Raw and Intermediate Materials

Many nanodays are based on the smectite clay, montmorillonite, a hydrated sodium calcium aluminum magnesium silicate hydroxide, (Na,Ca)(Al, Mg)6(Si40io)3 (OH) wH 2O. M ontmorillonite is found throughout the world in small quantities in its natural geological state. In large deposits, where the mineral is found in greater than 50% concentrations admixed vdth a variety of other minerals, it is known as bentonite. 

Commercially attractive deposits of bentonite are located in many geographical areas ranging from the United States (particularly in Wyoming) to Western Europe, the Mideast, China, and so on. 

Generally speaking, in characterizing a deposit the prospector/producer will look for the following information  

Crystallography Chemistry Particle size Morphology Charge 

After the overburden is removed, layers of clay are formed into disks and allowed to sundry before removal. The clay is removed from the pit in layers, and the ensuing stockpile is constructed layer by layer. This construction is done in an exacting manner to maximize crude day homogenization. 

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A production step can start only if the required quantities of raw and intermediate materials are available in the storage tanks, e.g., Ti can only be started when at least hi units of Si are present. 

We define the following parameters for the example process B0 = Bi = B2 = B3 = B4 = 20 d = d2 = 3 d3 = 2 b = 10 b2 = bz = 4. The initial amount of Si is 20 units and the goal of the production is to produce 8 units of S3 and 12 units of S4. The optimal schedule with respect to the makespan (the overall production time) is shown in Figure 10.2. Each occurrence of a task in the schedule is called an operation and the number of operations must be determined by the scheduler. The schedule in Figure 10.2 is obviously valid because it satisfies the requirements from Section 10.1.3. It is also optimal, because none of the operations can be shifted to the left to reduce the makespan which is determined by the last operation of T3. In the optimal schedule, 2 operations of both, T1 and T2, as well as 3 operations of T3 are necessary to meet the market demand. The optimal makespan is 10 and all raw and intermediate materials have been processed without overproduction of final products. 

Consider the situation when sufficient quantities of raw and intermediate materials are present and the resource automata in Figure 10.4 are waiting in the idle locations. Without a scheduler which exactly determines the next production step, either Ri or f 2 or Rj can start processing a batch. The possible actions are s(Ti), s(T2), s(T3) or w(e) with e e R-°. Hence, the scheduler has to choose from a set of possible decisions. This set is infinite because the waiting time e is a real number. 

Worldwide, ethyl alcohol is the basis for a huge alcoholic beverage industry, offering a wide range of products whetein the alcoholic content varies from a few to over 50% < 100 proof). Industrially, ethyl alcohol is very important high-tonnage raw and intermediate material for numerous processes, and is used extensively in solvents, antiseptics, antifreeze compounds, and fuels. 

Hydrogen cyanide (HCN) is a widely used high-volume raw and intermediate material in the world chemical industry. For the last several decades it has been increasingly supplied as a by-product of propylene ammoxidation—by... 

Example 5 (Batch pipeline sequencing). Suppose a one-to-one serial pipeline that connects two chemical sites. The provider site prodtices the raw and intermediate materials for the consumer site. Suppose that the consumer site produces Styrene-based chemicals such as Polystyrene and Styrene-Butadiene rubber. Raw materials for Styrene production are Benzene and Ethylene. Among others, a steam cracker provides Ethylene and Pygas, which is subsequently refined to Benzene. It is assumed that the capacities of these plants are unbalanced such that the deficit of Pygas and Benzene has to be imported. Additionally, the cracker feed, Naphtha, has to be imported. 

The general SCM matrix can be adapted to better reflect the specihc characteristics of basic chemical industry. In the traditional SC planning matrix, the material requirement planning modules are concerned with determining order quantities of raw and intermediate materials necessary to realize a pre-dehned production plan. These tasks are particularly challenging if the variety of handled materials is large.In basic chemical industry, however, the variety of raw and intermediate chemicals is comparatively small while their demand is high and mostly determined by the plants technical specifications. 

Another type of external uncertainty emerges from the suppliers side. Suppliers comprise all partners providing raw and intermediate materials which are not part of the considered chemical production network. Prom these external partners materials are suppUed to keep the production network working. Uncertainties affect the network s performance when orders cannot be fulfilled in the expected way. E.g. shipments arrive too late or not in the expected quantities. Such uncertainty can hardly be avoided, but has to be reflected in safety stocks and strategic supply planning. 

An industrial production process is always a chain of tasks and processes through which raw and intermediate material is fed and which finally results in various end products. A successful production process requires thus a seamless collaboration between many various components, of which many in fact comprise some optimization capability. Figure 2.2 (based on [9]) shows the decision layers of a typical batch process. Optimization is critical for each of these layers and an important aspect is that they should not work against each other in a competitive manner such that the total production targets are met. 

While concentrates and refined metal constitute the major material flows in lead, and are the ones for which regular statistics are most readily available, other industry raw and intermediate materials and products are also traded between East and West. Although accurate data is limited, China has been both a small importer and exporter of lead scrap in recent years, as have the Eastern European countries. In addition, there has been a small two-way trade in lead bullion in recent years. North Korea has regularly exported some 10-20000 tons of bullion annually, mainly to Japan, while the former USSR and Bulgaria have been minor, but sporadic, importers. The former USSR has also required the import of automotive lead-acid batteries, which it has satisfied with purchases from Italy and the former Yugoslavia, and from other Eastern Bloc countries. 

Raw materials and auxiliary products used in a process as well as materials of construction for equipment items can be the eause of scale-up effects . Pure raw and auxiliary materials must be used in laboratory studies to eliminate the influence of impurities on the ehoice of the process route, catalyst selection, and search for satisfactory process conditions. However, pure chemicals are usually too expensive to use for manufacture on a commercial scale. It is common practice to use raw materials of technical grade in a full-scale plant. These materials contain impurities, which can act as catalysts or inhibitors. They can react with reactants or intermediates, thereby decreasing yields and selectivities of desired produets. Therefore, raw materials of technical grade, even from different suppliers must first be tested on laboratory scale. 

In addition to the conventional pollutant constituents, USEPA made a survey of the presence of the 126 toxic pollutants listed as priority pollutants in refinery operations in 1977 [5]. The survey responses indicated that 71 toxic pollutants were purchased as raw or intermediate materials 19 of these were purchased by single refineries. At least 10% of aU refineries purchase the following toxic pollutants benzene, carbon tetrachloride, 1,1,1-trichloroethane, phenol, toluene, zinc and its compounds, chromium and its compounds, copper and its compounds, and lead and its compounds. Zinc and chromium are purchased by 28% of all refineries, and lead is purchased by nearly 48% of all plants. 

As a third category production-related performance measures reflect the monetary cashflow resulting from production operations. This includes costs for raw and auxiliary material consumption, labour costs of operators, opportunity costs for tied capital, and revenues due to sales of final and intermediate chemicals. A configuration of the network s logistical system affects the production system by providing prerequisites for normal production operations. I.e. a configuration assures that raw materials are available and that final and intermediate chemicals can be stored and delivered to customers. In this simulation study, these effects result in the availability or storability of intermediate chemicals. If material is unavailable or not storable (e.g. due to fully utilized. stock capacities), a disturbance of the production processes results such that plants have to reduce their production outcome or shut down. An appropriate measure to account for production disturbances is to measure the gap between planned and realized production for all plants associated to the considered... 

C. Acrylonitrile can be found as a liquid or vapor, and can also be found in polymer resins, rubbers, plastics, polyols, and other polymers having acrylonitrile as a raw or intermediate material. 

Security issues may not be crucial to the chemical engineering aspects of a change or trigger event, but they may take on the role of a necessary administrative or management consideration before the change can be implemented. For example, some raw or intermediate materials may be governed by agencies similar to the U.S. Bureau of Alcohol, Tobacco and Firearms (ATF),... 

What you don t have, can t leak. If we could design our plants so that they use safer raw materials and intermediates, or not so much of the hazardous ones, or use the hazardous ones at lower temperatures and pressures or diluted with inert materials, then many problems later in the design could be avoided. 

Polyamide and Intermediates, Techcon (U.K.) Ltd., London pubHshed monthly Nylon Intermediates andFiber, PCI— Fibers Raw Materials, West Sussex, U.K. pubHshed monthly World Nylon 6 and 66 Supply and Demand Report, PCI— Fibers Raw Materials, West Sussex, U.K. pubHshed annually Chemical Economic Handbook, Stanford Research Institute, Menlo Park, Calif., pubHshed and updated periodically. 

The toller needs to be familiar with all raw materials, intermediate materials, products and wastes, used, produced or generated, respectively, while operating the process. Tollers in the U.S. should comply with the Federal OSHA Hazard Communication Standard, codified as 29 CFR. 1910.1200 and any similar state right-to-know laws that are currently in force or may be enacted during the term of the contract. This is often stated in the contract. The contract may require the toller to inform its employees of the chemical hazards associated with products or chemicals and may also be responsible for training its employees in the proper handling methods. The toller has an obligation when in doubt about a product or chemical, to seek further information from the product s manufacturer. 

Simple mixing of raw materials and intermediates may present special problems when processing significantly larger quantities in comparison to the pilot process or laboratory bench amounts. All aspects of the toll should be considered while performing the PHA to identify potential problems caused by the scale-up. 

Is the new hazard due to potential inadvertent mixing in the staging areas or raw material and intermediates storage areas ... 

Clean up includes identifying, gathering, storing (when appropriate), and classifying materials associated with a specific toll. Decisions can then be made as to which raw materials, intermediates, and product will be shipped back to the client or kept by the toller. Some off-spec product, retained samples, or unused intermediates may be considered waste materials at this point. Equipment clean up can be extremely important to preserving quality and process safety integrity prior to the next production run of a new product. 

Advances in catalysis will result in the development of high yield, low waste manufacturing processes. Catalysts frequently allow the use of less reactive raw materials and intermediates, and less severe processing conditions. High yields and improved... 

Storage facilities for raw materials and intermediate and finished products may be located in isolated or adjoining areas. Hazardous materials should be isolated because they menace life and property when stored in large quantities. 

Raw Materials and Intermediate Products for Anionic Surfactant Synthesis... 

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