Feasibility

In the first class, azeotropic distillation, the extraneous mass-separating agent is relatively volatile and is known as an entrainer. This entrainer forms either a low-boiling binary azeotrope with one of the keys or, more often, a ternary azeotrope containing both keys. The latter kind of operation is feasible only if condensation of the overhead vapor results in two liquid phases, one of which contains the bulk of one of the key components and the other contains the bulk of the entrainer. A t3q)ical scheme is shown in Fig. 3.10. The mixture (A -I- B) is fed to the column, and relatively pure A is taken from the column bottoms. A ternary azeotrope distilled overhead is condensed and separated into two liquid layers in the decanter. One layer contains a mixture of A -I- entrainer which is returned as reflux. The other layer contains relatively pure B. If the B layer contains a significant amount of entrainer, then this layer may need to be fed to an additional column to separate and recycle the entrainer and produce pure B. 

At this stage, how great the excess of chlorine should be for Fig. 4.7c to be feasible cannot be specified. Experimental work on the reaction chemistry would be required in order to establish this. However, the size of the excess does not change the basic structure. 

Specifying the hot utility or cold utility or AT m fixes the relative position of the two curves. As with the simple problem in Fig. 6.2, the relative position of the two curves is a degree of freedom at our disposal. Again, the relative position of the two curves can be changed by moving them horizontally relative to each other. Clearly, to consider heat recovery from hot streams into cold, the hot composite must be in a position such that everywhere it is above the cold composite for feasible heat transfer. Thereafter, the relative position of the curves can be chosen. Figure 6.56 shows the curves set to ATn,in = 20°C. The hot and cold utility targets are now increased to 11.5 and 14 MW, respectively. 

It is important to note that shifting the curves vertically does not alter the horizontal overlap between the curves. It therefore does not alter the amount by which the cold composite curve extends beyond the start of the hot composite curve at the hot end of the problem and the amount by which the hot composite curve extends beyond the start of the cold composite curve at the cold end. The shift simply removes the problem of ensuring temperature feasibility within temperature intervals. 

So far it has been assumed that any hot stream could, in principle, be matched with any cold stream, providing there is feasible temperature diflerence between the two. Often, however, practical constraints prevent this. For example, it might be the case that if two... 

Figure 16.3 shows the situation below the pinch at the pinch. If a cold stream is matched with a hot stream with a smaller CP, as shown in Fig. 16.3a (i.e., a steeper slope), then the temperature differences become smaller (which is infeasible). If the same cold stream is matched with a hot stream with a larger CP (i.e., a less steep slope), as shown in Fig. 16.36, then temperature differences become larger (which is feasible). Thus, starting with ATmin at the pinch, for temperature differences to increase moving away from the pinch,... 

Temperature feasibility requires constraints on the CP values to be satisfied for matches between streams at the pinch. 

This is a case in which the tick-off" heuristic has caused problems. The match is infeasible, and its duty must be reduced to 6 MW to be feasible without either stream being ticked off (Fig. 16.226). 

Thus loops, utility paths, and stream splits offer the degrees of freedom for manipulating the network cost. The problem is one of multivariable nonlinear optimization. The constraints are only those of feasible heat transfer positive temperature difference and nonnegative heat duty for each exchanger. Furthermore, if stream splits exist, then positive bremch flow rates are additional constraints. 

Condition (3) applies to Eq. (C.2) when R = 1. Both conditions (1) and (2) are always true for a feasible heat exchange with positive temperature differences. 

For condition b to apply, for positive values of i , P> 2. However, P < 1 for feasible heat exchange. Thus, condition (b) does not apply. Consider now condition (a). Because... 

Keywords exploration, appraisal, feasibility, development planning, production profile, production, abandonment, project economics, cash flow... 

Having defined and gathered data adequate for an initial reserves estimation, the next step is to look at the various options to develop the field. The objective of the feasibility study is to document various technical options, of which at least one should be economically viable. The study will contain the subsurface development options, the process design, equipment sizes, the proposed locations (e.g. offshore platforms), and the crude evacuation and export system. The cases considered will be accompanied by a cost estimate and planning schedule. Such a document gives a complete overview of all the requirements, opportunities, risks and constraints. 

Based on the results of the feasibility study, and assuming that at least one option is economically viable, a field development plan can now be formulated and subsequently executed. The plan is a key document used for achieving proper communication, discussion and agreement on the activities required for the development of a new field, or extension to an existing development. 

Consideration of alternatives seeks to ensure that the proposer has considered other feasible options including location, scales, processes, layouts, operating conditions and the no action option. 

When preparing feasibility studies, it is often sufficient to estimate the number of wells by considering... 

When an oil or gas field has just been discovered, the quality of the information available about the well stream may be sparse, and the amount of detail put into the process design should reflect this. However, early models of the process along with broad cost estimates are needed to progress, and both design detail and cost ranges narrow as projects develop through the feasibility study and field development planning phases (see Section 12.0 for a description of project phases). 

As mentioned in Section 10.1, a typical project might be split into the following phases Feasibility... 

In the feasibility phase the project is tested as a concept. Is it technically feasible and is it economically viable There may be a number of ways to perform a particular task (such as develop an oil field) and these have to be judged against economic criteria, availability of resources, and risk. At this stage estimates of cost and income (production) profiles will carry a considerable uncertainty range, but are used to filter out unrealistic options. Several options may remain under consideration at the end of a feasibility study. 

Decommissioning is often a complex and risky operation. The five key considerations are the potential impact on the environment, potential impact on human health and safety, technical feasibility, costs of the plan, and public acceptability. 

CBR systems require that the operator is present during data interpretation. The operator has to provide the correct classification for the data that could not be interpreted by the system. This means that completely automatic CBR system is not feasible, but in case of the NDT inspection operator is almost always present. 

The sensitivity to defects and other control parameters can be improved by optimizing the choice of the probe. It appears, after study of different types of probes (ferritic, wild steel, insulator) with different geometries (dish, conical,. ..), necessary to underline that the success of a feasibility research, largely depends on a suitable definition of measure collectors, so that they are adapted to the considered problem. 

Earlier research has been focused on laboratory work to determine the feasibility of the method. Both experiments on real components and FEM simulations have been used. Simulations have been used as a guidance when deciding a suitable measurement arrangement. Examples of the information that can be obtained from FEM simulations will be demonstrated. 

The demonstrator whose goal is to establish feasibility studies and to size specific industrial tools is now operating in FRAMATOME Technical Center. 

This research examines the feasibility of a technique based upon the CT principle using a microfocus X-ray source with an image intensifier while the examined object is being rotated The attainable enlargement is up to 200. The data to be processed is collected from the whole surface of the image intensifier by a frame grabber and noise suppression is performed. 

The application of IP can facilitate or even make feasible some experimental techniques in NR, where the neutron source intensity poses a problem for imaging with radiographic films. 

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