Process fuel equivalent

The energy consumed in a process or the energy intensity of a process is expressed by the term process fuel equivalent (PFE) which is defined as... 

The air-intake used to induce air from the flight-altitude atmosphere plays an important role in determining the overall efficiency of ducted rockets. The air pressure built up by the shock wave determines the pressure in the ramburner. The temperature of the compressed air is also increased by the heating effect of the shock wave. The fuel-rich gaseous products formed in the gas generator burn with the pressurized and shock-wave heated air in the ramburner. The nozzle attached to the rear-end of the ramburner increases the flow velocity of the combustion products through an adiabatic expansion process. This adiabatic expansion process is equivalent to the expansion process of a rocket nozzle described in Section 1.2. 

Two emerging trends endorse the concept of heat-integrated processes first, the production of basic chemicals is moved close to oil and gas wells where crude oil or natural gas is processed in large stand-alone units [1]. Second, fuel cell systems require on-site and on-demand hydrogen production from primary fuels (i.e., natural gas, liquid hydrocarbons or alcohols) [2]. Net heat generation in these processes is equivalent to raw material and energy loss, and is therefore undesirable. 

SFAs with non-processible fuel composition, which will be unloaded from reactors of special deep-diving NPSs of the Northern Navy. Presumably, the total amount of this SNF is equivalent to 9 RC of such reactors [1] ... 

We can make generalizations only if we make extensive approximations. While not all methods of separation cen be readily generalized, some are summarized in the following discussions. To compare the fuel efficiencies of different separation processes, we derive the eppnoximate equation for fuel equivalent for each and compare the values,... 

Liquid fuels equivalent to existing commerical products (kerosine, diesel, jet fuel, high octane gasoline) can be produced using biomass type feedstocks. A summary of potential products and operating conditions is shown in Figure XII and Table XVI. The present status of the project is indicated in Table XVII. Liquid hydrocarbon yields of 50-100 gal/ton of feedstock (dry, ash free) are to be expected. The process is characterized by ... 

By converting different energy forms to their fuel equivalent, process energy intensity in equation (2.3) can be revised to give... 

However, there is a problem here with this simple aggregate approach Although energy in fuel equivalent is additive, feeds (F) are not because processes usually have different feeds with very different compositions. In other words, the problem with equation (2.10) is the dissimilarity in feeds, which cannot be added without treatment. 

To reveal the significance of FE calculations, let us assume a process receives 20klb/h of HP steam in which lOklb/h comes from a boiler with efficiency of 75% and another lOkIb/h from a boiler with efficiency of 85%. Obviously, the fuel required or fuel equivalent for the same amount of HP steam, that is, 10 klb/h, by the two boilers is very different The fuel equivalent from the boiler with 85% efficiency is 15.35 MMBtu/h, resulting in FE factor of 1.535 MMBtu/klb. The fuel equivalent... 

After converting all energy forms to fuel equivalent, these energy forms are leveled on the equal basis and thus we are ready to conduct energy balance. For a chemical process, energy balance is defined as... 

Kellogg (1974), reported in Rankin Wright, op at p 186. The comparison is made in terms of material fuel equivalent (MFE) for both processes, which takes into account direct and indirect fuel use, the use of surplus heat, and the fuel equivalent of saleable by-products for each processing stage. 

One goal of the present study is to develop a process model which can predict particle sizes, size distributions, and production rates for a specified precursor given the process parameter inputs (e.g. pressure, fuel equivalence ratio, flow rates, etc.). Such a model would inevitably involve complex gas phase chemistry which would be capable of predicting the chemical and thermal environment through which the precursor gas passes. Considerable progress has been made with combustion chemical mechanisms, especially for methane and hydrogen fuels. These full mechanisms can readily be applied to one-dimensional flows such as those in our study, and the numerical solution remains computationally tractable. 

De-enrichment of HEU from approximately 93% to 3% can be accompHshed using the depleted tails from the original enrichment process. These tails contain on the average 0.20% U. The de-enrichment of 11 of HEU uses 32 t of tads, yielding approximately 33 t of fuel having an enrichment of 3% U. Producing the same amount of 3% enriched uranium from natural sources would requite approximately 180 t of natural uranium metal. Therefore, 1 t of HEU is equivalent to 180 t of natural uranium. 

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