Cresol production figures

For example, the solvent products of a liquefaction carried out with a synthetic solvent (80% 2-methyl naphthalene, 18% p-cresol and 2% y-picoline) were shown (by gc/ms) to have formed a variety of dimeric products Figure 7 presents the gas chromatogram of this solvent after reaction in which the major components were identified ... 

Figure 2.2 Block diagram for p-cresol production (conventional) plant.

These compounds absorb ultraviolet radiation which is present within the troposphere (see figure IX-L-2), and their photochemistry may be important. The primary process (I) has been suggested to explain the o-cresol product observed (Klotz et al., 1998b, 2000). Process (II) has been suggested to occur from the 2-methyloxepin form (Vogel and Gunther, 1967 Kaubisch et al., 1972) ... 

I ovolac Synthesis and Properties. Novolac resins used in DNQ-based photoresists are the most complex, the best-studied, the most highly engineered, and the most widely used polymers in microlithography. Novolacs are condensation products of phenoHc monomers (typically cresols or other alkylated phenols) and formaldehyde, formed under acid catalysis. Figure 13 shows the polymerization chemistry and polymer stmcture formed in the step growth polymerization (31) of novolac resins. 

The catalytic activity of Mg/Al/O sample in m-cresol gas-phase methylation is summarized in Figure 1, where the conversion of m-cresol, and the selectivity to the products are reported as a function of the reaction temperature. Products were 3-methylanisole (3-MA, the product of O-methylation), 2,3-dimethylphenol and 2,5-dimethylphenol (2,3-DMP and 2,5-DMP, the products of ortho-C-methylation), 3,4-dimethylphenol (3,4-DMP, the product of para-C-methylation), and poly-C-methylated compounds. Other by-products which formed in minor amounts were dimethylanisoles, toluene, benzene and anisole (not reported in the Figure). 

Data of Figure 1 show that at low temperature the prevailing product was 3-MA, while the formation of C-methylated compounds was considerably lower. On increasing the reaction temperature, and hence the conversion of m-cresol, the selectivity to 3-MA rapidly decreased, while that to C-methylated compounds correspondingly increased. Amongst the latter, products of ortho C-methylation (2,3- and 2,5-DMP) were clearly favored with respect to that of para methylation (3,4-DMP). However, the formation of mono-C-methylated compounds was accompanied by consecutive polyalkylations, and the corresponding products became soon the prevailing ones, when the reaction temperature was raised above 350°C. 

The results of Figure 1 may in part be attributed to a consecutive reaction on 3-MA, the contribution of which becomes relevant at high m-cresol conversion. However, the comparison between the distribution of products obtained when starting either from m-cresol (Figure 1) or from 3-MA (Figure 2) evidences some important differences, in particular the selectivity to polyalkylates. This considerably increases in m-cresol methylation at above 300°C, and can be attributed to the consecutive C-methylation occurring on DMPs and 3-MA. This reaction becomes the dominant one at high temperature. 

The effect of temperature on the catalytic performance of Mg/Fe/O is reported in Figure 3. The behavior was quite different from that of the Mg/Al/O catalyst. The conversion of m-cresol with Mg/Fe/O was always lower than that with Mg/Al/O. The selectivity to 3-MA was almost negligible in the whole range of temperature. The selectivity to polyalkylates and to 3,4-DMP was also much lower than that observed with Mg/Al/O. Therefore, the catalyst was very selective to the products of ortho-C-methylation, 2,3-DMP and in particular 2,5-DMP. This behavior has to be attributed to specific surface features of Mg/Fe/O catalyst, that favor the ortho-C-methylation with respect to O-methylation. A different behavior of Mg/Al/O and Mg/Fe/O catalysts, having Mg/Me atomic ratio equal to 4, has also been recently reported by other authors for the reaction of phenol and o-cresol methylation [5], The effect was attributed to the different basic strength of catalysts. This explanation does not hold in our case, since a similar distribution of basic strength was obtained for Mg/Al/O and Mg/Fe/O catalysts [4],... 

In addition to the Fischer-Tropsch-derived material, coal-derived liquids were also recovered from low-temperature coal gasification (not shown in Figures 18.3 and 18.4). These products were processed separately to produce chemicals, such as phenols, cresols, and ammonia, as well as an aromatic motor gasoline blending stock.34 The latter was mixed with the Fischer-Tropsch-derived motor gasoline. 

Three additional circles have been added at the left of Figure 1 to represent the additional components involved in the production of synthesis gas. These involve the light gases H2 and CO, with N2, 02 and Ar as minor components water and ammonia with amines as minor components and cresols and other organic components. These three additional types of components produce a total of 15 combinations of interactions between the various types of components or 12 additional interactions. Thus the additional work to be done could be as much as four to five times the amount already done on oil and gas components. 

Figure 5- Gel permeation chromatogram of butylated -cresol-dicyclopentadiene reaction products.

Figure 5. Oxidation of toluene in acetonitrile under oxygen products benzaldehyde ( ), benzyl alcohol ( ), o-cresol (O) m-cresol (O), p-cresol ( ).

Figure 10.11 offers the general reaction network for the SCWO of cresol. This network shows three parallel paths for the oxidation of cresol by SCW. Three reaction intermediates are a hydroxybenzaldehyde via oxidation of the methyl substitute ring-opening products and phenol via demethylation. The end products are COz and HzO. The relative importance of the parallel pathways depends on the specific cresol isomer being oxidized. Figure 10.11 shows that phenol and hydroxybenzaldehydes are key organic intermediates in the reaction network, so the reaction network should also include the reaction paths for these compounds. Two parallel primary paths produce... 

The data in Figure 2 for trialkylated phenol products are similar to those in Figure 1, with two important differences. The abrupt change in effectiveness of the trialkylated phenols occurs when R is Ci0H2i to C12H25. Although in the more severe tests these compounds are about as effective as the 2,6-dialkyl-p-cresols, in the least severe test they are considerably less effective. It is evident that 2,4,6-trioctadecylphenol is also a very potent antioxidant. 

Formation of sub-bituminous coal seems to involve O loss through conversion of dihydroxy phenolic units (catechols) to monohydroxy units (phenols and alkylphenols), as shown in Fig. 4.7, based on the simple distribution of pyrolysis products, which are dominated by phenol, ortho-cresol (2-methylphenol) and 2,4-dimethylphenol (Hatcher 1990). Oxygenated aliphatic structures (alkyl hydroxyls and ethers) seem to be absent. Figure 4.8 shows the types of units present at various stages of biochemical coalification, based on a random hgnin polymer. 

Figure 3 m-Cresol conversion and selectivities to the main products as fiuictions of the reaction time. Catalyst Mg/Fe=1.5. 

As shown in Figure 3, the O- and C-alkylation products form through parallel reactions, and none of these products apparently undergo consecutive transformation. This may be due to the relatively low m-cresol conversion achieved under these conditions, and it can not be excluded that a consecutive contribution of 3-MA transformation to C-alkylated products might occur under conditions of higher m-cresol conversion. 

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