--%>

Linde liquefaction process

Liquefied natural gas (LNG) is produced using a Linde liquefaction process from pure methane gas at 3 bar and 280 K (conditions at point 1 in figure below). A three-stage compressor with interceding is used to compress the methane to 100 bar (point 2). The first stage compresses the gas from 1 bar to 5 bar, the second stage from 5 bar to 25 bar, and the tiiird stage from 25 bar to 100 bar. Between stages the gas Is isobarically cooled to 280 K. Each stage of the compressor can be assumed to operate reversibly and adiabaticaliy. The methane leaving the cooler is at 100 bar and 210 K (point 3). The flash dram is adiabatic and operates at! bar. The recycled methane leaving the heat exchanger (point 5') is at I bar and 200 K.

a) Calculate the fractions of vapour and liquid leaving the flash drum {Hint: write balance equations around the subsystem consisting of the heat exchanger, throttle valve and flash drum).

b) Calculate the temperature at the inlet of the compressor (point I).

c) Calculate the amount of work required for each kilogram of methane that passes through the compressor.

d) Calculate the amount of compressor work required for each kilogram of LNG produced.

e) Calculate

i) the heat removal after the first and second stages of the compressor,
ii) the heat removed in the cooler, and
iii) the heat exchanged in the heat exchanger.

Express all values in kJ/kg of methane that passes through the compressor.

Data: The thermodynamic properties of methane are given in the attached diagram.

71_diagram.jpg

   Related Questions in Chemistry

  • Q : Calculate PH value for a acetic acid 1.

    1. A solution of 0.100 M acetic acid is prepared. a) What is its pH value? b) If 20% of the initial acetic acid is converted to the acetate form by titration with NaOH, what is the resultant pH?

  • Q : Molar concentration of hydrogen 20 g of

    20 g of hydrogen is present in 5 litre of vessel. Determine he molar concentration of hydrogen: (a) 4  (b) 1 (c) 3 (d) 2 Choose the right answer from above.

  • Q : Strength of Nacl in solution To 5.85gm

    To 5.85gm of Nacl one kg of water is added to prepare of solution. What is the strength of Nacl in this solution (mol. wt. of nacl = 58.5)? (a) 0.1 Normal (b) 0.1 Molal (c) 0.1 Molar (d) 0.1 FormalAnswer:

  • Q : Relative lowering in vapour pressure of

    Give me answer of this question. "Relative lowering in vapour pressure of solution containing non-volatile solute is directly proportional to mole fraction of solute". Above statement is: (a) Henry law (b) Dulong and Petit law (c) Raoult's law (d) Le-Chatelier's pri

  • Q : Organic structure of cetearyl alcohol

    Can we demonstration the organic structure of cetearyl alcohol and state me what organic family it is?

  • Q : Net charge of a non-ionized atom

    Describe the net charge of a non-ionized atom?

  • Q : Colligative effect Choose the right

    Choose the right answer from following. Which one of the statements written below concerning properties of solutions, explain a colligative effect: (a) Boiling point of pure water decreases by the addition of ethano (b) Vapour pressure of pure water d

  • Q : Explain structure basicity of amines.

    Basic character of amines is related to their structural arrangement. Basic strength of amines depends on the relative ease of formation of the corresponding cation by accepting a proton from the acid. Greater the stability of cation is, more is basic strength of amine.Alkyl a

  • Q : Illustrate the Lewis Dot Structure

    Illustrate the Lewis Dot Structure for the CH4O.

  • Q : Explain the molecular mass with respect

    During the formation of polymers, different macromolecules have different degree of polymerisation i.e. they have varied chain lengths. Thus, the molecular masses of the individual macromolecules in a particular sample of the polymer are different. Hence, an average value of the molecular mass is