Multi-product pipelines

Material flows along multi-product pipelines are far more complicated to plan. The most prominent field of application for multi-product pipelines is the distribution of refinery products among a network of distribution terminals. The operating principle is essentially the same as for single product pipelines. However, as multiple materials pass the pipeline sequentially, the different materials have to be separated in some sense. Basically there are two options to separate batches of different materials 

The second option is simply to allow a mixture of successively injected materials. This transition mixture is often labelled as interface. This option is preferable as in many cases the set of materials to be transported is chemically homogeneous (e.g. crude oil derivatives). However, the interface is stiff a problem as it typically does not meet the chemical specifications of one of the parental materials. There are two ways to deal with the interface Either the interface is added to one of both parental materials where it does not harm in the further production processes or the interface has to be extracted (e.g. at the end of a serial pipeline) for a special treatment. No matter how interfaces are treated, transition efforts have to be faced. Hence, minimizing the number of interfaces is one objective to aim at when planning multi-product pipeline schedules. 

If transition efforts can be expressed in terms of costs, the total costs for pipeline transport can be used as the planning objective. In this context, total costs comprise transition costs, transport costs, and inventory costs. Transport costs account for operational pipeline costs, such as the energy costs for pumping. These costs are affected by the pipeline s pump rate which needs to be explicitly controlled and planned when the transported materials differ in viscosity or other physical properties. Inventory costs are 

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To categorize pipeline systems from an organizational point of view, two basic criteria can be used The number of products to be transported and the number of access points. Commonly, pipelines are designed for one product only, e.g. in the case of crude oil transports. This allows optimizing the pipeline s technological configuration with respect to the energy consumption. However, in chemical industry also multi-product pipelines are met when the intended chemicals to be transported are chemically similar. 

Each customer market is supplied via a multi-product pipeline from these tanks. The distribution pipelines can be fed simultaneously from multiple tanks to allow a blending of the (raw) products to final products. 

Another characteristic is whether a processor conserves the inflowing quantity or not. If non-usable or invaluable materials are produced during a transformation process, these can be dropped from the simulation model for the sake of brevity such that a total loss of material is modelled. Examples of such losses are off-spec materials produced after a mode changeover in a multi-purpose plant and interfaces in multi-product pipeline operation. 

Where aviation fuel treatment is concerned API and military specifications for quality apply. Where the fuel is heavily contaminated by suspended solids, the use of a micro-prelilter will extend the life of any coalescer cartridge and reduce operating costs. Where it is necessary to treat surfactant laden and discoloured fuels from multi-product pipelines, clay and fuUer s earth filters are used. 

A more complicated problem is met in the multi-product case where batches of products have to be routed through the pipeline (network) whereby a batch may also be split into sub-batches at pipeline forks. In the oases of multiple sources, additionally a coordinated pumping planning is required under consideration of the pumping capacity, the due dates of the batches, and the segment-wise flow balances. 

MirHassani, S. and Fani Jahromi, H. Scheduling multi-product tree-structure pipelines. Computers chemical engineering, 35(1) 165-176, 2011. 

It must be remembered that in multi-product businesses each product will have a different end-to-end pipeline time. Furthermore, where products comprise multiple components, packaging materials or sub-assemblies, total pipeline time will... 

Despite their low cost and abundant availability, the applications of monoterpenes as chiral synthons or building blocks for synthesis of chiral fine chemicals on an industrial scale have lagged far behind amino acids and carbohydrates. Most of the work in this area is related to multi-step total synthesis of complex natural products in laboratory scale. With the structures of new drug candidates in the research and development pipeline of pharmaceutical companies getting bigger and more complicated, the application of more sophisticated chiral building blocks such as the terpenes will... 

Transport kg/100 km Gas 2.5 6.0 90%-multi-stage Best means pipeline, truck, Hydro-Pac, Neuman Esser, PDC Machines, Inc., RIX Linde, Air Products, Praxair... 

The product obtained from wells on petroleum, natural gas and gas-condensate fields is invariably a multi-phase, multimaterial produced needs to be processed before it can be transported by pipeline and delivered to gasoline plants, oil refineries, and fractionating plants. In this context, engineers widely employ technological processes based on the principle of division (separation) of the native mixture into liquid and gaseous phases as a result of the action of intrinsic forces such as gravity or inertia. 

Figure 1.7 in Section 1.3 shows the value-adding chain, also called textile pipeline. Its production steps are raw fabric production, staple fiber yarn production, fabric production (weaving, knitting, braiding, multi-ply fabric production, non-woven production, and so on), finishing, and tailoring. Via trade approximately 1.9 million tons of textiles reach the market for use. 

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