Single-product pipelines

There might be additional chemical or technical restrictions that have to be taken into account for pipeline transport planning such as the interruptibility of pipeline operation. E.g. if a product remains too long in a pipeline without movement, chemical reactions may take place which may cause corrosion or polymerization processes. This would lead to a failure and cause expensive maintenance and/or cleaning operations. However, the most obvious technical restriction is probably the pump rate of a pipeline. The pump rate measures the transport speed on a volume-per-time basis. Typically, there is an upper bound for the tolerable pressure inside a pipeline determining the maximum pump rate (say p ). The realized pump rate might be smaller and depends on the power of pumps at the pumping stations.  

A relevant restriction to be fulfilled for operating pipeUnes is the flow balance. I.e., the input flow equals the output flow implying constant physical conditions (such as pressure) for all pipeline segments. For instance, assume a serially operated multi-access pipehne where N is the set of access points consisting of destination points and M feeding locations such that = 0 and JM = N. The flow rate p is measured 

Pj If local flow capacities exist, it follows additionally pj pj  

In contrast to common assumptions in inventory management, the demands of chemicals at chemical production sites are composed by the input and output flows of the related plants instead of a total number of orders within a period. This imphes that the uncertainty covered by safety stocks arises rather from technological sources than from external markets. Moreover, make-to-stock production is predominating in chemical industry because almost all products are commodities. 

In the case of continuously operated single-purpose plants the set of input and output chemicals is fixed (i.e. there is only one recipe used). However, the throughput of the plant can vary in most cases. I.e. there is a finite set of production modes each one associated to specific flow levels of all chemicals. As such plants are typically designed for maximal efficiency, the production mode associated with the maximum throughput is the intended state of production. A change to another mode is often forced by disturbances such as technical failures.  

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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... 

Flows of each production processor are generated in each period depending on the stock levels of the adjacent stock processors and. specific time series models.Flows between production processors use unidirectional single-product pipelines.. 4s non-delayed transport processors, these pipelines are omitted from the flovi chart of Figure j..9 for the sake of simplicity. Transport and turnover processors handle RTC and material flows. Both depend on each other and have to be planned simultaneously. 

Of special relevance among these types are the one-to-many and many-to-many networks as these show the most challenging planning problems. In the single product case, the main problem is to keep the flow in balance along the pipeline or pipeline segments such that inflow and outflow are equal at any time. 

Sufficient space should be allocated to fabricate the product pipeline into one string, thus enabling the pull back to be conducted in a single continuous operation. Tie-ins of successive strings during puUback may considerably increase the risk of unsuccessful installation. 

The first function of a wellsite is to accommodate drilling operations. However, a wellsite must be designed to allow access for future operations and maintenance activity, and in many cases provide containment in the event of accidental emission. Production from a single wellhead or wellhead cluster is routed by pipeline to a gathering station, often without any treatment. In such a case the pipeline effectively becomes an extension of the production tubing. If a well is producing naturally or with assistance from a down... 

The most basic subsea satellite is a single Subsea Wellhead with Subsea Tree, connected to a production facility by a series of pipelines and umbilicals. A control module, usually situated on the subsea tree, allows the production platform to remotely operate the subsea facility (i.e. valves, chokes). 

Multiple use—a single pipeline can be used for a variety of products. 

Air classifiers may have external or internal aerodynamic cycles. The former devices are constructed independently of dust collectors and fans and connected to them via pipelines. The internal-cycle (recirculating-air) devices contain these elements in a single unit, and hence need less production area and normally require lower investments. They have several technical shortcomings outlined in subsection 3.5. 

Product Losses Account must be taken of the product loss, the slow gas in the permeate (such as CH4), or the fast gas in the residue (such as H2). Figure 22-79 illustrates the issue for a membrane used to purify natural gas from 93 percent to pipeline quality, 98 percent. In the upper figure, the gas is run through a permeator bank operating as a single stage. For the membrane and module chosen, the permeate contains 63 percent CH4. By dividing the same membrane area into... 

Historically, the major players in the industry have been jacks-of-all-trades. Integrated businesses in which a single company controlled the entire process - from the supply of raw materials to the outlets for its products - were the norm. Because of the development of individual national markets and the lack of a significant pipeline infrastructure, Europe became even more integrated than North America. 

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