Partial oxidation coal gasification

Steam reforming Steam reforming Partial oxidation Coal gasification Electrolysis... 

The numerous coal gasification systems available today can be reasonably classified as one of three basic types a) moving-bed, b) fluidized-bed, and c) entrained-bed. All three of these types utilize steam, and either air or oxygen to partially oxidize coal into a gas product. The moving-bed gasifiers produce a low temperature (425 to 650°C 800 to 1,200°F) gas containing... 

Methanol as Source ofSNG. Methanol can be produced from a large range of feedstocks by a variety of processes. Natural gas. liquefied petroleum gas (LPG), naphthas, residua] oils, asphalt, oil shale, and coal are in the forefront as feedstocks to produce methanol, with wood and waste products from farms and municipalities possible additional feedstock sources, hi order to synthesize methanol, the main feedstocks are converted to a mixture of hydrogen and carbon oxides (synthesis gas) by steam reforming, partial oxidation, or gasification. The hydrogen and carbon oxides are then converted to methanol over a catalyst. 

Natural Gas Steam Reforming Residuum Partial Oxidation Coal K-T Gasification New... 

Partial oxidation (or gasification) is the uncatalyzed reaction of liquid hydrocarbons or coal with steam and oxygen at high temperature and high pressure to produce hydrogen and carbon oxides. There are two commercial... 

Finally, the noncatalytic route of partial oxidation or gasification can also produce synthesis gas. This can be applied for feedstocks ranging from natural gas to coal. 

From heavy oil or coal by partial oxidation or gasification. 

In certain economic circumstances it may be of interest to produce ammonia from feedstocks such as fuel oil or coal (see Sect. 6.5.1 and [676-691]). The technology for the production of synthesis gas from such feedstocks is partial oxidation or gasification (see Sect. 6.3.2). Partial oxidation of natural gas was used in a few early plants [137, 138, 807], and it was suggested in a few modern process schemes, for example by Foster Wheeler [808,809], but it is of no importance today. 

Partial oxidation of heavy Hquid hydrocarbons requires somewhat simpler environmental controls. The principal source of particulates is carbon, or soot, formed by the high temperature of the oxidation step. The soot is scmbbed from the raw synthesis gas and either recycled back to the gasifier, or recovered as soHd peUetized fuel. Sulfur and condensate treatment is similar in principle to that required for coal gasification, although the amounts of potential poUutants generated are usually less. 

Capital costs which foUow the same trend as energy consumption, can be about 1.5 to 2.0 times for partial oxidation and coal gasification, respectively, that for natural gas reforming (41). A naphtha reforming plant would cost about 15—20% more than one based on natural gas because of the requirement for hydrotreatiag faciUties and a larger front-end needed for carbon dioxide removal. 

Partial oxidation as carried out in gasification produces carbon monoxide, hydrogen gas, carbon dioxide, and water vapor. The carbon dioxide reacts with hot carbon from the coal to produce carbon monoxide, and steam reacts with the carbon to produce carbon monoxide and hydrogen. The hydrogen can react with carbon through direct hydrogen gasification ... 

Conventional Transportation Fuels. Synthesis gas produced from coal gasification or from natural gas by partial oxidation or steam reforming can be converted into a variety of transportation fuels, such as gasoline, aviation turbine fuel (see Aviation and other gas turbine fuels), and diesel fuel. A widely known process used for this appHcation is the Eischer-Tropsch process which converts synthesis gas into largely aHphatic hydrocarbons over an iron or cobalt catalyst. The process was operated successfully in Germany during World War II and is being used commercially at the Sasol plants in South Africa. 

The synthesis gas for methanation, containing hydrogen and carbon oxides, is produced by gasification of coal by partial oxidation and/or by the reaction with steam. 

The Shell process uses partial oxygen gasification. Because insufficient oxygen exists for complete combustion (20-30% of the oxygen required for complete combustion is used), only a fraction of carbon in the coal is oxidized completely to C02. The heat released from this combustion provides most of the energy needed for endothermic coal gasification reactions and raises the gasifier temperature. Some steam is usually added to prevent excessive... 

Coal gasification is a process that converts coal from a solid to a gaseous fuel through partial oxidation. Once the fuel is in the gaseous state, undesirable substances, such as sulfur compounds and coal ash, may be removed from the gas. The net result is a clean, transportable gaseous energy source. 

The heat required for gasification is essentially supplied by the partial oxidation of the coal. Overall, the gasification reactions are exothermic, so waste heat boilers often are used at the gasifier effluent. The temperature, and therefore composition, of the product gas is dependent upon the amount of oxidant and steam, as well as the design of the reactor that each gasification process utilizes. 

Today, different processes (steam reforming, autothermal reforming, partial oxidation, gasification) are available and commercially mature for hydrogen production from natural gas or coal. These processes would have to be combined with technologies for C02 capture and storage (CCS), to keep the emissions profile low. A power plant that combines electricity and hydrogen production can be more efficient than retrofitted C02 separation systems for conventional power plants. 

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