Purification of natural gases

Claim 1

A METHOD OF PURIFYING A GAS CONTAINING CONTAMINANTS WHICH WILL SOLIDIFY WHEN THE GAS IS IN THE LIQUID STATE WHICH COMPRISES (A) LIQUEFYING THE GAS UNDER SUPERATMOSPHERIC PRESSURE AND REDUCING ITS TEMPERATURE TO A TEMPERATURE ABOVE THAT AT WHICH THE CONTAMINANTS SOLIDIFY, (B) PASSING THE LIQUIFIED GAS TO AN EXPANSION CHAMBER OPERATING AT A PRESSURE LOWER THAN THE ORIGINAL PRESSURE OF THE FEED GAS TO CAUSE A REDUCTION IN TEMPERATURE SO THAT A SLURRY OF SOLID CONTAMINANTS IN THE LIQUIFIED GAS IS FORMED ACCOMPANIED BY A FLASH-OFF OF VAPOR, (C) CONDENSING THE FLASHED-OFF VAPOR BY HEAT EXCHANGE WITH COLD PURIFIED LIQUIFIED GAS AS MEMTIONED IN (E) BELOW AND RETURNING THE CONDENSED FLASHED-OFF VAPOR TO THE SLURRY IN THE EXPANSION CHAMBER, (D) PASSING THE SLURRY OF SOLID CONTAMINANTS IN LIQUEFIED GAS FROM THE EXPANSION CHAMBER TO A SEPARATOR OPERATING AT A PRESSURE LOWER THAN THE EXPANSION CHAMBER, IN WHICH SEPARATOR COLD PURIFIED LIQUEFIED GAS SEPARATES FROM A CONCENTRATED SLURRY OF SOLID CONTAMINANTS IN LIQUEFIED GAS, (E) PASSING COLD PURIFIED LIQUIFIED GAS FROM THE SEPARATOR IN HEAT EXCHAGE WITH THE FLASHED-OFF VAPORS FROM THE EXPANSION CHAMBER TO CONDENSE SAID VAPORS AND THEN TAKING THE PURIFIED LIUQIEFIED GAS OFF AS PRODUCT AND (F) WITHDRAWING FROM THE SEPARTOR A CONCENTRATED SLURRY OF THE SOLID CONTAMINANTS.

Claim 2

A METHOD OF PURIFYING A GAS CONTAINING CONTAMINANTS WHICH WILL SOLIDIFY WHEN THE GAS IS IN THE LIQUID STATE WHICH COMPRISES (A) LIQUEFYING THE GAS UNDER SUPERATMOSPHERIC PRESSURE AND REDUCING ITS TEMPERATURE TO A TEMPERATURE ABOVE THAT AT WHICH THE CONTAMINANTS SOLIDIFY, (B) PASSING THE LIQUIFIED GAS TO AN EXPANSION CHAMBER OPERATING AT A PRESSURE LOWER THAN THE ORIGINAL PRESSURE OF THE FEED GAS TO CAUSE A REDUCTION IN TEMPERATURE SO THAT A SLURRY OF SOLID CONTAMINANTS IN THE LIQUIFIED GAS IS FORMED ACCOMPANIED BY A FLASH-OFF OF VAPOR, (C) CONDENSING THE FLASHED-OFF VAPOR BY HEAT EXCHANGE WITH COLD PURIFIED LIQUIFIED GAS AS MEMTIONED IN (E) BELOW AND RETURNING THE CONDENSED FLASHED-OFF VAPOR TO THE SLURRY IN THE EXPANSION CHAMBER, (D) PASSING THE SLURRY OF SOLID CONTAMINANTS IN LIQUEFIED GAS FROM THE EXPANSION CHAMBER TO A SEPARATOR OPERATING AT A PRESSURE LOWER THAN THE EXPANSION CHAMBER, IN WHICH SEPARATOR COLD PURIFIED LIQUEFIED GAS SEPARATES FROM A CONCENTRATED SLURRY OF SOLID CONTAMINANTS IN LIQUEFIED GAS, (E) PASSING COLD PURIFIED LIQUIFIED GAS FROM THE SEPARATOR IN HEAT EXCHAGE WITH THE FLASHED-OFF VAPORS FROM THE EXPANSION CHAMBER TO CONDENSE SAID VAPORS AND THEN TAKING THE PURIFIED LIUQIEFIED GAS OFF AS PRODUCT AND (F) WITHDRAWING FROM THE SEPARTOR A CONCENTRATED SLURRY OF THE SOLID CONTAMINANTS.