Hydrogen from steam-methane reformation

The production of hydrogen from steam methane reforming results from the following two reversible steps ... 

Average cost of hydrogen from steam methane reforming... 

Hydrogen from steam-methane reforming with CO2 capture. 20th Annual International Pittsburgh Coal Conference, Argonne National Laboratory, Pittsburgh,... 

Hydrogen and Carbon Dioxide Production from Steam-Methane Reformer Off Gas Production of Ammonia Synthesis Gas Hydrogen Recovery fiom Refinery Off Gases Methane-Carbon Dioxide Separation from Landfill Gas... 

Wang, Y.-N. and Rodrigues, A.E. Hydrogen production from steam methane reforming coupled with in situ C02 capture Conceptual parametric study. Fuel, 2005, 84 (14—15), 1778. 

Carbon dioxide-methane separation Solvent vapor recovery Hydrogen and carbon dioxide recovery from steam-methane reformer off-gas Hydrogen recovery from refinery off-gas Carbon monoxide-hydrogen separation Alcohol dehydration Production of ammonia synthesis gas Normal-isoparaffin separation Ozone enrichment... 

Hydrogen and carbon dioxide recovery from steam-methane reformer ofF-gas, coke oven gas, ethylene ofF-gas, coal gasiheation, etc. PSA [16. 17]... 

Synthesis gas produced from steam methane reforming has a H2/CO ratio of approximately 6 1, much higher than required for most applications. Table 2 [4] shows the H2/CO ratios required for major syngas-derived petrochemicals. From Table 2, the required H2/CO ratio is typically between 0 and 2. To produce lower H2/CO ratios, hydrogen can either be separated from the syngas product or CO2 can be recycled to the reformer. 

Ye, G., Xie, D., Qiao, W., Grace, J. R., Lim, C. J. (2009). Modeling of fluidized bed membrane reactors for hydrogen production from steam methane reforming with Aspen Plus. International Journal of Hydrogen Energy, 34, 4755—4762. 

Figure 3.3 Schematic representation of hydrogen permeation through dense proton-conducting membrane obtained from steam methane reforming (Kniep et al., 2011).

Hydrogen Liquefaction. Hydrogen can be produced from caustic—chlorine electrolytic cells, by decomposition of ammonia or methanol, or by steam—methane reforming. Hydrogen recovered by these methods must be further purified prior to Hquefaction. This is generally achieved by utilizing pressure swing adsorption methods whereby impurities are adsorbed on a soHd adsorbent. 

The analysis showed, with various "value adders" (e.g., oxygen sales and carbon-emission-offset credits), the cost of wind-source gaseous hydrogen delivered by pipelines from production point to distant markets (about 200-1000 mi.) at an untaxed wholesale energy unit cost will be competitive with market prices (in 2005) of gasoline and hydrogen fuel made from natural gas by steam methane reforms (SMRs). 

The (additional) costs of C02 capture in connection with hydrogen production from natural gas or coal are mainly the costs for C02 drying and compression, as the hydrogen production process necessitates a separation of C02 and hydrogen anyway (even if the C02 is not captured). Total investments increase by about 5%-10% for coal gasification plants and 20%-35% for large steam-methane reformers (see also Chapter 10). 

For the first decades, all roadmaps show a focus on fossil-based hydrogen production options, mainly onsite and decentral steam methane reformers (SMR), electro-lysers and hydrogen as a by-product from the chemical industry. In some regions, hydrogen is also produced to a certain extend by nuclear, electrolysis, biomass and waste gasification. Later on, with a significant increase of hydrogen, the production... 

Steam methane reforming (SMR) is the most widely practiced commercial process for the production of syngas and hydrogen almost 50% of the world s hydrogen production comes from natural gas. Two equilibrium reactions, steam reforming and the water-gas shift (WGS) reaction, are at the heart of the hydrogen production process ... 

Methane is an important starting material for numerous other chemicals. The most important of these are ammonia, methanol, acetylene, synthesis gas, formaldehyde, chlorinated methanes, and chlorofluorocarbons. Methane is used in the petrochemical industry to produce synthesis gas or syn gas, which is then used as a feedstock in other reactions. Synthesis gas is a mixture of hydrogen and carbon monoxide. It is produced through steam-methane reforming by reacting methane with steam at approximately 900°C in the presence of a metal catalyst CH4 + H20 —> CO + 3H2. Alternately, methane is partially oxidized and the energy from its partial combustion is used to produce syn gas ... 

---