Catalyst defined

Process for converting para- Ni/Al203 catalyst, DeFine process 65... 

All of these points contribute to a better process economy than the classical process offers. UOP estimates the cost of a plant (50,000 t/a LAB capacity) with Pacol plant, DeH-9 as catalyst, DeFine- and Detal step at around 45 million. Compared to the first plants with similiar capacities of the early 1980s, in which... 

In many macroscopic systems, the massive behavior is a convoluted answer to many microscopic features of the system. For example, the catalysis of the electrooxidation of an organic molecule may be generated by some local arrangement of atoms on a catalyst, defined at the atomic level. If some hypotheses are available to explain the enhancement of the reaction, this can be checked by inserting these hypotheses in the model. In a first approximation, a qualitative explanation is often sought. If this is... 

How do metallocene catalysts define the molecular weight distribution and tacticity of polypropylene ... 

UHV surface analysis, apparatus designs, 36 4-14 see also Ultrahigh vacuum surface analysis mechanisms, 32 313, 319-320 Modified Raney nickel catalyst defined, 32 215-217 hydrogenation, 32 224-229 Modifying technique of catalysts, 32 262-264 Modulated-beam mass spectrometry, in detection of surface-generated gas-phase radicals, 35 148-149 MojFe S CpjfCOlj, 38 352 Molar integral entropy of adsorption, 38 158, 160-161... 

During the investigations, the learning proceeded on two classes of catalysts defined as bad and good according an objective function, which gives more importance to the production of the target molecule styrene than to the consecutive reaction product ethylbenzene. 

I did learn, though, that what the "alumina" did to the etlmol depended upon the "alumina". As Professor Burwell told me much later, and which I think 1 understand only now,". .. these are not compounds, they are materials. .. ". Any catalyst, defined as you like in chemical terms, is a MATERIAL, not a well-defined chemical substance. It is therefore subject to any number of events, physical or chemical, that can alter its behavior. My old work with ethanol employed a commercial alumina, HARSHAW Al-0104 and I had no idea as to the exact chemical composition. When I started making my own alumina, things became clearer because I could observe, at the least, different appearing materials resulting fi om variations in preparation - thus, maybe not all the same stuff . (This is not to denigrate HARSHAW their alumina was a respected and widely used material, but it was a MATERIAL). 

As with many attempts to calculate a constant from a linear plot such as, for example, the Linear Free Energy Relationship (LFER) plot frequently applied by organic chemists, the few end points largely define the value. This is the case for the plot used to calculate m and c. The data obtained for three conversion levels (up to 10 vol% water addition, up to 20 vol% water addition and all data) have been used to calculate values for k and m (Table 10). The rate constant calculated for the three cases is a constant k= 1.115 0.045) while the values of m differ. The value of m for less than 10 vol% water addition is small (0.21), the value for less than 20 vol% water addition is intermediate (0.65), while a value of 0.93 is obtained when all of the data are used. While it is apparent that a water term is needed for the kinetics to describe the effect of water during FTS with a cobalt catalyst, defining the exact equation will be a demanding task. 

Performance of the trickle-bed reactor was gauged by SO2 removal and its conversion to sulfuric acid. SO2 removal is the sum of the SO2 converted to H2SO4 and SO2 dissolved in the wash liquor hence, it is always greater than the conversion. The productivity of the catalyst, defined as the mass in g H2SO4 produced/g carbomh, measures the size of the reactor and thus indirectly the pressure drop. It is used to eompare... 

Figure 14.11. Scanning electron microscope image of a typical VPO catalyst defined as a rosette .

The feed gas contams 10 volume% SO2, 14 volmne% O2, and 76 volume% N2. In this example, the use of cesium-promoted catalyst results in a 21 % decrease in SO2 emissions. Case 1 uses all conventional (potassium promoted) catalyst. Defined below Table 28.1. 

---