Chemicals purchasing specifications

The advent of a large international trade in methanol as a chemical feedstock has prompted additional purchase specifications, depending on the end user. Chlorides, which would be potential contaminants from seawater during ocean transport, are common downstream catalyst poisons likely to be excluded. Limitations on iron and sulfur can similarly be expected. Some users are sensitive to specific by-products for a variety of reasons. Eor example, alkaline compounds neutralize MTBE catalysts, and ethanol causes objectionable propionic acid formation in the carbonylation of methanol to acetic acid. Very high purity methanol is available from reagent vendors for small-scale electronic and pharmaceutical appHcations. 

Provides a purchase specification to facilitate the manufacture, procurement, installation, and testing of vibration, axial position, and bearing temperature monitoring systems for petroleum, chemical, and gas industry services. Covers the minimum requirements for monitoring radial shaft... 

Specifications. Purchase specifications have to be defined first. Then, quality control of catalyst samples which are representative of the purchased catalyst lots, can be implemented to compare actual chemical and physical properties with the range of values stated in the purchase specifications. 

Information on purchased catalysts should include the lot numbers and dates of manufacture, and the amount of water and other volatile matter still contained on the catalyst. Specifications should provide data for chemical analyses, and physical-mechanical and physical-chemical properties. The latter information should include data concerning the average shape and sizes of particles, including oversized particles, fines content, and other measures of physical integrity. An example of information which could be included in purchase specifications for a fixed bed catalyst is shown in the following Table II. 

Standard Quality Control Procedure. A standard quality control procedure vas established in Exxon Chemical Company in 1984. Operating plants were offered in-house assistance for developing appropriate purchase specifications, and for monitoring the quality of lot samples of purchased commercial catalysts and adsorbents. 

Workers at The Solution Makers noticed that recent shipments of solid iron (III) chloride and solid nickel (II) chloride purchased from ICCNA to make 1000 ppm solutions of iron and nickel appeared to be a slightly different color compared to the same chemicals purchased earlier. When they prepared the solutions, they too appeared to be a slightly different color compared to solutions prepared earlier. They are suspicious that these chemicals are out-of spec (meaning they do not meet the specifications required by law) due to a contaminant. Before they start pointing fingers and say that ICCNA s chemicals are out-of-spec, however, they would like to have an independent analysis done by our laboratory. The contract does not call for us to identify a contaminant. Our purpose is to simply discover whether or not there is, in fact, a colored contaminant present. The Solution Makers have given us samples of both the clean iron (III) chloride and nickel (II) chloride and also the chemicals suspected of being contaminated. 

However, the socially optimal degree of persistence is not necessarily ensured through market mechanisms, since persistence redounds to the benefit or detriment of many individuals other than the purchaser. Specifically, since chemicals that are persistent must be active within one of the various basic environmental media (atmospheric, hydrological or organic), this activity will also be experienced by the many others in contact with the same medium. Since this activity may be undesirable from the perspective of the many other persons subjected to it, they might prefer a lower level of persistence than would the individual who is making the purchase decision without taking their preferences into account. 

Fired heaters are available for providing heat transfer media of the types described in Section 13.2, including hot water, steam, mineral oils, silicon oils, chlorinated diphenyls (Dowtherm A), and molten (fused) salts. Fired heaters are also used as reactors, such as reformers in petroleum refineries and for pyrolysis of organic chemicals. Purchase costs for these specific types of fired heaters, based on heat duty, are presented in Table 16.32. 

Testing prior to unloading. Get a sample from every dry and liquid chemical dehvery (compressed gases are exempt). Conduct the special tests included in the purchasing documents. These tests include, at least, appearance (for all liquid and dry chemicals) and specific gravity (for liquids). AWWA standards or other chemical industry standards list the appearance requirements, which may include color, odor, clarity, and visible foreign matter. 

This method is not intended for use in purchasing specifications because the conditions of processing plastic compounds vary widely, and the degree of correlation of data obtained by this method with chemical and physical properties has not been completely determined. However, despite this limitation, this method does yield data of value in establishing such correlations and in judging the quality of extruded PVC pipe. 

If you cannot specifically answer these questions, then you have not formulated a proper research project. The choice of computational methods must be based on a clear understanding of both the chemical system and the information to be computed. Thus, all projects start by answering these fundamental questions in full. The statement To see what computational techniques can do. is not a research project. However, it is a good reason to purchase this book. 

Purchases of manganese ore are made on the basis of user requirements, individual specifications, and availabiUty. Most grades of manufactured manganese chemicals are subject to government and commercial specifications, many of which apply to specific uses. Prices of metallurgical manganese ore reached a high of 3.78/t in 1990 (Fig. 13). 

Key contents of a purchase profile report for a specific chemical are identity, location, and capacity of primary vendors expected additions or deletions of capacity and their timing captive use/merchant supply status of each vendor pricing history pricing induences (feedstock, energy, etc) demand by use and anticipated growth and demand in the purchaser company up to five or ten years ahead. 

There is a difference of opinion as to whether a chemical buyer or purchasing-research analyst should be product or division oriented. Those who favor product orientation cl aim they achieve a broader and deeper understanding of the outlook for the chemicals they buy and this leads to sound purchasing strategy. Proponents of the division orientation cl aim that the product-oriented analyst has too many chemicals to foUow (up to 100 specific chemicals in some companies with 10 to 15 as principal purchases). If, instead, division needs are paramount in the mind of the analyst, more profitable buys can be made. The weakness of this latter argument is that in multidivisional, multibillion doUar chemical companies, this division-oriented analyst may have as many chemicals to foUow as a product-oriented counterpart. 

All aspects of the material s chemical, mechanical and physical properties which are included in the specification should be capable of measurement and certification. For critical duties all material supplied should be fully tested and certified by competent approved, independent test laboratories. All items of plant should be purchased with material certification. Additional certification is required in cases where the fabricator, in manufacturing an item of plant, used techniques such as welding or heat treatment which may affect the corrosion behavior of the construction materials. 

Many small laboratories use kitchen cabinets, also available in wood or steel, and are quite happy with them. Normal prices of high quality kitchen cabinets are not much lower than those of the laboratory variety, but special bargains are often available. They come in far fewer types of units, which make the laboratory benches less adaptable to specific uses. Finishes are not made to resist chemicals, and the overall construction is seldom of the heavy-duty type. In a microbiological laboratory where they have been used for years, however, workers have been pleased with them. They were adequate for the light duty service and were purchased when a local dealer had a clearance sale. 

Poor pharmacokinetics and toxicity are important causes of costly late-stage failures in drug development. It is generally recognized that, in addition to optimized potency and specificity, chemical libraries should also possess favorable ADME/Tox and druglike properties [77-80]. Assessment of druglike character is an attempt to decipher molecular features that are likely to lead to a successful in vivo and, ultimately, clinical candidate [81-83]. Many of these properties can be predicted before molecules are synthesized, purchased, or even tested in order to improve overall lead and library quality. 

Capital cost estimates for chemical process plants are often based on an estimate of the purchase cost of the major equipment items required for the process, the other costs being estimated as factors of the equipment cost. The accuracy of this type of estimate will depend on what stage the design has reached at the time the estimate is made, and on the reliability of the data available on equipment costs. In the later stages of the project design, when detailed equipment specifications are available and firm quotations have been obtained, an accurate estimation of the capital cost of the project can be made. 

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