Lean advantages

Lean Oil. The selection of lean oil for an absorber is an economic study. A light lean oil sustains relatively high lean oil loss, but has the advantage of high mols/gal compared to a heavier lean oil. The availability of a suitable... 

Chapters Three, Five and Six have covered the synthesis of physical mass-exchange networks. In these systems, the targeted species were transferred from the rich phase to the lean phase in an intact molecular form. In some cases, it may be advantageous to convert the transferred species into other compounds using reactive MSAs. Typically, reactive MSAs have a greater capacity and selectivity to remove an undesirable component than physical MSAs. Furthermore, since they react with the undesirable species, it may be possible to convert pollutants into other species that may either be reused within the plant itself or sold. 

The new pressure loss equation presented here is based on determining two parameters the velocity difference between gas and conveyed material and the falling velocity of the material. The advantage of this method is that no additional pressure loss coefficient is needed. The two parameters are physically clear and they are quite easily modeled for different cases by theoretical considerations, which makes the method reliable and applicable to various ap>-plications. The new calculation method presented here can be applied to cases where solids are conveyed in an apparently uniform suspension in a so-called lean or dilute-phase flow. 

We have been studying the novel process for CO2 separation named membrane/absorption hybrid method. The advantages of this process are that high gas permeance and selectivity were obtained. The concept of this process is shown in Fig. 1. Both feed gas and absorbent solution are supplied to the inside of hollow fibers. While Ae liquid flows upward inside the hollow fibers, absorbent solution absorbs CO2 selectively and it becomes a rich solution. Most of rich solution permeates the membrane to the permeate side maintained at reduced pressure, where it liberated CO2 to become a lean solution. Compared to a conventional gas absorption... 

Results obtained in full pressure tests demonstrated the following advantages of rich fuel over lean fuel catalytic combustion ... 

The determination of the thickness of the layers of fat and lean tissue in animal flesh is the most popular use of ultrasound in the food industry at present [5,6]. In fact there are over a hundred references pertaining to this application of ultrasound in the Food Science and Technology Abstracts (1969-1993). In contrast to most other applications of ultrasound in the food industry, which have rarely developed further than use in the laboratory, there are a number of commercial instruments available for grading meat quality [6, 30-32]. This application is based on measurement of time intervals between ultrasonic pulses reflected from boundaries between layers of fat, lean tissue and bone. Ultrasonic techniques have the advantage that they are fairly cheap, easy to operate and give predictions of meat quality of live animals. Other examples of thickness determinations include liquid levels in cans or tanks, thickness of coatings on confectioneries, egg shell thickness. 

A lean NOx trap (LNT) (or NOx adsorber) is similar to a three-way catalyst. However, part of the catalyst contains some sorbent components which can store NOx. Unlike catalysts, which involve continuous conversion, a trap stores NO and (primarily) N02 under lean exhaust conditions and releases and catalytically reduces them to nitrogen under rich conditions. The shift from lean to rich combustion, and vice versa, is achieved by a dedicated fuel control strategy. Typical sorbents include barium and rare earth metals (e.g. yttrium). An LNT does not require a separate reagent (urea) for NOx reduction and hence has an advantage over SCR. However, the urea infrastructure has now developed in Europe and USA, and SCR has become the system of choice for diesel vehicles because of its easier control and better long-term performance compared with LNT. NOx adsorbers have, however, found application in GDI engines where lower NOx-reduction efficiencies are required, and the switch between the lean and rich modes for regeneration is easier to achieve. 

Moreover the comparison of 3S and TET installations under transonic and supersonic regimes clearly shows 3S advantages, providing that gas flow is not essentially lean. 

Amperometric mode An advantage of the lambda sensor as described above is its sensitivity close to the 2=1 point where the oxygen activity in the exhaust changes rapidly with burn conditions and consequently so too does the cell e.m.f. The disadvantage is that under lean-bum (oxygen-rich) conditions the log dependence on oxygen activity renders the cell insufficiently sensitive to provide effective control. This shortcoming has led to the introduction of sensors used in the amperometric mode discussed below and illustrated schematically in Fig. 4.40. 

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