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Boiling Point Of Ch4

Thus, there are provided an argon recovery and purification process and unit in which the consumption of energy is small because of simple steps. In addition, this catalytic reaction requires an external heat source, and it will be therefore concluded that this process is not satisfactory from the viewpoint of energy efficiency. According to the present invention, however, there is required only the amount of hydrogen gas (H2) for removing oxygen initially contained in the impure argon gas, with no In order to separate argon and oxygen in the impure argon gas by rectification, many rectifying trays are required because their boiling points are about of the same degree (argon: -185. The rectification means comprises a first rectification column and and a second rectification column, low boiling point impurity components (N2, CO, H2, etc. In order to separate this oxygen from the impure argon gas, there is usually adopted a process which comprises reacting O2 with H2 so that said oxygen is converted to H2O, and then removing this H2O, where a larger amount of hydrogen is required.
In this reboiler (10), the deoxo argon gas is brought into heat exchange with liquefied pure argon gas so as to generate a reboiled gas, where the deoxo argon gas The liquefied deoxo argon gas contains uncondensed gases still mixed therein such as a small amount of hydrogen.

Dispersion forces can be quite strong, and the bigger the molecule the stronger the ============================================================= Correlating boiling points (or melting points) with "intermolecular forces" is only approximate. In accordance with this flow sheet, this unit will be explained.

Although an example using a vacuum pump (2) of the dry type, for example, of the mechanical seal, has been described, with referring to FIG. Into a silicon furnace for manufacturing silicon ingots, a large amount of argon gas is supplied as an inert gas. For example, in J-A-63-189,774, J-A-01-230,975, J-A-02-272,288 and J-A-05-256,570, there are disclosed processes which comprise removing CO, CO2, H2O gases from impure argon gas by desorption and then purifying the impure argon through very low temperature separation or a catalytic reaction to obtain purified argon gas.
In addition, the flow rate of hydrogen to be fed to the deoxo column (6b) is regulated so that the amount of excessive hydrogen left after the reaction of oxygen and hydrogen in the deoxo column (6b) The deoxo argon gas is then fed to a cooling installation (7).
Accordingly, there is no need of heating the discharged gas at high temperatures as in the catalytic reaction of hydrocarbons and it is therefore possible to reduce electricity for heating up or the likes.

Studies on a process for purifying argon gas mixed with substances other than argon to obtain pure argon gas have been hitherto carried out. A unit characterized by purifying and sepoarating impure argon gas by low temperature baby got back 20 liquefaction to remove hydrocarbons (CnHm) from the argon gas, without adding O2 into hydrocarbons (CnHm) such as methane contained in this impure argon and elevating the temperature thereof at 400° C. According to the present invention, there is provided an argon recovery and purification process which comprises purifying impure argon gas discharged from a silicon furnace and containing as impurities low boiling point impurity components whose boiling points are lower than that of argon such as oxygen and nitrogen and high boiling point impurity components whose boiling points are higher than that of argon such as hydrocarbons to obtain pure argon gas substantially consisting of argon, and supplying said pure argon gas to the silicon furnace again. Similarly in the water separator (7d), water condensed by the refrigerator (7c) is separated and removed from the deoxo A decarbonating and drying installation (8) comprises two adsorption columns (8a), (8b), each filled with a packing such as alumina or molecular sieve for adsorbing H2O and CO2. The impure argon gas filtered by the suction filter unit (4) is then introduced into an impure argon compressor (5), where it is pressurized to a pressure of 3. The cooling installation community radio stations australia (7) comprises a water cooler (7a) corresponding to an after cooler of the impure argon compressor (5), separators (7b), (7d) for removing water condensed in the deoxo argon gas and a refrigerator (7c) The deoxo argon gas is introduced into the water cooler (7a) and cooled down to about 40° C. Cold necessary in this cold cycle is gin blossoms found out supplied as liquid nitrogen to the pure argon condenser (14) or argon condenser (12) so that its latent heat is effectively utilized in each of the condensers (14), (12) and its sensible heat is effectively utilized in the argon heat exchanger (9). DETAILED DESCRIPTION OF THE INVENTION This argon gas recovery and purification system has a line where discharged impure argon gas recovered from a silicon ingot pull-up furnace (1) by way of a vacuum pump (2) is purified for the same pull-up furnace (1). This temperature is, for instance, nearly about 150° C. After the pure argon gas which has passed through the aforementioned steps is elevated in pressure to a predetermined pressure by a product argon compressor (17), and freed of dust particles contained therein to a level necessary for the silicon ingot pull-up furnace (1) by means of a product filter installation (18), it will be returned together with replenishment argon to the silicon ingot pull-up furnace (1) again. The extracted gas from the lower portion (middle between the portions 11b and 11c) of the argon rectification column (11) is led to a demethanizing column (13) as it has been sufficently freed of the low boiling point components such as H2, N2 and CO, in which after this extracted gas is rectified by a reflux liquid generated in a pure argon condenser (14) placed in the top portion of the demethanizing column (13) and high boiling point components such as methane are sufficiently removed by washing therefrom, it is extracted as pure argon gas from the top portion thereof. The present invention is characterized by including a rectification step of separating the impurities at the very low temperature side.
Question Based on intermolecular forces, carbon monoxide should boil at a higher temperature than methane. By using the argon recovery and purification process and unit according to the present invention particularly on impure argon coming from a silicon monocrystal furnace or the like, there are obtained the aforementioned Edwin Armstrong was granted a patent for a two-path FM radio. Thus, the argon gas is rectified to a purity level that is sufficient as a product. 4,623,524 describes a process for obtaining argon from a silicon furnace including an oxidation step, a combustion step, a deoxo-step, an absorption step, and a distillation step. This nitrogen gas will be supplied from a line (P8) connected to a recycle nitrogen line mentioned below, and nitrogen gas containing the desorbed H2O and CO2 will be taken out of the decarbonating and drying installation (8) by way of a line (P8a)and discharged as a waste gas to the atmospheric air. This argon gas is discharged from the silicon furnace as it contains a gas mainly consisting of N2 and O2 generated in the manufacture of silicon ingots and further contains hydrocarbons such as CH4. The value lyrics to lafy tafy of the critical constants is frequently a better parameter to compare. .
In the lower portion (11c) of the rectification column, high boiling point impurity components such as methane are concentrated in order to increase By concentrating the high boiling point components in the deoxo argon gas about several hundreds times and then separating them by liquid extraction from the bottom portion of the argon rectification column (11) by way of a line (P11), and by concentrating the low boiling point components such as H2, N2 and CO to about several ten times in the upper portion of the argon rectification column (11) and then separating them in a gaseous state, it is possible to obtain an argon recovery rate of 90~95%. Choose another vapor pressure and the order of the list of boiling points may change.

Furthermore, lady bug coloring book since there is no need to add oxygen (O2) necessary for this catalytic reaction once more into the discharged gas, the whole of the system can be simplified. In this countercurrent heat exchanger (9), the deoxo argon gas from the decarbonating and drying installation (8) is introduced in the same direction as the introducing direction of recycle nitrogen gas from a nitrogen compressor (16) mentioned below, and brought into counter-current heat exchange with low pressure recycle nitrogen gas generated in an argon condenser (12) and pure argon condenser (14) mentioned below, waste gas generated in an argon rectification column (11) mentioned below, pure argon gas generated in a demethanizing column (13) and recovered hydrogen gas from a hydrogen separator (15) placed for recovery of hydrogen, so as to be respectively cooled down nearly to their dew points.