Process design stages

When considering the possibility of using internal combustion drivers, evaluate process requirements and costs. If a low-cost, gaseous fuel is available, gas engines and gas turbines may surpass other drivers in economical installation and operation. In the initial process design stage, a method of establishing the cost of purchase, installation, and operation for drivers is needed. 

This chapter covers the preparation of the preliminary P and I diagrams at the process design stage of the project. 

In this thesis an Inherent Safety Index for conceptual chemical process design is presented. This is required, since inherent safety should be considered in the early phases of design when the major decisions on the chemical process are made. The presented methodology allows such a consideration since the index is based on the knowledge available in the preliminary process design stage. 

It is also possible to circumvent these mechanical design decisions at the early process design stage by rewriting the differential equations (4.9) in terms of V, the volume of the reactor, instead of in terms of the length /. This is our chosen approach here. In it the independent variable V will vary from V = 0 to V = Vr = Vend = 1.0 m3. 

Safety check lists can provide a uselul guide for the main items to be considered during the process design stage. It must be remembered that no list is ever complete and other considerations and techniques should also be applied. Safety check lists can be found in Coulson and Richardson, Volume 6 (1983 pp. 301-303) IChemE Flowsheeting for Safety (1976) Wells (1980) and Balemans (1974). 

Process simulation refers to the numerical solution of process models. At the process design stage, process simulation often refers to the numerical solution of an entire process flowsheet. 

The outline of this section is as follows First is a listing and discussion of the general hierarchical rules to be evaluated during the process design stage. Then, because reactors and separators form the heart of a chemical process, specific aspects of P2 heuristics as applied to reactors and separators are discussed in somewhat more detail. 

As soon as the final process-design stage is completed, it, becomes possible to make accurate cost estimations because detailed equipmept specifications and definite plant-facility information are available. Direct price quotations based"... 

During the process design stage the Project Manager can start controlling the final project cost and avoid unpleasant surprises by ... 

Conceptual estimates are typically prepared during the advanced R D and early process design stages. They are normally used to build the preliminary project economics, prepare preliminary execution plans, and develop cost estimates for the preparation of a complete process design (Phase 1) and a definitive cost estimate. The Phase 0 design package, described in Chapter 6, contains all the information required for conceptual estimates. See Table 9.1 for an example of a conceptual estimate. 

The best contribution the Project Manager can make in the scoping and process design stages is to ... 

Table 20.1 Process Design Stages, Issues, and Tools...

Specific raw material cost (Csrm) Qrm can be used as an economic indicator at the basic conceptual process design stage. This indicator assumes 100% reaction yield, i.e., the minimum raw material cost is computed. Some process design routes can be discarded when Csrm exceeds the targeted product value. The following equation shows how to obtain this indicator ... 

Responsibility [38]. Each category has several criteria. A number of these criteria can neither be evaluated at the process designs stage nor be quantified. Thus more research needs to be done in this area to come up with measures that can be helpful in decision making during the design stage. 

Banimostafa A, Papadokonstantakis S, Hungerbiihler K. Evaluation of EHS hazard and sitstainabihty metrics during early process design stages using principal component analysis. Process Saf Environ Prot 2012 90 8-26. 

Challenges for Model-Based Life Cycle Inventories and Impact Assessment in Early to Basic Process Design Stages... 

LCI ASPECTS IN EARLY TO BASIC PROCESS DESIGN STAGES... 

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