Hydrocarbon load

Firewater Monitors Process Areas Hydrocarbon Storage Areas Hydrocarbon Loading Areas... 

Mixtures of porous ammonium nitrate prills with liquid hydrocarbons, loaded uncartridged by free pouring or by means of -+ Air Loaders are extensively used under the name ANFO blasting agents. 

Figure 3 shows the load of hydrocarbons in the liquid solvent phase as a function of solvent to soil ratio. From the data one can conclude that there is a maximum of the hydrocarbon load in water versus solvent to soil ratio. The left rising branch of the curve can be explained by the low extraction results shown in Figure 2. At low solvent to soil ratios only a small amount of hydrocarbons are extracted from the soil material. This amount rises with increasing solvent to soil ratio, so does the load in the liquid phase. When extraction results reach a considerable...

A major component of the reactive hydrocarbon loading are the biogenic hydrocarbons. As previously indicated, the hydrocarbon oxidation chemistry is integral to the production of ozone. Globally, the contribution of NMHC to net photochemical production of ozone is estimated to be about 40%. ... 

UV-VIS spectra (Perkin-Elmer Lambda 9) were registered in reflectance using a evacuable optical cell. Powder of zeolites (around 500 mg) were placed into the cell, pretreated as the IR samples. The following measurements were performed, monitoring the generation of surface species at increasing (i) hydrocarbon loading and (ii) temperature. 

Figure 9 shows the binary adsorption data of n-hexane and 2-methylpentane at 433 K as a function of the gas-phase ratio of the hydrocarbons. Obviously, the n-hexane loading monotonically decreases upon an increase of the partial pressure and loading of the 2-methylpentane. The total hydrocarbon loading only sUghtly decreases at high 2-methylpentane fraction in the gas phase. The preference for adsorption of n-hexane over the monobranched isomer is in line with the above-mentioned entropic considerations. 

The first approach to be checked industrially for the development of detailed mechanisms and the technique of chemical lumping has been worked out at the Polytechnic Institute in Milan for steamcracking The modelled hydrocarbon loads include ethane, propane, the naphthas and even vacuum-distilled diesel fuel, i.e. complex mixtures of hydrocarbons possessing from two to forty carbon atoms. 

SPYRO is a computer program for calculating a steamcracking reactor with hydrocarbon loads ranging from ethane to the naphthas. The computer program contains a detailed reaction mechanism for the pyrolysis of molecules containing from 1 to 4 carbon atoms and lumped mechanisms for larger species. The approach developed by the authors has been validated industrially. 

Retrofitting Selected Water Networks for Increase in Hydrocarbon Load... 

Figure 12.6 Retrofit solutions of original solutions C and C for 100% increase in hydrocarbon load (HL) in each process interconnections are the same as those in the original solution.

Figure 12.8 Simultaneous minimization of fresh water flow rate and total flow rate through regeneration units, for water network design/revamping for 50% and 100% increase in hydrocarbon load in the refinery processes considered.

In the water network revamping for increase in hydrocarbon load, two different values for increase in hydrocarbon load (50 and 100% for each process) are considered. In total, three different values of hydrocarbon load in each process unit (that is, normal, 50% increase, 100% increase) are useful to understand the shift of Pareto-optimal front with change in hydrocarbon load. Here, concentration of each contaminant in waste water is limited at 400 ppm (the same as in the original design). 

Figure 12.8 shows the Pareto-optimal fronts obtained for three different hydrocarbon loads. Four non-dominated solutions (1, 2,3 and 4), obtained with 50% increase in hydrocarbon load, have similar values of both objective functions as the non-dominated solutions... 

All non-dominated solutions (except solution 12) for 100% increase in the hydrocarbon load require only two treatment units (reverse osmosis, and API separator with ACA) as end-of-pipe treatment. In general, FW and TRU are significantly larger for the non-dominated solutions obtained with 100% increase in hydrocarbon load compared with those obtained with 50% increase. Owing to this, H2S and NH3 concentrations are well below the discharge limit (that is, 50 ppm). Hence, in this case, only two treatment units are required as end-of-pipe treatment. 

Other studies found persistent PAHs in organisms from chronically polluted environments. For example, mussels transplanted from a chronically polluted bay to clean waters retained a large percentage of their hydrocarbon load over a 10-wk period (DiSalvo et al. 1975). Chronically exposed clams (Mercenaria mercenarid) lost only 23% of their total aromatic hydrocarbons after 97 d of exposure in clean seawater (Boehm and Quinn 1977), and a persistent fraction of accumulated hydrocarbons found in oysters (Crassostrea virginica) was probably due to sequestering of PAHs in a stable compartment within the organism (Stegeman and Teal 1973). There is evidence that in some cases a rapid, first-order elimination occurs initially, followed by a much slower rate of release that is a function of the time of exposure. For example, fast and slow elimination of naphthalene, which varied by more than 100-fold, was detected between tissues within mussels (Mytilus edulis) (Widdows et al. 1983). 

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