The invention relates to an absorber column and to the use thereof for separation of unwanted, especially acidic, gas constituents, for example carbon dioxide and hydrogen sulfide, from a crude synthesis gas by absorption with an absorbent, especially under low load states of the absorber column in relation to the synthesis gas velocity. According to the invention, a defined concentration of carbon dioxide in the clean synthesis gas is established by mixing at least a portion of the absorbent regenerated by flash regeneration with the absorbent regenerated by means of hot regeneration prior to the recycling thereof into the absorber column.

An exhaust gas cleaning system comprises a first sub system including a scrubber unit comprising a scrubber arranged to wash the exhaust gas with a scrubber fluid, and a centrifugal separator arranged in communication with the scrubber unit for receiving the scrubber fluid after washing and separate it into a first and a second fraction, which second fraction is more polluted than the first fraction. The exhaust gas cleaning system further comprises a second sub system including a membrane filter arranged in communication with the centrifugal separator for receiving the first fraction output from the centrifugal separator and separating it into a third and a fourth fraction, which fourth fraction is more polluted than the third fraction. A method for cleaning exhaust gas onboard a ship involves cleaning an exhaust gas onboard a ship.

A process for recovering nitric acid or salts thereof, comprising: contacting, in the presence of water, an water-immiscible ionic liquid of the formula [A.sup.+][X.sup.−], wherein [A.sup.+] represents a phosphonium or ammonium cation and [X.sup.−] represents a counter anion which is NO.sub.3.sup.−, an halide anion displaceable by NO.sub.3.sup.−, or both, with a fluid which contains HNO.sub.3 and at least one more mineral acid, or precursors of said acids, and partition, under mixing, said acids between aqueous and organic phases and form nitrate-loaded ionic liquid of the formula [A.sup.+][NO.sub.3.sup.−].sub.z>0.25 where Z indicates a molar amount of nitrate held in the ionic liquid beyond the positions occupied by the nitrate counter ions; separating the so-formed mixture into an organic phase comprising a nitrate-loaded ionic liquid of the formula [A.sup.+][NO.sub.3.sup.−].sub.z>0.25 and an aqueous phase consisting of a nitrate-depleted aqueous solution that contains the other mineral acid(s); stripping the nitric acid from said nitrate-loaded ionic liquid to create an aqueous nitrate solution and regenerate ionic liquid of the formula [A.sup.+][NO.sub.3.sup.−].sub.z≥0 with reduced nitrate loading, or unloaded [A.sup.+][NO.sub.3.sup.−].sub.z=0 ionic liquid.

A method for recovering CO.sub.2 in the Rectisol process. The method includes at least the following steps: performing reduced-pressure flash distillation treatment on the CO.sub.2-rich methanol liquid, and outputing the CO.sub.2 desorbed gas obtained after the reduced-pressure flash distillation treatment as a product gas; performing heat exchange flash distillation treatment on a first methanol treatment liquid obtained after the reduced-pressure flash distillation treatment, and outputing the CO.sub.2 desorbed gas obtained after the heat exchange flash distillation treatment as a product gas; performing vacuum flash distillation treatment on a second methanol treatment liquid obtained after the heat exchange flash distillation treatment, and outputing the CO.sub.2 desorbed gas obtained after the vacuum flash distillation treatment as a product gas. Reduced-pressure flash distillation treatment, heat exchange flash distillation treatment and vacuum flash distillation treatment are sequentially performed on the CO.sub.2-rich methanol liquid in this method.

A multi-stage system comprising a digester, a bioreactor, a scrubber, a biofilter, and a membrane filter extracts and purifies biogas from a wastewater feed. The digester separates raw biogas from wastewater, the wastewater is then purified with a three-stage bacterial process in a bioreactor. The scrubber receives raw biogas from the digester under pressure, dissolving waste gases and purifying the methane, which can be further condensed and purified in the membrane filter. The bioreactor receives waste gases from the scrubber and membrane filter, with the ammonia portion of the waste gases rising through water from the bioreactor and being converted by annamox bacteria into nitrogen gas. The multiply recycled gas and water feeds produce a biogas having high purity and reduced atmospheric emissions of waste gases.

The present invention relates to a biomimetic-hybrid solvent system for simultaneous capture of H.sub.2S and CO.sub.2 from any gaseous composition. The present invention also relates to a process for upgradation of biogas to bio CNG by removing gaseous contaminants, including microbial removal of H.sub.2S, to obtained purified CO.sub.2. The biomimetic-hybrid solvent system contains three components selected from tertiary amine compounds, a functional colloidal fluid, and an enzyme mimic.

The concerns a process for producing formic acid, (a) a carbon capture step in which a source of carbon dioxide is contacted with an amine solution in an amine scrubber, to obtain an ammonium bicarbonate solution, where the carbon capture uses a chilled amine solution having a temperature in the range of 0-20 ° C.; (b) inducing crystallization in the ammonium bicarbonate solution to obtain a concentrated ammonium bicarbonate solution; (c) subjecting the concentrated ammonium bicarbonate solution to a hydrogenation step to obtain an ammonium formate; and (d) heating the ammonium formate to a temperature in the range of 50-150 ° C., to obtain a gaseous product containing the amine and a liquid product stream containing formic acid. The application further concerns a system for performing the process.

An apparatus for treating gaseous pollutants includes a gas inlet part, a first treatment unit, a second treatment unit and a non-mechanical flow-guiding device. The gas inlet part includes a gas inlet chamber and at least one guide pipe. The guide pipe communicates with the gas inlet chamber and guides an effluent stream from a semiconductor process to the gas inlet chamber. The first treatment unit is coupled to a bottom end of the gas inlet part and is configured to abate the effluent stream. The non-mechanical flow-guiding device is coupled to the first treatment unit. The flow-guiding device is configured to guide the effluent stream to move toward an opening. The second treatment unit is coupled to the flow-guiding device via the opening, receives the effluent stream from the first treatment unit and further abates the effluent stream.

A natural gas dehydration apparatus that is configured to provide dehydration of natural gas as the natural gas exits from a natural gas well. The apparatus of the present invention includes a vessel body having an interior volume. Disposed within the interior volume of the vessel body is a dehydrating fluid such as but not limited to methanol. The vessel body is oriented in an upright position and includes an inlet member operably coupled to the lower end thereof that provides introduction of natural gas into the vessel body. The inlet member includes an end section in the interior volume of the body and facilitates the introduction and percolation of natural gas through the methanol. A discharge pipe member directs the natural gas from the interior volume of the vessel body. A fill member provides introduction of additional methanol while a screen member controls methanol mist.

A membrane modification method for improving liquid membrane separation of carbon dioxide (CO.sub.2) includes grafting an organic substance containing an amine group on a porous membrane material, and loading water into pore channels of the porous membrane material to prepare a supported liquid membrane for a gas mixture separation experiment of CO.sub.2. In the method, the amine group is introduced through chemical grafting to make the water being alkaline when used as membrane liquid. Compared with an alkaline solution as the membrane liquid, the method can avoid the loss of active alkaline substances and increase the permeation flux of CO.sub.2.