Process and apparatus for the cooling of a co2-rich flow
AssigneeL'Air Liquide, Societe Anonyme pour l'Etude et l’Exploitation des Procedes Georges Claude
InventorsMartin RAVENTOS, Richard DUBETTIER-GRENIER, Mathieu LECLERC, Thomas MOREL
Life of this patent
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Abstract
In a process for the recovery of cold from a methane-rich fluid for the cooling of a flow rich in carbon dioxide, cold is provided to a first heat exchanger for the cooling of the flow by the evaporation of an intermediate fluid by exchange of heat with the methane-rich fluid in order to form at least one condensed intermediate fluid flow at at least one pressure level; at least a part of the intermediate fluid evaporated in a second heat exchanger is condensed at at least one pressure into at least one flow.
Claims21
A process for the recovery of cold from a methane-rich fluid, for example liquefied natural gas, for the cooling and optionally the liquefaction, indeed even the separation, of a flow rich in carbon dioxide, in which:
- a. the flow rich in carbon dioxide is cooled and optionally condensed, at least partially, in a first heat exchanger at a pressure of greater than 5 bar abs, indeed even of greater than 13 bar abs;
- b. cold is provided for stage i) by the evaporation of an intermediate fluid containing at least 80 mol % of ethane or of ethylene at at least one pressure level, preferably at a single pressure level;
- c. at least a part of the intermediate fluid evaporated in stage ii) is condensed in a second heat exchanger at at least one pressure into at least one flow, preferably at a single pressure into a single flow, by exchange of heat with the methane-rich fluid to form at least one condensed intermediate fluid flow;
- d. the at least one condensed intermediate fluid flow is pressurized by means of a pump,
- e. heating the at least one flow pressurized by the pump in the second heat exchanger up to an intermediate temperature of the exchanger, the intermediate temperature being a temperature greater than that of a cold end of the second heat exchanger and lower than that of the hot end of the second heat exchanger, and then sending the at least one flow to the first heat exchanger in order to be evaporated according to stage ii).
An apparatus for the recovery of cold from a methane-rich fluid, for example liquefied natural gas, for the cooling and optionally the liquefaction, indeed even the separation, of a flow rich in carbon dioxide, the apparatus comprising:
- a first heat exchanger;
- a second heat exchanger;
- means for sending, to be cooled and optionally to be condensed, at least partially, the flow rich in carbon dioxide into a first heat exchanger;
- a closed intermediate fluid cycle comprising means for sending the intermediate fluid, containing at least 80 mol % of ethane or of ethylene, to be evaporated in the first exchanger at at least one pressure level, preferably at a single pressure level, means for sending the evaporated fluid to be condensed in the second heat exchanger at at least one pressure into at least one flow, preferably at a single pressure into a single flow, by exchange of heat with the methane-rich fluid, to form at least one condensed intermediate fluid flow;
- a pump for pressurizing the at least one condensed intermediate fluid flow;
- means for sending the flow from the pump to the second heat exchanger in order to be heated up to an intermediate temperature of the exchanger, the intermediate temperature being a temperature greater than that of a cold end of the second heat exchanger and lower than that of the hot end of the second heat exchanger;
- and
- means for extracting the heated flow from the second heat exchanger at the intermediate temperature being connected to the means for sending the intermediate fluid containing at least 80 mol % of ethane or of ethylene to be evaporated into the first exchanger.
Dependencies are inferred from the claim text.