Systems and methods for separating a biogas or other gaseous material into its constituent parts, including solid methane and carbon dioxide, using liquid nitrogen in a processing chamber. The individual parts may be extracted from the processing chamber. Separation and extraction can be performed on a mobile processing plant.

Methods of controlling hydrogen sulfide concentration of a biogas occupying an anaerobic membrane bioreactor (AnMBR) containing a submerged membrane are disclosed herein. Methods of controlling dissolved sulfide concentration of a mixed liquor within the AnMBR are disclosed. The methods include directing wastewater containing sulfur and a chemical oxygen demand (COD) to an AnMBR, withdrawing at least a fraction of the biogas from the AnMBR, directing a pre-determined amount of the withdrawn biogas to a scrubber, directing a remainder of the withdrawn biogas to a gas distributor, and directing the scrubbed biogas to the AnMBR. Systems for treating wastewater having sulfur and COD are disclosed. The systems include an AnMBR, a scouring gas closed loop, a scrubber, and a control mechanism for directing biogas to the scrubber and to a gas distributor. Methods of retrofitting a system for treating wastewater having sulfur and COD are disclosed.

This invention relates to a process and apparatus for growing agricultural products with a reduced abundance of radioactive carbon-14 (.sup.14C) by employing centrifugal separation of atmospheric gases to selectively remove carbon dioxide (CO.sub.2) with .sup.14C. Agricultural products with reduced .sup.14C content can be grown in controlled environments with filtered atmospheric gases for the benefit of reducing harmful damage to human DNA that is unavoidable with our current food chain, due to the natural abundance of .sup.14C in atmospheric gases. Bilateral and unilateral compression helikon vortex apparatus provide efficient and economical removal of CO.sub.2 with .sup.14C from atmospheric gases with a single filtration pass, which is ideally suited for large scale agricultural production.

A process for the removal of hydrogen sulfide and sulfur recovery from a H.sub.2S-containing gas stream by catalytic direct oxidation and Claus reaction through two or more serially connected catalytic reactors, wherein a specific control of the oxygen supplement is operated. The control and improvement of the process is obtained by complementing, in each major step of the process, the H.sub.2S-containing gas stream by a suitable flow of oxygen, namely before the H.sub.2S-containing gas stream enters the Claus furnace, in the first reactor of the process and in the last reactor of the process. Especially in application in a SubDewPoint sulfur recovery process the H.sub.2S/SO.sub.2 ratio is kept constant also during switch-over of the reactors R1 and R by adding the last auxiliary oxygen containing gas directly upstream the last reactor R so that the H.sub.2S/SO.sub.2 ratio can follow the signal of the ADA within a few seconds.

Disclosed is an absorbent containing an amine for absorption of an acid gas in a biogas, and a biogas purification system using the same.

Disclosed are a CHA zeolite membrane and a method of preparing the same, and more particularly, a CHA zeolite membrane having high capacity to separate CO.sub.2/N.sub.2 and CO.sub.2/CH.sub.4 even under wet conditions using a membrane produced using a synthetic precursor having a controlled ratio of Si and Al, a method of preparing the same, and a method of capturing and removing carbon dioxide using the membrane.

Embodiments provide a method of compound removal from a fluid. The method includes contacting one or more metal organic framework (MOF) compositions with a fluid and sorbing one or more compounds, such as CO.sub.2, H.sub.2S and condensable hydrocarbons. One or more of CO.sub.2, H.sub.2S and condensable hydrocarbons can be sorbed simultaneously or in series. The metal organic framework can be an M-soc-MOF.

A carbon dioxide recovery system that recovers carbon dioxide from a hybrid vehicle traveling in a CO.sub.2 recovery area including a CO.sub.2 recovery road in which a stationary CO.sub.2 recovery device collecting and recovering carbon dioxide from the atmosphere is provided acquires a residual charging capacity of the battery and position information of the hybrid vehicle and guides the hybrid vehicle such that the hybrid vehicle travels on the CO.sub.2 recovery road using a notification device when the residual charging capacity is equal to or less than a predetermined SOC threshold value while the hybrid vehicle is traveling in the CO.sub.2 recovery area.

A multi-stage process to remove contaminant gases from raw methane streams is provided. The present technology is an innovative solution to recover and purify biogas by use of a process having at least two pressure swing adsorption stages. Taking advantage of the presence of carbon dioxide in the raw biogas streams, nitrogen and oxygen are bulky removed in the first stage, using selective adsorbents, and a nitrogen and oxygen-depleted intermediate stream is yielded to the second stage. The second stage employs an adsorbent or adsorbents to selectively remove carbon dioxide and trace amounts of remaining nitrogen and oxygen, thus producing a purer methane stream that meets pipeline and natural gas specifications.

A separation and purification coupled process with a high helium yield and diversified products is provided. The process is as follows. Firstly, a low-concentration helium-containing gas after being pressurized and pre-treated enters a two-stage and two-section membrane separation unit to produce a helium product with a medium concentration by concentrating stage by stage through the membrane separation unit. A part of the helium with medium concentration enters an adsorption unit for further concentration to produce a helium product above grade A.