A novel sublimation purification method is provided. Moreover, a novel sublimation purification apparatus is provided. A purification method using a purification apparatus including a purification portion where a substance is purified by vaporization, a temperature adjustment means, a gas supply means, and a gas discharge means is provided. In the purification method, the inside of the purification portion is made to have a first pressure with use of the gas discharge means, a temperature gradient is generated in the purification portion with use of the temperature adjustment means such that the substance is purified, the pressure in the purification portion is then set at a second pressure with use of the gas supply means, and the purification portion is cooled with use of the temperature adjustment means. The second pressure is higher than the first pressure and the second pressure is higher than or equal to an atmospheric pressure.

Plant and process for the production of liquid methane from a feed gas stream comprising at least methane and carbon dioxide. A feed gas stream is injected into a CO.sub.2 crystallizer in countercurrent fashion against a stream of predominantly liquid methane, thereby crystallizing amounts of carbon dioxide from the feed gas stream. Gaseous methane recovered from the CO.sub.2 crystallizer is liquefied at a liquefaction exchanger.

Plant and process for the production of liquid methane from a feed gas stream comprising at least methane and carbon dioxide. A feed gas stream is injected into a CO.sub.2 crystallizer in countercurrent fashion against a stream of predominantly liquid methane, thereby crystallizing amounts of carbon dioxide from the feed gas stream. Gaseous methane recovered from the CO.sub.2 crystallizer is liquefied at a liquefaction exchanger.

Methods and systems for separating a desublimatable compound from hydrocarbons is disclosed. A feed fluid stream, consisting of a hydrocarbon and a desublimatable compound, is passed into an upper chamber of a vessel. The feed fluid stream is cooled in the upper chamber, thereby desublimating a portion of the desublimatable compound out of the feed liquid stream to form a product gas stream and a desublimatable compound snow which is collected in the lower chamber of the vessel. A lower portion of the desublimatable compound snow is melted to form a liquid desublimatable compound stream such that an upper portion of the solid desublimatable compound snow remains as an insulative barrier between the upper chamber and the liquid desublimatable compound stream. The liquid desublimatable compound stream is removed at a rate that matches a production rate of the solid desublimatable compound snow, thereby maintaining the insulative barrier.

Methods and systems for separating a desublimatable compound from hydrocarbons is disclosed. A feed fluid stream, consisting of a hydrocarbon and a desublimatable compound, is passed into an upper chamber of a vessel. The feed fluid stream is cooled in the upper chamber, thereby desublimating a portion of the desublimatable compound out of the feed liquid stream to form a product gas stream and a desublimatable compound snow which is collected in the lower chamber of the vessel. A lower portion of the desublimatable compound snow is melted to form a liquid desublimatable compound stream such that an upper portion of the solid desublimatable compound snow remains as an insulative barrier between the upper chamber and the liquid desublimatable compound stream. The liquid desublimatable compound stream is removed at a rate that matches a production rate of the solid desublimatable compound snow, thereby maintaining the insulative barrier.

A preprocessing method comprises a sintering step of heating a solid material container filled with a solid material using a temperature which is lower than either the melting point or sublimation of the solid material, whichever is lower, and crystallizing at least part of the solid material, and an impurity removal step of heating the solid material container filled with the solid material using a temperature which is lower than either the melting point or sublimation of the solid material, whichever is lower, and removing at least part of the impurities included in the solid material.

A preprocessing method comprises a sintering step of heating a solid material container filled with a solid material using a temperature which is lower than either the melting point or sublimation of the solid material, whichever is lower, and crystallizing at least part of the solid material, and an impurity removal step of heating the solid material container filled with the solid material using a temperature which is lower than either the melting point or sublimation of the solid material, whichever is lower, and removing at least part of the impurities included in the solid material.

The present invention provides an apparatus for desubliming a target compound from a first gas mixture comprising the target compound, comprising: a desublimation means comprising a surface onto which desublimation of the target compound can occur, an inlet through which the first gas mixture can enter the apparatus such that it comes into contact with the surface of the desublimation means, a target compound recovery region, an outlet through which the target compound can leave the target compound recovery region and a cooling means that cools the desublimation means wherein the desublimation means comprises a continuous path that passes through the cooling means and the target compound recovery region and wherein the desublimation means is movable such that the surface continuously circulates between the cooling means and the target compound recovery region, along the path.

The present invention provides an apparatus for desubliming a target compound from a first gas mixture comprising the target compound, comprising: a desublimation means comprising a surface onto which desublimation of the target compound can occur, an inlet through which the first gas mixture can enter the apparatus such that it comes into contact with the surface of the desublimation means, a target compound recovery region, an outlet through which the target compound can leave the target compound recovery region and a cooling means that cools the desublimation means wherein the desublimation means comprises a continuous path that passes through the cooling means and the target compound recovery region and wherein the desublimation means is movable such that the surface continuously circulates between the cooling means and the target compound recovery region, along the path.

Vertical desublimation apparatus for crystalline iodine production, comprising: a gas intake, through which vapor can be fed into the apparatus, and a gas exhaust, through which residual air can be discharged; at least one downstream duct comprising a downstream duct inlet and a downstream duct outlet, wherein the intake is fluidically connected to the downstream duct inlet; at least one upstream duct comprising an upstream duct inlet and an upstream duct outlet, wherein the exhaust is fluidically connected to the upstream duct outlet; at least one downstream condenser pipe arranged adjacent to the downstream duct and at least one upstream condenser pipe arranged adjacent to the upstream duct, wherein a cooling medium can be fed through the condenser pipes; a collecting receptacle for collecting crystallized iodine and liquid water arranged at the bottom of the apparatus, fluidically connecting the downstream duct outlet and the upstream duct inlet, the collecting receptacle having a bottom outlet.