Soak time

The stmcture of residual char particles after devolatilization depends on the nature of the coal and the pyrolysis conditions such as heating rate, peak temperature, soak time at the peak temperature, gaseous environment, and the pressure of the system (72). The oxidation rate of the chat is primarily influenced by the physical and chemical nature of the chat, the rate of diffusion and the nature of the reactant and product gases, and the temperature and pressure of the operating system. The physical and chemical characteristics that influence the rate of oxidation ate chemical stmctural variations, such as the... 

Another way to examine the effeet of earbon partiele size on kineties is to look at the bleed emissions from a earbon eanister [20,35]. Bleed emissions are those emissions that oecur prior to break through. They are the result of the diffusion of gasoline vapor components that ean develop during extended soak times between purge and adsorption events. 

There is a redundancy of flexibility in the design of FCC catalysts. Variation in the amount and type of zeolite, as well as the type of active matrix, provide a great deal of catalyst options that the refiner can employ to fit its needs. For smaller refiners, it may not be practical to employ pilot plant facilities to evaluate different catalysts. In this case, the above methodology can still be used with emphasis shifted toward using the MAT data to compare the candidate catalysts. It is important that MAT data are properly corrected for temperatu. soaking time, and catalyst strippability effects. 

Materials used in the activation with KOH include high volatile bituminous coal C, coal semi-coke CS, pitch mesophase PM, pitch semicoke PS and commercial activated carbon AC. The semi-cokes CS and PS were produced by the heat treatment of corresponding parent materials at 520°C with a heating rate of 5°C/min and 2 hours soaking time. The preparation of mesophase PM comprised the soaking of coal-tar pitch at 450°C for 7 h with a continuous stirring. All the treatments were performed under argon in a vertical Pyrex retort of 45 mm diameter. 

The soak time seems to have a less pronounced effect on porosity development during treatment at 800°C. A considerable porosity (VT = 1.04 cm3/g and Sbet = 2570 m2/g) is created within the early period of reaction and a limited change of the parameters occurs with prolonged heating to 3 h (Fig. 3a). Again, the widening of pores, as evidenced by an increase of both the mesopore ratio and the micropore width, is the most noticeable result of extended reaction time (Fig. 3b). 

Singh, V. and Eckhoff, S.R. 1996. Effect of soak time, soak temperature and lactic acid on germ recovery parameters. Cereal Chem. 73, 716-720. 

Fig. 18.9 Left part - device performance as a function of soaking time for Ti02-based devices using nanographene/porphyrin hybrids (closed) and porphyrin dyes (open). Right part - device performance as a function of soaking time for ZnO-based devices using nanographene/porphycene hybrids (closed) and porphycenes (open).

Unfortunately, there are not many publicly released test results for portals (test results are generally classified). Testing is typically done by two methods. TSA testing is conducted using patches of cloth upon which calibrated quantities of explosives are deposited. These patches are adhered to various locations on people to test for collection and detection efficiency. The quantities of explosives placed on these patches represent levels of contamination the TSA has determined are typically for bomb carriers. Another method primarily used by overseas users is to place bulk explosives on individuals and test for the detection of actual contamination. In order for the test to be realistic, the concealed explosives must be on an individual sufficiently long for contamination to occur, though generally the soak time is only several minutes, rather than the more extended periods expected of an actual bomber. 

Soak time Equilibration time, start short, 1 hr... 

A general summary of temperatures and heat-soak times that are favorable for the formation... 

Nature of the feed stock to the unit. Adding 10 to 15% cracked residuum to a reduced crude feed increased the lump yield 10 to 15% at constant temperature and constant soaking time. 

The soaking time also depends on whether the powder has been previously dried (to 1.5-2% of volatile matter) or only predried (to 10-15% of volatile matter). In the latter case soaking is much more effective although there is a danger that stability may be reduced. 

By varying the soak time, pyrolysis temperature, and heating rate, the compositional, structural, and electrochemical characteristics of the carbonaceous products may be tailored in a wide range. 

Precleaning inspections of the parts may also help in establishing the proper temperature and concentration at which to operate the bath. Quite often, bath temperatures and/or concentrations are increased in an attempt to improve efficiency. While this works in many cases, some soils can become set at higher temperatures and concentrations. When bath oils and solids are present on a part, the rapid removal of the oil due to higher bath temperature creates a difficult-to-remove solid. Proper cleaning may require a lower temperature, longer soak time, and some form of agitation. 

Measurement of Volatile Matter Release Rates. Volatile matter release rates from anthracite were determined by using the apparatus shown diagram-matically in Figure 1. The power input to the 1-kw., 20-volt Hoskins tube furnace and transformer was controlled by means of a Leeds Northrup durationadjusting type program controller which permitted linear heating rates up to 20°C. per min. to be selected with varying soak times and temperatures. A maximum temperature of 1000°C. was used since this was the maximum temperature at which the furnace could be operated continuously. The temperature of the furnace was measured by a chromel-alumel thermocouple inside a... 

Rate of Release of Hydrogen from St. Nicholas Anthracite at Selected Temperatures as a Function of Soak Time. Initial rates of H2 release from a 150 X 200 mesh fraction of St. Nicholas anthracite were determined at temperatures between 700° and 755°C. and are shown in Figure 7. Zero time starts when the sample reached the designated maximum temperature. It is seen that after the carrier gas was displaced from the apparatus, the rate of H2 release at each temperature studied was constant over the interval of times plotted in Figure 7—i.e., the rate of H2 release did not depend on the amount of H2 remaining on or in the anthracite. From these initial rates of H2 release an activation energy of 96 kcal./mole is calculated. When the soak time at a particular temperature below 755°C. was extended sufficiently, the rate of... 

The solid so obtained was introduced in two different sealed refractory crucibles and immersed in a coke bed. One of the crucibles was submitted to the following thermal treatment in an electric furnace 20-1000 "C at 5"C/min. heating rate, followed by 3 h soaking time at this temperature, obtaining a porous solid composite called SC-100. The other crucible was treated in equal conditions but varying the final temperature to 1550 °C, obtaining in this case another porous composite called SC-155. The SC-155 showed a little volumetric expansion respect to the SC-100 material. (The names SC-100 and SC-155 means S= silica C= carbon and the number is the treatment temperature in °C/10). 

Coupling agent Abrasion scratch" Microwave bacon (cycles) Boil-and-soak time (h)r... 

Samplea Evacuation Time, hours 1 Soak Time in Monomer,c hours Nitrogen Pressure, psig Polymer Loading, % wt... 

All experiments in this study were carried out under conditions where C02 and styrene are miscible. The solubilities of C02 and ethylbenzene (a model for styrene) in HDPE were determined at 80 °C and 243 bar. The HDPE samples were immersed in either pure C02 or a 36 wt % ethylbenzene/C02 solution within pressure vessels under these conditions for various times. Figure 10.1 shows results of a typical desorption experiment to determine the mass uptake of ethylbenzene for a given soak time the equilibrium mass uptake was found to be 4% and this was reached after approximately 5 h. Figure 10.2 illustrates the mass uptakes as a function of soak time the diffusivity of ethylbenzene in C02-swollen HDPE under these conditions was calculated by curve fitting to be 9.23 x 10 7 cm2/s. Attempts to determine the equilibrium mass uptake of neat ethylbenzene in HDPE at 80 °C failed because ethylbenzene dissolves polyethylene under these conditions. 

Figure 1. The effect of the soaking time in CAS solution on percent graft." Conditions 0.025 M CAS, 1 M AA, reaction time of 10 h at 35°C.

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