--%>

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 : Molecular Properties Symmetry Molecular

    Molecular orbitals and molecular motions belong to certain symmetry species of the point group of the molecule.Examples of the special ways in which vectors or functions can be affected by symmetry operations are illustrated here. All wave functions soluti

  • Q : P- block why pentahalids are more

    why pentahalids are more covalent than tetrahalids

  • Q : Molarity of Nacl solution When 5.85 g

    When 5.85 g of NaCl (having molecular weight 58.5) is dissolved in water and the solution is prepared to 0.5 litres, the molarity of the solution is: (i) 0.2 (ii) 0.4 (iii) 1.0 (iv) 0.1

  • Q : The Liver Is Responsible For Much Of

    The Liver Is Responsible For Much Of The Pentose Phosphate Activity Explain

  • Q : Explain Vapour Pressure Composition A

    A pressure composition diagram for a liquid vapor system can be used to show the composition of the liquid and equilibrium vapor.Vapor equilibrium data are useful in the study of distillations. It is of value to have diagrams showing not only the vapor pre

  • Q : Concentration of Sodium chloride

    Provide solution of this question. If 25 ml of 0.25 M NaCl solution is diluted with water to a volume of 500ml the new concentration of the solution is : (a) 0.167 M (b) 0.0125 M (c) 0.833 M (d) 0.0167 M

  • Q : Molecular mass from Raoults law Provide

    Provide solution of this question. Determination of correct molecular mass from Raoult's law is applicable to: (a) An electrolyte in solution (b) A non-electrolyte in a dilute solution (c) A non-electrolyte in a concentrated solution (d) An electrolyte in a liquid so

  • Q : Entropy is entropy on moleculare basis

    is entropy on moleculare basis relates to the tras.,vib.,and rotational motions?

  • Q : Extensive property Choose the right

    Choose the right answer from following. Which one of the following is an extensive property: (a) Molar volume (b) Molarity (c) Number of moles (d) Mole fraction

  • Q : Problem on Clausius equation of state

    If a gas can be described by the Clausius equation of state: P (V-b) = RT Where b is a constant, then:  (a) Obtain an expression for the residual vo