Quantity of Product

The preparative proeedures described in ehapter 4 strietly hold only for the quantities (5-10 g) of product indicated. Simply scaling the quantities up or down to produce different amounts of iron oxide does not always produce the desired result. Crucial factors involved in altering the scale of a preparation are the ratio of reactant to Fe (e. g. OH/Fe or oxi-dant Fe), suspension concentration, pFI and temperature. Unless proved to be irrelevant, these variables should be held constant when the procedure is scaled up or down. Nomially, this can be achieved quite readily when small reaction volumes ( 0.5 L) are used. With larger volumes or when a reactant has to be added constantly (e.g. oxygen or base to a Fe system) this may be more difficult. The alternative then is to produce larger quantities in separate batches. 

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Table 5.15 gives some physical-chemical characteristics of selected main refinery streams capable of being added to the diesel fuel pool. Also shown is the weight per cent yield corresponding to each stock, that is, the quantity of product obtained from the feedstock. 

To decompose the acetone semicarbazone, warm 58 g. with 50 ml. of concentrated hydrochloric acid until it just dissolves. Cool in ice the semicarbazide hydrochloride separates as a thick crystaUine mass. Filter at the pump through a sintered glass funnel, and wash with a small quantity of alcohol and then with ether dry in the air. The yield of pure semicarbazide hydrochloride, m.p. 173° (decomp.), is 35 g. A further quantity of product may be obtained either by saturating the mother liquor with hydrogen chloride or by treating it with twice its volume of alcohol and then with ether. 

Method 1. Dissolve 76 g. of thiourea in 200 ml. of warm water in a 750 ml. or 1 litre round-bottomed flask. Dilute the solution with 135 ml. of rectified spirit and add 126-5 g. of benzyl chloride. Heat the mixture under reflux on a water bath until the benzyl chloride dissolves (about 15 minutes) and for a further 30 minutes taking care that the mixture is well shaken from time to time. Cool the mixture in ice there is a tendency to supersaturation so that it is advisable to stir (or shake) the cold solution vigorously, when the substance crystallises suddenly. Filter off the sohd at the pump. Evaporate the filtrate to about half bulk in order to recover a further small quantity of product. Dry the compound upon filter paper in the air. The yield of hydrochloric acid filter off the sohd which separates on cooling. Concentrate the filtrate to recover a further small quantity. The yield of recrystalhsed salt, m.p. 175° is 185 g. some of the dimorphic form, m.p. 150°, may also separate. 

Strain development programs can mn into millions of doUars. This combined with the status of the strain in the overall process makes the strains extremely valuable and manufacturers rarely deposit useful cultures in one of the commercial coUections (14). Nevertheless, commercial coUections exist and are a very valuable, often used source of microorganisms that have shown some promise of producing smaU or minute quantities of products having real or possible commercial appHcations. These strains are often useful in augmenting in-house activities or as starters for a development program. 

Prices for the different material groups (F —F ) are largely influenced by product size and shape and the quantity of production. Apart from product shape, the main price-determining factor is the performance factor K Prices for the powder, a sintered anisotropic ring, and a sintered anisotropic segment are roughly on the order of 1, 2, and 5, respectively. 

In 1990, U.S. milk production was 67.4 X 10 t from neatly 10.1 X 10 cows. In the United States there has been an increase in quantity of production with a decrease in number of dairy cows. The wodd production in 1987 was 463.4 X 10 t from 50 X 10 cows. Table 12 gives the 1990 production and utilization of fluid and milk products (15). Table 13 gives the total U.S. pet capita consumption. 

Scale-Up Principles. Key factors affecting scale-up of reactor performance are nature of reaction zones, specific reaction rates, and mass- and heat-transport rates to and from reaction sites. Where considerable uncertainties exist or large quantities of products are needed for market evaluations, intermediate-sized demonstration units between pilot and industrial plants are usehil. Matching overall fluid flow characteristics within the reactor might determine the operative criteria. Ideally, the smaller reactor acts as a volume segment of the larger one. Elow distributions are not markedly influenced by... 

Nitration of 4-(2-thienyl)- (301) and 4-(3-thienyl)-pyrazoles (302) mainly occurs on the thiophene ring, but when acetyl nitrate is used as the nitration agent small quantities of products nitrated on the pyrazole ring are isolated (position of the nitro group uncertain) (80CS( 15)102). Pyrazol-l -ylpyridines (303) undergo electrophilic reactions (bromination, chlorination and nitration) preferentially in the pyrazole ring. Thus, the nitration of (303 R = R = = H) either with a mixture of nitric acid and sulfuric acid at 10-15 °C or with... 

Content of prime - tertiary peroxide groups was measured by the quantity of products of complete decay, which were measured by chromatography. It is known that the main contents in products of the complete decay of Oct-MA-TBPMM samples are acetone and 2,2-dimethylpropanol, which arise in reactions of chain fragmentation of tert-butylperoxy radical or in reaction of chain transfer of this radical. In this case the sum of acetone and 2,2-dimethylpropanol molecules is equal to the quantity of peroxide groups in polymer. As an internal standard we used chloroform. 

Manufacturing Facility location where work will be performed Yield definition of the quantity of product to be produced from a given quantity of raw materials... 

The unit was built in a loop because the needed 85 standard m /hour gas exceeded the laboratory capabilities. In addition, by controlling the recycle loop-to-makeup ratio, various quantities of product could be fed for the experiments. The adiabatic reactor was a 1.8 m long, 7.5 cm diameter stainless steel pipe (3 sch. 40 pipe) with thermocouples at every 5 centimeter distance. After a SS was reached at the desired condition, the bypass valve around the preheater was suddenly closed, forcing all the gas through the preheater. This generated a step change increase in the feed temperature that started the runaway. The 20 thermocouples were displayed on an oscilloscope to see the transient changes. This was also recorded on a videotape to play back later for detailed observation. 

An additional quantity of product of lesser purity can be obtained as a second crop by evaporation of the pentane. 

The grade and quantity of product required were set on a meter. The driver inserted an authorization card and pressed the Start button. The required quantity was then delivered automatically. The filling arm had to be lowered before filling could start. 

Space time yield refers to the quantity of product that can be produced in a reactor in a given time. It is a function of both selectivity and activity. Maximum efficiency is reached when this number is high, but if production schedules are not full, lower numbers may be tolerated. Acceptable catalyst life can be extended if space-time yield demands are not heavy. Catalyst cost thus becomes a function of the demands put upon it. 

A flask heated in an oil bath is fillad with 600 ml water and 60 g (1 mol) glacial acatic acid (or an equivalent quantity of diluted acetic acid). While stirring 235 g (1.1 mols) anhydrous p-aminobenzenesulfonamidoguanidine (or an equivalent quantity of a nonanhydrous product) and 122 g (1 mol) sodium acetylacetonate 100% purity (or an equivalent quantity of product of a lower purity) are introduced into the flask while stirring. 

The reaction between hydrogen gas and oxygen gas proceeds more quickly if we mix the gases and then ignite the mixture with a spark. A violent explosion results. Even so, the quantity of product, water, and the heat evolved are the same per mole of hydrogen reacting as in controlled burning. 

Many product designs are inherently limited by the economics of the process that must be used to make them. For example, to date TSs are not blow molded, and they have limited extrusion possibilities. Many hollow products, particularly very large ones, may be produced more economically by the rotational process than by blow molding. The need for a low quantity of products may eliminate certain molding processes and indicate the use of casting or others. 

Film and sheet can, in principal, be made by calendering or by extrusion. Factors that govern the advantages and disadvantages (limitations) of each process can interact in a complex way. Factors to be considered include (1) type of material to be processed, (2) quantity of product to be produced, (3) thickness... 

The ageing and decay characteristics of catalysts are of immense importance in defining the economics of processes. The simplest criterion that can be applied is that of total productivity during the life of the catalyst and also loss of productivity during the shut down required for catalyst replacement. Figure 2 illustrates notional performances for two catalysts A and B in hypothetical processes in which productivity is simply a measure of quantity of product produced. Catalyst A has a lower initial productivity but is more stable in use and dies off at a much lower rate than catalyst B, which has a high initial productivity which falls relatively... 

Tenet (iv). The influence of a barrier layer in opposition to the progress of reaction may be expected to rise as the quantity of product, and therefore the thickness of the interposed layer, is increased [35,37,38]. Thus, the characteristic kinetic behaviour of the overall process may be expected to include contributions from both geometric factors and the barrier effect, though in specific instances one or other of these may be dominant. 

The theoretical yield of a reaction is the maximum quantity (amount, mass, or volume) of product that can be obtained from a given quantity of reactant. The quantities of products calculated from a given mass of reactant in Section L were all theoretical yields. The percentage yield is the fraction of the theoretical yield actually produced, expressed as a percentage ... 

Since a 5 per cent, increase in Kjj/kj produces a 10 per cent, increase in the square, it follows that the ratio anticipated for the rates of reaction would be eilAl]fRT, and if An lies between 10,000 and 20,000 cals./gm. mole., as is probable, the rate ratio is between 5 and 27, approximately. Thus, since the ratio of the quantities of product is that of the rates of reaction, the product of reaction II would form between 83 per cent, and 96-5 per cent, of the total yield. 

The main disadvantage of all these systems is the Hmitation of scale-up. Monoclonal antibodies are produced by multiplying the hollow fiber systems and stirred tank reactors with membrane aeration are known up to 100 liter. Small quantities of product can be produced by these systems but they are not suitable for real industrial scale-up. 

Even though silicon is extremely abundant, only one silicon-containing compound appears in the list of top 50 industrial chemicals. That is sodium silicate, Na2 Si03, used for the manufacture of silica gel and glass. Nevertheless, with the advent of the electronic age silicon has become an extremely important substance that is the primary ingredient of most semiconductors. Because these are microscale devices, the quantity of production of silicon remains small compared with that of fertilizers and construction materials. Although relatively small in quantity, the value of silicon products is quite high. 

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