Environmental aspects

A comparison of the environmental bottom line for reusable and single-use textiles reveals quite a few surprises and does away with a number of preconceived notions about nonwoven based products the solution that seems at first more expensive can be more efficient in terms of safety, economy and also ecology patterns (see Figs 12.2 and 12.3). Itis necessary to be cautious against the rejection of single-use medical devices on the basis of over-simplified environmental arguments. One must approach and estabhsh the environmental impact, as well as 

1 Life-cycle of the product (adapted from Furness, J.)- 

3 Life-cycle of a reusable product (adapted by EDANA). 

As expected from Table 5.7, this environmental quotient for conventional oxo processes (basis Co catalysts) and for the manufacture of the bulk chemical -butanal is actually about 0.6-0.9, depending on the definition of the term target product. The range 0.6-0.9 

TABLE 5.7. E factors of different processes for the hydroformylation of propene 

Whereas this important quotient is calculated solely from the product spectrum, process simplifications are a consequence of combining the rhodium catalyst with the special two-phase process. Compared with the conventional oxo process and with other variants (which, for example, include disadvantegeously thermal separation of the oxo reaction products from the catalyst) the procedure is considerably simplified (as shown in several papers, e.g., [2,12]). 

The solvent water reliably averts the risk of fire, which was inherent in the old cobalt-based process as a result of leaking highly flammable, metal carbonyls. The technique with its built-in extinguishing system reliably prevents such fires, and the painstaking 

All of the systems described present certain environmental aspects, which require consideration during the operation of the processes. These can conveniently be considered for the different stages of production. 

Hirschler, D. A., Gilbert, L. F., Nature of Lead in Automobile Exhaust Gas, Arch. Environ. Health 8 [1964] 297/313. 

Anonymous, Survey of Lead in the Atmosphere of Three Urban Communities, U.S. Department of Health, Education, and Welfare, Public Health Service, Cincinnati, January 1965. 

Snyder, L. J., Determination of Trace Amounts of Organic Lead in Air, Composite Sample Method, Anal. Chem. 39 [1967] 591/5. 

A properly designed process for production of optically active compounds will introduce the asymmetric centre as early as possible in the synthesis. 

This ensures optimum economics since unwanted isomeric ballast is not carried through the process, and everything else being equal, halves the waste. Furthermore, at least in the case of agrochemicals, the environment is loaded with only half the amount of substance, i.e. the part which is bioactive. 

It comes as a surprise to many people that the number of kilos of waste (largely inorganic salts) per kilo of product is much larger in fine chemical or pharmaceutical production than it is for bulk and petrochemicals. The reason is that catalytic processes are much in evidence for the latter, whereas for the former, batch processes using stoichiometric methods are the rule. 

Sheldon has used the concepts of atom utilisation and environmental acceptability to assess environmental impact for a given process [13]. Environmental constraints are rendering the use of classical stoichiometric methods prohibitive, and there is a general trend towards cleaner catalytic processes, which are particularly in evidence in chemical and biological asymmetric synthesis. 

Sheldon defines atom utilisation as the ratio of the molecular weight of the desired product to the sum of all the material used (excluding solvents). 

During the next five decades fossil fuels, of which the use of coal will be prominent, are expected to provide the lowest-cost options for producing liquid and gaseous fuels (Speight, 2007, 2008, 2009, 2011). 

For example, the risk of tire or explosion is a significant concern which has to be addressed at an early stage of the design of every gasifier. Co-gasification units are likely to be small and have limited availability of highly qualified staff, or may even run unmanned. Hence, safety systems have 

FIGURE 20.10 Process effluents from coal gasification. (From Braunstein, H.M. et al., Environmental health and control aspects of coal conversion An information overview, Report ORNL-EIS-94, Oak Ridge National Laboratory, Oak Ridge, TN, 1977.) 

Some of the streams contain valnable by-products such as hydrocarbon oils, sulfur, ammonia, as well as valuable elanents in (and properties of) the ash (Braunstein etal., 1977 Probstein and Hicks, 1990). 

The gas from any gasification process is inherently toxic, because of essential components such as carbon monoxide and unwanted components. However, this inherent toxicity is not the reason for gas cleaning because the gas should never be released to the atmosphere directly. 

Ain Dust emissions from approved manufacturing plant must not exceed a total mass flow of 5 g h or a mass concentration of 1 mg m for the sum of lead and chromium (TA-Luft) [3.141]. 

Water According to latest German wastewater legislation [3.142] for inorganic pigment manufacturing processes discharging directly into public streams of water, mass Umits for lead and chromium related to approved tormes of armual production 

Local or regional authorities, even for non-direef discharges into municipal sewer systems, might set lower limits. 

Waste Waste containing lead chromate pigments that cannot be recycled must be taken to a special waste disposal site under proper control. 

The organic chemical industry uses and generates both large numbers and large quantities of a wide variety of solvents, metal particulates, acid vapors, and unreacted monomers. These chemicals are released to all media including air, water, and land. The potential sources of pollutant outputs by media are shown below in Table 1.2 [7]. 

TABLE 1.2 Potential Releases During Organic Chemical Manufacturing 

Air Point source emission stack, vent (e.g., laboratory hood, distillation unit, reactor, storage tank vent), material loading/unloading operations (including rail cars, tank trucks, and marine vessels). Fugitive emissions pumps, valves, flanges, sample coUection, mechanical seals, relief devices, tanks. Secondary emissions waste and wastewater treatment units, cooling tower, process sewer, sump, spill or leak areas. Equipment wash solvent or water, lab samples. 

Liquid wastes (organic surplus chemicals, product washes or 

Solid wastes old equipment or insulation, packaging material, reaction by-products, spent carbon or resins, drying aids. Unlined ditches, process trenches, sumps, pumps, valves, or fittings, wastewater treatment ponds. 

As long ago as 1936, Sir Robert McCarrison, in his Cantor Lecture to the Royal Society of Arts, Manufactures and Commerce, said  

The situation has not changed markedly since Sir Robert s most revealing statement quoted above except that the pressures for such decisions have increased by many orders of magnitude, not the least of which arises because of our increased life expectancy at birth, our increasingly stressful lifestyle, desires to prepare food rapidly, and by the fact that many life-threatening conditions from the early part of this century are treatable, thanks to modern therapy. 

Last century, chemists involved in the food industry were primarily interested in compiling analyses of major components of foods such as carbohydrates, fats, and proteins. Improved analytical techniques paralleled by a greater awareness from physiologists and physicians, led to breakthroughs in terms of diet and cancer, obesity and heart disease, etc. 

Other food components present at far lower concentrations such as trace elements, flavour stimulants, colouring agents, vitamins, required 

Secondly, the quality of life is very much linked to the quality of food which commences with the attractiveness of its presentation and packaging through to the aromas produced during cooking, to the taste stimulation upon ingestion and through to the nutritional benefits. Much of this behavioural aspect of food is linked in with the exact chemical speciation of the material being imbibed. 

The EU Paint Directive 2004/42/EC defines a VOC as an organic compound having an initial boiling point lower than or equal to 250 C at the atmospheric pressure of 101.3 kPa. In the EU, the VOC is calculated by the following formula, and is expressed as mass per unit volume  

In the United States, as per the Environmental Protection Agency (EPA), a VOC is defined as any compound of carbon, excluding carbon monoxide, carbon dioxide, carbonic acid, metallic carbides or carbonates, and ammonium carbonate, which participates in atmospheric photochemical reactions.  

It should be noted that unlike in the EU, the US EPA uses photochemical reactivity of organic compounds as a criterion to identify an organic solvent as a VOC. The US EPA has released a list of exempt solvents that have negligible photochemical reactivity. Methyl acetate, acetone, tert-butyl acetate, dimethyl carbonate and propylene carbonate are some examples of exempt solvents important for the coating industry. Per the US EPA, VOC concentration is calculated according to the following formula and expressed as mass per unit volume  

The procedures specified by the US EPA for testing paint products for compliance with VOC limits are described in Federal Reference Method 24, which employs several ASTM test standards. VOC values for waterborne or solventborne coatings are calculated by the following formula  

YQ( (wt% of volatiles - wt% of water - wt% of exempt solvent)(denslty of coating) 100-Volume % of water-Volume % of exempt solvents 

The production and use of chlorine, as well as certain chlorinated substances bear risks for human health and the environment. International discussions are underway on legally-binding conventions and protocols thereof Matters of concern include the use of mercury, asbestos, chemicals having an ozone-depletion potential (e.g., chloro- 

Fluorinated surfactants can affect the environment by their occurrence in air or water. Some fluorinated surfactants are sufficiently volatile to be present in air  

Fluorinated surfactants are used in small quantities and, for this reason, do not constitute a heavy burden on the environment. The largest concentrations of fluorinated surfactants can be found in the industrial environment, where they can be more readily contained. Fluorinated surfactants used in fire-fighting foams (see Chapter 8) are of recent environmental concern [14]. The population at large is not exposed to fluorinated surfactants in the same way as to hydrocarbon-type surfactants. Unlike hydrocarbon-type surfactants, fluorinated surfactants are not used in household detergents. Hence, fluorinated surfactants do not come in frequent contact with the skin and are not inevitably ingested like small amounts of hydrocarbon-type surfactants. 

The aquatic toxicity of a chemical depends not only on its intrinsic toxicity but also on its biodegration rate. Chemicals which are toxic but are degraded at a rapid rate may not affect aquatic life. However, most fluorinated surfactants are biochemically stable and their aquatic toxicity is not reduced by degradation. 

The aquatic toxicity of fluorinated surfactants has been studied by Knaack and Walther [16]. The biochemical oxygen demand of three fluorinated surfactants was measured by the Warburg method, using a mixed bacterial culture. The fluorinated surfactants tested were the following  

Prescher et al. [17] studied the aquatic toxicities of four fluorinated surfactants to guppy Poecilia reticulata) and green algae (Monoraphidium griffithif). 

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The potential advantages of LPG concern essentially the environmental aspects. LPG s are simple mixtures of 3- and 4-carbon-atom hydrocarbons with few contaminants (very low sulfur content). LPG s contain no noxious additives such as lead and their exhaust emissions have little or no toxicity because aromatics are absent. This type of fuel also benefits often enough from a lower taxation. In spite of that, the use of LPG motor fuel remains static in France, if not on a slightly downward trend. There are several reasons for this situation little interest from automobile manufacturers, reluctance on the part of automobile customers, competition in the refining industry for other uses of and fractions, (alkylation, etherification, direct addition into the gasoline pool). However, in 1993 this subject seems to have received more interest (Hublin et al., 1993). 

The environmental performance of companies within the industry is normally subject to the legislative requirements of the host government, but is increasingly becoming scrutinised by the public, as available information and general levels of awareness increase. Major companies see responsible management of the environmental aspects of their operations as crucial to the future of their business. The approval of loans from major banks for project finance is usually conditional on acceptable environmental management. 

Environmental Aspects. Airborne particulate matter (187) and aerosol (188) samples from around the world have been found to contain a variety of organic monocarboxyhc and dicarboxyhc acids, including adipic acid. Traces of the acid found ia southern California air were related both to automobile exhaust emission (189) and, iadirecfly, to cyclohexene as a secondary aerosol precursor (via ozonolysis) (190). Dibasic acids (eg, succinic acid) have been found even ia such unlikely sources as the Murchison meteorite (191). PubHc health standards for adipic acid contamination of reservoir waters were evaluated with respect to toxicity, odor, taste, transparency, foam, and other criteria (192). BiodegradabiUty of adipic acid solutions was also evaluated with respect to BOD/theoretical oxygen demand ratio, rate, lag time, and other factors (193). 

Secondary and micronutrients in fertilizers. Raw material resources for fertilizers. Environmental aspects,... 

Environmental Aspects. More than two-thirds of aluminum cans are recaptured and returned for recycling into more cans. Because of the heat of melting, the use of post-consumer recycled cans is safe for beverage contents. Not only does recycling save on mass of materials, it also saves the energy of manufacture from aluminum ore (see Recycling, nonferrous metals). 

The complex nature of coal as a molecular entity (2,3,24,25,35,37,53) has resulted ia the chemical explanations of coal combustion being confined to the carbon ia the system. The hydrogen and other elements have received much less attention but the system is extremely complex and the heteroatoms, eg, nitrogen, oxygen, and sulfur, exert an influence on the combustion. It is this latter that influences environmental aspects. 

J. A. Hamshar, H. D. Terzian, and L. J. Scotti, "Clean Fuels From Coal by the COED Process," paper presented at EPA Symposium on Environmental Aspects of Fuel Conversion Technology, St. Louis, Mo., May 1974. 

Eleventh AESF/EPA Conference on Environmental Controlfor the Suface Finishingindustry, Feb. 5—7, 1990, American Electroplaters and Surface Finishers Society, Orlando, Fla., 1990 Environmental Aspects of the Metal Finishingindustry, United Nations Environmental Program, Technical Report Service No. 1, Industry and Environmental Office, Paris, 1989. 

Environmental aspects, as well as the requirement of efficient mixing in the mixed acid process, have led to the development of single-phase nitrations. These can be divided into Hquid- and vapor-phase nitrations. One Hquid-phase technique involves the use of > 98% by weight nitric acid, with temperatures of 20—60°C and atmospheric pressure (21). The molar ratios of nitric acid benzene are 2 1 to 4 1. After the reaction is complete, excess nitric acid is vacuum distilled and recycled. An analogous process is used to simultaneously produce a nitrobenzene and dinitrotoluene mixture (22). A conversion of 100% is obtained without the formation of nitrophenols or nitrocresols. The nitrobenzene and dinitrotoluene are separated by distillation. 

J. G. Speight, Gas Processing Environmental Aspects andMethods, Butterworth Heinemaim, Oxford, U.K., 1993. 

Image duplication and output. Image distribution. Environmental aspects. Economic aspects. 

Beryllium, beryllium-containing aUoys, and beryUium oxide ceramic in soHd or massive form present no hazard whatsoever (31). SoHd shapes may be safely handled with bare hands (32) however, care must be taken in the fabrication and processing of beryUium products to avoid inhalation of airborne beryUium particulate matter such as dusts, mists, or fumes in excess of the prescribed workplace exposure limits. Inhalation of fine airborne beryUium may cause chronic beryUium disease, a serious lung disease in certain sensitive individuals. However, the vast majority of people, perhaps as many as 99%, do not react to beryUium exposure at any level (33). The biomedical and environmental aspects of beryUium have been summarized (34). 

Reactive Chemicals Exposure. The ha2ards associated with exposure to reactive chemicals vary with the chemicals produced. The multitude of chemicals produced electrochemically precludes a detailed discussion of these ha2ards. Material Safety Data Sheets (MSDS) are available from suppHers. Anyone contemplating the production of a chemical must become thoroughly familiar with all safety, health, and environmental aspects of such production. 

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