Conceptual process design flow sheets

Predesign (Conceptual design) flow sheet preliminary pid feasibility study preliminary operation instructions material balance energy balance process concept operating conditions sketch of layout isi, pns (coarse Dow F E Index, Mond Index, Hazop)... 

The preliminary conceptual process design and the corresponding flow sheet have shown an efficiency of 39-41% (LHV). These values depend on assumptions regarding the operability of the electrolyser and the crystalliser, which separates components in the spent anolyte and catholyte. 

Most of the principles of inherent safety are useful in the preliminary design phase even most process details are still missing. This is represented in Table 4 which shows in which project phase each inherent safety feature should be considered. In fact the opportunities for installing inherent safety features decrease as the design progresses (Kletz, 1991). It can be seen from Table 4 that most features can be considered in the conceptual and flow sheet stage. 

One of the most important factors that determines the column configuration is the formulation (or goals) of the separation task with respect to the total flow sheet. Although a mixture may consist of C components, it does not mean that all C products are necessary. The components contained in streams recycled into the process (e.g., unreacted reactants recycled to the reactor) usually do not have to be separated from each other. Also separation of streams that are later mixed (blended) should be avoided, if possible. The separation system needs to be optimized together with the entire plant, either simultaneously or in a hierarchical approach, as described by Douglas (The Conceptual Design of Chemical Processes, McGraw-ffill, New York, 1988). 

The conceptual design starts with balance calculations and preliminary studies. After that the block diagrams of the processes are created, which can be completed into preliminary flow sheets in the basic engineering phase. In this phase all necessary main equipment inquiry specifications, as well as other process equipment, pump, motor and tank lists are created. 

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