A process for absorbing carbon dioxide from a gas stream containing carbon dioxide, including the steps of contacting the gas stream with an aqueous composition including a substituted heteroaromatic compound having a six-membered heteroaromatic ring with from 1 to 3 nitrogen atoms in the heteroaromatic ring and at least one substituent wherein at least one of the substituents is of formula —R.sup.1NH.sub.2 wherein R.sup.1 is selected from C.sub.1 to C.sub.6 alkylene and ethers of formula —R.sup.2—O—R.sup.3— wherein R.sup.2 and R.sup.3 are C.sub.1 to C.sub.3 alkylene.

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.

Disclosed is a process for regenerating a hybrid solvent used to remove contaminants from a fluid stream and to provide an improved yield of purified fluid. Said process comprises a purification unit (12) and at least one regeneration unit (40) wherein make-up water (72) is added to the regenerated lean hybrid solvent (55) prior to reuse in the first purification unit and no water is recycled into the regeneration unit.

Hydrogen sulfide is removed from a gas stream by bubbling a gas stream having ≥100 ppm hydrogen sulfide through a scavenging mixture. The scavenging mixture includes: 1) at least one sweetener selected from the group consisting of triazines, oxazolidines, hemiacetals, and mixtures thereof, and 2) at least one reaction catalyst selected from the group consisting of dipropyl amine (DPA), diethyl amine (DEA), dimethyl amine (DMA), pyrrole, and mixtures thereof. The scavenging mixture interacts with the hydrogen sulfide to produce a cleaned gas stream having ≤ 5 ppm hydrogen sulfide.

A method for maintaining solvent quality in a gas treating system involves calculating, by an advisory system for continuous monitoring of the gas treating system, a water content deficit in the solvent of the gas treating system, calculating, by the advisory system, a water makeup rate compensating for the water content deficit, and displaying, in an interactive user interface of the advisory system, the water makeup rate.

A system and a process for capturing Carbon Dioxide (CO.sub.2) from flue gases are disclosed. The process comprises feeding a flue gas comprising CO.sub.2 to at least one Rotary Packed Bed (RPB) absorber rotating circularly. A solvent may be provided through an inner radius of the RPB absorber. The solvent may move towards an outer radius of the RPB absorber. The solvent may react with the flue gas in a counter-current flow. The process further includes passing the flue gas through at least one of a water wash and an acid wash to remove traces of the solvent present in the flue gas. Finally, the solvent reacted with the CO.sub.2 may be thermally regenerated for re-utilizing the solvent back in the process.

The present disclosure is directed to systems and methods for reforming methane into hydrogen and a hydrocarbon fuel. In example embodiments, the methane reformer integrates a photocatalytic steam methane reforming (P-SMR) system with a subsequent photocatalytic dry methane reforming (P-DMR) system.

The invention relates to a low-cost and high-efficiency absorption-desorption decoupling method for contaminant-CO.sub.2 synergistic capture. According to the method, an optimization model of absorption-desorption decoupling control for contaminant-CO.sub.2 synergistic capture under different working conditions is built, the optimization objective is to obtain high-purity liquid contaminants and CO.sub.2 at low cost and efficiently, and an adaptive penalty function is constructed to transform a solution of a constrained optimization problem into that of an unconstrained optimization problem, thereby controlling parameters in a real-time, precise and stable manner. Moreover, supported by means of flue gas pre-scrubbing and cooling, multi-stage intercooling and column-top demisting, the method of the present invention achieves efficient capture of contaminants and CO.sub.2. According to the invention, the absorption process is decoupled from the desorption process, and the coordinated control of temperature-pH-liquid-gas ratio and rich liquid flow-desorption temperature in all cycles is carried out to realize the synergistic capture-regeneration-concentration of contaminants and CO.sub.2 with high efficiency and low energy consumption, thereby reducing the high cost of the traditional method where a flue gas cleaning system and a carbon capture system operate separately.

Disclosed herein is a method and system for CO.sub.2 removal from a gas stream using a diamine solvent having a Formula I
R.sup.1(R.sup.2)N-L.sup.1-NH—R.sup.3  Formula I.
With respect to Formula I, each of R.sup.1 and R.sup.2 independently is aliphatic, cycloaliphatic, or R.sup.1 and R.sup.2 together with the nitrogen to which they are attached, form a heterocyclyl ring; L.sup.1 is aliphatic, cycloaliphatic, or L.sup.1 and R.sup.1 together with the nitrogen to which they are attached form a heterocyclyl ring; and R.sup.3 is aliphatic, cycloaliphatic, cycloalkylalkyl, or alkoxyalkyl. And/or the compound may have a viscosity of less than 75 cP at a CO.sub.2-loading of 40 mol % and at a temperature of 40° C.

A process and device for enhancing the chemical protection capability of a collective protection filter whereby the process stream exiting the collective protection filter is passed through an Auxiliary Filter. The auxiliary filter containing an ammonia removal media, such as zirconium hydroxide impregnated with zinc chloride (ZnCl.sub.2/Zr(OH).sub.4), an oxidizing media, preferably zirconium hydroxide impregnated with potassium permanganate (KMnO.sub.4/Zr(OH).sub.4), and a methyl bromide removal media, preferably activated carbon impregnated with triethylenediamine (TEDA/carbon). The auxiliary filter and process are configured to remove toxic industrial chemicals including NH.sub.3, NO.sub.x (mixtures of NO and NO.sub.2) and CH.sub.2O, and CH.sub.3Br.