The present invention discloses a preparation method of a catalyst with white carbon black modified by ZrNdO and use thereof, and belongs to the field of catalyst technologies. In the present invention, an organic solvent evaporation induced self-assembly method is used to load ZrNdO onto white carbon black to obtain a mesoporous ZrNdO/white carbon black catalyst. The mesoporous ZrNdO/white carbon black catalyst in the present invention has high catalytic activity, contains uniformly distributed mesopores with a relatively large average aperture, and has a simple preparation process, etc.

The invention relates to a process for recovering methane from digester biogas or landfill gas. More specifically, the invention pertains to biomethane production that substantially removes carbon dioxide from a digester biogas or landfill gas using first, second, and third purification stages each comprising one or more membranes selective for carbon dioxide over methane. A retentate from the first stage is separated by the one more membranes of the second stage into a second state retentate, forming a biomethane product gas. A permeate from the first stage is separated by the one or more membranes of the third stage into a third stage retentate and a third stage permeate. Recovery of methane from the the biogas is boosted by feeding the third stage retentate to the first purification stage. The recovery may be optionally further boosted by compressing the second stage permeate with the biogas at a main compressor.

A composite absorbent filter media having adsorption and/or absorption properties for the filtration of ester oils from a liquid includes a graphene and/or graphite composite mixed into a final emulsion, which is subsequently heat treated or cured, cooled, compressed, and dried. The resultant adsorption/absorption media is then disposed within a plug structure having an ingress and egress for liquids mixed with ester oils to pass through. Alternatively, the resultant adsorption/absorption media is disposed into a fabric and formed as a wall used to enclose oil-filled equipment. The media adsorbs/absorbs the ester oils from the liquid, while allowing the liquid to disperse and pass through.

Adsorbent materials are disclosed, along with filter elements containing the adsorbent materials methods of using adsorbents to remove siloxane contaminants from a gas stream. The method includes providing an adsorbent material that has been washed with an acid and passing a gas through the adsorbent material so as to reduce siloxane levels in the gas. A filter element for reducing siloxane levels in a gas includes a first adsorbent material, the first adsorbent material comprising an acid-washed adsorbent; and a second adsorbent material, the second adsorbent material comprising an acid-impregnated adsorbent.

The present disclosure generally relates to systems and methods for the combustive abatement of waste gas formed during the manufacture of semiconductor wafers. In particular, the systems described herein are capable of combusting air-polluting perfluorocarbons, including those having high greenhouse gas indexes such as hexafluoroethane (C.sub.2F.sub.6) and tetrafluoromethane (CF.sub.4), as well as particulate-forming silicon dioxide precursors, such as silane (SiH.sub.4) and tetraethoxysilane (Si(OC.sub.2H.sub.5).sub.4, abbreviated TEOS), with greater efficiency and lower energy usage than prior abatement systems. More particularly, and in one preferred embodiment, the present disclosure is directed to a waste gas abatement system that utilizes a combination of non-combustible and combustible gases (or gas mixtures) for thermal combustion, which are directed through multiple permeable interior surfaces of a reaction chamber, efficiently combusting waste gas and preventing undesirable accumulation of solid particulate matter on the chamber surfaces.

A system for chemical vapor densification includes a reaction chamber having an inlet and outlet; a trap; a conduit fluidly coupled between the outlet of the reaction chamber and the trap; a cryogenic cooler fluidly coupled to the trap though a frustoconical conduit; a first exit path from the cryogenic cooler that vents hydrogen gas to an exhaust; and a second exit path from the cryogenic cooler that recirculates silane and hydrocarbon-rich gas back to the inlet of the reaction chamberand a related method places a substrate in the reaction chamber; establishes a sub-atmospheric pressure inert gas atmosphere within the reaction chamber; densifies the substrate by inputting virgin gas into the reaction chamber; withdraws effluent gas from the reaction chamber; extracts silane and hydrocarbon-rich gas from the effluent gas; and recirculates the silane and hydrocarbon-rich gas back to the reaction chamber.

A process for combined removal of siloxanes and sulfur-containing compounds from biogas streams, such as streams from landfills or anaerobic digesters, comprises heating the biogas stream and optionally mixing it with air, feeding the gas to a first filter unit with high temperature resistance, injecting a dry sorbent into the first filter unit to capture siloxanes present in the gas, recycling part of the exit gas from the first filter unit to the inlet thereof for the sulfur-containing compounds to be captured by the dry sorbent or optionally to a second filter unit inlet for the sulfur-containing compounds to be captured by a sulfur-specific sorbent and recovering clean gas from the first or optionally from the second filter unit.

The present invention relates to zeolitic adsorbents based on agglomerated crystals of FAU zeolite containing barium and/or potassium, with large external surface area, combining optimum properties in terms of selectivity and mechanical strength. These adsorbents find applications in the separation of cuts of C8-aromatic isomers and notably of xylenes, in the separation of isomers of substituted toluene such as nitrotoluene, diethyltoluene, toluenediamine, in the separation of cresols, and in the separation of polyhydric alcohols such as sugars.

Oxygen is removed from a gas feed such as a landfill gas, a digester gas or an industrial CO.sub.2 off-gas by removing sulfur-containing compounds and siloxanes from the feed gas, heating the feed gas, injecting one or more reactants for oxygen conversion into the heated feed gas, carrying out a selective catalytic oxygen conversion in at least onesuitable reactor and cleaning the resulting oxygen-depleted gas. The reactants to be injected comprise one or more of H.sub.2, CO, ammonia, urea, methanol, ethanol and dimethylether (DME).

Contaminant treatment methods and systems are described. Methods utilize biodegradable, non-toxic materials that can carry one or more functionalities useful for the remediation of fluids such as liquid or gaseous waste streams, chemical spills, etc. The carrier materials carry one or more functional groups that can target particular contaminants of a fluid for removal and/or modification to a more benign form. Targeted contaminants can include components of gaseous and/or liquids such as, and without limitation, gaseous discharges including VOCs and potentially hazardous contaminants such as organophosphorous compounds.