Process Engineering Equipment Handbook 2009 Part 12 pptx

Ozone O-23 of the protocol will be a two-stage process. The first stage consists of replacing a CFC by an HCFC and the second stage involves replacing an HCFC by a zero-ODP refrigerant, usually an HFC. This section considers only the costs of the first stage. HCFC costs are estimated separately. The dollar cost per kilogram of displaced ozone-depleting refrigerant is a constant cost which, when multiplied by the kilograms saved in each year, yields a stream of payments whose net present value is equal to the net present value of the total incremental costs of implementing the protocol for this sector. This cost is obtained by dividing the net present value of all incremental costs by the net present value of displaced ozone-depleting refrigerant. For the developed countries, the cost estimation framework for converting away from CFCs in Refrigeration and Air Conditioning provides an estimate of $4.62 per kilogram for the developed countries. For the Article 5(1) countries, the TEAP Replenishment Report (1996) provides an estimate of the upper bound incremental cost per kilogram of replacing CFCs in air-conditioning and refrigeration applications. Many lower cost reduction approaches such as improved service procedures are also available in Article 5(1) countries. Our overall cost estimate is based on a weighted average cost per kilogram. In this weighted average, 60 percent of refrigerant consumption is replaced at the same cost as in developed countries, 10 percent is at a cost premium of 1.5 relative to developed countries and the remaining 40 percent is at the upper bound incremental cost of $15.61 per kilogram from TEAP (1996). Using these data, the cost estimate in this report is that replacing CFCs in this sector in Article 5(1) countries costs $8.15 per kilogram. Total costs for this sector are based on the cost per kilogram estimates described above and on estimates of the gap between consumption of CFC refrigerants with and without the Montreal Protocol controls. Figure O-15 shows the consumption patterns in the controls and no-controls scenarios. Based on these data, estimated costs for replacing CFC refrigerants are $95.4 billion for the global total. This is broken down into costs of $47.7 billion in the developed countries and $47.7 billion in the Article 5(1) countries. All costs are measured as a present value over the time period 1989 to 2060 and are expressed in constant 1997 dollars using a discount rate of 5 percent. In the Article 5(1) countries, we use the cost per kilogram estimate for solvents that is provided in the TEAP Replenishment Report (1996) as a measure of upper bound incremental costs. The data shown in that report have been weighted by country type to produce an incremental upper bound cost estimate of $15.84 per kilogram in the Article 5(1) countries. Improved conservation practices suggest and the technology transfer practices of multinational firms suggest that half of the adjustments should occur at the same cost as in developed countries. A further 40 percent of adjustments are costed at 1.5 times the estimated cost in developed countries and 10 percent of adjustments are costed at the upper bound incremental cost. These calculations generate an overall cost per kilogram in Article 5(1) countries of $2.82. Total costs are based on the costs per kilogram and on estimates of the difference between consumption with and without controls for CFC-113. The two consumption scenarios are shown graphically in Fig. O-16. Using these data, this report estimates global costs for this sector of $18.7 billion. This is the present discounted value of costs at a discount rate of 5 percent measured over the time period 1989 to 2060 and expressed in 1997 dollars. These costs include $16.5 billion for the developed countries and $2.2 billion for the Article 5(1) countries. Sterilants. Prior to the development of the Montreal Protocol controls, CFC-12 was used extensively as a diluent with ethylene oxide (EO) to produce the sterilant gas used by hospitals and commercial sterilizers. We estimate that 1989 global consumption of CFC-12 in this application was approximately 23,000 tonnes, with only very small quantities used in Article 5(1) countries. In this application, CFC-12 was used to reduce the flammability of the EO and accounted for 88 percent of the mixture with EO accounting for 12 percent. The resulting 12/88 mixture was released to the environment at the end of the sterilization cycle. Many options to reduce and then eliminate the consumption of CFC-12 were pursued in this sector with different costs associated with each. Conservation, for example, led to significant consumption reductions. Sterilizers that previously had O-24 Ozone FIG. O-15 Consumption of CFCs in refrigerants under Montreal Protocol and no-controls scenarios. (Source: Environment Canada.) Ozone O-25 been run partly full were run only when full. The major advantage of 12/88 units related to sterilization of medical devices made of polyvinylchloride or polyethylene compounds that melt or deform at the high temperatures of steam sterilization. Restricting the use of 12/88 units to only these items accounted for a further reduction in the use of CFC-12. Large commercial sterilizers were able to convert to a product that was an EO-nitrogen blend to eliminate the use of CFC-12 entirely and some hospitals were able to use small units with only EO. In addition, a drop- in substitute for 12/88 was developed in which the CFC-12 was replaced with HCFC-124. The preceding paragraph suggests that many options with different control costs FIG. O-16 Consumption of CFCs in solvents under Montreal Protocol and no-controls scenarios. (Source: Environment Canada.) contributed to the phase-out of the use of CFC-12 in sterilant gas. In our assessment of the costs of replacing CFC-12, we have developed a weighted average cost per kilogram reflecting the different costs of each option. The conservation and steam sterilization options involve cost reductions in that expensive CFCs and their replacements did not have to be purchased in the same quantities. The EO conversion of contract sterilizers and the switch to HCFC-124 involved substantial costs. In 1986, for example, the cost of CFC-12 in 12/88 units was approximately $1.50 per kilogram whereas our estimate of the cost of HCFC-124 is approximately $12.00 per kilogram. However, we estimate that HCFC-124 replaced CFC-12 in only 15 percent of sterilant applications. Overall, we estimate an average cost per kilogram of $1.43 for replacing the use of CFC-12 in sterilization. We estimate that in the absence of the Montreal Protocol, 1989 global consumption of approximately 23,000 tonnes of CFC-12 would have grown at 2 percent per year until 2060. See Fig. O-16. Calculated from the beginning of the impacts of the Montreal Protocol until 2060, we estimate control costs of $1.3 billion in discounted 1997 dollars. Since almost all of the 12/88 systems were found in developed countries, we estimate that $1.2 billion of these costs should be allocated to developed countries with $0.1 billion to Article 5(1) countries. Reference and Additional Reading 1. Soares, C. M., Environmental Technology and Economics: Sustainable Development in Industry, Butterworth-Heinemann, 1999. O-26 Ozone P Packaging The most common materials used in packaging are paper, plastics, and paper coated with plastics. See Environmental Accountability; Plastics; Pulp and Paper. Paper (see Pulp and Paper) Pipe (see Some Commonly Used Specifications, Codes, Standards, and Texts) Plastics This is an industry that has a vast network of products and producers, as well its own detailed handbooks. For the process engineer, two revolutionary developments on the horizon are worth a look, although neither has yet resulted in gross-scale production. Today’s* growing environmental awareness has forced many businesses to modify their operations and their marketing strategies in response to consumer demands. For instance, a wide range of products available in the market now claim to be “environmentally friendly.” Most kinds of plastic, however, can make no such claim. Widely used to make an almost unlimited number of everyday consumer goods, plastic is generally not biodegradable. As a result, plastic waste has built up, creating a growing disposal problem and posing a threat to the ecology. To make the problem even worse, some types of plastic release potentially harmful chemicals into the atmosphere when incinerated. In the United States and Western Europe, recycling is becoming the preferred way of “getting rid of ” plastic waste. Even in less powerful economies, such as Thailand, some companies have been recycling a limited quantity of plastic for the past few years. But each time plastic is recycled, its quality declines. This means that recycled plastic can mostly be used to manufacture relatively inexpensive, low- quality goods. Another problem with recycling is that it is often difficult to separate plastic waste from other types of refuse. For recycling to work, there must be an efficient garbage sorting system in place. Also, some types of plastic, most notably thermosetting plastics, cannot be recycled at all. This is why researchers have been at work developing another, more environmentally friendly type of plastic, one that is biodegradable. The processes by which plastic degrades naturally can be divided into these four types: 1. Environmental degradation. Environmental degradation is the process by which plastic gradually degrades as a result of surrounding environmental factors, such as sunlight, heat, water, atmospheric conditions, and microorganisms. P-1 * Source: Adapted from extracts from Chantravekin, “Biodegradable Plastic: An Alternative for Better Environment,” NPC Focus, Vol. 5, No. 24, February 1997. 2. Photodegradation. This is the process by which plastic slowly degrades in the presence of sunlight or ultraviolet rays. 3. Oxidative degradation. This is the degradation that results when plastic reacts chemically with oxygen or ozone in the air. 4. Biodegradation. Biodegradation occurs when microorganisms such as bacteria and fungi break down the carbon atoms in the plastic molecules. The key factors that determine the speed at which plastic degrades include the molecular weight and structure of the plastic; its melting point and crystallinity; the volume of microorganisms, temperature; moisture; pH factor; and the quantity of nutrients in the surrounding environment. Generally, it has been found that plastics with low molecular weight, a low melting point, and a relatively low level of crystallinity or a straight molecular structure degrade more quickly than other types of plastic. Degradation occurs because microorganisms release an enzyme that is used to break down the carbon molecules contained in plastic into carbon dioxide and water in the case of aerobic respiration or into other organic substances by the temperature at which the enzyme can function most cost-effectively. Generally speaking, naturally occurring biopolymers, such as polypeptides, polynucleotides, and polysaccharides are most subject to natural degradation, whereas synthetic polymers like polyethylene, polystyrene, and polyvinyl chloride are most resistant. However, there are two types of synthetic polymers that are biodegradable. These are aliphatic polyesters, including polycarpolactone, which is used in the manufacture of medical equipment, artificial organs, and contraceptive devices, and polyethylene glycol, which is used to produce lubricants and coating materials. Polyethylene plastic bags that contain a starch filler are another attempt to produce goods with a minimal impact on the environment. But because polyethylene is highly resistant to the process of natural degradation, only the starch filler degrades when the bags are subjected to soil burial. This is why this particular type of plastic is not classified as biodegradable but rather as biodistegrable. Once the filler has degraded, small pieces of plastic remain, and unlike most polyethylene plastic, these pieces have greatly reduced mechanical properties, such as tensile strength and elongation. Just how reduced these properties are depends on the amount of filler used in the manufacture of the bags. Biodegradable plastics are attracting considerable attention at present, but because they are still relatively expensive, their use is currently restricted almost exclusively to the medical field. Attempts to extend the use of biodegradable plastics to the production of everyday consumer items are being led by a U.S. company called Bioplastics Inc. The company is a joint project between Michigan State University and the Michigan Biotechnology Institute. The company has experimented with a reactive blending process combining cornstarch and polycarpolactone to produce a polymer alloy resin, which goes by the trade name ENVAR. ENVAR’s most outstanding feature is that it has mechanical properties comparable to those of low-density polyethylene (LDPE), thereby making it suitable for use in the manufacture of plastic film and sheeting. ENVAR can be used to produce consumer items such as plastic garbage bags and shopping bags. What distinguishes ENVAR from polyethylene, however, is that it is biodegradable. In soil burial tests, ENVAR was found to be 100 percent biodegradable, its carbon atoms having been converted into carbon dioxide after only three weeks. ENVAR’s other principal advantage is that because cornstarch is an inexpensive commodity, the biodegradable plastic is cheaper than synthetic polycarpolactone. This should help to make the dream of using biodegradation plastics in everyday lives a reality. P-2 Plastics Two chief advantages could be gained by adapting biodegradable plastics technology to, for instance, countries like Thailand. First, the problem of safety disposing of plastic waste would be greatly reduced. The country’s landfills would be less severely taxed by the thousands of tons of plastic waste that are sent for burial every day. Second, the country would find an answer to the trade barriers erected by the European Community against Thai exports of tapioca starch. By using the native-grown starch in the production of biodegradable plastic, the country would add greatly to the value of this crop. To do this, it would be necessary first to submit the starch to a process of plasticization to obtain thermoplastic tapioca starch. This then would be combined with polycarpolactone in a reactive blending process to produce biodegradable plastic resin with similar properties to ENVAR resin. The major drawback to this proposal, however, is that because polycarpolactone is a specialty chemical, it is relatively expensive. This would, in turn, make the production of biodegradable plastic more expensive than other types of plastic. Nevertheless, it will probably not be long before we begin to see biodegradable plastic goods in markets around the world. It will take cooperation between the private and government sectors and a joint commitment to improving environmental conditions. Electric Plastics* Engineers at AGFA in Köln, Germany, were facing a critical problem with the production of photofilm in the late 1980s. Static discharges were ruining the huge, costly rolls of the company’s film; induced by friction, the little electric sparks generated big losses. The engineers’ investigation showed that the inorganic salts AGFA traditionally used as an antistatic coating failed to work when the humidity dropped below 50 percent. These water-soluble ionic compounds also washed away after developing, again leaving the photofilm vulnerable to stray sparks. AGFA turned to parent company Bayer AG in Krefeld, Germany, to see whether its central research arm could develop a new low-cost antistatic agent. The antistatic coating had to operate independent of air humidity, with a surface resistance greater than 10 8 ohms square; it had to be transparent and free of heavy metals; and it had to be produced from a waterborne solution. The most promising candidate to fill these criteria was, surprisingly, an electrically conductive polymer material known as polythiophene. Such polymers have always had great commercial potential because of their unusual ability (for a plastic) to provide a path for electrons, but they had not found any wide commercial applications to that point. Following a thorough development effort involving the selection of the ideal polythiophene derivative, its subsequent synthesis, and its polymerization, the Bayer research team succeeded in inventing an aqueous processing route for the plastic coating. As of early 1998, more than 10,000 m 2 of AGFA photographic film had been coated with the conductive polymer. Now the chemical company is marketing the polythiophene under the trade name Baytron. The material could also be used to make plastics paintable by adding the conductive agent first, or in the electrodes of small, high-performance tantalum capacitors found in telecommunications, computer, and automotive products. Plastics P-3 * Source: Adapted from extracts from Ashley, “Electric Plastics,” Mechanical Engineering, ASME, April 1998. Another significant potential application is in the through-hole plating of circuit boards. The chemical process of depositing the initial layers of copper into these holes requires formaldehyde, a known carcinogen. Blasberg Oberflae-chentechnik in Soligen, Germany, has patented a method using polythiophene as the first coat instead of the electroless copper. The new plating technology has been licensed to several Japanese circuit-board makers and to Enthone Inc., a subsidiary of ASARCO Inc. in West Haven, Conn. Long-time researchers on conductive polymers point to Bayer’s Baytron polythiophene as the most notable success story in the field. As with most new materials, finding sufficient demand is the key to convincing manufacturers to go into full-scale production. Antistatic applications have a huge potential, but conductive polymers have yet to make many inroads. The once highly acclaimed technology has been reduced to the point that the only successful large application—antistatic coatings for AGFA photofilm—is for internal company use. Companies from Alstom and AlliedSignal to Westinghouse and W.R. Grace have tried to make conductive polymers into a success, but they have reportedly curtailed or aborted their research. Even though one application for the material—flat-panel displays for televisions and computers—is starting to involve researchers again, much of the payoff for this technology lies in the future. That future looked a lot brighter for conductive polymers in the 1980s. Probably the most significant commercialization of conductive polymers was for flexible, long- lived batteries that were produced in quantity by Bridgestone Corp. and Seiko Co. in Japan and by BASF/Varta in Germany. Fifteen years ago, when they first came to the market, interest in conductive-polymer batteries was high. In the end, though the batteries worked, they were difficult to sell because their costs were not significantly lower than those of the competition. So the battery products were withdrawn due to insufficient demand. (Researchers at the Johns Hopkins Applied Physics Laboratory in Baltimore recently developed a nontoxic, flexible, all-plastic battery made from another class of conductive plastics called fluorophenylthiophenes, but little is expected of the technology.) Another once-promising product incorporating conductive polymers is Contex, a fiber that has been manufactured by Milliken & Co. in Spartanburg, S.C., since 1990. The fiber is coated with a conductive-polymer material called polypyrrole and can be woven to create an antistatic fabric. Milliken had been interested in using this type of antistatic technology for its carpet products. The material’s best chance for success was in military applications. Polypyrrole was approved for use in the U.S. Navy’s A-12 stealth attack carrier aircraft. The polymer was to be used in edge cards—components that dissipate incoming radar energy by conducting electric charge across a gradient of increasing resistance that the plastic material produces. The A-12 program has been canceled, however. Milliken also tried to market ultralight camouflage netting based on Contex to help conceal military equipment and personnel from near-infrared and radar detection, but the company lost a U.S. Army contract for conductive camouflage material in 1997. Despite a recent modest contract with NASA to produce conductive-polymer electromagnetic shielding for the space shuttle, Milliken’s research program was in financial jeopardy by early 1998. Despite ups and downs, electrically conductive polymers have attracted a substantial amount of attention since they were accidentally discovered two decades ago, when a Tokyo Institute of Technology student added too much catalyst to a batch of polyacetylene. When the resulting silvery film was later doped with various oxidizing agents at the University of Pennsylvania in Philadelphia, it became conductive, and the race was on to invent new conductive polymers. Conductive polymers are long, carbon-based chains composed of simple repeating units called monomers. When the Japanese student made his fortuitous error, he P-4 Plastics converted the standard single-bond carbon chains to polymer backbones with alternating single and double bonds, a change that provided a pathway for free- electron-charge carriers. To make the altered polymer materials conductive, they are doped with atoms that donate negative or positive charges (oxidizing or reducing agents) to each unit, enabling current to travel down the chain. Depending on the dopant, conductive polymers exhibit either p- or n-type conductivity. The most extensively studied conductive-polymer systems are based on polyaniline, polythiophene, polypyrrole, and polyacetylene. The principal attractions of these polymers over conventional conducting materials are their potential ease of processing, relative robustness, and light weight. Successful commercial applications require a fine balance of conductivity, processability, and stability, but until recently, materials researchers could not obtain all three properties simultaneously. Conductive polymers are much more electrically conductive than standard polymers but much less than metals such as copper. (See Table P-1.) In practice, the conductivity of these materials is characterized by low-charge carrier mobility— a measure of how easily electric charge moves. This characteristic limits response speed in the case of a transistor, for example, making such a device rather inefficient. Still, efforts to produce semiconductor devices from conductive polymers are proceeding. In 1994, a team at the Laboratory of Molecular Materials in Thais, France, made a field-effect transistor from polythiophene using printing techniques. Rolling up, bending, and twisting did not affect the transistor’s electrical characteristics. The opportunity to produce relatively low-cost semiconductor devices that are insensitive to mechanical deformation is an attractive one. Probably the most exciting development in this area is the intensifying effort to use conductive polymers to produce flat, flexible plastic screens for TVs and computers. See Fig. P-1. This screen technology emerged from the discovery that certain conductive polymers, such as poly-p-phenylenevinylene, emit light when sandwiched between oppositely charged electrodes, a configuration that fits in well with current flat- panel display designs. The current leader in this work is Cambridge Display Technology (CDT) in Cambridge, England. CDT recently entered into a collaboration with Japanese electronics maker Seiko-Epson to develop light-emitting polymer screens. Philips Electronics NV in the Netherlands is also working on a portable telephone using such a display. Other licensees include Hoechst AG in Germany and Uniax Corp. in Santa Barbara, Calif. While it is likely to be some time before this technology Plastics P-5 TABLE P-1 Electrical Conductivity of Conductive Polymers and Other Conducting Materials Material (Year Conductivity Discovered) Amperes Conducted per Volt Centimeter Conducting Polymers Polyacetylene (1977) 1.7 ¥ 10 5 Polypyrrole (1979) 7.5 ¥ 10 3 Poly-p-phenylene (1979) 1 ¥ 10 3 Poly-p-phenylenevinylene (1979) 5 ¥ 10 3 Polyaniline (1980) 2 ¥ 10 2 Polythiophene (1981) 1 ¥ 10 3 Other Conducting Materials Copper—good conductor 5.8 ¥ 10 7 Silicon—semiconductor 4 ¥ 10 -4 Quartz—insulator 2 ¥ 10 -17 [...]... legislation can make a process plant the potential recipient of an order to shut down or curtail operations Massive changes in process systems, requiring retrofits and P-8 Pollutants, Chemical; Pollutants, (from) Chemical Processes; Pollutant Indicators; Pollutants, Toxic; Pollutants, Toxic Chemicals reengineering, may result Increasingly, the process engineer must also be, in part, an environmental—or... 17.008 2,730.773 0.000 12. 258 0.480 10.400 7.579 2,222.089 790.216 0.000 0.011 0.000 4.000 0.480 9.144 0.133 2.354 92.003 1 .120 537.561 2,558.541 3,333.492 51.067 1,116.417 1.242 2,293.897 0.130 28.597 0.021 12, 132.317 0.169 2,142.220 27.609 3,087.366 3.806 30,403.335 17.000 2. 112 28.157 0.005 1.914 4,448.431 894.763 32.442 44.094 84.592 704.496 64.920 1.001 9.000 0 .125 0.000 205.405 P -12 Pollutants, Chemical;... 1,356.821 1,195.917 385.748 303.610 200.720 177.317 162.331 111.802 108.052 92.000 85.753 64.608 33.995 18 .126 17.529 7.260 6.582 4.545 2.136 2.046 1.083 1.043 0.631 0.510 0.385 0.260 0.255 0.255 0.255 0.153 0.142 0.130 0.130 0.130 0.130 0.130 0.130 0.130 0.130 0.130 0.130 0.130 0.130 0 .125 0 .125 0 .125 0 .125 0 .125 0.104 0.010 16—Plastic products industries Substance Name Dichloromethane Methyl ethyl ketone... 314.172 270.362 197.046 178.702 174.470 159.636 121 .578 98.510 91. 512 89.736 80.631 79.130 61.034 58.893 52.459 51.067 35.038 27.829 27.478 25.720 23.340 22.452 21.580 17.821 17.510 17.505 15.832 14.611 13 .120 12. 256 10.941 10.400 10.311 10.037 9.000 8.396 8.194 8.090 7.545 7.449 7.448 6.504 6.156 6.137 P-26 Pollutants, Chemical; Pollutants, (from) Chemical Processes; Pollutant Indicators; Pollutants,... 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 82.840 Underground Land Total Releases* 14, 512. 520 4,632.582 3,883.785 1,007.064 826.717 774.000 672.720 377.250 329.454 37.400 33.470 20.240 15.776 13.246 12. 900 12. 014 10.690 4.081 3.728 3.670 3. 512 3.493 3.102 1.071 0.587 0.160 0.130 0.000 0.000 0.000 0.000 0.000 0.000 27,195.362 07—Crude petroleum and natural gas industries... 292.430 119. 212 62.476 18.681 18.207 13.143 13.000 11.160 10.614 0.003 0.000 558.926 27—Paper and allied products industries Substance Name Methanol Sulfuric acid Chlorine Air Water 8,229.524 352.996 1,930.280 11,973.449 2,719.703 0.000 Underground 0.000 0.000 0.000 Land 125 .928 0.000 0.000 Total Releases* 20,329.031 3,072.959 1,931. 812 Pollutants, Chemical; Pollutants, (from) Chemical Processes; Pollutant... 0.000 Land Total Releases* 0.000 0.000 0.000 0.000 12. 624 15.300 0.000 10.800 0.000 0.000 1.854 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 1,273.236 670.091 125 .664 97.863 24.581 19.175 16.941 10.800 10.267 2.200 1.854 0.500 0.421 0.298 0.026 0. 012 0.000 0.000 0.000 0.000 0.000 P-16 Pollutants, Chemical; Pollutants, (from) Chemical Processes; Pollutant Indicators; Pollutants, Toxic;... Releases 133.287 3,841.890 79.130 5.878 0.889 19.556 60.326 34.609 26,465.316 1,900 .121 1,193.082 0.005 2.517 19.398 3,980.656 352.184 2,675.468 0.000 0.142 15.435 7.276 92.804 310.180 1.141 103.616 1,248.821 0.000 91. 512 3.699 0.000 96.041 0.000 26.168 18.135 2,086.098 1,735.537 Pollutants, Chemical; Pollutants, (from) Chemical Processes; Pollutant Indicators; Pollutants, Toxic; Pollutants, Toxic Chemicals... Tetrachloroethylene Nitric acid Aluminum (fume or dust) Total 1,721.135 1,242.286 1,132.400 937.295 507.649 398.601 101.345 19. 912 212. 710 92.400 76.165 0.000 0.000 22.800 14.000 0.000 3.000 0.000 1.200 0.090 0.039 0.000 0.000 0.000 0.000 16,995.844 Water 5.273 0.000 0.000 0.010 9 .128 0.440 188.077 221.560 0.315 2.430 17.390 26.700 25.000 0.000 0.000 0.316 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000... 777.575 655.459 649.644 419.483 135.097 122 .180 104.118 100.624 96.472 82.795 80.399 76.945 60.566 37.180 37.133 35.560 21.092 20.800 19.075 15.300 13.845 13.190 5.075 5.055 4 .127 3.702 3.668 1.460 1.162 0.911 0.874 0.323 0.260 0.130 0.010 0.004 0.002 0.000 0.000 0.000 0.000 0.000 0.000 20,608.427 30—Fabricated metal products industries (except machinery and trans equipment industries) Substance Name . HCFC -124 involved substantial costs. In 1986, for example, the cost of CFC -12 in 12/ 88 units was approximately $1.50 per kilogram whereas our estimate of the cost of HCFC -124 is approximately $12. 00. of CFC -12 entirely and some hospitals were able to use small units with only EO. In addition, a drop- in substitute for 12/ 88 was developed in which the CFC -12 was replaced with HCFC -124 . The. (from) Chemical Processes; Pollutant Indicators; Pollutants, Toxic; Pollutants, Toxic Chemicals P-7 reengineering, may result. Increasingly, the process engineer must also be, in part, an environmental—or