Wednesday, May 15, 2019
Steam Reforming and the Production of Hydrogen Gas Essay
Steam Reforming and the return of Hydrogen gasoline - Essay ExampleAbout 50% of the global production of Hydrogen is produced by this butt(www.getenergysmart.org/Files).eg. activated carbon filters, pressurisation and depending on the reformer design, either pre heated and mixed with processed go or directly injected with the water into the reformer without the need for an external heat exchanger. The water is normally demineralised using grant water conditioning systems. Two options are available for reforming one option is high pressure reforming at a working pressure upto 16 bar. The other option is to use low pressures (1.5 bar) with increased transformation ratios (www.global-hydrogn-beus-platform.com).2.2 Steam Methane Reforming The process involves the use of high temperature steam (700C) which is reacted with natural squander( primarily methane) to produce Hydrogen. Methane reacts with steam downstairs 3- 25 bar pressure in the presence of a particle accelerator to p roduce Hydrogen, Carbon Monoxide and a relatively small amount of Carbon Dioxide. This process is endothermic and hence heat must be supplied to the process to proceed. (www1.eere.energy.gov)The methane steam reforming reaction is endothermic. Hence this reaction requires a high process temperature to proceed. As the itemize of moles also changes for the reaction, the reaction is facilitated by as low a pressure as possible to exploit the Methane conversion rate. Another way to shift the equilibrium to the right side is to increase the ratio of steam to methane. Overall, the conversion rate of methane is a function of pressure, temperature and steam/ Methane ratio. The reformer reactor consists of catalyst filled tubes touch by a fire box that provides the heat for the reaction as shown in the process be given diagram ( Fig.3)Water Gas shift ReactionCO + H2O CO2 + H2 (H = - 41.2kJ/mol) (2)The water gas shift reaction is exothermic and needs as low a temperature as possible to p roceed. found on Le Chateliers principle, the WGS reaction rate(1) Increases with increase in steam fraction in the adit gas(2) Decreases with increase in Hydrogen in the inlet gas(3) Decreases with increase in temperature The reactor temperature influences the flame temperature of the reactants. Hence at higher temperature more Methane is converted and less Hydrogen.The presence of a catalyst such as Nickel helps in the formation of Hydrogen rich reformate. The heat required for the offset reaction is obtained by the combustion of fuel gas and/ or purge tail gas from the prostate specific antigen system. Following the reforming step, the synthesis gas is fed into the CO conversion reactor to produce additional Hydrogen. This process occurs in two stages consisting of a High Temperature trade ( HTS ) reactor at 350C and a Low Temperature Shift ( LTS ) at 190 to 210C.High temperature shift catalysts have an Iron Oxide-Chromium Oxide basis while LTS catalysts consist of Copper Oxi de.3.0 Gas Purification Hydrogen purification by means of pressure swing adsorption (PSA). The PSA units clutches hydrogen
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