Method and apparatus for continuous contact of supercritical fluid with particulate solids

In a method of introducing particulate solid matter into a pressure vessel through which a fluid continuously flows at high, supercritical, pressure, which comprises introducing the particulate solid matter into an isolatable pressurizable vessel, isolating said pressurizable vessel, increasing the pressure within said pressurizable vessel until the pressure therein is substantially the same as that of the supercritical fluid in said pressure vessel, and discharging the particulate solid matter from said pressurizable vessel to said pressure vessel, the improvement which comprises:

• (a) maintaining a supply of said fluid at an intermediate, non-supercritical pressure, at which pressure said fluid exists in both the liquid and gaseous state;
• (b) introducing into said pressurizable vessel said fluid, in the gaseous state, from said supply of said fluid maintained at said intermediate pressure, to raise the pressure within said pressurizable vessel;
• (c) introducing into said pressurizable vessel said fluid, in the liquid state, from said supply of fluid to further raise the pressure within said vessel to approximately the pressure of the fluid in said supply;
• (d) introducing, into said pressurizable vessel, said fluid in the supercritical state, to further raise the pressure within said vessel to the high, supercritical pressure prevailing in said pressure vessel;
• and
• (e) placing the pressurizable vessel and the pressure vessel in communication for introducing particulate solids to said pressure vessel from said pressurizable vessel.

In a method of discharging particulate solid matter into an isolatable pressurizable vessel from a pressure vessel through which a fluid continuously flows at high, supercritical, pressure which comprises isolating said pressurizable vessel, increasing the pressure in said pressurizable vessel until the pressure therein is substantially the same as that of the supercritical fluid in said pressure vessel, and discharging the particulate solid matter from said pressure vessel to said pressurizable vessel, the improvement which comprises

• (a) maintaining a supply of said fluid at an intermediate, non-supercritical pressure, at which pressure said fluid exists in both the liquid and gaseous state;
• (b) introducing into said pressurizable vessel said fluid, in the gaseous state, from said supply of said fluid maintained at said intermediate pressure, to raise the pressure within said pressurizable vessel;
• (c) introducing into said pressurizable vessel said fluid, in the liquid state, from said supply of fluid to further raise the pressure within said vessel to approximately the pressure of the fluid in said supply;
• (d) introducing, into said pressurizable vessel, said fluid in the supercritical state, to further raise the pressure within said vessel to the high, supercritical pressure prevailing in said pressure vessel;
• and
• (e) placing the pressurizable vessel and pressure vessel in communication for discharging particulate solids from said pressure vessel to said pressurizable vessel.

In an apparatus for continuously passing a fluid at high operating pressure through a pressure vessel for contacting particulate solids in said pressure vessel while periodically moving particulate solids downwardly through said pressure vessel, said apparatus comprising:

• a pressure vessel;
• an upper pressurizable vessel receiving particulate solids at substantially atmospheric pressure and for charging said solids into said pressure vessel at said high operating pressure;
• a lower pressurizable vessel for receiving a quantity of particulate solids discharged from said pressure vessel at said high operating pressure and for discharging said particulate solids at low pressure;
• means for continuously passing a fluid at high operating pressure through said pressure vessel for contacting particulate solids therein;
• means for periodically increasing the pressure in said upper and lower pressurizable vessels to facilitate periodic charging of particulate solids from said upper pressurizable vessel into the upper end of said pressure vessel and periodic discharging of particulate solids from the lower end of said pressure vessel into said lower pressurizable vessel;
• means for periodically decreasing the pressure in said upper and lower pressurizable vessels to facilitate introduction of particulate solids into said upper pressurizable vessel at atmospheric pressure and periodic discharge of particulate solids from said lower pressurizable vessel at low pressure;
• the improvement which comprises:
• an intermediate pressure vessel for storing said fluid at an intermediate pressure which is substantially greater than atmospheric pressure and substantially less than said high operating pressure;
• wherein said means for periodically increasing said pressure in said upper and lower pressurizable vessels comprises:
• means for conveying fluid in the gaseous and liquid state from said intermediate pressure vessel to said upper and lower pressurizable vessels to raise the pressure therein to said intermediate pressure;
• and
• means for conveying said fluid at said high operating pressure to said upper and lower pressurizable vessels to raise the pressure therein to said high operating pressure;
• and
• wherein said means for periodically decreasing the pressure in said upper and lower pressurizable vessels comprises:
• means for conveying fluid at said high operating pressure from said upper and lower pressurizable vessels to said intermediate pressure vessel to lower the pressure to said intermediate pressure;
• and
• means for pumping said fluid from said upper and lower pressurizable vessels into said intermediate pressure vessel to lower the pressure below said intermediate pressure.

In an apparatus for continuously contacting particulate solids in an elongate column by continuously flowing a supercritical fluid at high pressure through a bed of solids in the column while periodically moving the particulate solids downwardly through the column, said apparatus comprising:

• an elongate, substantially vertical pressure vessel;
• an upper isolatable pressurizable vessel for periodically introducing particulate solids into the top of the pressure vessel;
• means for increasing the pressure in said upper pressurizable vessel to said high pressure for introduction of particulate solids from said upper pressurizable vessel to said pressure vessel;
• means for decreasing the pressure in said upper pressurizable vessel from said high pressure for introduction of a fresh supply of particulate solids to said pressurizable vessel;
• a lower isolatable pressurizable vessel for periodically receiving particulate solids discharged from the lower end of the pressure vessel;
• means for increasing the pressure in said lower pressurizable vessel to said high pressure for receiving particulate solids discharged from said pressure vessel;
• and
• means for decreasing the pressure in said lower pressurizable vessel from said high pressure for discharging particulate solids from said lower pressurizable vessel;
• and
• pump means for continuously circulating a flow of supercritical fluid at high pressure through said column for contacting particulate solids therein;
• the improvement wherein said apparatus further comprises:
• means for interconnecting the outlet side of said circulating pump means in fluid communication with said upper pressurizable vessel for facilitating discharge of particulate solids from said upper pressurizable vessel into said pressure vessel;
• and
• means for interconnecting the inlet side of said circulating pump means in fluid communication with said lower pressurizable vessel for facilitating discharge of particulate solids from said pressure vessel into said lower pressurizable vessel.