Abstract: A sulfur recovery process including a Claus reaction wherein sulfur-containing compounds are converted to elemental sulfur in the presence of a stoichiometric excess of hydrogen sulfide. The sulfurous compounds in the tail gas of the Claus reaction are separated for recycle using crystallization. Liquid carbon dioxide absorption is used to separate substantially all sulfur-containing compounds from a residual tail gas suitable for venting to the atmosphere.

Abstract: An improved crystallization process is disclosed for separating a crystallizable material and an excluded material which is at least partially excluded from the solid phase of the crystallizable material obtained upon freezing a liquid phase of the materials. The solid phase is more dense than the liquid phase, and it is separated therefrom by relative movement with the formation of a packed bed of solid phase. The packed bed is continuously formed adjacent its lower end and passed from the liquid phase into a countercurrent flow of backwash liquid. The packed bed extends through the level of the backwash liquid to provide a drained bed of solid phase adjacent its upper end which is melted by a condensing vapor.

Abstract: A process for separating acid gases such as CO.sub.2, H.sub.2 S, and SO.sub.2, other sulfur-containing molecules such as COS, and other relatively high boiling point impurities from lower boiling point components of a gas stream comprises: dehydrating the gas stream and contacting it, at an elevated pressure and at substantially the dew point temperature of carbon dioxide therein, with a liquid carbon dioxide refrigerant-absorbent to absorb such impurities other than CO.sub.2, and separating the liquid carbon dioxide and absorbed impurities; condensing CO.sub.2, and separating the liquid carbon dioxide and absorbed impurities; and condensing CO.sub.2 from the residual gas stream at such pressure, preferably by indirect heat exchange. A crystallization process is also disclosed for separating the liquid carbon dioxide and absorbed impurities.

Abstract: A crystallization process is disclosed for separating a crystallizable material and an excluded material which is at least partially excluded from the solid phase obtained upon freezing a liquid mixture of the materials. The solid phase is formed and melted at spaced locations in a liquid mixture of the materials and, within the liquid mixture, internal solid and liquid flows are maintained in opposite directions to effect separation of the materials. The solid phase is formed by evaporative cooling of the liquid mixture and melted by direct contact with a condensing vapor phase of the materials, each of these operations being performed substantially at the prevailing triple point locus conditions in the respective locations in the liquid mixture.

Abstract: A method for heating agglomerating slurries in association with a method and apparatus for heating such slurries to supercritical conditions by electrical resistance. A feed slurry and a dilution stream are passed in admixture to a heating zone, and heated. A portion of the heated admixture is separated to provide the dilution stream, which is substantially free of agglomerating solids, to lower agglomeration in the heating zone. Preferably, the solid particles of the dilution stream are comminuted between separation of the dilution stream and before admixture with the feed slurry.

Abstract: An adiabatic expansion orifice assembly for substantially instantaneously passing a coal slurry from a high pressure region to a low pressure region and a corresponding process are disclosed. The orifice assembly includes a housing having an exit end wall and a passageway through the housing. The passageway terminates in a substantially cylindrical portion or opening adjacent the exit end wall. The effective dimensions of the opening provide a flow rate whereby the slurry passes from the high pressure region through the opening to the low pressure region in less than a predetermined period of time, most preferably less than approximately 0.3 microseconds.The corresponding process involves passing a coal slurry through an orifice in less than the predetermined period of time. This process provides substantially instantaneous transition from a high pressure region to a low pressure region.

Abstract: A shattered hydrocarbonaceous product comprising a mixture of discrete comminuted hydrocarbonaceous particles having a volumetric mean particle size equivalent to less than about 5 microns in diameter separate from or in admixture with discrete inorganic and mineral particles having a mean particle size substantially the same as in the unshattered original solid is disclosed. The shattered product is produced by the explosive comminution of a slurry of fluid permeable hydrocarbonaceous solid which was heated and pressurized to supercritical conditions and then permitted to suddenly expand. The product hydrocarbonaceous fraction is substantially scissioned from the mineral fraction and has a lower density, greater solvent solubility and different reactivity to oxygen than does the feed solid. This hydrocarbonaceous fraction also includes a subfraction of particles having a particle size, by volume distribution, of less than about 2 microns in diameter which contain substantially no sulfur compounds.

Abstract: A constant pressure system for pumping a coal slurry includes a slurry pump mechanically driven by a hydraulic motor which, in turn, is driven by a hydraulic pump. The output of the hydraulic pump is controlled by a pressure sensitive flow control valve that maintains the hydraulic fluid pressure drop as a constant across the hydraulic motor. The system assures a constant hydraulic motor output torque, driving the slurry pump at a constant delivery pressure.

Abstract: A method and apparatus for heating fluids, such as an agglomerating slurry of coal and water, to supercritical conditions, wherein an electrical current is passed directly through the fluid. The fluid is directed through a container and heated by passing an electric current between a conductor positioned within the container and the interior surface of the container. The current passes through the fluid, and the electrical resistance of the fluid dissipates the electrical current into heat energy, resulting in the direct heating of the fluid. The rate of heating is preferably controlled by adding an electrolyte to the fluid.

Abstract: A process is disclosed for treating a fluid-permeable hydrocarbonaceous solid, such as coal, containing an admixture of hydrocarbonaceous components and mineral and sulfur components, to separate the solid into a hydrocarbonaceous enriched fraction and a mineral and sulfur enriched fraction. The process involves comminuting the solid in the presence of a low molecular weight alcohol under conditions sufficient to substantially scission the hydrocarbonaceous components from the mineral and sulfur components and to selectively comminute the hydrocarbonaceous components. The resultant product is thereafter separated into the enriched hydrocarbonaceous fraction and the enriched mineral and sulfur fraction.In a preferred embodiment of the process, the hydrocarbonaceous solid is mixed with a low molecular weight alcohol, such as methanol, to form a slurry. The slurry is then heated and pressurized to a temperature and pressure above the critical temperature and pressure of the alcohol.

Abstract: A pressure relief apparatus for a high pressure slurry processing system is disclosed. The apparatus includes a pressure container, an escape member in the container inlet and a flow restrictor in the container outlet.

Abstract: An apparatus for connecting a power supply to an electrode within a high pressure, high temperature vessel is disclosed. The apparatus includes a conductor extending through the vessel such that the net force exerted upon the conductor by the vessel pressure is negligible. An elastomeric material seals the vessel conductor interface and the apparatus cools the sealing material to avoid softening thereof.

Abstract: A process for separating acid gases such as CO.sub.2, H.sub.2 S, and SO.sub.2, other sulfur-containing molecules such as COS, and other relatively high boiling point impurities from lower boiling point components of a gas stream comprises: dehydrating the gas stream and contacting it, at an elevated pressure and at substantially the dew point temperature of carbon dioxide therein, with a liquid carbon dioxide refrigerant-absorbent to absorb such impurities other than CO.sub.2, and separating the liquid carbon dioxide and absorbed impurities; condensing CO.sub.2, and separating the liquid carbon dioxide and absorbed impurities; condensing CO.sub.2 from the residual gas stream at such pressure, preferably by indirect heat exchange; contacting the residual gas stream at such pressure with a second refrigerant-absorbent below the triple point temperature of carbon dioxide, and separating additional carbon dioxide therewith.