Other

Ironite Products Company

Gas Sweetener, Inc.

Irwin Fox

Alvin Samuels

The present invention provides a method for separately removing mercaptans and hydrogen sulfide from a hydrocarbon gas stream by passing the gas through a bed which includes iron oxide which catalyzes the formation of disulfides and trisulfides from mercaptans and also reacts with at least part of the hydrogen sulfide to form acid-stable solids; causing the di- and trisulfides to exit the bed in the gas phase; and removing and recovering the di- and trisulfides by adsorption or condensation. Any remaining hydrogen sulfide may be scavenged from the gas stream by passage through a bed containing iron oxide similar to that used first above. If the gas stream contains substantial amounts of hydrocarbon aerosols, they should be filtered out in advance of the bed.

Separately removing mercaptans and hydrogen sulfide from gas streams

A mineral carrier for those iron oxides which react to remove hydrogen sulfide and mercaptans from fluid streams. The new carrier avoids the problem encountered with wood chip beds of bed solidification which occurs when reacted oxide particles adhere to each other. Calcined montmorillonite, for example, possesses the necessary crush strength, porosity, insolubility in water and wettability, to maintain bed perviousness and avoid caking as reaction continues to the full capacity of the oxide.

Disposable oxide carrier for scavenging hydrogen sulfide

Non-hydrated iron oxides utilized in moistened permeable beds to react hydrogen sulfide present in natural gas do not totally lose their reactivity when the beds give up their moisture to dry gas. Lessening of their reactivity attendant to dryness is signalled by a rise in H.sub.2 S level in the gas at or somewhat in advance of the reactor outlet. On such signal water is injected into the inflowing gas stream, reviving the bed's reactivity and permitting continuation of gas sweetening until the reactive potential of the oxide is substantially fully utilized, with minimal water addition.

Restoring reactivity of gas sweetening oxide beds

Adding sodium sulfite in the slurry of the iron oxide slurry process for scavenging hydrogen sulfide described in U.S. Pat. No. 4,246,244, eliminates excessive foaming on start-up, stabilizes the suspension of the oxide particles in the slurry, lessens clogging of reacted particles, which otherwise interferes with cleaning out the reactor vessel, and so materially buffers the slurry as to minimize corrosion of the reactor vessel and piping. Further, adding small amounts of oxygen to the gas stream, which would be expected to cause corrosion, does not do so; instead it prolongs the usefulness of the reactant oxide particles and affords increased acid-stability to the reaction products.

Sulfite-oxide process for scavenging hydrogen sulfide

A composition suitable for scavenging oxygen from aqueous systems, for example those used in well drilling, is provided which comprises a mixture of an oxygen-reactive sulfite and/or bisulfite (sulfite component) and an amount of iron oxide particles sufficient to catalyze the reaction between oxygen and the sulfite component. These particles have certain properties as further described herein. These compositions also serve as corrosion inhibitors in aqueous systems, such as drilling muds, to protect steel components from corrosion. A method is also provided for using such compositions in aqueous systems to scavenge oxygen from such systems, and also H.sub.2 S, if present.

Scavenging oxygen from aqueous systems

Use of ferri-magnetic reactive iron oxide particles to react hydrogen sulfide in water, hydrocarbon liquids or drilling mud affords quick, effective scavenging of these liquids without accumulation of particulate matter and without wasting the reactive particles. The reaction product is environmentally safe, so that it may be disposed of on a simple waste heap. A quantity of the magnetic iron oxide particles, principally a synthetic porous Fe.sub.3 O.sub.4, is suspended in the liquid. The quantity added is in excess of that required for the reaction with the hydrogen sulfide in order to speed the reaction time and provide a large margin of safety. In use, the reactive iron oxide particles contact and react the hydrogen sulfide, forming a non-magnetic particulate product of reaction. Thus, if used to scavenge a drilling mud, this contact and reaction occurs as the mud, bearing the drill cuttings, rises through the drilling formation. By passing the liquid, or at least that portion of it which includes all particulate matter, through a magnetic separator, substantially all, or at least the greater part of, the unreacted oxide particles are recovered for re-use. Since the unreacted particles are characterized by low remanent magnetism, after the magnetic separation they are readily re-suspended in such liquid.

Use of magnetic separation in scavenging hydrogen sulfide

Substantially dry iron oxide particles having a high surface area, a high kinetic 'K' value and composed of a crystalline phase of Fe.sub.3 O.sub.4 together with an amorphous Fe.sub.2 O.sub.3 moiety or portion and having a surface area of at least 4 m.sup.2 /.sub.g are useful for scavenging hydrogen sulfide from other gases containing it. A cartridge type device is provided containing such particles intermixed with inert particulate matter, e.g. sand, useful as a means for scavenging hydrogen sulfide from such other gases.

Highly reactive iron oxide agents and apparatus for hydrogen sulfide

Iron oxide particles composed of a crystalline phase of Fe.sub.2 O.sub.3, Fe.sub.3 O.sub.4 and combinations thereof together with an amorphous Fe.sub.2 O.sub.3 moiety or portion and having a surface area of at least 3.5 m.sup.2 /g are useful for scavenging hydrogen sulfide from substantially anhydrous non-aqueous liquids, particularly substantially anhydrous hydrocarbon liquids, for example, kerosene.

Reactive iron oxide agents for scavenging hydrogen sulfide from

Iron oxide particles having a high surface area, a high kinetic K value and composed substantially of amorphous Fe.sub.2 O.sub.3 and crystalline Fe.sub.2 O.sub.3 are drilling mud additives suitable for scavenging hydrogen sulfide. Such particles do not adversely affect the rheological properties of the mud and when reacted with hydrogen sulfide form reaction products which are acid stable. Upon completion of drilling, the drilling mud containing these iron oxide particles and their reaction products with H.sub.2 S may be left in place between the inner casing and the formation wall or the outer casing as a packer fluid.

Method of using a reactive iron oxide drilling mud additive

A process for scavenging hydrogen sulfide from hydrocarbon gases utilizes iron oxide particles of unique chemical and physical properties. These particles have large surface area, and are comprised substantially of amorphous Fe.sub.2 O.sub.3 containing a crystalline phase of Fe.sub.2 O.sub.3, Fe.sub.3 O.sub.4 and combinations thereof. In scavenging hydrogen sulfide, the iron oxide particles are suspended in a liquid which enters into intimate mixing contact with hydrocarbon gases; the hydrogen sulfide is reacted at an exceptional rate and only acid-stable reaction products are formed. Thereafter, the sweetened hydrocarbon gases are collected.

Process for scavenging hydrogen sulfide from hydrocarbon gases

Iron rich dusts created during steelmaking, as in the basic oxygen and open hearth processes, are useful for scavenging hydrogen sulfide. For example, basic oxygen furnace dusts, which are in more abundant supply, are found to consist of fine, nearly spherical particles of iron oxide whose crystalline composition comprises Fe.sub.3 O.sub.4 (major portion) and Fe.sub.2 O.sub.3 (minor portion) as seen by X-ray diffraction. Their great surface area makes them highly reactive to hydrogen sulfide gas. Their reaction yields unexpected products, namely, free sulfur and iron hydroxides. According to the present invention such iron rich dusts are used in water slurries through which sour hydrocarbon gas is bubbled, and in water based drilling muds to scavenge hydrogen sulfide encountered in well drilling.

Use of steel plant waste dusts for scavenging hydrogen sulfide

An iron oxide having the ideal composition Fe.sub.3 O.sub.4 has a unique high porosity, substantially spherical particle structure. Used in oil and gas well drilling muds, it scavenges hydrogen sulfide. It also improves the rheological properties of the mud, maintains its stability under high temperatures, and functions as a mud weighting material. Upon completion of drilling, the drilling mud containing the porous Fe.sub.3 O.sub.4 additive may be left in place between the inner casing and the formation wall or the outer casing as a packer fluid.

Growing community of inventors

Ballwin, MO, United States of America

Irwin Fox