Phenol material balance

When the Freeman and Lewis rate constants are applied to an experimental situation and integrated. Fig. 7 results. This figure shows the same fundamental trends seen in the data. There are some differences, however. The Freeman and Lewis measurements, as presented in their Fig. 2, appear to exceed the available phenol by about 39%. This is probably one reason why Zavitsas et al. state that the Freeman rate constants do not fit the data [80], Flowever, the calculations made using their rate constants do maintain the overall material balance. As presented here, they are not as precise as they could be because the calculation interval has been set at 1 h. Flowever, they are as good as the data at this level. 

But, the mass of activated carbon needed to remove 1 kg of phenol from the waste streams can be evaluated through material balance. 

A liquor, consisting of phenol and cresols with some xylenol, is separated in a plate column. Given the following data complete the material balance ... 

The simple phenol system has been discussed here at some length, because material balance is obtained and mechanistic details are fairly well understood. However, according to the data in Tables 3.5 and 3.6, there is a very noticeable gap in the material balance in the case of the hydroxylated benzoic acids, although some aspects such as the acid-catalyzed water elimination, in salicylate also more pronounced in the case of the para-OH-adduct radical, are very similar (Mark and von Sonntag, unpubl.). Interestingly, addition of Fe(III) to oxidize the intermediates also did not improve the material balance (Tables 3.5 and 3.6). From this, it follows that the underlying chemistry of the salicylate and the other hydroxybenzoate systems are at present not yet adequately understood, and the... 

Figure 5.10 Steps and materials balance for copper production using phenolic oximes as cation exchange solvent (reprinted from [27] with permission from Elsevier).

The catalysts are Al203 Si02 (possibly as zeolites) and oxide mixtures of Mg, B, A1 and Ti. These can be combined with additional co-catalysts such as Ce, V or W. With a large excess of ammonia, the selectivity to aniline is 87% to 90% at a phenol conversion of 98%. The by-products are diphenylamine and carbazole. This technology is used at one plant by Sunoco (previously Aristech Chemical) in Ohio and at another plant in Japan. The economics of this process are favorable if low-cost phenol is available, and high-purity aniline is desired. Capital costs are low because benzene nitration is avoided. A typical process sketch along with a material balance is shown in Figure 20.2139. 

In this paper, experimental results on solvolysis of wood in an acidified water-phenol mixture are presented. The process conditions -temperature, time, liquid to solid ratio, solvent composition-, are investigated and it is shown that mild conditions allow to directly solvolyse wet chips. Solvolysis products are gases (few percent), water, light products and heavy oil. Analysis of material balances shows that wood dissolution involves a condensation reaction between phenol and cellulose. 

In this paper, a solvolysis process of wood is presented using phenol as solvent medium. Its characteristics are examined in term of material balances, the role of phenol in the solvolysis reaction as well as the origin of the water produced. Then, the solvolysis product is upgraded through a hydrotreatment, the purpose of which is to Increase the proportion of light fractions as well as to produce a satisfactory solvent to be recycled in the solvolysis step. 

The first step is solvolysis and, as proposed by YU, we used phenol or phenol based solvents to perform the dissolution of wood, which should be complete, in order to avoid a difficult solid-liquid separation. So we carried out a lot of experiments in order to find the optimal conditions, i.e., a quantity of phenolic solvent as small as possible, low temperature and low pressure. Analysis of material balances of different runs shows that it is necessary to keep the weight solvent/wood above 4. To complete the dissolution of wood, the minimum amounts of water and phenol in the solvent mixture are respectively 20 wt % and 25 wt % (Figures l.a and l.b). In this case, the liquid phase is completed... 

The material balance is set up through the analytical procedure summarized in Figure 2. Five fractions were separated and evaluated water, light oil, heavy oil, free phenol and linked phenol, which cannot be separated by physical methods. The crude mixture is first distilled, giving two fractions. The light one contains water, phenol and light products. The heavy one while anhydrous, contains free phenol, the concentration of which is evaluated by gas chromatography. 

Combining the masses of pollutants in the permeate and the concentrate on a daily basis did not provide a good material balance, relative to the feed. Only when the material in the washwater was also included was all the material accounted for. Based on the volume of washwater used in each washing operation, approximately 200 gallons, about 8 % of the masses of the designated pollutants are retained on the membrane or in tbe liquid in the system. Table 11 provides a summary of the contribution of tbe different streams for each two-day period between wash operations. The relative distribution of pollutants in the washwater was very similar to that in the concentrate, with PAHs far exceeding the phenols. However, the concentration of pollutants in flie washwater was similar to the feedwater. 

Phenol Cumene Production, the Process, and Material Balance... 

Since the oil embargo of 1974, the price of phenol has almost tripled and the balance of supply and demand has become unfavorable to the users. Consequently, new sources of dependable phenolic materials are urgently needed. 

It is interesting to consider what would happen if the feed had not been introduced on the thirteenth plate. This calculation has been carried out and the results plotted in Fig. 9-11. Up to the thirteenth plate, the results are obviously identical with those given in Fig. 9-10 but above this plate, the change of concentration per plate is much less in Fig. 9-11. By the twenty-sixth plate, all the components have become almost asymptotic, and increasing the plates to an infinite number would make little difference in the concentrations from those for the twenty-sixth plate. Thus it is impossible to obtain the desired separation without having plates above the feed plate, since the asymptotic ratio of phenol to o-cresol is less than the desired ratio in the distillate. The limit to this asymptotic ratio is obvious from Fig. 9-11 since the o-cresol, m-cresol, xylol, and residue must all flow down the column, their concentrations cannot decrease below the value necessitated by material balance for their removal from the still. Although the concentration of the phenol is not limited by the same factor as the heavier components, it is limited by the fact that its value cannot exceed 1 minus the sum of the concentration of the heavier fractions and since a minimum limit for the heavier components is fixed, a maximum for the phenol is likewise fixed. The condition illustrated in Fig. 9-11 around twentieth to twenty-sixth plate is termed pinched in i.c., conditions are so pinched that effective rectification is not obtained. As soon as the feed plate is passed, this pinched-in condition would be relieved, since the heavier components would decrease rapidly, as in Fig. 9-10, thereby allowing the phenol to increase. 

The basic materials are sufficiently stable in sulfuric acid not to require the expensive phenolic resin impregnation. Traces of adhesive are applied to hold the glass mat in order to achieve the total thickness. This separation system may be expensive to manufacture, a fact certainly largely balanced by savings in positive active mass, but it also has some indisputable advantages. 

These yields are also given on the basis of 100 g of original dry coal before fractionation. The bottom line of the table shows the mass of each fraction obtained from 100 g of dry coal. For every 100 g of original dry coal an additional 100 g of extraneous material was present. Elemental balances and other evidence (]J showed this to be made up almost entirely of phenol chemically combined with the coal material, with traces present of residual solvent associated with the fractions as a result of the coal preparation and fractionation scheme. Note that with fractions A and B no solid residue was obtained. 

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