Conversion process evaluations

Fox, J. M., Chen. T. P, and Degen, B. D., Direct Methane Conversion Process Evaluation, Final Report, U.S. Department of Energy Contract DE-AC22-87PC79814, August 1988. 

C. D. Kalfadehs and E. M. Magee, Evaluation of Pollution Control in Fossil Fuel Conversion Processes, Eiquefaction, Section 1, COED Process, EPA-650/2-74-009e, Environmental Protection Agency, Washiagton, D.C., 1975. 

MIBK Direct Conversion ofMcetone over Heterogeneous Catalyst-Sumitomo, Process Evaluation Research Planning (PERP), Topical Reports, Vol. Ill, Chem Systems Inc., Tarrytown, NY, 1988. 

Process Evaluation and Improvement. As homogeneous asymmetric hydrogenation processes are scaled up, one major concern is cost because the catalyst is usually expensive. Hence, several criteria for a commercially viable process (2), including selectively, conversion, catalyst loading (S/C, the molar ratio of substrate to catalyst), reaction time, and TOF (turnover frequency, the ratio of catalyst loading to reaction time), should be considered to evaluate the process and provide a guide for improvement. 

In nature, the ability of organisms to convert contaminants to both simpler and more complex molecules is very diverse. In light of our current limited ability to measure and control biochemical pathways in complex environments, favorable or unfavorable biochemical conversions are evaluated in terms of whether individual or groups of parent compounds are removed, whether increased toxicity is a result of the bioremediation process, and sometimes whether the elements in the parent compound are converted to measurable metabolites. These biochemical activities can be controlled in an in situ operation when one can control and optimize the conditions to achieve a desirable result. 

However, the area-related energy yield is not the sole criteria for evaluating the energy efficiency of a crop species and/or a fuel type. The energy inputs (CED) of cultivation and conversion processes (see Table 5.7), the DM losses, the energetic use of by-products and the further ways of utilisation must also be considered. 

The potential of these reactions for methane production can be compared in terms of theoretical yields and heat recovery efficiencies. Theoretical methane yield is defined by the chemical equations. Theoretical heat recovery efficiency is defined as the percent of the higher heating value of the coal which is recovered in the form of methane product. These idealized parameters provide a measure of the ultimate capability of conversion systems and are useful for evaluating actual conversion processes. 

Infrared absorption is one of three standard test methods for sulfur in the analysis sample of coal and coke using high-temperature tube furnace combustion methods (ASTM D-4239). Determination of sulfur is, by definition, part of the ultimate analysis of coal (Chapter 4), but sulfur analysis by the infrared method is also used to serve a number of interests evaluation of coal preparation, evaluation of potential sulfur emissions from coal combustion or conversion processes, and evaluation of the coal quality in relation to contract specifications, as well as other scientific purposes. Infrared analysis provides a reliable, rapid method for determining the concentration of sulfur in coal and is especially applicable when results must be obtained rapidly for the successful completion of industrial, beneficiation, trade, or other evaluations. 

In designing a microbial conversion process many important aspects require careful consideration, for example, the selection of a compound to be synthesized, a survey of available substrates, and the routes or reactions needed. Another point (the most important one) is to find microbial enzymes which are suitable for the processes designed, and to subsequently evaluate the enzyme s potential. Moreover, the discovery of a new enzyme or a new reaction provides a clue for designing a new microbial transformation process. To find microbial enzymes that are suitable as potent catalysts, the capabilities of well-known enzymes or reactions need to be reassessed, and novel microbial strains or enzymes need to be discovered. Screening may be one of the most efficient and successful ways of searching for new or suitable microbial enzymes. 

M. Applications of Second Law Analysis to the Design, Evaluation and Optimization of Fuel Conversion Processes... 

Ishida, M. and Nishida, N., "Evaluation of Coal Conversion Processes from an Energy Efficient Use Viewpoint (II) ... 

PRASAD V. NEVREKAR is an associate chemical engineer with the Institute of Gas Technology. His current responsibilities include analysis and evaluation of data for various coal conversion processes. He earned... 

In practice, within the framework of this book, this petrochemical process evaluation is limited to the production of second aeration intermediates. Moreover, it does not lead to the identihcation of a single solution, but to the consideration of several different schemes, in as much as each offers a technologically viable answer. It also consists in emphasizing the technical requirements of the conversion operations planned, as well as potential unfeasibiiities related to the inherent facts of the problem this means the need to propose alternative solutions, requiring a minimum of adaptation of the basic data. 

It is well known that SO2 is a water soluble gas and its oxidation occurs in an oxygen saturated solution namely in the presence of ion metals, which may act as catalysts. A first order rate constant for its conversion to sulphate has been assigned the conversion process in the atmosphere leads however to several oxidation products SO3, H2SO4, NH4HSO4 (NH4)2S04 etc. so that the evaluation of the mechanism and rates of the heterogeneous paths of SO2 oxidation within the troposphere have a great interest for atmospheric scientists. 

Polymerization rate of the process evaluated at t) /2 and expressed as % conversion over time... 

Criteria for evaluating the suitability of biomass for a pyrolysis conversion process to obtain solid, liquid and gaseous fuels are developed based on the properties of the pyrolysis products. 

Pyrolysis results are very important for coal characterization, as all conversion processes of coal such as combustion, liquefaction, and gasification start with a pyrolytic step. For this reason, pyrolysis was frequently used for the analysis of coals [17,18). Pyrolysis data were correlated with coal composition, coal characterization and ranking [18a], prediction of coal reactivity as well as of other properties related to coal utilization. Techniques such as Py-MS, Py-GC/MS with different ionization modes, Py-FTIR, or evolved gas analysis (EGA) [19] were described for coal analysis. Programmed temperature pyrolysis is another technique that has been proposed [17] for a complete evaluation of the two types of molecules present in coal. 

Computers are used extensively in automatic plant process control systems. The computers must convert signals from devices monitoring the process, evaluate the data using the programmed engineering equations, and then feed back the appropriate control adjustments. The equations must be dimensionally consistent. Therefore, a conversion factor must be part of the equation to change thfe measured field variable into the proper units. 

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