Gasification Daily Question: 12/8/2016 – Process calculation question (5 points for participation, 10 points for a correct answer)
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This post was last edited by tfx511024 on 2016-12-9 at 19:31. Daily question on gasification: Process calculation problem for 2016-12-8 (5 points for participation, 10 points for a correct answer). This question relates to the calculation of the steam-to-gas ratio at the outlet of the gasification unit: The process conditions are as follows – the temperature at the outlet of the water-coal slurry gasification scrubber (also known as carbon scrubber) is 238 degrees Celsius, with a gauge pressure of 5.7 MPa. What is the steam-to-gas ratio at the outlet of this carbon scrubber under these conditions? (The compression factor is taken as 0.95; the result for this problem is: vapor-to-gas ratio: 1.375) Please list the calculation steps, which should be valid. The results are on the third floor.
This is quite difficult; it takes some time to learn it
This post was last edited by tfx511024 on 2016-12-9 19:32. Gas ratio: the molar ratio of water vapor to dry gas in water gas. By consulting the saturation steam temperature-pressure chart, it is found that the saturated vapor pressure of water at 238°C is 3.285 MPa. Let: n1: molar amount of water; n2: molar amount of dry gas. P: total pressure of the water gas, P = 5.7 + 0.1 = 5.8 MPa. P1: partial pressure of water vapor; since the water in the raw gas is in a saturated state, P1 = 3.285 MPa. P2: partial pressure of dry gas, P2 = P – P1 = 2.515 MPa. V: volume flow rate of the water gas. T: temperature of the water gas. Z1: compressibility factor of water vapor, Z1 = 1. Z2: compressibility factor of dry gas, Z2 = 0.95. Using the equation of state for real gases: 1) P1V = Z1n1RT; 2) P2V = Z2n2RT. From equations 1) and 2), it can be determined that n1/n2 = 3.285 / (2.515 * 0.95) = 1.375
The saturated vapor pressure at 238°C is 3.23 MPa; 3.23/((5.7-3.23)*0.95) = 1.3765182
I really can’t do this; please send it to me
I really can’t do it; let’s learn it*
Is it the third-floor algorithm that’s correct, or is it the fourth-floor algorithm? I’ve been using the algorithm from floor 4 :)
I really can’t do this calculation; let’s learn it!* There were tremendous gains! Thank you!
This post was last edited by pyp222 on 2017-1-3 at 10:32. The ratio of voltage divisions can be used directly to determine the value; after all, it’s not a research institution, so extremely accurate results aren’t necessary. The water vapor ratio is simply the saturated vapor pressure of steam at the current temperature divided by the partial pressure of dry gas; 3.285/(5.8-3.285) = 1.306
Looking at these two formulas, shouldn’t the final result be n1/n2 = p1z2/p2z1? What exactly is the problem? I hope experts can help answer it