The present application pertains to methods for making metal oxides and/or citric acid. In one embodiment, the application pertains to a process for producing calcium oxide, magnesium oxide, or both from a material comprising calcium and magnesium. The process may include reacting a material comprising calcium carbonate and magnesium carbonate. Separating, concentrating, and calcining may lead to the production of oxides such as calcium oxide or magnesium oxide. In other embodiments the application pertains to methods for producing an alkaline-earth oxide and a carboxylic acid from an alkaline earth cation-carboxylic acid anion salt. Such processes may include, for example, reacting an alkaline-earth cation-carboxylic acid anion salt with aqueous sulfur dioxide to produce aqueous alkaline-earth-bisulfite and aqueous carboxylic acid solution. Other useful steps may include desorbing, separating, and/or calcining.

The present invention relates to an improved process and system for purifying a gas, preferably an energy gas, containing aromatic compounds and isolating a fraction of aromatic compounds from said gas. In the process according to the invention, the gas is contacted with a washing liquid in step (a), at a temperature of 15-250° C., to obtain a purified gas, which is depleted in aromatic compounds, and a spent washing liquid wherein the aromatic compounds are dissolved. The spent washing liquid is stripped in step (b) with a stripping gas comprising at least 50 vol. % steam, to obtain a stripped washing liquid which is advantageously reused in step (a) and a loaded stripping gas comprising the aromatic compounds. The aromatic compounds are separated from the loaded stripping gas in step (c) by condensation of the steam and/or the aromatic compounds comprised in the loaded stripping gas to obtain an immiscible composition and isolating the aromatic compounds therefrom. The cleared stripping gas which is advantageously reused in step (b).

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 method for providing a fuel includes providing biogas from a plurality of biogas sources, the biogas from each biogas source produced in a process comprising filling a vessel with raw biogas or partially purified biogas to a pressure of at least 1500 psig and transporting the filled vessel to a centralized processing facility by vehicle. A fuel is produced in a fuel production process that includes feeding the biogas transported to the centralized processing facility to a biogas upgrading system that is configured to provide a carbon dioxide removed from the biogas. The removed carbon dioxide is provided for transport by vehicle and/or pipeline and/or sequestered to offset greenhouse gas emissions attributed to compressing the biogas for transport.

Polyamines with lengths carefully tailored to the framework dimensions are appended to metal-organic frameworks such as Mg.sub.2(dobpdc) (dobpdc4-=4,4′-dioxidobiphenyl-3,3′-dicarboxylate) with the desired loading of one polyamine per two metal sites. The polyamine-appended materials show step-shaped adsorption and desorption profiles due to a cooperative CO.sub.2 adsorption/desorption mechanism. Several disclosed polyamine-appended materials exhibit strong ability to capture CO.sub.2 from various compositions. Increased stability of amines in the framework has been achieved using high molecular weight polyamine molecules that coordinate multiple metal sites in the framework. The preparation of these adsorbents as well as their characterization are provided.

Methods for removing reduced sulfur compounds, such as hydrogen sulfide, from fluids employing a ferric iron salt that exhibits unusually high solubility in aqueous, alkaline solutions and has strong affinity for capture and oxidation of reduced sulfur compounds. Alkaline aqueous ferric iron salt and solutions thereof useful for removing reduced sulfur compounds from fluids and various methods of production of such salts and solutions. In addition, methods of regenerating the alkaline aqueous ferric iron salt solutions after capture of hydrogen sulfide or other reduced sulfur compounds, generally by exposure to oxygen in air. The alkali metal carbonate salt preferably comprises potassium carbonate and/or potassium bicarbonate. The alkaline aqueous ferric iron salt solutions generally comprise ferric ions, potassium ions, carbonate ions, and bicarbonate ions, optionally with one or more organic additives. In addition, aqueous-soluble, ferric iron salts and ferric iron containing solids prepared by removal of aqueous medium from solutions herein.

Embodiments of the present disclosure describe methods of removing one or more compounds from a fluid comprising contacting a metal-organic framework (MOF) composition having a square-octahedral topology with a fluid containing one or more of CH.sub.4 and O.sub.2, sorbing one or more of CH.sub.4 and O.sub.2 with the MOF composition, and storing one or more of the CH.sub.4 and O.sub.2 with the MOF composition.

The invention relates to an installation and a method for treating hydrogen sulphide. In particular, the invention relates to an installation and a method comprising at least one system for oxidizing hydrogen sulfide to sulfur (S) and water (H.sub.2O) with a solid reagent and at least one oxidizing system with an agent for oxidizing the solid reagent present in the reduced state, wherein the system of oxidizing the hydrogen sulfide to sulfur and the system for oxidizing the solid reagent, are so arranged that the hydrogen sulfide is not brought into contact with the agent oxidizing the solid reagent.

The invention is directed to a process to convert a sulphur compound to bisulphide by direct or indirect transfer of electrons from a cathode of a bio-electrochemical cell to the sulphur compound under anaerobic conditions and in the presence of mixed culture comprising methanogens and suitably also a anaerobic or facultative anaerobic bacteria. The sulphur compound may be a thiol like methanethiol or ethanethiol or a polysulphide, like dimethyl disulphide.

An adsorption material is disclosed that comprises a metal-organic framework and a plurality of Hgands. The metal-organic framework comprising a plurality of metal ions. Each respective ligand in the plurality of ligands is amine appended to a respective metal ion in the plurality of metal ions of the metal-organic framework. Each respective ligand in the plurality of ligands comprises a substituted 1,3-propanediamine. The adsorbent has a CO2 adsorption capacity of greater than 2.50 mmol/g at 150 mbar CO2 at 40° C., Moreover, the adsorbent is configured to regenerate at less than 120° C. An example ligand is diamine 2,2-dimethyl-1,3-propane-diamine. An example of the metal-organic framework is Mg2(dobpdc), where dobpdc.sup.4− is 4,4′-dioxidobiphenyl-3,3′-dicarboxylate. Example applications for the adsorption material are removal of carbon dioxide from flue gas and biogasses.