METHOD OF PRODUCING ESPECIALLY PURE SATURATED HYDROCARBONS C-C Russian patent published in 2020 - IPC C07C7/00 C07C9/08 C07C9/10 B01D53/02 B01D53/00 C10G25/05 C10G45/10 C10G45/12 

FIELD: chemistry.

SUBSTANCE: invention relates to organic chemistry and specifically to the technology of cleaning and drying liquefied hydrocarbon gases, particularly for producing coolants, and can be used in gas and chemical industry. Described is a method of producing especially pure saturated hydrocarbons C₃-C₄, such as especially pure propane or especially pure isobutane, which includes preliminary purification of technical liquefied hydrocarbon gas, such as propane, isobutane, n-butane, from mercaptans in adsorber, subsequent purification of liquefied hydrocarbon gas from unsaturated hydrocarbons C₃-C₄ in chemical reactor, purification of liquefied hydrocarbon gas from hydrocarbon and air impurities in rectification unit and drying of end product, wherein during preliminary cleaning from mercaptans using adsorber with diameter of 500–900 mm, filled with adsorbent with layer height of 900 mm, wherein liquefied hydrocarbon gas is fed into adsorber at a rate providing contact time of 0.5–6.0 hours at temperature of minus 20 °C – plus 30 °C and pressure of 0.1–1.6 MPa, wherein the adsorbent used is silica gel impregnated with a saturated solution of copper (II) sulphate or chloride, further purification from unsaturated hydrocarbons C₃-C₄ liquefied hydrocarbon gas in amount of 300–500 kg is carried out in a chemical reactor with a hydrogenation catalyst loaded therein in amount of 5 kg, at temperature of minus 20 °C – plus 30 °C and pressure of 0.3–1.6 MPa, wherein hydrogen is fed into reactor in amount of 0.6–1.0 m³ and hydrogenation catalyst used is aluminosilicate with palladium applied in amount of 0.5 wt%, and purification from hydrocarbon and air impurities is carried out by periodic rectification under pressure corresponding to pressure of hydrocarbon gas at temperature of 35–40 °C, in equipped with tanks for fraction collection to rectification unit, consisting of cube with capacity of 1.6 m³, columns with height of 4 m and diameter of 0.2 m, filled with spring nozzle, and shell-and-tube reflux with a heat exchange surface of 10 m², at that, hydrocarbon gas purified from mercaptans and unsaturated hydrocarbons in amount of 700 kg is loaded into stillage of rectification plant, and in process of purification from hydrocarbon and air impurities head fraction of light hydrocarbons is extracted from dephlegmator at rate of up to 12 kg/h, then with reduction of their concentration to 0.05 wt % of target product is selected at rate of 40 kg/h, and in front of vessel for collecting especially pure propane or especially pure isobutane there installed is adsorber filled with zeolite NaA or NaX and drying target product after rectification purification.

EFFECT: simple and economical method of producing industrial-grade highly pure products used in analytical chemistry as components of calibration mixtures and in refrigerating equipment as coolants, high quality of cleaning and drying liquefied hydrocarbon gases, which enables to obtain, on an industrial scale, high-quality, highly pure propane and especially pure isobutane.

4 cl, 2 tbl