Method and apparatus for effecting subsurface, controlled, accelerated chemical reactions

In a method for effecting accelerated chemical reactions between at least two reactants, the steps of:

• flowing an influent fluid with a first reactant downwardly through the downgoing flow passage at a selected flow rate to a selected depth below the ground surface to form a hydrostatic column of fluid exerting a pressure sufficient to cause said first reactant and a second reactant at said selected depth to react at an accelerated reaction rate and pass farther down through a reaction zone extending through said downgoing flow passage a selected distance below said selected depth whereby reaction products are produced and the fluid is heated in said reaction zone;
• introducing said second reactant in the form of a stream of gas into the influent fluid distant from the reaction zone generally in the area of the ground surface at a selected pressure and flow rate to form a series of Taylor-type gas bubbles that are carried down through said downgoing flow passage with said influent fluid to said reaction zone to chemically react with said first reactant at a substantially more rapid rate than at ground surface temperature and atmospheric pressure;
• and
• flowing the heated fluid and reaction products from said reaction zone back up to substantially ground surface level in an upgoing flow passage in heat exchange relation to the downflowing fluid as an effluent fluid.

In a method for effecting accelerated reactions between reactants in a fluid comprising the steps of:

• flowing an influent fluid downwardly through a downgoing flow passage to a selected depth below the ground surface to form a hydrostatic column exerting a pressure sufficient to cause an accelerated reaction between selected reactants, introducing a stream of gas into the influent fluid distant from a reaction zone in the area of the ground surface at a selected pressure such that the gas is entrained in said influent fluid to form a series of enlarged bubbles in the fluid, each characterized by a generally cylindrical body portion and a generally spherical cap portion, and is carried downwardly with said influent fluid;
• gradually increasing the pressure and temperature on the influent fluid and gas bubbles from substantially ground level down in one of two concentric flow passages with the depth being sufficient to cause reactants in the gas and fluid to chemically react in a reaction zone at a substantially more rapid rate than at ground surface temperatures and atmospheric pressure in an exothermic manner whereby reaction products are produced and the fluid is heated;
• flowing the reaction products and heated fluid back up to ground surface level in said other concentric flow passage in heat exchange relation to the downflowing fluid;
• controlling the temperature of said reaction zone from controls generally in the area of the ground surface level by adding heat to said fluid in said reaction zone when the temperature of said fluid in said reaction zone is below a selected temperature and removing heat from said fluid in said reaction zone when said fluid in said reaction zone is above a selected temperature, said adding and removing of heat from fluid in said reaction zone being delimited to fluid in said reaction zone, such that the maximum reaction rate is achieved but the vapor pressure of the fluid at the local temperature is always less than the local pressure to prevent a boiling of said influent fluid;
• controlling the flow rate and pressure of said influent fluid and said effluent fluid from controls at the ground surface level;
• and
• controlling the concentration of said reactants in relation to one another and in relation to the liquid content of said influent fluid from controls at the ground surface level.

In a method of effecting accelerated chemical reactions for use in the wet oxidation of sewage sludge, the steps of:

• flowing an influent sewage sludge fluid having a selected C.O.D. at a controlled, selected flow rate and selected pressure downwardly in a downgoing flow passage to a selected depth below the ground surface to form a hydrostatic column of fluid exerting a pressure sufficient to cause combustible materials to burn in the presence of oxygen at an accelerated reaction rate and pass down through the downflowing flow passage through a reaction zone extending a selected distance below said selected depth whereby reaction products are produced and the fluid is heated;
• introducing a stream of air with oxygen into the influent fluid at a controlled selected flow rate and pressure in the area of the ground surface so as to produce a series of Taylor-type gas bubbles that travel downwardly with said influent fluid to said reaction zone and rapidly mix the oxygen in the bubbles with the water content to cause a rapid oxidation, followed by flowing the heated fluid and reaction products back up to substantially ground surface level in an upflowing flow passage in heat exchange relation to the downflowing fluid as an effluent fluid;
• and
• controlling the temperature of said reaction zone by adding heat to said fluid in said reaction zone when the temperature of said fluid in said reaction zone is below a selected temperature and removing heat from said fluid in said reaction zone when said fluid in said reaction zone is above a selected temperature to accomplish a maximum reaction rate with the vapor pressure of the influent fluid at the local temperature being maintained always lower than the local pressure to prevent boiling of the influent fluid.

In apparatus for effecting accelerated chemical reactions, the combination comprising:

• a reactor including first and second pipe portions defining a downgoing flow passage and an upgoing flow passage in heat exchange relation to the downgoing flow passage, said reactor being suspended from above in a subterranean hole and in spaced relation to said hole, said downgoing flow passage extending from substantially the ground surface to a depth sufficient to cause a downflowing fluid therein to form a hydrostatic column of fluid to exert a pressure and provide a temperature sufficient to cause two reactants in the fluid at said selected depth to react at an accelerated rate, said downgoing flow passage extending down from said selected depth to form a reaction zone whereby reaction products are produced and said fluid is heated in said reaction zone;
• means for pumping an influent fluid with at least two reactants from substantially the ground surface level through said downgoing and upgoing passages whereby an effluent fluid with reaction products is passed from said reactor;
• and
• means for controlling the temperature of said reaction zone by adding heat to said fluid in said reaction zone when the temperature of said fluid in said reaction zone is below a selected temperature and removing heat from said fluid in said reaction zone when said fluid in said reaction zone is above a selected temperature to maintain a substantially maximum reaction rate without boiling of the fluid in said reaction zone.

In apparatus for effecting direct wet oxidation of combustible materials in a stream of sewage sludge and like stream of waste materials, the combination comprising:

• a reactor extending from ground surface down into the earth into a hole including an outer pipe portion and an inner pipe portion in spaced concentric relation with the outer pipe portion defining an outer flow passage between the outer and inner pipe portions and an inner flow passage in the inner pipe portion, said outer pipe portion having a closure at the lower end and said inner pipe portion terminating above said cap closure to form a hydraulic U-tube through which fluids flow from the ground surface down to the earth and back up in a continuous flow, one of said flow passages through which downflowing fluid is passed extending to a depth sufficient to cause a downflowing fluid therein to form a hydrostatic column of fluid to exert a pressure sufficient to cause two reactants in the fluid at said selected depth to react at an accelerated rate, said one flow passage extending down from said selected depth to a further selected depth to form a reaction zone whereby heat is released to heat said fluid and reaction products are produced in said reaction zone;
• means for flowing a sewage sludge fluid from substantially the ground surface down through one of said flow passages at a controlled flow rate and selected pressure;
• means for adding a diluent fluid to said sewage sludge fluid at a controlled flow rate and selected pressure to achieve a blend of influent fluid having a selected C.O.D.;
• means for adding a stream of gas to said influent fluid at substantially ground surface at a selected controlled flow rate and a selected controlled pressure through an outlet facing the downstream end of the passage carrying the downflowing fluid to form a train of Taylor-type gas bubbles in the influent fluid that are carried downwardly in said one flow passage,
• whereby in the reaction zone the oxygen carried in the bubbles causes a rapid oxidation to burn the combustible materials, produce reaction products, and heat the fluid, and said pumping means moves said reaction products and heated fluid back up through said other flow passage with heat being transferred to said downflowing fluid to reduce the temperature of said upflowing fluid;
• and
• means for controlling the temperature of said reaction zone by adding heat to said fluid in said reaction zone when the temperature of said fluid in said reaction zone is below a selected temperature and removing heat from said fluid in said reaction zone to maintain a maximum reaction rate without boiling of the fluid in the reaction zone.