1782 results about "Carbonation" patented technology

Hydrogen is produced from solid or liquid carbon-containing fuels in a two-step process. The fuel is gasified with hydrogen in a hydrogenation reaction to produce a methane-rich gaseous reaction product, which is then reacted with water and calcium oxide in a hydrogen production and carbonation reaction to produce hydrogen and calcium carbonate. The calcium carbonate may be continuously removed from the hydrogen production and carbonation reaction zone and calcined to regenerate calcium oxide, which may be reintroduced into the hydrogen production and carbonation reaction zone. Hydrogen produced in the hydrogen production and carbonation reaction is more than sufficient both to provide the energy necessary for the calcination reaction and also to sustain the hydrogenation of the coal in the gasification reaction. The excess hydrogen is available for energy production or other purposes. Substantially all of the carbon introduced as fuel ultimately emerges from the invention process in a stream of substantially pure carbon dioxide. The water necessary for the hydrogen production and carbonation reaction may be introduced into both the gasification and hydrogen production and carbonation reactions, and allocated so as transfer the exothermic heat of reaction of the gasification reaction to the endothermic hydrogen production and carbonation reaction.

The invention relates to a method to withdraw silicon and aluminum in sequence from coal ash; a NaOH solution with a mass concentration larger than 40 percent is used for leaching the coal ash, the silicon of the coal ash is dissolved in the form of sodium silicate, and after being separated, sodium silicate solutions and alkaline leaching residues with a ratio between aluminum and silicone more than or equal to 2 are produced; the dissolved sodium silicate solution is condensed into sodium silicate solutions of different concentrations, or used for preparing white carbon through a carbonation method; the alkaline residues are used for producing Al(OH)3 through a sodalime sintering method or limestone sintering method and further producing Al2O3, and the residues after the aluminum being extracted are made into stuff or used for producing concrete. The invention breakthroughs the original idea of directly extracting Al2O3 from the coal ash, and adopts the wholly novel technical route of extracting silicon first and aluminum secondly, thereby enhancing the aluminum silicon ratio of the alkali leached residues, simplifying the technique of extracting Al2O3, and increasing the extracting rate of aluminum from the coal ash.