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How do you convert BTU per lb to BTU per scf?
Btu / scf = Btu / lb X MW / 379.5 where: MW = molecular weight of the gas, lb / lb-mol The constant 379.5 is the molar volume at standard conditions of 14.696 psia and 60°F
How do you convert mmscfD to mscf?
To convert from million standard cubic feet per day (mmscfD) to standard cubic feet (scf), you need to multiply the value in mmscfD by 1,000,000 (since 1 mmscf equals 1,000,000 scf). Additionally, if you want to convert the daily rate into an hourly rate, you can divide the daily value by 24. For example, if you have a flow rate of 1 mmscfD, it equals 1,000,000 scf per day or approximately 41,667 scf per hour.
How do you calculate the volume of natural gas in a pipeline?
You could use the following Rule of Thumb: Multiply the square of the inside diameter, in inches, by the gauge pressure, in psi; multiply this by 0.372; the answer is the approximate number of cubic ft of gas (standard conditions) in 1,000 ft of line, e.g 7 inch ID pipeline, 8km long, operating at 65 barg: 8 km = 26246 ft = 26.246 kft 65 Bar = 942.7 psi so, 7 x 7 x 942.7 x 0.372 = 17183.5356 scf / 1000 ft of line, so total gas in 26246 ft of line = 17183.5356x26.246=450999.0753576 = 0.45 MMSCF of gas. Or, you could use, Pv=znRT, assume a z of, say 0.9 , lets say the pipeline is at 6 deg (normal temperature for a shutin subsea pipeline in the north sea) 65x (Pi x 0.1778 x 0.1778 x 8000/4) = 0.9 x n x 8.314x10-5)x (273+6) n = 618523 moles 1 kmol of a gas occupies 22.441 Nm3 at standard conditions t.f 618.523 kmol should ocupy 618.523 x 22.441 = 13880.274643 Nm3. 1 Nm3 = 37.326 SCF, therefore, 13880.274 Nm3 = 518095.131324618 SCF = 0.52 MMSCF.(Nm3 to SCF conversion seems to have different factors, I've seen it range from 34.89 to 38.9!!!). Not very far from the 0.45 the rule of thumb calculated!!!. It should be noted that the standard volume is independent of the particular gas in the pipeline, so we don't need to knwo the MW or density. Any gas at a given P&T will have the same number of moles (and hence standard cubic feet), the actual mass in kg will ofcourse depend on the molecular weight. Riz If you mean standard or normal volume, in case the pressure is considerably higher than the atmospheric value, you need to use an expression for the compressibility factor or take it from a table, depending on the values of pressure and temperature in the pipeline. You can then use a state equation for the gas (knowing its molecular mass), from which you'll be able to calculate its density at working conditions. By multiplying the density by the physical volume of the pipeline pi*D^2/4*L (L=length, D=diameter) you obtain the mass of gas, which divided by the standard or normal density gives you the desired volume.
How many cubic feet of nitrogen are needed to raise the pressure in an 8 inch diameter pipe 400 feet long to 20 psi?
To calculate the amount of nitrogen gas required to raise the pressure in a pipe, we need to follow these steps: 1. Calculate the volume of the pipe in cubic feet. 2. Apply the Ideal Gas Law to determine how much nitrogen is needed to achieve the desired pressure. Step 1: Calculate the Volume of the Pipe The formula for the volume of a cylinder (which is the shape of the pipe) is: V = \pi \times r^2 \times h where: • r is the radius of the pipe (half the diameter), • h is the length of the pipe. Given: • Diameter of the pipe, d = 8 inches, • Length of the pipe, h = 400 feet. First, convert the diameter to feet: d = \frac{8 \text{ inches}}{12 \text{ inches per foot}} = 0.6667 \text{ feet} The radius r is half of that: r = \frac{0.6667}{2} = 0.3333 \text{ feet} Now, calculate the volume: V = \pi \times (0.3333)^2 \times 400 \approx 139.3 \text{ cubic feet} Step 2: Apply the Ideal Gas Law The Ideal Gas Law in terms of volume and pressure is: PV = nRT Where: • P is the pressure, • V is the volume, • n is the amount of gas (in moles), • R is the ideal gas constant, • T is the temperature. To find the additional volume of nitrogen required to increase the pressure to 20 psi, we’ll compare the initial and final states of the gas assuming temperature and the amount of gas are constant. Using the relationship between pressure and volume at constant temperature and gas amount: \frac{P_1 \times V_1}{T_1} = \frac{P_2 \times V_2}{T_2} Since temperature T and n (number of moles) are constant, we can simplify it to: P_1 \times V_1 = P_2 \times V_2 Assuming the initial pressure P_1 is 0 psi (no pressure), the entire volume of the pipe must be filled with nitrogen at the final pressure of 20 psi. Hence, the amount of nitrogen required is equal to the pipe’s volume at that pressure. Thus, 139.3 cubic feet of nitrogen gas is required to raise the pressure in the pipe to 20 psi, assuming no initial pressure.
