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.

An aqueous solvent composition is provided, comprising a nucleophilic component having one or more sterically unhindered primary or secondary amine moieties, a Brønsted base component having one or more basic nitrogen moieties, a water-soluble organic solvent, and water. A biphasic composition is provided, comprising one or more carbamate compounds, one or more conjugate acids of Brønsted base, a water-soluble organic solvent, and water. A biphasic CO.sub.2 absorption process is also provided, utilizing the biphasic solvent composition.

To provide a carbon dioxide separation composition which is excellent in carbon dioxide desorption efficiency (desorption amount/absorption amount) and durability to nitrogen oxides, and a method for separating carbon dioxide.

A carbon dioxide separation composition, containing at least one amine compound selected from the group consisting of an amine compound represented by the following formula (1):

##STR00001## wherein R.sup.1 to R.sup.3 each independently represent a hydrogen atom or a C.sub.1-4 alkyl group, and an amine compound represented by the following formula (2):

##STR00002## wherein R.sup.10, R.sup.11, R.sup.12, R.sup.13 and R.sup.14 each independently represent a hydrogen atom, a C.sub.1-4 alkyl group, a hydroxy group, a hydroxymethyl group, a 2-hydroxyethyl group or a C.sub.1-4 alkoxy group, a and b are each independently 0 or 1 and satisfy the relation a+b=1, and R.sup.15 is a hydrogen atom, a C.sub.1-4 alkyl group, a methoxymethyl group, a methoxyethoxymethyl group or a 2-hydroxyethyl group.

Provided is a gas-treating device including: an absorption device that receives an absorbent to absorb an acidic compound in a gas to be treated into the absorbent; a release device into which the absorbent having absorbed the acidic compound in the absorption device is introduced; a heater for heating the absorbent in the release device to release the acidic compound contained in the absorbent from the absorbent; and a multi-fluid heat exchanger for heating the absorbent before being supplied from the absorption device to the release device by a fluid containing the acidic compound discharged from the release device and the absorbent before being supplied from the release device to the absorption device.

Intensification techniques are described for enhancing biocatalytic CO.sub.2 absorption operations, and may include the use of a rotating packed bed, a rotating disc reactor, a zig-zag reactor or other reactors that utilize process intensification. Carbonic anhydrase can be deployed in the high intensity reactor free in solution, immobilized with respect to particles that flow with the liquid, and/or immobilized to internals, such as packing, that are fixed within the high intensity reactor.

A carbon dioxide recovery system for collecting carbon dioxide from an exhaust gas generated in a facility including a combustion device includes: a first exhaust gas passage through which the exhaust gas containing carbon dioxide flows; a fuel cell including an anode, a cathode disposed on the first exhaust gas passage so that the exhaust gas from the first exhaust gas passage is supplied to the cathode, and an electrolyte transferring, from the cathode to the anode, a carbonate ion derived from carbon dioxide contained in the exhaust gas from the first exhaust gas passage; and a second exhaust gas passage diverging from the first exhaust gas passage upstream of the cathode so as to bypass the cathode. A part of the exhaust gas is introduced to the second exhaust gas passage.

The present invention relates to a method for continuous removal of carbon dioxide, the method comprising the steps of: a) preparing an aqueous solution containing an amine-based compound and an acidic calcium compound; b) bringing a gas containing carbon dioxide to be treated into contact with the aqueous solution to prepare a calcium carbonate precipitate; and c) recovering the calcium carbonate and then adding a basic calcium compound to the residual aqueous solution, wherein after step c), step b) and step c) are repeatedly performed. The removal of carbon dioxide by the method of the present invention has advantages of requiring low energy and being capable of mineralizing and removing carbon dioxide at a fast rate without a separate time for induction.

An aqueous solvent composition is provided, comprising a nucleophilic component having one or more sterically unhindered primary or secondary amine moieties, a Brønsted base component having one or more basic nitrogen moieties, a water-soluble organic solvent, and water. A biphasic composition is provided, comprising one or more carbamate compounds, one or more conjugate acids of Brønsted base, a water-soluble organic solvent, and water. A biphasic CO.sub.2 absorption process is also provided, utilizing the biphasic solvent composition.

A process for removing hydrogen sulfide and carbon dioxide from a fluid stream comprises a) an absorption step in which the fluid stream is contacted with an absorbent comprising an aqueous solution (i) of an amine of the general formula (I) ##STR00001##
in which R.sub.1, R.sub.2 and R.sub.3 are each independently selected from C.sub.1-4-alkyl and C.sub.1-4-hydroxyalkyl; each R.sub.4 is independently selected from hydrogen, C.sub.1-4-alkyl and C.sub.1-4-hydroxyalkyl; each R.sub.5 is independently selected from hydrogen, C.sub.1-4-alkyl and C.sub.1-4-hydroxyalkyl; X is OH or NH(CR.sub.1R.sub.2R.sub.3); m is 2, 3, 4 or 5; n is 2, 3, 4 or 5; and o is 0 or 1; and optionally (ii) at least one tertiary amine, where the molar ratio of (i) to (ii) is greater than 0.05; wherein at least 90% of the hydrogen sulfide is removed from the fluid stream and selectivity for hydrogen sulfide over carbon dioxide is not greater than 8, wherein a CO.sub.2— and H.sub.2S-laden absorbent is obtained; b) a regeneration step in which at least a substream of the CO.sub.2— and H.sub.2S-laden absorbent is regenerated and a regenerated absorbent is obtained; and c) a recycling step in which at least a substream of the regenerated absorbent is recycled into the absorption step a). The process allows a high level of hydrogen sulfide removal with a simultaneously high coabsorption of carbon dioxide.

Disclosed herein are acid gas absorbents that afford high acid gas (CO2) absorption amount per unit volume and high absorption speed and can prevent the absorbent components from diffusing. The acid gas absorbent contains an amine compound of the formula (1) and a cyclic amine compound of the formula (3) or (3′): ##STR00001##