United States wastefulness

Synthetic Processes. Traditional Solvay plants produce large volumes of aqueous, chloride-containing waste which must be discharged. This fact, in addition to a noncompetitive cost position, is largely responsible for the demise of U.S. synthetic plants. In countries other than the United States, waste is sent to the ocean, rivers, or deep underground wells. The AC and NA coproduct processes produce less aqueous waste than the traditional Solvay and NA mono processes. Related environmental concerns are added whenever a plant complex includes lime quarries and ammonia-producing equipment. 

Transport. In the United States waste transportation is regulated by the NRC and the Department of Transportation (DOT). Packaging and... 

If one just concentrates on the radioactive material in SNF, the volume is very small, especially compared to waste from other power production practices. However, one can only discuss the separated radioactive material if it has undergone extensive reprocessing. If SNF is to be isolated, as in a place such as Yucca Mountain, with perhaps 70 miles of tunnels, the volume is that of the interior of this minor mountain. Isolation of up to 100,000 metric tons of SNF in Yucca Mountain means that for the United States, approximately all the SNF made to date and that expected in the operating lifetime of all current reactors can be put there. Approximately 2,000 metric tons of SNF are produced each year in the United States. Waste volume and placement depend on the amount of compaction and consolidation at the sites. The plans for the Yucca Mountain present a realistic and understandable picture of the volume of SNF. 

A. United States— Waste Isolation Pilot Plant... 

July 1988, New Jersey shores. In the summer of 1988, medical waste washed ashore at several public beaches along the east coast of the United States. Waste transporters improperly had dumped the materials at sea. It created a panic that summer for those using the Atlantic Ocean beaches. ... 

In the short term, especially in the United States, waste-repository capacity is a significant issue. The long-term capacity of the Yucca Mountain repository could be increased significantly by separating plutonium and americium from spent reactor fuel. 

ElectraTherm, United States Waste heat recovery 50 >93 Fluid R-245fa Expander twin screw... 

The most important source of helium is the natural gas from certain petroleum wells in the United States and Canada. This gas may contain as much as 8 % of helium. Because helium has a lower boiling point Table 12.1) than any other gas, it is readily obtained by cooling natural gas to a temperature at which all the other gases are liquid (77 K) almost pure helium can then be pumped off. The yearly production in this way may be many millions of m of gas. but something like 10 m per year is still wasted. 

Of the 200 million tons of municipal solid waste collected in the United States in 1993 (1), 22% was recycled while 62% was placed in landfills and 16% incinerated (2). Plastics comprised 9.3% of these materials. The number of U.S. residential collection programs increased from 1,000 in 1988 to more than 7,000 involving more than 100 million people in 1993 (2). Approximate 1994 U.S. recycling rates are given in Table 1. 

EranMin Associates Limited, "Characterization of Municipal SoHd Waste in the United States, 1994 Update," Report No. EPA 530-94-042, Nov. 1994. 

The heat of hydration is approximately —70 kj /mol (—17 kcal/mol). This process usually produces no waste streams, but if the acrylonitrile feed contains other nitrile impurities, they will be converted to the corresponding amides. Another reaction that is prone to take place is the hydrolysis of acrylamide to acryhc acid and ammonia. However, this impurity can usually be kept at very low concentrations. American Cyanamid uses a similar process ia both the United States and Europe, which provides for their own needs and for sales to the merchant market. 

Olefins are produced primarily by thermal cracking of a hydrocarbon feedstock which takes place at low residence time in the presence of steam in the tubes of a furnace. In the United States, natural gas Hquids derived from natural gas processing, primarily ethane [74-84-0] and propane [74-98-6] have been the dominant feedstock for olefins plants, accounting for about 50 to 70% of ethylene production. Most of the remainder has been based on cracking naphtha or gas oil hydrocarbon streams which are derived from cmde oil. Naphtha is a hydrocarbon fraction boiling between 40 and 170°C, whereas the gas oil fraction bods between about 310 and 490°C. These feedstocks, which have been used primarily by producers with refinery affiliations, account for most of the remainder of olefins production. In addition a substantial amount of propylene and a small amount of ethylene ate recovered from waste gases produced in petroleum refineries. 

Table 5 presents typical operating conditions and cell production values for commercial-scale yeast-based SCP processes including (63) Saccharomjces cerevisae ie, primary yeast from molasses Candida utilis ie, Torula yeast, from papermiU. wastes, glucose, or sucrose and Klujveromjces marxianus var fragilis ie, fragihs yeast, from cheese whey or cheese whey permeate. AH of these products have been cleared for food use in the United States by the Food and Dmg Administration (77). 

MSW incinerators (qv) are typically designed to reduce the volume of soHd waste and to generate electricity in condensing power stations. Incineration of unprocessed municipal waste alone recovers energy from about 34,500 t/d or 109 million metric tons of MSW aimuaHy in some 74 incinerators throughout the United States. This represents 1.1 EJ (1.05 x 10 Btu) of energy recovered aimuaHy (18). Additionally there are some 20 RDE facihties processing from 200 to 2000 t/d of MSW into a more refined fuel (19). Representative projects are shown in Table 10. 

The market penetration of synthetic fuels from biomass and wastes in the United States depends on several basic factors, eg, demand, price, performance, competitive feedstock uses, government incentives, whether estabUshed fuel is replaced by a chemically identical fuel or a different product, and cost and availabiUty of other fuels such as oil and natural gas. Detailed analyses have been performed to predict the market penetration of biomass energy well into the twenty-first century. A range of from 3 to about 21 EJ seems to characterize the results of most of these studies. 

Another factor is the potential economic benefit that may be realized due to possible future environmental regulations from utilizing both waste and virgin biomass as energy resources. Carbon taxes imposed on the use of fossil fuels in the United States to help reduce undesirable automobile and power plant emissions to the atmosphere would provide additional economic incentives to stimulate development of new biomass energy systems. Certain tax credits and subsidies are already available for commercial use of specific types of biomass energy systems (93). 

A survey of commercial thermal gasification in the United States shows that few gasifiers have been installed since 1984 (115). Most units in use are retrofitted to small boilers, dryers, and kilns. The majority of existing units operate at 0.14 to 1.0 t/h of wood wastes on updraft moving grates. The results of this survey are summarized in Table 36. Assuming all 35 of these units are operated continuously, extremely unlikely, the maximum amount of LHV gas that can be produced is about 0.003 to 0.006 EJ/yr (222—445 td /d). 

Helium from Natural Gas. Recovery of helium from a given natural-gas stream depends almost entirely on the total economic picture of the stream. In the United States, the lowest practical helium level that is recovered is most frequendy 0.3 vol %, although helium is frequendy ignored, and hence wasted, in streams containing somewhat high concentrations. In other parts of the wodd where political considerations sometimes interact with the economic, the use of helium concentrations lower than 0.3 vol % maybe dictated. 

Regulations. In order to decrease the amount of anthropogenic release of mercury in the United States, the EPA has limited both use and disposal of mercury. In 1992, the EPA banned land disposal of high mercury content wastes generated from the electrolytic production of chlorine—caustic soda (14), accompanied by a one-year variance owing to a lack of available waste treatment faciUties in the United States. A thermal treatment process meeting EPA standards for these wastes was developed by 1993. The use of mercury and mercury compounds as biocides in agricultural products and paints has also been banned by the EPA. 

California and Minnesota have placed restrictions on the disposal of fluorescent light tubes, which contain from 40—50 mg of mercury per tube, depending on size. After batteries, fluorescent lamps are the second largest contributor of mercury in soHd waste streams in the United States (3,14). A California law classifies the disposal of 25 or more fluorescent lamp tubes as hazardous waste. In Minnesota, all waste lamps generated from commercial sources are considered hazardous waste. Private homes are, however, exempt from the law (14). Other states have proposed similar regulations. Several companies have developed technologies for recovering mercury from spent lamps (14). 

A goal of reducing total mercury releases in the United States by 33% between 1988 to 1992, and 50% by 1995 was set by the EPA. The 1992 goal was more than achieved United States reportable mercury releases were reduced by 39% by 1991 (26). In the United States, discards of mercury in municipal soHd waste streams were approximately 643 t in 1989 (3). As a result of increased restrictions on the use and disposal of mercury, by the year 2000 mercury in municipal soHd waste streams is expected to be about 160 t (3). 

However, since the naphthalene produced from petroleum is of high purity and quaUty, the production of refined naphthalene by such chemical treatments essentially has ceased in the United States. Not only are such treatments expensive, but they also generate a significant amount of waste sludge, which creates additional costs for appropriate waste-disposal faciUties. 

---