The Feasibility of Processes

But these observations, and other similar ones, could still hardly suggest the need for a second law. One could argue that experience suffices to predict these phenomena. 

Let us, however, consider the following device proposed by an inventor (and discussed in Example 2.6) Air enters his device at atmospheric pressure and temperature, say 300 K, and leaves in two streams that have 

We concluded, in Example 2.6, that the device does not violate the first law the enthalpy lost by the cold stream can be found in the hot one. Notice, also, that the device does not involve flow of heat from a cold to a hot body or gas flow from a low pressure to a high one or any unmixing of gases. 

It should, therefore, be feasible. Yet, our intuition suggests that this may not be the case. 

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From the viewpoint of LCVD or LCVT, whether a steady-state luminous gas phase can be used or not makes the most important difference in the feasibility of processing. In the example used above, the choice is only in the feeding mechanism, and the batch operation of LCVD or transient state LCVD could be a factor only in the beginning of vacuum-to-vacuum operation. 

Described here are some results which show the feasibility of processing wastes in molten salts into usable fuels. The molten salt acts as a reaction medium for the conversion of the waste into a low heating value gas (by reaction with air) and the simultaneous retention of potential acidic pollutants in the molten salt. The waste is converted to a fuel gas by reacting it with deficient air, that is, insufficient air for complete conversion to CO2 and H2O. Results are presented for a high-sulfur oil refinery waste, rubber, wood, leather scraps, and waste X-ray film. These waste streams represent a small segment of the large variety of wastes which may be processed using molten salts. 

The general area of chemical synthesis covers virtually all segments of the chemical industry—oil refining, bulk or commodity chemicals, fine chemicals including agrochemicals, flavors, fragrances etc., and pharmaceuticals. Economics generally dictates the feasibility of processes that are practical. ... 

In the experiments of Part I, we found indications that the blends of PP and LCPl also could be processed successfully below the melting temperature T ) of the LCP. Consequently, we carried out injection-molding and extrusion experiments with premixed blends of PP and LCP at a lower temperature without melting of the fibrillar LCP. This was done to ascertain the feasibility of processing PP/LCP blends as composites and to compare the properties of these and conventional melt-processed blends. In preliminary extrusion experiments, we found three processing temperature regions with three different morphologies [52]. 

Goal determination of the feasibility of process improvements requiring a reaction to be run under conditions of rapid simultaneous decomposition of substrate and product... 

The LUC further offers solutions to several issues like the feasibility of processes and the impact of the biorefinery on society. The impact of CO2 emissions due to the production of forest-based feedstocks can easily be calculated by adding the ongoing carbon emission to LUC and the production process (Delucchi, 2011). 

The feasibility of processes and the efficient energy utilization in carrying them out represent the original objectives of thermodynamics and the reason for its name. Actually, the second objective has been traditionally of interest to power engineers, mostly mechanical, while chemical engineers paid only lip service to it, when energy cost was very low. 

We are ready now to carry out entropy change calculations and use them in applications of the second law, such as the establishment of the feasibility of processes and the efficient utilization of energy in them. 

Our discussion of the laws of thermodynamics in the 2nd and 3rd Chapters indicates that their application, combined with knowledge of thermophysical properties, provides for the evaluation of the feasibility of processes and, as we will see in the next Chapter, for the efficient energy utilization, i.e. the first objective of chemical engineering thermodynamics. 

We have concluded, thus far, the discussion of the first objective of chemical engineering thermodynamics the evaluation of the feasibility of processes and the efficient energy utilization in them. Before we proceed with the second one, the evaluation of thermophysical properties of fluids, we consider next intermolecularforces because they are useful in understanding the behavior of fluids as well as phase equilibrium, which is part of the third objective. 

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. 

In some liquid-phase processes, catalyst components are slowly leached from the catalyst bed and eventually the catalyst must be replaced. The feasibility of this type of process involves economics, ie, the costs of catalyst maintenance and keeping a unit out of service for catalyst replacement, and product quality and safety, ie, the effects of having catalyst components in the product and their ease of removal. 

Examining the feasibility of increasing the charging amounts or shortening turnaround times for batches might be the reason for testing. Both of these items can raise issues that potentially affect process safety. 

San Diego Gas Electric s system was originally installed as a research project. The intent of the research project was to test the hardware in this application, test the feasibility of operating such a system remotely with no local operators, and to prove the economics. Similar systems had been installed within process plants where operators were present to start and stop the system and monitor its operation. However, this was the first system installed on a natural gas transmission system with completely remote operation. 

The data used to generate the maps is taken from a simple statistical analysis of the manufacturing process and is based on an assumption that the result will follow a Normal distribution. A number of component characteristics (for example, a length or diameter) are measured and the achievable tolerance at different conformance levels is calculated. This is repeated at different characteristic sizes to build up a relationship between the characteristic dimension and achievable tolerance for the manufacture process. Both the material and geometry of the component to be manufactured are considered to be ideal, that is, the material properties are in specification, and there are no geometric features that create excessive variability or which are on the limit of processing feasibility. Standard practices should be used when manufacturing the test components and it is recommended that a number of different operators contribute to the results. 

The principal technological changes in the engineering control of air pollution were the perfection of the motor-driven fan, which allowed large-scale gas-treating systems to be built the invention of the electrostatic precipitator, which made particulate control in many processes feasible and the development of a chemical engineering capability for the design of process equipment, which made the control of gas and vapor effluents feasible. 

It is not feasible here to go in any detail into the history of processing methods let it suffice to point out that that history goes back to the Victorian beginnings of polymer technology. Thus, as Mossman and Morris (1993) report, the introduction of camphor into the manufacture of parkesine in 1865 was asserted to make it possible to manufacture more uniform sheets than before. Processing has always been an intimate part of the gradual development of modern polymers. 

Estimation of the free-energy change associated with a reaction permits the calcula-aon of the equilibrium position for a reaction and indicates the feasibility of a given chemical process. A positive AG° imposes a limit on the extent to which a reaction can x cur. For example, as can be calculated using Eq. (4.2), a AG° of 1.0 kcal/mol limits conversion to product at equilibrium to 15%. An appreciably negative AG° indicates that e reaction is thermodynamically favorable. 

Identification of waste characteristics that limit the effectiveness or feasibility of technologies is an important part of the screening process. Technologies clearly limited by these waste characteristics should be eliminated from consideration. Waste characteristics particularly affect the feasibility of on-site methods, direct treatment methods, and land disposal (on/off-site). 

During regular operations to identify potential improvements for the next plant. Process improvement studies can then demonstrate the feasibility of inherent safety improvements so they can easily be incorporated into the design of the next plant or in major revamps of existing facilities. 

Thermal and catalytic incinerators, condensers, and adsorbers are the most common methods of abatement used, due to their ability to deal with a wide variety of emissions of organic compounds. The selection between destruction and recovery equipment is normally based on the feasibility of recovery, which relates directly to the cost and the concentration of organic compounds in the gas stream. The selection of a suitable technology depends on environmental and economical aspects, energy demand, and ease of installation as well as considerations of operating and maintenance. 7 he selection criteria may vary with companies or with individual process units however, the fundamental approach is the same. 

The advantages of low-level hoods are listed in Table 13.17. The first step is to verify that the general principle of local capture of emissions is acceptable and feasible for the process. The next step is to establish the most efficient hood geometry. In most cases, this involves a balancing of the degree of process interference tolerable against the degree of emission source enclosure required. 

This is a very sensible requirement and should have been included in ISO 9001 (see Part 2 Chapter 9). However, it should have been placed either under the heading Design control or under Process control, since the feasibility review in this context is not concerned with the feasibility of the project before commencing design but the feasibility of manufacturing the product following completion of design. 

Several chiral selectors have been used in the separation of enantiomers by distillation [198]. Among them, the bisalcohol 8 (Fig. 1-6) has permitted obtainment of the ketone (+)-9 with an enantiomeric excess of 95 %. This example shows the feasibility of the process even though, in this particular case, the price of the chiral selector might prohibit scale-up of the separation. 

A wide variety of physical properties are important in the evaluation of ionic liquids (ILs) for potential use in industrial processes. These include pure component properties such as density, isothermal compressibility, volume expansivity, viscosity, heat capacity, and thermal conductivity. However, a wide variety of mixture properties are also important, the most vital of these being the phase behavior of ionic liquids with other compounds. Knowledge of the phase behavior of ionic liquids with gases, liquids, and solids is necessary to assess the feasibility of their use for reactions, separations, and materials processing. Even from the limited data currently available, it is clear that the cation, the substituents on the cation, and the anion can be chosen to enhance or suppress the solubility of ionic liquids in other compounds and the solubility of other compounds in the ionic liquids. For instance, an increase in allcyl chain length decreases the mutual solubility with water, but some anions ([BFJ , for example) can increase mutual solubility with water (compared to [PFg] , for instance) [1-3]. While many mixture properties and many types of phase behavior are important, we focus here on the solubility of gases in room temperature IFs. 

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