Many times the designer is given the mole fraction of each component in the feed stream but is not given the mole flow rate for the stream. It may be necessary to estimate the total number of moles in the feed stream (F) from an expected stock tank oil flow rate. As a first approximation, …

Read More…# Category: Fluid Properties

## Liquid Flow Rate

The liquid flow rate in moles per day for a given inlet stream can be determined from Equation 3-17. In our example, for an inlet stream rate of 10,000 moles per day, the liquid flow rate is: The liquid flow rate in barrels per day can be derived from: where Q1 = liquid flow rate, …

Read More…## Liquid Specific Gravity

Remembering that the weight of each component is the number of moles of that component times its molecular weight (pounds = MW X moles), the specific gravity of the liquid is given by: Column 5 lists a specific gravity for each component in the liquid phase at standard conditions except as noted. It would be …

Read More…## Liquid Molecular Weight Calculation

The molecular weight of the liquid stream is calculated from the weighted average liquid component molecular weight given by: This is calculated in Table 3-3. Column 2 is as in Table 3-2 and Column 3 is the liquid stream composition for 100 moles of feed as calculated in Table 3-1, Column 7. Column 4 is …

Read More…## Gas Flow Rate

If the flow rate of the inlet stream is known in moles per day then the number of moles per day of gas flow can be determined from: where V = gas flow rate, moles/day F = total stream flow rate, moles/day L = liquid flow rate, moles/day Derivation of Equation 3-13 Once the mole …

Read More…## Molecular Weight of Gas

The molecular weight of the stream is calculated from the weighted average gas molecular weight given by: The molecular weight of the gas stream of Table 3-1 is calculated in Table 3-2. Column 2 lists the molecular weight of the components from standard reference sources. Column 3 lists the number of moles of each component …

Read More…## Fluid Properties Viscosity Part 2

In the absence of any laboratory data, correlations exist that relate viscosity and temperature, given the oil gravity. The following equation relating viscosity, gravity, and temperature was developed by Beggs and Robinson after observing 460 oil systems: The data set from which this relationship was obtained included a range of between 16° and 58° API …

Read More…## Fluid Properties Viscosity Part 1

This property of a fluid indicates its resistance to flow. It is a dynamic property, in that it can be measured only when the fluid is in motion. Viscosity, therefore, is simply the ratio at any shear rate of the shear stress to the shear rate. There are two expressions of viscosity, absolute (or dynamic) …

Read More…## Specific Gravity and Density

Specific gravity of a liquid is the ratio of the density of the liquid at 60°F to the density of pure water. API gravity is related to the specific gravity by the following equation: The specific gravity of a gas is the ratio of the density of the gas to the density of air at …

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