Proposed is a pretreatment desulfurization system including a desulfurization agent storage tank for storing a liquid-phase pretreatment desulfurization agent and a metering pump for supplying the liquid-phase pretreatment desulfurization agent from the desulfurization agent storage tank to a fuel supply line through which marine fuel oil is supplied to a marine engine in a predetermined ratio. Since a fluid mixture composed of the marine fuel oil and the pretreatment desulfurization agent is supplied to the marine engine, sulfur oxides are adsorbed and removed during combustion of the fluid mixture.

A de-hydrogenation catalyst and its use in dehydrogenation of hydrocarbons. The catalyst has low cracking activity and comprises gallium or gallium and platinum on an essentially non-acidic and amorphous alumina-phosphate or silica-alumina-phosphate support with an empirical chemical composition of [Al2O3][SiO2].sub.Y[P2O5].sub.Z, wherein Y is between 0 and 0.2 and Z is between 0.01 and 1.1, with a BET surface area above 50 m.sup.2/g, as measured by N2 adsorption experiment.

A de-hydrogenation catalyst and its use in dehydrogenation of hydrocarbons. The catalyst has low cracking activity and comprises gallium or gallium and platinum on an essentially non-acidic and amorphous alumina-phosphate or silica-alumina-phosphate support with an empirical chemical composition of [Al2O3][SiO2].sub.Y[P2O5].sub.Z, wherein Y is between 0 and 0.2 and Z is between 0.01 and 1.1, with a BET surface area above 50 m.sup.2/g, as measured by N2 adsorption experiment.

A method for removal of sulfide from a stream, the method comprising preparing a metal-chelant complex, designated M-Yn, where M is a divalent or trivalent cation, Y comprises a gluconic acid, glucaric acid or derivative thereof, and n is from about 1 to about 3; contacting a mixture comprising M-Yn and a base with a sulfide stream under conditions suitable for the formation of a metal-sulfide species; and contacting the metal-sulfide species with an oxidizing agent to form a soluble metal sulfide species. A method for removal of sulfide from a stream, the method comprising preparing a sulfide scavenging mixture comprising a base and a metal-complex characterized by Structure I;

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contacting the sulfide scavenging mixture with a sulfide stream under conditions suitable for the formation of a metal-sulfide species; and contacting the metal-sulfide species with an oxidizing agent to form a soluble metal sulfide species.

A method for removal of sulfide from a stream, the method comprising preparing a metal-chelant complex, designated M-Yn, where M is a divalent or trivalent cation, Y comprises a gluconic acid, glucaric acid or derivative thereof, and n is from about 1 to about 3; contacting a mixture comprising M-Yn and a base with a sulfide stream under conditions suitable for the formation of a metal-sulfide species; and contacting the metal-sulfide species with an oxidizing agent to form a soluble metal sulfide species. A method for removal of sulfide from a stream, the method comprising preparing a sulfide scavenging mixture comprising a base and a metal-complex characterized by Structure I;

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contacting the sulfide scavenging mixture with a sulfide stream under conditions suitable for the formation of a metal-sulfide species; and contacting the metal-sulfide species with an oxidizing agent to form a soluble metal sulfide species.

Proposed is a pretreatment desulfurization method for marine fuel oil. The method includes a step of preparing a pretreatment desulfurization agent including (a) at least one oxide selected from the group consisting of SiO2, Al2O3, Fe2O3, TiO2, MgO, MnO, CaO, Na2O, K2O, and P2O3, (b) at least one metal selected from the group consisting of Li, Cr, Co, Ni, Cu, Zn, Ga, Sr, Cd, and Pb, and (c) at least one liquid composition selected from the group consisting of sodium tetraborate (Na2B4O7.10H2O), sodium hydroxide (NaOH), sodium silicate (Na2SiO3). and hydrogen peroxide (H2O2). The method also includes a step of feeding the pretreatment desulfurization agent to a fuel supply line through which marine fuel oil is supplied to a marine engine at a certain ratio so that a fluid mixture containing the marine fuel oil and the pretreatment desulfurization agent is supplied to the marine engine, thereby adsorbing and removing sulfur oxides during combustion of the fluid mixture.

The crude oil sludge treatment agent is mixed with crude oil sludge and water and used for treatment of the crude oil sludge under alkali conditions. The crude oil sludge treatment agent contains green rust. The crude oil sludge treatment agent may further contain either or both a metal and a metal ferrite. The metal and the metal of the metal ferrite are one or more selected from the group consisting of aluminum, yttrium, zinc, copper, tin, chromium and silicon. The crude oil sludge treatment agent may also contain one or more selected from the group consisting of aluminum ferrite, yttrium ferrite and zinc ferrite. The crude oil sludge treatment method includes a mixing step in which crude oil sludge, water and green rust are mixed under alkali conditions.

A treatment composition for remediating for remediating H.sub.2S and other contaminant(s) in contaminated liquids, comprising: 0.1-10.0 weight % collectively of at least one hydroxide compound; 0.01-3.0 weight % collectively of at least one organic acid selected from a group consisting of fulvic acid and humic acid; 0.01-10.0 wt % of a chelating agent; and at least 75% weight of water.

A treatment composition for remediating for remediating H.sub.2S and other contaminant(s) in contaminated liquids, comprising: 0.1-10.0 weight % collectively of at least one hydroxide compound; 0.01-3.0 weight % collectively of at least one organic acid selected from a group consisting of fulvic acid and humic acid; 0.01-10.0 wt % of a chelating agent; and at least 75% weight of water.

A treatment process for remediating H.sub.2S and other contaminants in liquids includes: partially filling a closed vessel with a contaminated liquid containing ≥5 ppm H.sub.2S with a head space above the liquid within the vessel where gasses released from the liquid from the liquid collect; separately providing a treatment composition in the head space so that the gasses from the liquid may contact the treatment composition; and permitting the contact between the vapors from the liquid and the treatment composition to continue until a collective concentration of H.sub.2S in the liquid and in the head space is <5 ppm. The treatment composition includes an aqueous solution containing at least one hydroxide compound, a collective concentration of the at least one hydroxide compound in the aqueous solution is in a range of 35-55 weight %, and the aqueous solution constitutes at least 80 weight % of the treatment composition.