Heating process optimization

While process design and equipment specification are usually performed prior to the implementation of the process, optimization of operating conditions is carried out monthly, weekly, daily, hourly, or even eveiy minute. Optimization of plant operations determines the set points for each unit at the temperatures, pressures, and flow rates that are the best in some sense. For example, the selection of the percentage of excess air in a process heater is quite critical and involves a balance on the fuel-air ratio to assure complete combustion and at the same time make the maximum use of the Heating potential of the fuel. Typical day-to-day optimization in a plant minimizes steam consumption or cooling water consumption, optimizes the reflux ratio in a distillation column, or allocates raw materials on an economic basis [Latour, Hydro Proc., 58(6), 73, 1979, and Hydro. Proc., 58(7), 219, 1979]. 

Most other rotor parts in gas turbines are individually forged. This includes compressor wheels, spacers, distance pieces, and stub shafts. All are made from quenched and tempered low-alloy steels (Cr-Mo-V or Ni-Cr-Mo-V) with the material and heat treatment optimized for the specific part. The intent is to achieve the best balance of strength, toughness with ductility, processing and nondestructive evaluation capability, particularly when it is recognized that some... 

Shenoy, U. V. (1995). Heat Exchange Network Synthesis Process Optimization by Energy and Resource Analysis. Gulf Phb. Co., Houston, TX. 

Curing of Polyimlde Resin. Thermoset processing involves a large number of simultaneous and interacting phenomena, notably transient and coupled heat and mass transfer. This makes an empirical approach to process optimization difficult. For instance, it is often difficult to ascertain the time at which pressure should be applied to consolidate the laminate. If the pressure is applied too early, the low resin viscosity will lead to excessive bleed and flash. But if the pressure is applied too late, the diluent vapor pressure will be too high or the resin molecular mobility too low to prevent void formation. This example will outline the utility of our finite element code in providing an analytical model for these cure processes. 

Virtual prototyping will be the future method to develop new reactors and chemical processes. With a good description of the fluid dynamics, and mass and heat transfer in the reactor, the specific chemical reactions and physical properties of the fluid can be changed and a process optimization can be performed in virtual... 

Interview with Worz/BASF in a special on heat exchangers giving expert opinion on compact heat exchangers, feasibility and problems of large-scale implementation of micro reactors measuring tool for process optimization exotic status. scale-up unit-construction kit industrial implementation in 5 years [216],... 

I., Using micro heat exchangers as diagnostic tool for the process optimization of a gas phase reaction, in Proceedings of the VDE World Microtechnologies Congress, MICRO.tec 2000,... 

Athier, G. P. Roquet L. Pibouleau et al. Process Optimization by Simulated Annealing and NLP Procedures. Application to Heat Exchanger Network Synthesis. Comput Chem Eng 21 (Suppl) S475-S480 (1997). 

Regenass, W. (1997) The development od Stirred-Tank Heat Flow Calorimetry as a Tool for Process Optimization and Proces safety. Chimia, 51,189-200. 

Should the economics of the above-described new process favor a switch from the present AIC process (see Case Study 2) to one based on dihydrohypoxanthine new investment might be justified in new production equipment.81 A switch to the microwave option versus the conventional heating option would depend on the outcome of process optimization work on both. If a rapid clean reaction in near-quantitative yield were realized by optimizing the microwave conditions, then it would prove worthwhile to engineer a simple continuous flow reactor for further development work. The case in favor of adopting the microwave-assisted process would be further enhanced if the solution from the microwave reactor could be used directly in the next process step (thus eliminating the need for isolation equipment). 

The simulation program has been extensively used for process optimization studies as it permits accurate prediction of isomer distribution and heat release. It offers theoretical explanations for isomer control practices arrived at through several years of plant operating experience. The model was used in designing laboratory experiments to study mass transfer under various process conditions and reactor configuration. Since mass transfer and chemical kinetics are simultaneously important in this process, a model is necessary to "filter out" the kinetics effects for mass transfer correlations. The results of our laboratory studies will be presented in future papers. 

Further development and process optimization is planned during the second year of the demonstration program. Included in the program will be evaluation of alternate components, testing alternate concepts for heat recovery, and gasifying a wider range of coals. 

In this paper we will discuss the application of a general batch reactor model that considers the reaction kinetics, heats of reaction, heat transfer properties of the reactor, physical properties of the reactants and the products, to predict 1) The concentration profile of the products, thus enabling process optimization 2) Temperature profile during the reaction, which provides a way to avoid conditions that lead to a thermal runaway 3) Temperature profile of the jacket fluid while maintaining a preset reactor temperature 4) Total pressure in the reactor, gas flow rates and partial pressure of different components. The model would also allow continuous addition of materials of different composition at different rates of addition. 

A novel fuel processor is configured at NETL to integrate the fuel cell system for process optimization and system control. In the proposed system, startup occurs by firing an internal combustor in the dual reactor reformer, which provides heat to the ATR reformer via conduction as well as supplying heat to the fuel cell cathode via direct exhaust from the combustor. 

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