Chemicals and Raw Materials

In-Plant Waste Control. Pollution can be reduced or eliminated by process modification, chemical and raw materials substitution, or recovery of by-products. In addition, process modification generally increases product yield by incorporating control devices. 

Many materials in common use today have obvious reactivity hazards, for example, explosives, laboratory chemicals, and raw materials to make plastics and other useful products. Yet they are handled safely every day. How Their hazards have been recognized and controlled so that undesirable events (those which can cause loss and harm) do not happen. Your first source of information for controlling hazards should always be your material supplier. 

The petrochemical and chemical industries are the traditional industries for IR analyzers. The needs are extremely diverse and the versatility associated with process IR spectral measurements make the analyzers a good fit. Products manufactured by the petrochemical and chemical industries range from commodity materials (basic chemicals and raw materials) to fully formulated or compounded end-use products. Value-added products (formulated products) often require an advanced spectral analyzer, such as a process FTIR, whereas commodity chemicals are often served by a traditional IR photometer. 

President s Materials Policy Commission, Resources for Freedom, 5 vol., June, 1952. Study of raw material requirements of the United States, 1950-1975. Major sections on chemicals, metals, minerals, fuels, agriculture, forest resources, water, and ocean resources. Forecasts demand for major chemicals and raw materials up to 1975. 

As catalysts improve, less energy will be required for the production of industtial chemicals, and raw material and by-products will become more benign. 

The chemical industry is a valued customer of the railroads. Nine per cent of the gross revenue of the U. S. railroads is derived from the transportation of chemicals. The transportation of chemicals and raw materials which enter into their manufacture runs into millions of carloads annually. Tank cars used in rail transportation are furnished by the Shippers and there are over 45,000 of these cars in use today. Most of these cars are expensive, highly specialized equipment, developed over the years for our peculiar needs. 

Big repertories of spectra of many chemicals and raw materials are published by suppliers of equipment (Perkin Elmer, Cambridge Instruments, etc.). The experienced chemist can read the spectra and tell the types of polymers or rubbers or resins contained in the formulation and the reactive sites. Thus, this is also a way to analyze an unknown or competitive product, although one needs first to separate the various raw materials by classic laboratory techniques. 

Amino acids are used in feeds (214), food (214), parenteral and enteral nutrition (93), medicine (215), cosmetics (216), and raw materials for the chemical industry (217). 

The standard ASTM PCE test is relative and used extensively only for alumina—siUca refractories and raw materials (see Table 5). However, the upper service limit is generally several hundred degrees below the nominal PCE temperature because some load is generally appHed to the refractory duriag service. In addition, chemical reactions may occur that alter the composition of the hot face and therefore the softening poiat. The relationship between PCE numbers and temperature is described ia ASTM C24. 

Depending on energy and raw material costs, the minimum economic carbon disulfide plant size is generaHy in the range of about 2000—5000 tons per year for an electric furnace process and 15,000—20,000 tons per year for a hydrocarbon-based process. A typical charcoal—sulfur facHity produces approximately 5000 tons per year. Hydrocarbon—sulfur plants tend be on the scale of 50,000—200,000 tons per year. It is estimated that 53 carbon disulfide plants existed throughout the world in 1991 as shown in Table 2. The production capacities of known hydrocarbon—sulfur based plants are Hsted in Table 3. The United States carbon disulfide capacity dropped sharply during 1991 when Akzo Chemicals closed down a 159,000 ton per year plant at Delaware City, Delaware (126). The United States carbon disulfide industry stiH accounts for about 12% of the total worldwide instaHed capacity. 

Chemically Synthesized Powders. Chemical synthesis provides a means of produciag powders for manufacturiag advanced ceramics. Disadvantages of chemically synthesized raw materials are expense and difficulties ia scale-up and availabihty. Additionally, ultrafine particle-size powders produced by chemical synthesis pose some unresolved processiag problems ia the areas of handling and mixing. 

An important element of pollution prevention is the selection of environmentally benign chemical reactions, raw materials, solvents, and products. Over the past few years, significant progress has been made in this area. This chapter provides a brief overview of the recent advances in synthesizing green reactions and species. For more detailed discussion, the reader is referred to Anastas and lliamson (1996), Anastas and Farris (1994), and Chase (1995). 

An example of the way in which process competition works in the manufacture of plastics is the story of acrylonitrile. The first process for the production of this plastic was based upon the reaction between hydrogen cyanide and acetylene, both hard to handle, poisonous, and explosive chemicals. The raw material costs were relatively low as compared to materials for other monomers, but the plant investment and manufacturing costs were too high. As a result, originally acrylonitrile monomer (1950s) sold for about 30 cents per pound and the future of the material looked dim as other plastics such as polyethylene became available at much lower prices due to their lower production costs. 

PVC is transformed into various chemical products/ raw materials. In the pre-treatment step light plastics such as PE, PP, wood and the like are sorted out, as are sand, iron, steel, brass, copper and other metallic pollutants. 

A Microsoft Excel (Version 5.0 or higher) spreadsheet template form has been developed which allows the calculation of the complete reaction mass efficiency (RME) according to equation (4.1) and raw material cost (RMC) for any chemical transformation. Lines are numbered and line instructions are embedded in the same manner as a personal income tax form. Green metrics are evaluated to determine the greermess of the experiment in a rigorous quantitative way and to determine the bottom line cost of carrying out the experiment. Formula entries are inserted in appropriate cells to facilitate computation. Any... 

In this chapter, we focus on strategies, tools and metrics that help chemical choosers to green their chemical product inventories and to benchmark progress. The term chemical chooser applies to those who purchase chemicals for use in the development of formulated products or those who purchase formulated chemical products for use in their use in activities such as maintenance, repair and operations. Most product manufacturers are chemical and material choosers in contrast to chemical or raw material manufacturers who process, synthesize and supply chemicals as raw materials. 

Once the inventory of chemicals in raw materials or products is complete, the next step on the path to integrating green chemical inventories is to assess and evaluate the associated hazards. Using the following rather simplistic distinctions helps to assess and evaluate hazards. Each of these distinctions brings with it a different set of strategies, tools and metrics. 

---