Incremental process ratios

One of the significant uncertainties in applying these reaction path calculation results to mass transfer processes in nature is the ratio of the reactive surface area to the total surface area, which is needed to calculate the extent of reaction that will occur in any given time increment. This ratio is known as the effective surface area and may vary from 10 to 10 (Helgeson et al. 1984 Bruton 1986 White and Peterson 1990 Harrison and Tempel 1992 Harrison and Thyne 1992). By using a range of effective... 

Figure 5.3 shows light olefin yields of DCC process in four refineries with different feedstocks at reaction temperatures of 545-565°C. The propylene yield can reach 23 wt% with paraffinic feed, and about 18-19 wt% with intermediate-based feed. The propylene/ethylene ratio is about 3.5-6.2, much higher than that of steam cracking. The DCC operation can be modified to further increase the yield of propylene. For example, recycling a part of DCC cracked naphtha to the reactor resulted in a propylene yield increment of 3.5 wt % in Jinan Refinery [16]. 

Using dissolution techniques, it was observed that the 10 and 25% 6F-PAI (ODA-based) could be co-dissolved with PBI using DMAc. Solution blends with PBI-PAI ratios ranging from 20/80 to 80/20, in 20% increments, were visually homogeneous and contained no insoluble materials. At 15-20% solids concentration, these blends were processible and showed no sign of polymer precipitation for at least 24 h. Transparent, apparently miscible, blend films were cast from the solution blends of PBI and 10% 6F-PAI. 

EXAMPLE 10-2 The data from a differential vaporization on a black oil at 220°F are given below. Prepare a table of solution gas-oil ratios, relative oil volumes, and relative total volumes by this differential process. Also include z-factors and formation volume factors of the increments of gas removed. 

The supersaturation in condensers arises for two reasons. First, the condensable vapor is generally of higher molecular weight than the noncondensable gas. This means that the molecular diffusivity of the vapor will be much less than the thermal diffusivity of the gas. Restated, the ratio of NSc/Npr is greater than 1. The result is that a condenser yields more heat-transfer units dTg/(Tg — Tt) than mass-transfer units dYg/(Yg — Yt). Second, both transfer processes derive their driving force from the temperature difference between the gas Tg and the interface Tt. Each incremental decrease in interface temperature... 

This developed miscibility process results in a miscible fluid, that is capable of displacing all the oil which it contacts in the reservoir... The efficiency of this displacement is controlled by the mobility (ratio of relative permeability to viscosity) of each fluid. If the displacing fluid (i.e. carbon dioxide) is more mobile than that being displaced (i.e. crude oil) then the displacement will be relatively inefficient. Some of the residual oil saturation will never come into contact with carbon dioxide. Both laboratory and field tests have indicated, that even under favourable condition, injection of 0.15-0.6 10 m of carbon dioxide is required for recovery of an additional barrel (0.16 m ) of oil". Here our goal is to obtain a mass ratio of CO2 to incremental oil of 1 to 4, on the basis of the Bonder s data. 

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