The invention discloses a hydrogenation method for liquefied gas fraction, which is characterized by comprising the following steps of: filling at least one section of catalyst
bed layer into a reactor, introducing a liquefied gas fraction
raw material and
hydrogen into the reactor from one or more sections of catalyst
bed layers to contact a catalyst and perform hydrogenation saturation reaction, and reacting olefin in the liquefied gas fraction and the
hydrogen to generate
alkane and release a large amount of heat; after heat exchange, feeding the
reaction product into a gas-liquid separator and separating the
reaction product into a
gas phase and a
liquid phase, and introducing the separated
gas phase flow into the reactor to perform repeated use; and introducing a part of separated
liquid phase flow serving as a cyclic
reaction product back to the reactor, and introducing the other part of the separated
liquid phase flow serving as a liquefied gas fraction hydrogenation product out of the reactor to perform reuse. The hydrogenation product obtained by the method is saturated light
hydrocarbon fraction which can be directly used as a
raw material for an
ethylene cracking device and also can be fractionated and
cut into
propane, n-
butane and iso-
butane and the like serving as high value-added chemical base raw materials so as to increase the economic benefit of an oil refining enterprise.