocarbon such as propane or natural gas) to reduce nitrogen oxides to nitrogen and, in the process, combust any remaining free oxygen in the tail gas. This consumes significantly more fuel than a selective reduction system, but the energy thus generated is mostly retrieved as power in the expander. Platinum, palladium, and rhodium, either in the form of pellets or as a honeycomb, are typically used as catalysts in these systems. The minimum temperature for inlet tail gas depends on the fuel in use and its ignition temperature. Hydrogen, which has the lowest ignition temperature, requires about 150—200°C. A large temperature rise due to combustion, about 130°C for every volume percent of oxygen, places a limit on total oxygen content for tail gas exiting the absorber. Eree oxygen tends to be consumed preferentially and fuel must be fed in slight stoichiometric excess to the oxygen. Leftover hydrocarbons are discharged to the atmosphere, including small amounts of carbon monoxide and hydrogen cyanide. Relatively few nitric acid plants use this method of abatement, which was one of the first available when source performance standards were introduced in 1971.  [c.43]

In an economic comparison of these three common abatement systems, a 1991 EPA study (58) indicates extended absorption to be the most cost-effective method for NO removal, with selective reduction only matching its performance for small-capacity plants of about 200—250 t/d. Nonselective abatement systems were indicated to be the least cost-effective method of abatement. The results of any comparison depend on the cost of capital versus variable operating costs. A low capital cost for SCR is offset by the ammonia required to remove the NO. Higher tail gas NO  [c.43]

Antiques, household furniture, kitchen cabinets, pianos, aircraft, and buildings can have their useful life extended by removing the old coating and applying new. Original equipment manufacturers (OEMs) remove coatings from rejected parts to avoid scrapping the items. Finish removers are used to remove lead paint from woodwork, windows, or entire buildings to abate the risk of lead exposure. There are over 104 different industries that use finish removers (2). The use of and need for finish removers will probably expand with the increasing importance of recycling (qv), refinishing, and the restoration of durable items.  [c.550]

Amendments of 1990 control the abatements of all materials ia the air.  [c.17]

Two voluntary iacentives being adopted by many U.S. chemical companies are 33—50 reduction ia toxic releases and Responsible Care. Using 1988 as a baseline, the 33—50 program seeks a 33% reduction ia emission from the plant of the Hsted toxic chemicals by the end of 1992 and a 50% by 1995. The chemicals that are on the Environmental Protection Agency Hst and relevant to the inorganic pigments iadustry are cadmium, chromium, lead, nickel, and their compounds (49). As the U.S. government seeks the absolute reduction of toxic discharge, the production levels are not considered in this incentive, ie, with increased production levels companies have to use more efficient abatement systems to meet this regulation.  [c.17]

Plant layout and noise suppression material are two general noise abatement methods. Plant layout does not affect noise levels at any given point however, noise can be abated by screening off a section of the plant. An example of this is to orient cooling towers with their closed faces toward the critical location. This method must also consider wind direction to balance air draft. Tankage can be located to act as a noise screen.  [c.83]

Several states that have a large number of CPI plants offer various types of tax incentives. Louisiana, for instance, offers a 10-yr tax exemption from property taxes on buildings, equipment, and improvements to land (2). Texas, which has a large petrochemical industry, offers a 7-yr tax abatement program. Neither of these states have a state income tax. Both states offer a tax credit for each job created and provide free worker training.  [c.88]

Noise abatement Noise attenuation Noise insulatois  [c.685]

Several general reviews of adipic acid manufacturing processes have been pubHshed since it became of commercial importance in the 1940s (42—46), including a very thorough report based on patent studies (47). Adipic acid historically has been manufactured predominantly from cyclohexane [110-82-7] and, to a lesser extent, phenol [108-95-2]. During the 1970s and 1980s, however, much research has been directed to alternative feedstocks, especially butadiene [106-99-0] and cyclohexene [110-83-8], as dictated by shifts in hydrocarbon markets. AH current industrial processes use nitric acid [7697-37-2] in the final oxidation stage. Growing concern with air quaHty may exert further pressure for alternative routes as manufacturers seek to avoid NO abatement costs, a necessary part of processes that use nitric acid.  [c.240]

Many existing applications iavolve small adsorption systems foi home and automobile applications, eg, refrigerant dryiag ia automobile air conditioneis, dual-pane wiadow desiccants, medical oxygen systems, and muffler coiiosion protection. Such small adsorption systems will continue to be developed for new uses ia iadoor air pollution and odor abatement and for the enhancement of the performance of other equipment and appliances. For example, adsorption-based control of the composition of air ia refrigerators can provide improvements ia the storage of fmits and vegetables.  [c.288]

J. W. Jones, "Estimating Performance and Costs of Retrofit SO2 and NO Controls for Acid Raia Abatement," MGS ExtendedA.bstract Preprint ACS Division of Environmental Chemistry Meeting (June 5—11, 1988, Toronto, Ontario).  [c.416]

Irritation ndSensitization. Low molecular weight aldehydes, the halogenated afiphatic aldehydes, and unsaturated aldehydes are particularly irrita ting to the eyes, skin, and respiratory tract. The mucous membranes of nasal and oral passages and the upper respiratory tract can be affected, produciag a burning sensation, an iacreased ventilation rate, bronchial constriction, choking, and coughing. If exposures are low, the initial discomfort may abate after 5 to 10 min but will recur if exposure is resumed after an iatermption. Furfural, the acetals, and aromatic aldehydes are much less irritating than formaldehyde and acroleia. Reports of sensitization reactions to formaldehyde are numerous.  [c.473]

Fertilizer Production. The fertilizer iadustry, like the chemical iadustry as a whole, is fully subject to stringent aatioaal, state, and local antipoUution regulations. For the most part, abatement of pollution ia the fertilizer iadustry is handled by employment of standard procedures such as the scmbbiag of gaseous effluents and purification treatment for Hquid effluents. Problems that are somewhat unique to the iadustry are nitrous oxide emissions from nitric acid plants and granular fertilizer plants, particulate emissions from ammonium nitrate and urea prilling towers, strip mining of phosphate ore, gypsum disposal from wet-process acid plants, and fluorine emissions from phosphate processing and from gypsum disposal ponds.  [c.246]

Combustion. Biomass combustion accounted for about 4% of total U.S. energy consumption in 1992, primarily in the industrial, residential, and utiHty sectors. Electric power capacity fueled by biomass grew from 200 MW in the early 1980s to about 6000 MW in 1992. The direct combustion of biomass for heat, steam, and power has been, and is expected to continue to be, the principal end use of biomass energy. Conventional biomass-fired technology uses a variety of combustion equipment designs that are usually capable of burning a wet, nonhomogeneous fuel with large variations in moisture content and particle size (141). Spreader stoker-fired boilers have evolved from the designs of the past to systems which include several designs for controUed fuel distribution and automatic ash removal. Research on biomass combustion has focused on improvements of existing systems with respect to ease of operation, increased efficiency, and lower capital and operating costs emission controls and abatement and development of new technologies to permit utilization of soHd biomass fuels in a wider range of appHcations (142). Some of the biomass combustion research developments since the early 1930s include whole-tree burning technologies (143), cyclonic incineration of waste biomass (144), direct wood-fired gas turbines (145), improved combustion cycles for biomass (141), fluid-bed biomass combustion (146), pulverized biomass combustion (147), catalytic wood-burning stoves (148), cofiring of biomass and fossil fuels to reduce emissions (149), and control of biomass combustion to reduce emissions (150). Even though the burning of biomass is one of the oldest energy producing methods used, research continues to make significant advancements in the art and science of  [c.45]

Economics. In the early 1990s, the cost of electricity generated from geothermal energy varied from about 3.5—100/kWh (22). The cheapest electricity came from The Geysers, where steam can be deflvered to the power plant for less than 20/kWh of electricity generating potential (23). Electricity costs from hot-water resources using flashed steam and binary plants, respectively, are progressively higher. In addition to the usual power plant costs, other significant up-front capital costs, including resource exploration, drilling, and field development, must be covered before a geothermal plant can begin producing revenue. Accordingly, capital financing carries an added risk in geothermal projects because continued supply of fuel is not assured until considerable capital has been expended. Environmental concerns may also add to the capital costs of a hydrothermal plant. Hydrogen sulfide abatement systems can mn several million dollars. The exact costs vary with the composition of the gas to be treated. Liquid-dominated resources which are high in dissolved soflds incur added capital and operating costs to pay for the collection and disposal of the spent brine and any precipitated soHd residues.  [c.267]

E. D. Spinosa, P. M. Stephan, and J. R. Schorr, Review of Literature on Control Technology which Abates Air Pollution and Conserves Energy in Glass Melting  [c.317]

Reduction. Hydrogen peroxide reduces stronger oxidizing agents such as chlorine, sodium hypochlorite, potassium permanganate, and ceric sulfate. The last two are used for the volumetric deterrnination of hydrogen peroxide. The abiUty of hydrogen peroxide to reduce chlorine and hypochlorite leads to the use ofH202 as a pollution abatement treatment for industrial waste streams (see Wastes, industrial).  [c.472]

A complex of glycoHc acid with ferrous ion can cataly2e the oxidation of hydrogen sulfide. This abiUty is used in the abatement of dissolved hydrogen sulfide in steam condensates from geothermal power generators. Glycohc acid and its low molecular weight polymers are used for oil well acidification, complexing with metals (especially iron) during cleaning operations, or water flooding. The easy degradabiUty is advantageous for these apphcations.  [c.517]

J. J. Breen and C. R. Stroup, eds., EeadPoisoning Exposure, Abatement, Regulation, Lewis Pubhshers/CRC Press, Boca Raton, Fla., 1995.  [c.78]

Environmental regulations compel operations to abate dust, control wastewater discharge, and abide by noise-control regulations (11) (see Air POLLUTION CONTROL methods Noise POLLUTION AND abatementmethods). Drilling dust is ehmiaated by fabric filters that are a part of modem drilling rigs. Soil banks are planted with vegetation to reduce dust and erosion trees, snow fences, and berms serve as wiad barriers at vulnerable locations.  [c.169]

Most fugitive dust is derived from spillage of stone fines and overburden soil from conveyors, bucket elevators, loading spouts, tmcks, etc from stockpiled-processed stone and spall piles that become air-dried and then wind-blown and from tmck traffic and wind on plant roads. Spillage can be minimized by a variety of practices including not overloading conveyor belts, elevators, and tmcks better coordination of the stone-feed flow reducing conveyor gravity drops use of enclosures at vulnerable transfer points use of retractable loading spouts that fit tightly in circular ports of tank tmcks hberal appHcation of rainbird-type jet-spray systems on stockpiles watering unpaved areas removing dust from paved surfaces with vacuum-cleaning equipment reducing tmck speed or using pneumatic pumplines in place of tmcks. Successful dust abatement requires a weU-supervised, unremitting campaign, supported by all levels of management.  [c.170]

Principal areas of environmental management (19) in minerals processing are tailings and other waste treatment and disposal, water discharge and protection of ground and surface waters, acid mine drainage, land reclamation, restoration and abatement, mine subsidence, mine closure, dust control, air emissions, and the elements or minerals that cause environmental pollution in subsequent operations such as smelting or burning of coal. Such regulations as the Clean Air Act have high impact on the industry. Laws in the 1990s require that permits for new mine openings be coveted by a huge performance bond. The release of the bond is contingent on the completion of all requited reclamation, restoration, and abatement work on the permit area. A significant amount of research and development is being conducted to address the environmental issues in mineral processing. Many newer technologies have already become available.  [c.396]

Historically, different design philosophies between the United States and Europe have led to the development of two basic types of weak acid plant the high monopressure and the dual-pressure processes. The high monopressure process has been favored in the United States because of its lower capital cost and traditionally lower energy and ammonia prices. In Europe, where allowable capital payback periods and energy costs have traditionally been higher, the dual-pressure process evolved. In the 1990s, these processes continue to advance in design and are competitive on a worldwide basis (22). Many Hcensors offer both designs. Eigures 1 and2 show examples of the two kinds of processes. The different types of NO abatement systems illustrated in these diagrams are interchangeable for either process.  [c.40]

Process Licensors. Some of the well-known nitric acid technology licensors are fisted in Table 3. Espindesa, Grande Paroisse, Humphreys and Glasgow, Rhfyne Poulenc, Uhde, and Weatherly are all reported to be licensors of weak acid technology. Most weak acid plant licensors offer extended absorption for NO abatement. Espindesa, Rhfyne Poulenc, Weatherly, and Uhde are also reported (53,57) to offer selective catalytic reduction (SCR) technology.  [c.45]

T. G. Otchy and K. J. Herbert, "First Large Scale Catalytic Oxidation System for PTA Plant CO and VOC Abatement," S5th MnnualAir and Waste Management Association Meeting, Air Waste Management Association, Pittsburgh, Pa., 1992.  [c.501]


See pages that mention the term Abatement : [c.209]    [c.669]    [c.225]    [c.43]    [c.44]    [c.48]    [c.83]   
Industrial ventilation design guidebook (2001) -- [ c.1255 , c.1256 , c.1257 , c.1258 , c.1259 , c.1260 , c.1261 , c.1262 , c.1263 , c.1264 , c.1265 , c.1404 ]