The invention relates to a process for carrying out
liquefaction and heavy
hydrocarbon treatment on
natural gas, which comprises a low temperature
liquefaction process and a heavy
hydrocarbon treatment process. The low temperature
liquefaction process comprises the following step that mixed
refrigerant provides refrigerating capacity for the
natural gas which is subjected to partial heavy
hydrocarbon removal in the heavy hydrocarbon treatment process so as to implement cooling, complete heavy hydrocarbon removal and liquefaction on the
natural gas in a cold box to obtain LNG (
Liquefied Natural Gas); the heavy hydrocarbon treatment process comprises the following steps that the natural gas rich in heavy hydrocarbon is subjected to partial heavy hydrocarbon in a heavy hydrocarbon washing
tower and the removed heavy hydrocarbon sequentially enters a deethanizing column and a rectifying column to be subjected to removal of light components and be separated into LPG (
Liquefied Petroleum Gas) and light oil. According to the process disclosed by the invention, by-products, i.e. the LPG and the light oil, are also produced when the LNG is produced, the process
route is advanced and the process is economical and reliable; the process can be suitable for the condition that
raw material gas comprises
aromatic hydrocarbon such as
benzene and the like, the
aromatic hydrocarbon such as the
benzene and the like are removed along with the heavy hydrocarbon component and the cold box is prevented from being frozen and blocked; the process has large operation elasticity and can be suitable for natural gas heavy hydrocarbon content in a
large range; the mixed
refrigerant is adopted to circulate the flow and provide refrigerating capacity and gas-phase and liquid-phase refrigerants respectively enter the cold box to carry out heat exchange, so that heat exchange curves of cold and hot fluids are further matched; and the adopted refrigerating flow can effectively avoid liquid accumulation at the bottom of the cold box.