An additive manufacturing apparatus including a chamber, a build platform movable in the chamber such that layers of flowable material can be successively formed across the build platform, a unit for generating an energy beam for solidifying the flowable material, a scanning unit for directing the energy beam onto selected areas of each layer to solidify the material in the selected areas and a getter for absorbing oxygen, nitrogen and/or hydrogen from atmosphere in the chamber.

Process for catalytic oxidative removal of at least one oxidisable gaseous compound from a gas mixture comprising the at least one oxidisable gaseous compound as well as oxygen through the use of an oxidation catalyst, whereby the gas mixture is not a combustion flue gas, characterised in that the oxidation catalyst was produced through the use of at least one exothermic-decomposing platinum precursor.

A system and method of pre-purification of a feed gas stream is provided that is particularly suitable for pre-purification of a feed air stream in cryogenic air separation unit. The disclosed pre-purification systems and methods are configured to remove substantially all of the hydrogen, carbon monoxide, water, and carbon dioxide impurities from a feed air stream and is particularly suitable for use in a high purity or ultra-high purity nitrogen plant. The pre-purification systems and methods preferably employ two or more separate layers of hopcalite catalyst with the successive layers of the hopcalite separated by a zeolite adsorbent layer that removes water and carbon dioxide produced in the hopcalite layers.

A system and method of pre-purification of a feed gas stream is provided that is particularly suitable for pre-purification of a feed air stream in cryogenic air separation unit. The disclosed pre-purification systems and methods are configured to remove substantially all of the hydrogen, carbon monoxide, water, and carbon dioxide impurities from a feed air stream and is particularly suitable for use in a high purity or ultra-high purity nitrogen plant. The pre-purification systems and methods preferably employ two or more separate layers of hopcalite catalyst with the successive layers of the hopcalite separated by a zeolite adsorbent layer that removes water and carbon dioxide produced in the hopcalite layers. Alternatively, the pre-purification systems and methods employ a hopcalite catalyst layer and a noble metal catalyst layer separated by a zeolite adsorbent layer that removes water and carbon dioxide produced in the hopcalite layer.

A system and method of pre-purification of a feed gas stream is provided that is particularly suitable for pre-purification of a feed air stream in cryogenic air separation unit. The disclosed pre-purification systems and methods are configured to remove substantially all of the hydrogen, carbon monoxide, water, and carbon dioxide impurities from a feed air stream and is particularly suitable for use in a high purity or ultra-high purity nitrogen plant. The pre-purification systems and methods preferably employ two or more separate layers of hopcalite catalyst with the successive layers of the hopcalite separated by a zeolite adsorbent layer that removes water and carbon dioxide produced in the hopcalite layers. Alternatively, the pre-purification systems and methods employ a hopcalite catalyst layer and a noble metal catalyst layer separated by a zeolite adsorbent layer that removes water and carbon dioxide produced in the hopcalite layer.

The present invention relates to the use of solid metal materials for catalyzing the hydration of carbon dioxide. It also relates to methods of and apparatus for hydrating carbon dioxide and capturing carbon. The solid metal materials may be nickel nanoparticles. The invention finds particular application in the sequestration of carbon dioxide either at the point of release or from the atmosphere.

A system and method of pre-purification of a feed gas stream is provided that is particularly suitable for pre-purification of a feed air stream in cryogenic air separation unit. The disclosed pre-purification systems and methods are configured to remove substantially all of the hydrogen, carbon monoxide, water, and carbon dioxide impurities from a feed air stream and is particularly suitable for use in a high purity or ultra-high purity nitrogen plant. The pre-purification systems and methods preferably employ two or more separate layers of hopcalite catalyst with the successive layers of the hopcalite separated by a zeolite adsorbent layer that removes water and carbon dioxide produced in the hopcalite layers.

Systems and methods of continuous operation of a urea-SCR system at low temperatures (200-350° C.) in the presence of high SOx containing flue gas are described. The methods comprise introducing a solution of urea and an NO.sub.2 forming compound, preferably an alkaline earth metal nitrate, into an exhaust stream before the exhaust stream contacts an SCR catalyst.

A sparging evaporator for an inerting system including an outer vessel, an inner vessel within the outer vessel, and a plenum formed between the inner and outer vessels. The outer vessel includes a gas inlet for receiving inlet gas into the plenum, and a liquid inlet for receiving liquid fuel into the plenum. The inlet gas in the plenum generates a gas pressure that is exerted against a free surface of the liquid fuel in the plenum thereby forcing the liquid fuel and the inlet gas through an inlet of the inner vessel. The inner vessel contains a lattice structure that promotes liberation of fuel vapor from the liquid fuel and enables the inlet gas in the liquid fuel to sparge the fuel vapor in the liquid fuel, thereby forming a fuel-enriched gas mixture that can be fed to a reactor of the inerting system.

A method and apparatus for cleaning and recycling stack gas from coal-fired power plants, from natural or propane burning heating plants, or from cement kilns by using renewable catalysts of zeolite to separate pollutants into recyclable and reusable materials. The method reduces from the stack gas carbon monoxide (CO), carbon dioxide (CO.sub.2), nitrogen oxide (NOx), sulfur oxide (SOx) as well as halogens such as chloride and fluorides and trace metals particularly, mercury, lead, and zinc. The method and apparatus also result in production of fertilizer products by purging with gaseous or liquid nitrogen the zeolite beds through which the stack gas flows. The oxygen generated may be recycled to the burners in the plant.