Hydrogen by partial oxidation

Table 10.14 provides some essential information concerning the production of hydrogen by partial oxidation of a VR. By-products are carbon dioxide and hydrogen sulfide. 

Hydrogen by partial oxidation of residual oil is the second most economical process. It shows the lowest sensitivity to raw material cost. 

Velu, S., Suzuki, K., and Osaki, T. Selective production of hydrogen by partial oxidation of methanol over catalysts derived from CuZnAl-layered double hydroxides. Catalysis Letters, 1999, 62 (2), 159. 

Agrell, J., Germani, G., Jaras, S.G., and Boutonnet, M. Production of hydrogen by partial oxidation of methanol over ZnO-supported palladium catalysts prepared by microemulsion technique. Applied Catalysis. A, General, 2003, 242 (2), 233. 

Generally, a pre-reforming ofthe fuel is carried out, whereby part of hydrocarbon is reformed in an external reactor and the remainder is internally reformed. Methane and other hydrocarbons can also be converted to hydrogen by partial oxidation (POX) this is an exothermic process which is often combined with endothermic steam reforming, and leads to an autothermic conversion of methane. 

COMBINED PLASMA-CATALYTIC PRODUCTION OF HYDROGEN BY PARTIAL OXIDATION OF HYDROCARBON FUELS... 

As in the case of coal, synthetic natural gas can be produced from heavy oil by partially oxidizing the oil to a mixture of carbon monoxide and hydrogen... 

Synthesis Gas Chemicals. Hydrocarbons are used to generate synthesis gas, a mixture of carbon monoxide and hydrogen, for conversion to other chemicals. The primary chemical made from synthesis gas is methanol, though acetic acid and acetic anhydride are also made by this route. Carbon monoxide (qv) is produced by partial oxidation of hydrocarbons or by the catalytic steam reforming of natural gas. About 96% of synthesis gas is made by steam reforming, followed by the water gas shift reaction to give the desired H2 /CO ratio. 

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. 

Several important chemical reactions for the conversion of coal to methane are shown in Table 2. Steam conversion involves the reaction of coal with steam to produce hydrogen and carbon monoxide. Hydrogen conversion is a reaction in which coal and hydrogen react to form methane. Oxygen conversion produces hydrogen and carbon monoxide by partial oxidation of coal. Methan-ation involves a reaction in which methane and water are produced from carbon monoxide and hydrogen. The water gas shift reaction between carbon monoxide and steam produces carbon dioxide and hydrogen. 

Fluidised catalysts are also used in the synthesis of high-grade fuels from mixtures of carbon monoxide and hydrogen, obtained either by coal carbonisation or by partial oxidation of methane. An important application in the chemical industry is the oxidation of naphthalene to phthalic anhydride, as discussed by Riley(131). The kinetics of this reaction are much slower than those of catalytic cracking, and considerable difficulties have been experienced in correctly designing the system. 

Hydrogen production by partial oxidation is similar to production by catalytic steam reforming. The process basically involves the conversion of steam, oxygen and hydrocarbons to hydrogen and carbon oxides. The process proceeds at moderately high pressures with or without a catalyst depending on the feedstock and process selected. The catalytic POX, which occurs at about 865 K, will work with feedstock ranging from methane to naphtha. The non-catalytic POX, which occurs... 

Hydrogen as the most efficient and cleanest energy source for fuel-cell power is produced by partial oxidation followed by the water gas-shift reaction and reforming of hydrocarbons or methanol [58]. A small amount of CO (0.3-1%) in the so-produced H2 must be selectively removed because CO greatly poisons Pt/C and Pt-M/C electrocatalysts in proton-exchange-membrane (PEM) fuel cells [59, 60]. PROX of CO in excess H2 is a key reaction in the practical use of H2 in PEM fuel-cell systems. 

Hydrogen production by partial oxidation of SRC-II oil versus steam reforming of refinery gases and naphtha. 

Sulfur Plant Acid gas (hydrogen sulfide and carbon dioxide) is fed to a sulfur plant, where the hydrogen sulfide is converted to elemental sulfur by partial oxidation with air. 

Fii>. 1.6. Hydrogen maniirndure by partial oxidation. Texaco procc.ss. 

---