Hydrogen-rich reformate gas

Abstract In this paper, we discuss the results of a preliminary systematic process simulation study the effect of operating parameters on the product distribution and conversion efficiency of hydrocarbon fuels in a reforming reactor. The ASPEN One HYSYS-2004 simulation software has been utilized for the simulations and calculations of the fuel-processing reactions. It is desired to produce hydrogen rich reformed gas with as low as possible carbon monoxide (CO) formation, which requires different combinations of reformer, steam to carbon and oxygen to carbon ratios. Fuel properties only slightly affect the general trends. 

Figure 5. Block scheme of a FC generator set c, commercial fuel in r, reformer Hj, hydrogen rich reforming gas HjjO, water vapour p, fuel-cell stack cc, direct current output i, invertor ca, alternating ciurent output cp, process heat cr, recoverable heat.

The proton exchange membrane fuel cell (PEMFC) has been extensively studied in the last two decades for many applications and especially for low emissions vehicles.Pure hydrogen is the ideal fuel for the PEMFC. However, it cannot be stored practically in sufficient quantities on-board a vehicle and, therefore, there is a need for an adequate supply infrastructure. On-board H2 production from liquid fuel such as methanol is considered as a promising method for fuel cell vehicle application. Hydrogen-rich reformed gas presents 1-2% of CO. Unfortunately, this CO concentration cannot be tolerated by the PEMFC electrodes at low operating temperature. In order to avoid... 

In contrast to pure hydrogen, hydrocarbons are converted in a reforming process, generating a hydrogen-rich reformate gas that can be fed to the fuel cell. Steam reforming, in principle, is an endothermic process that requires an external heat supply. Compared to autothermal reforming, the reformate gas is not diluted with nitrogen. 

Coal gasification technology dates to the early nineteenth century but has been largely replaced by natural gas and oil. A more hydrogen-rich synthesis gas is produced at a lower capital investment. Steam reforming of natural gas is appHed widely on an iadustrial scale (9,10) and ia particular for the production of hydrogen (qv). 

This excess hydrogen is normally carried forward to be compressed into the synthesis loop, from which it is ultimately purged as fuel. Addition of by-product CO2 where available may be advantageous in that it serves to adjust the reformed gas to a more stoichiometric composition gas for methanol production, which results in a decrease in natural gas consumption (8). Carbon-rich off-gases from other sources, such as acetylene units, can also be used to provide supplemental synthesis gas. Alternatively, the hydrogen-rich purge gas can be an attractive feedstock for ammonia production (9). 

Solasys - an R D project to (1) Demonstrate the process of steam reforming of methane with the aid of solar energy to produce hydrogen-rich synthesis gas as a gas turbine fuel. (2) Explore the possibility of solar reformer interface with fuel cells. 

Hydrogen separation from primary gas mixture Reforming gas Blast-furnace gas Hj, CO, CO2, CHj, HjO 200.000Nm /h Hydrogen rich product gas (Syngas Hi, CO)... 

Based on these developments, the foreseeable future sources of ammonia synthesis gas are expected to be mainly from steam reforming of natural gas, supplemented by associated gas from oil production, and hydrogen rich off-gases (especially from methanol plants). 

The catalyst is then transferred back to the first process reactor and is reheated to the reforming process temperature at the reactor inlet using a flow of hydrogen-rich process recycle gas, thereby achieving reduction of the platinum to a catalyticaUy active state. 

As a constituent of synthesis gas, hydrogen is a precursor for ammonia, methanol, Oxo alcohols, and hydrocarbons from Fischer Tropsch processes. The direct use of hydrogen as a clean fuel for automobiles and buses is currently being evaluated compared to fuel cell vehicles that use hydrocarbon fuels which are converted through on-board reformers to a hydrogen-rich gas. Direct use of H2 provides greater efficiency and environmental benefits. ... 

Several types of nonthermal plasma systems have been reported in the literature for reforming of hydrocarbons to hydrogen-rich gas ... 

The authors concluded that for the production of hydrogen-rich gas, diesel fuel could be reformed by exhaust gas at temperatures typical of exhaust gas temperatures (from 200 to 700°C). 

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