Cryogenic gel having a methane component and process for making same

A process for the continuous gelling of a liquid cryogen including methane comprising the steps of generating a stream of the cryogen at about the saturation point for the cryogen;

• reducing the pressure of the stream to flash vaporize a portion of the liquid cryogen to transform the stream into a flow of cryogen vapor and finely dispersed cryogen droplets suspended in the vapor;
• injecting a vaporized gelling agent into the flow, the agent being selected from the class consisting of water and methyl alcohol;
• and separating the flow into a condensed phase comprising cryogen liquid and gelling agent and a gaseous phase comprising cryogen vapor;
• whereby the gelling agent in the condensed phase causes the gelation of the latter.

A process for the continuous gelling of a liquid cryogen including a majority of methane comprising the steps of generating a stream of the cryogen at a predetermined pressure;

• giving the cryogen stream a temperature which is in the vicinity of the boiling point for the liquid cryogen at the predetermined pressure;
• reducing the pressure of the liquid cryogen in the flowing stream at an expansion point for the stream so that a minor portion of the cryogen becomes vaporized while a remainder of the cryogen becomes atomized to thereby transform the cryogen stream into a flow of cryogen vapor and cryogen droplets;
• injecting into the flow a vaporized gelling agent at a rate selected so that the volume of the vaporized gelling agent at least about equals the volume of the cryogen vapor, the gelling agent being a solid at the temperature of the liquid cryogen and a liquid or a gas at ambient temperatures, the gelling agent being capable of forming a chemical complex with the methane, and segregating from the flow the cryogen droplets and the chemical complex;
• whereby the chemical complex causes the gelling of the segregated cryogen droplets to thereby form a cryogen gel.

A process for the continuous transformation of a liquid cryogen including at least about 70 mole percent of liquid methane into a cryogen gel for storage or shipment of the cryogen gel at a predetermined storage pressure, the method comprising the steps of:

• pressurizing the liquid cryogen so that it exceeds the predetermined storage pressure by at least about 5 psi;
• giving the pressurized, liquid cryogen a temperature so that upon the reduction of the pressure of the liquid cryogen to about the storage pressure no more than about 20% by weight of the liquid cryogen substantially instantaneously vaporizes;
• flowing the liquid cryogen to an expansion station;
• reducing the pressure on the liquid cryogen flowing past the expansion station to about the storage pressure;
• whereby a portion of the liquid cryogen vaporizes and a remainder is atomized into liquid cryogen droplets to form a cryogen vapor-droplet flow;
• injecting into the flow a vaporized gelling agent selected from the class consisting of water and methyl alcohol in an amount so that the gelling agent constitutes at least about 0.1% by weight of the cryogen gel;
• whereby the injected gelling agent solidifies and forms finely dispersed gelling particles;
• segregating the flow into a condensed phase comprising liquid cryogen and particles and into a gaseous phase comprising primarily cryogen vapor;
• and collecting the condensed phase in a container;
• whereby the particles in the liquid phase cause the gelling of the liquid cryogen in the condensed phase to form said cryogen gel.

A gelled cryogen liquid produced by:

• (a) adjusting the temperature of a flowing stream of liquefied natural gas to a temperature approximately equal to the saturation temperature;
• (b) flashing the stream of natural gas to a lower pressure, whereby a mixture of gas and liquid droplets is formed;
• (c) injecting a vaporized gelling agent into the flowing mixture of gas and liquid in an amount not exceeding 25% by weight of the amount of the liquid and gas mixture flowing thereby, said gelling agent being selected from the class consisting of water and methyl alcohol, whereby the liquid droplets of natural gas are solidified;
• and
• (d) separating the solidified droplets from the vapor to form a product stream of gelled cryogen liquid.