Monoliths types

Insulation - The steel shell of the stack is lined for its entire length with monolithic type castable refractory. 

The newly developed monolithic-type column has also found application in the HPLC determination of wine phenolics. Red wine samples were filtered and injected into the column without any other pretreatment. Separations were performed in an ODS monolithic column (100 X 4.6mm i.d.) at 30 1°C. Solvent A was methanol-double-distilled water (2.5 97.5, v/v) at pH 3 with H3P04, and solvent B consisted of methanol-double-distilled water (50 50, v/v) at pH 3 with H3P04. Conditions of gradient elution were as follows 0-lQmin 100... 

M. Castellari, E. Sartini, A. Fabiani, G. Arfelli and A.Amati, Analysis of wine phenolics by high-performance liquid chromatography using a monolithic type column. J. Chromatogr.A 973 (2002) 221-227. 

Cabrera K. Lubda D. Eggenweiler H. Minakuchi H. Nakanishi K. A new monolithic-type HPLC column for fast separations. Journal of High Resolution Chromatography, 2000, 23, 93-99. 

Cabrera, K., Lubda, D., Eggenweiler, H.-M., Minakuchi, H. and Nakanishi, K., A New Monolithic-type HPLC Column for Fast Separations, J. High Resolut. Chromatogr., 23 93-99, 2000. 

Murthy S., Fedorov G, 2003. Radiation heat transfer analysis of the monolith type solid oxide fuel cell. Journal of Power Sources 124(2), 453—458. 

Fig. 8.10. Top view of different monolith types and the corresponding MRI-visualization of the liquid flow in one channel.

In a second set of experiments, different monolith types - Sulzer DX -packings and katapak-S - were tested under varying gas flow rates in countercurrent operation. The scatter of the data points in Fig. 8.24 was caused by the slightly changing water concentrations in the organic liquid. 

In this section, only general findings will be discussed which are valid for all packings investigated. Differences between the monolith types or between distillation packings and monoliths, which can be explained by the different flow patterns, are discussed in Section 8.4. 

However, no significant differences in the performance of the three monolith types are observed. As shown in Fig. 8.30, the water contents for all four monolith... 

Fig. 8.34. Per-pass-octanol-conversion for different monolith types plotted over inlet octanol conversion (2 m column length,...

The internal structure of the resulting polymeric microspheres depends on the solubility of the peptide/protein in the polymer before being spray dried leading to the formation of reservoir- or matrix-type products (see Figure 1). When the initial dispersion is solution, the final product obtained following spray drying is matrix or monolithic type, that is, polymer particles with a dissolved or dispersed nature of the active ingredient (defined as microspheres). Conversely, when the initial... 

Figure 9 Surface area/volume ratio of the monolith types of Table 3, as a function of the pilch / .

Shi et al.154 recently studied the steam reforming of isooctane in a monolithic type reactor simulated by a three-dimensional CFD model. They considered global reactions to represent steam reforming of isooctane, which include steam reforming of isooctane to syngas as expressed in Equation 2.48, WGS reaction as shown in Equation 2.2, and the net reaction by combining these two reactions to produce H2 and C02 as shown in Equation 2.51 ... 

Another example is monolithic-type reactors, which have found their main application in the field of combustion. A monolith bed allows better autothermic operations with a minimal pressure-drop. This concept was used to improve performances in commercial methanol into formaldehyde conversion by adding a... 

The monolith-type prolinol 165 was prepared from the (trimethylsilyl) ethoxycar bonyl (Teoc)-protected monomers (Scheme 3.48). Although the asymmetric borane... 

A ceramic (cordierite) monolith-type three-way automotive exhaust catalyst was used for laboratory-simulated sintering and activity tests and was characterized at Aliieo-Signa1 Materials Research Center. The catalyst contained platinum and rhodium at a weight ratio of 5 to and a total noble metal loading of approximately 1.1 weight percent based on the weight of the... 

Most research on controlled release polymeric systems has, however, centered on compositions in which a drug is either encapsulated in the center of a polymeric membrane (reservoir type) or dispersed throughout the polymer (monolithic type). The drug diffuses through the polymeric material to the surface where it is released to the body fluids. Such systems have been used to give... 

The emission limits by model year 1989/1990 are close to the US standards and therefore the same systems can be applied. Controlled threeway monolith type catalysts, predominantly single bed, are the preferred choice (Ref. 5, 6, 7). The catalyst formulations are modified to cope with European driving conditions (Ref.8,9). 

Four companies manufacture and supply monolith-based catalysts in the USA Degussa, Engelhard, Johnson Matthey and Allied-Signal (UOP). In Japan and Europe the car industry applies only monolithic type catalysts. 

Accordingly the key first stage of manufacturing a monolithic type catalyst is formulation of the wash coat and uniform application over the internal surface of the monolith. Although commercial processes are proprietary with little detail available, the coating is generally fixed, by calcination, at elevated temperature. 

THE EFFECT OF THE CHEMICAL NATURE OF THE WASH-COAT ON THE CATALYTIC PERFORMANCE OF CO OXIDATION CATALYSTS OF MONOLITH TYPE. 

The Effect of the Chemical Nature of the Wash-Coat on the Catalytic Performance of CO Oxydation Catalysts of Monolith type",... 

Those that allow the skin to control the rate of drug absorption (Figure 2.8) and are known as the Monolithic type... 

As illustrated in fig. 2, the pollution abatement system that is being used in gasoline-fuelled engines is a complex one, consisting of several parts. From a chemical point of view, the catalytic converter is the place where the chemistry occurs. Monolith-type catalysts are now employed in the automotive industry (fig. 7). 

The decision as to which monolith type to use is therefore dependent on the type of application, but commercial availability and carbon type should also be evaluated. Cordierite and Mast monoliths are commercially available, whereas ACM is not. When cordierite is used in combination with CNFs, possible cracking of the support can occur. For ACM monoliths, the open structure allows high carrier loading and prevents cracking upon the growth of CNF. For integral carbon monoliths in combination with biocatalysts, the pore size and chemistry of the carbon must be tuned to match the properties of the biocatalyst. 

Pressure Drop. - Pressure drop is an important factor in the design of a catalyst. Pressure drops at catalyst inlet and outlet are negligible compared to wall friction. Therefore, pressure drop for monolith type catalyst can be calculated as follows. Pressure drop on the wall friction... 

There are few data that show accurately the amount of nitrogen that leaches through soils under field conditions. Most of the data that are available have necessarily been obtained from lysimeters. These are of two kinds, the filled-in and the monolith types. In the filled-in type the soil is removed from the field, thoroughly mixed by horizons, and placed in tanks in the natural order. The tanks commonly vary from 1 to 5 ft. in diameter and may be 1.5 to 6 ft. in depth. In the other less common monolith lysimeter the sod profile is left undisturbed and is surrounded by a metal or concrete wall. The soil may be removed intact from its original location, or it may merely be surrounded by a wall and left in place. In both types of lysimeters the percolation is collected and analyzed at frequent intervals. The lysimeter method is obviously an artificial system that has been subject to many criticisms. Nevertheless, it has furnished much valuable information, especially on the effect of comparative treatments, but seldom can the data be considered in a quantitative way as a measure of what is happening under field conditions. Since Allison (1955, 1965) has summarized the results obtained in several lysimeter experiments, the subject need not be considered further in the present discussion. 

Not only does the bulk chemical industry employ all of the membrane separation processes, but partly because of that, the sector gives home also to all of the various physical embodiments of membranes flat sheets, plate and frame, pleated cartridges, tubular, hollow fibre, capillary module, and spiral w ound. More particularly, this end Use sector has considerable demaitd for membranes able to resist high temperature or highly corrosive fluids, such that metallic membranes and ceramic materials, especially of the monolith type w ith parallel cylindrical chambers, are w idely used. 

While more CO-tolerant fuel cells are being developed, efforts in developing more selective catalysts to remove higher amounts of CO (0.5-1.0%) from the hydrogen-reach reformate prior to entering the cell are continuing. These efforts are accompanied by cost reduction. Monolithic types of catalysts, especially those containing Pt, have already been successfully demonstrated in the PROX process. Nevertheless, some other inexpensive catalytic systems, e.g. copper-cerium, also remain attractive for low-temperamre operation. 

Concrete, as discussed previously, is also a good attenuator of gamma rays and is superior to water. This is mainly a result of the presence of moderately high mass number elements, such as calcium and silicon. As a general shield material, there is much to recommend about concrete it is strong, inexpensive, and adaptable to both block and monolithic types of... 

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