An air cleaner for a fuel cell system includes a housing, a first filter, and a second filter. The first filter is arranged inside the housing and collects dust contained in air. The second filter is arranged side by side with the first filter in an air flowing direction inside the housing and adsorbs impure gas contained in air. The first filter includes a filtering member, which has nonwoven fabric and filter paper adhered to the nonwoven fabric. The filter paper is located on a downstream side in the air flowing direction of the nonwoven fabric and has a higher packing density than the nonwoven fabric. The second filter includes a base member having a honeycomb structure with through-holes and adsorbent, which is provided on inner surfaces of the through-holes and adsorbs the impure gas.

A flue-gas purification system includes a flue-gas cycling system, a reactor, and an absorbent adding system having at least a catalytic absorbent, wherein the catalytic absorbent is being gasified for reacting with the flue-gas in the reactor in a homogenous gas-gas phase reacting manner. Therefore, the purification system has fast reaction rate between the pollutants of the flue-gas and the catalytic absorbent, which is preferably ammonia, to efficiently remove pollutants, so as to effectively purify the flue-gas.

The present invention is generally directed to processes and systems for the purification and conversion of CO.sub.2 into low-carbon or zero-carbon high quality fuels and chemicals using renewable energy. In one aspect, the present invention provides a process for producing a stream comprising at least 90 mol % CO.sub.2. In certain cases, the CO.sub.2 stream is processed to make low carbon fuels and chemicals. In this process at least a portion of the CO.sub.2 is reacted with a stream comprising H.sub.2 in a Reverse Water Gas Shift (RWGS) reactor to produce a product stream that comprises CO.

The invention relates to a method and a plant for treating or regenerating spent bleaching sands/earths from a plant for the production of biofuel, in particular from the bleaching pre-treatment of feedstocks of plant origin that are used for the production of biofuels.

The method comprises a first pre-treatment step in which the bleaching earths mixed with neutral water or with gummy acid water are neutralised by adding a base, preferably calcium hydroxide, in order to bring the pH to neutrality.

Subsequently the neutralised bleaching earths are subjected to anaerobic digestion by a biomass comprising anaerobic bacteria. During the digestion biogas, which may optionally be subjected to purification, and a solid/liquid suspension are generated.

The solid/liquid suspension is subsequently separated into a solid component comprising the bleaching earths and a liquid component comprising the digestate.

The bleaching earths are then subjected to heat treatment, at a temperature between 400 C. and 600 C.

Then follows a reactivation of the heat-treated bleaching earths with the aid of an acid solution and drying of the regenerated earths to render them usable in a plant for the production of biofuels.

Certain exemplary embodiments can provide a system, machine, device, manufacture, circuit, composition of matter, and/or user interface adapted for and/or resulting from, and/or a method and/or machine-readable medium comprising machine-implementable instructions for, activities that can comprise and/or relate to, reacting reactants comprising a ferric/ferrous chelate and a sour gas stream.

Both a system and a method for scrubbing a contaminated gas stream with a glycerol solution are disclosed. The system includes a contaminated gas stream in need of purification, along with a column which receives the contaminated gas stream. A glycerol solution is also received by the column and is used to scrub the contaminated gas stream in the column. The glycerol solution is used to reduce at least three contaminants from the gas stream, and includes greater than 50% glycerol and less than 98% glycerol. In one embodiment, the glycerol solution includes between 0.5% to 10% salts, wherein the salts are sodium based, potassium based or a combination thereof. The salts act catalytically to convert glycerol and carbon dioxide to glycerol carbonate.

Systems and methods for separating hydrogen sulfide from carbon dioxide in a high-pressure mixed stream are disclosed herein. The methods include receiving the high-pressure mixed stream in an oxidation reactor and at an inlet pressure of at least 0.3 megapascals. The high-pressure mixed stream includes 0.01 to 5 mole percent hydrogen sulfide and at least 90 mole percent carbon dioxide. The methods further include oxidizing the high-pressure mixed stream with an oxidant to generate a high-pressure oxidized stream, includes oxidized hydrogen sulfide and carbon dioxide, at an oxidation pressure of at least 0.3 megapascals. The methods also include separating the high-pressure oxidized stream into an oxidized hydrogen sulfide product and a carbon dioxide product and generating the carbon dioxide product at a pressure of at least 0.3 megapascals. The systems include the high-pressure mixed stream, an oxidation reactor, and a separation assembly.

A process for removing sulfur from a gas containing sulfur compounds as H2S, SO2, COS, CS2 . . . , in a quantity of up to 15% wt; particularly gases emanating from the Claus process: A first hydrogenation of the sulfur compounds into H2S, the hydrogenation gas being used to regenerate a deactivated bed of oxidation catalyst, both being carried out at 200-500 C. After sulfur removal, the resulting gas undergoes a second hydrogenation step and then a direct oxidation step, said step being operated under the dew point of sulfur to trap the formed sulfur in the catalyst. In the further cycle, the gas streams are switched so as to regenerate the catalyst in run which is deactivated.

The present application provides a hydrophilic and hydrophobic composite packing-based rotating packed bed and a system. A hydrophobic packing and a hydrophilic packing are formed into a composite packing. When said packing cuts liquid, the hydrophobic packing can sufficiently disperse the liquid so as to make the dispersion of the liquid in the packing zone more uniform, and the wettability of the hydrophilic packing allows the liquid to spread sufficiently so as to increase the wetting efficiency of said packing. The phenomenon of droplet aggregation caused to liquid in a single hydrophobic packing zone and the phenomenon of reduction of liquid turbulence caused to liquid in a single hydrophilic packing zone can be avoided. Therefore, applying a hydrophilic and hydrophobic composite packing to a rotating packed bed can further improve the mass transfer and mixing performance thereof.

Organic sulfur compounds contained in refinery off gas streams having either high ort low concentrations of olefins are converted to hydrogen sulfides which can be then be removed using conventional amine treating systems. The process uses a catalytic reactor with or without a hydrotreater depending on the olefin concentration of the off gas stream. The catalytic reactor operates in a hydrogenation mode or an oxidation mode to convert a majority of organic sulfur compounds into hydrogen sulfides.