New formulation for pyrite scale removal from oil and gas wells and a method of pyrite scale removal are disclosed. The chemical formulation is composed of K.sub.2B.sub.4O.sub.7-4H.sub.2O, in a concentration of about 9-20 wt. % of the composition, preferably about 14 wt. % of the composition. The new formulation has the ability to dissolve pyrite without generation of the toxic H.sub.2S. Furthermore, the new formulation is cheaper and has very low corrosion rate compare to 15 wt. % HCl with corrosion inhibitor. The disclose method uses the disclosed new formulation to dissolve iron sulphide scale, performed at about 100-150° C. and about 500-2000 psi.

A solvent system for the removal of acid gases from mixed gas streams is provided. Also provided is a process for removing acid gases from mixed gas streams using the disclosed solvent systems. The solvent systems may be utilized within a gas processing system.

A fluid filter, filtering medium composition, and associated process for removing contaminants from feed and exhaust fluids used in fuel cell electricity generation, laboratories, the semiconductor and other industries to improve performance and extend useful equipment lifetimes and to clean fluids of sulfur compound contaminants, as well as to remove noxious NOx contaminants from feed and exhaust gases.

A gas treatment method includes: a process (a) of allowing gas to be treated in which a target substance to be treated is mixed with air to pass through inside a housing, the target substance to be treated exhibiting volatility at room temperature and belonging to at least one substance selected from a group consisting of carbon compounds, nitrogen compounds, and sulfur compounds; a process (b) of introducing ozone into a space through which the gas to be treated flows inside the housing at 200° C. or lower; a process (c) of stirring the gas to be treated after the process (b); and a process (d) of heating the gas to be treated to 300° C. or higher after executing the process (c).

Sorbent compositions containing calcium and iodine are added to coal to mitigate the release of mercury and/or other harmful elements into the environment during combustion of coal containing natural levels of mercury.

A solvent system for the removal of acid gases from mixed gas streams is provided. Also provided is a process for removing acid gases from mixed gas streams using the disclosed solvent systems. The solvent systems may be utilized within a gas processing system.

A scrubbing solution for removing contaminants, including particularly hydrogen sulfide, from a fluid. The scrubbing solution includes at least one scrubbing reagent which has a primary or secondary amine and an acid, which may be phosphoric acid. The fluid being scrubbed is passed through the scrubbing solution. The contaminants react with the scrubbing reagent securing them in the scrubbing solution. The fluid being scrubbed and the scrubbing solution are then separated. The scrubbing solution is heated and, if the scrubbing solution is under pressure, the pressure is reduced. The acid facilitates thorough removal of the contaminants, and especially the hydrogen sulfide, from the scrubbing solution. The scrubbing solution is then ready for reuse. Because the scrubbing solution is rendered substantially free of hydrogen sulfides, it can absorb other sulfide contaminants that might not otherwise be absorbed.

In a reaction product of at least one phenol compound with aldehyde(s), the phenol compound(s) reply to formula (II): wherein-R represents a hydrogen atom or a hydrocarbyl group comprising from 1 to 30 carbon atoms, -x is 1 or 2, -R.sup.1 is a linear alkyl or alkenyl group having 15 carbon atoms if x is 1, -R.sup.1 is hydrogen if x is 2, -R.sup.2 represents a hydrogen atom or a hydrocarbyl group comprising from 1 to 30 carbon atoms, and its use as a hydrogen sulphide and/or mercaptans scavenger in hydrocarbon compositions and in water-based compositions such as water-based drilling fluids.

Systems and methods for sulfur-compound removal from hydrocarbon liquids may include at least one tank defining a chamber with top and bottom ends, a gas inlet into the chamber, a gas outlet from the chamber, a fluid inlet into the chamber, and a fluid outlet from the chamber. A fluid circulation assembly creates a hydrocarbon liquid flow on a liquid path, and a gas circulation assembly circulates a gas flow along a gas path. The gas inlet and outlet and the fluid inlet and outlet of the tank may be arranged to create a crossflow and counterflow of the liquid and gas flows in the chamber of the tank such that sulfur-containing compounds are transferred from the liquid to the gas flow. A gas processor assembly may remove sulfur-containing compounds from the gas flow before recirculating the gas flow. The gas flow may be predominantly nitrogen (N2) gas.

A scrubbing solution for removing contaminants, including particularly hydrogen sulfide, from a fluid. The scrubbing solution includes at least one scrubbing reagent which has a primary or secondary amine and an acid, which may be phosphoric acid. The fluid being scrubbed is passed through the scrubbing solution. The contaminants react with the scrubbing reagent securing them in the scrubbing solution. The fluid being scrubbed and the scrubbing solution are then separated. The scrubbing solution is heated and, if the scrubbing solution is under pressure, the pressure is reduced. The acid facilitates thorough removal of the contaminants, and especially the hydrogen sulfide, from the scrubbing solution. The scrubbing solution is then ready for reuse. Because the scrubbing solution is rendered substantially free of hydrogen sulfides, it can absorb other sulfide contaminants that might not otherwise be absorbed.