The Hydrogen Economy Opportunities, Costs, Barriers, and R&D Needs (2004) / Chapter Skim
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8. Hydrogen Production Technologies
8. Hydrogen Production Technologies
Pages 91-105
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From page 91... ...
and priorities in the use of natural gas for a hydrogen economy would only incontext of hydrogen production and the possible future "hy- crease imports further, and as a result the committee considdrogen economy." The committee understands that the DOE ers natural gas to be a transitional fuel for distributed generaprograms outside the Office of Hydrogen, Fuel Cells, and tion units, not a long-range fuel for centralized plants for the Infrastructure Technologies have other objectives and pri- hydrogen economy. orities besides those related to hydrogen, and the committee The primary ways in which natural gas, mostly methane, did not review those other programs vis-à-vis that of produc- is converted to hydrogen involve reaction with either steam ing hydrogen.
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From page 92... ...
It would also include development tion, and companies have already provided one-of-a-kind of a system design for a typical fueling facility, including the units in the size range of interest.1 Whether it will be pos- generation appliance, compression, high-pressure storage insible to utilize partial oxidation or autothermal reforming for corporating the latest storage technology, and dispensers. the distributed generation of hydrogen appears to depend on With today's technology, the ancillary systems cost about 30 developing new ways of recovering oxygen from air or sepa- percent as much as the reformer.
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From page 93... ...
The gas can be cleaned in con ventional ways to recover hydrogen and a high-concentration Department of Energy give appropriate attention in its program to the development of an integrated fueling facility, CO2 stream that is easily isolated and sent for disposal. Syngas produced from current gasification plants can be used in a including the generation appliance and its ancillary sub variety of applications, often with multiple applications from systems, to minimize cost and to improve efficiency, safety, a single facility.
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From page 94... ...
· Advanced water-gas-shift reactors using sulfur-tolerant Recommendation 8-4. Because there are a number of simicatalysts, larities between the integrated gasification combined cycle · Novel membranes for hydrogen separation from car process and the coal-to-hydrogen process, the committee bon dioxide, endorses the continuation of both programs in tandem at · Technology concepts that combine hydrogen separa budget levels that are determined to be adequate to meet the tion and water-gas shift, and programs goals.
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From page 95... ...
pointed out that the use of nuclear reactors to supply The United States derived about 20 percent of its electric the heat needed in the steam methane reforming (SMR) proity from nuclear energy in 2002 (EIA, Electric Power cess is potentially more economic than their use for water Monthly, 2003)
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From page 96... ...
Among these is the gen production include the following: 1. The efficiency of thermochemical schemes to accom 4Charles Forsberg, Oak Ridge National Laboratory, "Production of Hydrogen Using Nuclear Energy," presentation to the committee, January 22, plish water splitting without any CO2 emissions should be 2003.
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From page 97... ...
The examination of rily to meet industrial chemical needs. While more expensive several options for promising cycles, including the process than steam reforming of natural gas, electrolysis may play kinetics, the ability of materials to withstand the aggressive an important role in the transition to a hydrogen economy chemistry and temperatures, the separation of fluids, and because small facilities can be built at existing service staoverall efficiency of the systems requires a higher level of tions.
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From page 98... ...
. In both technologies, water is to-hydrogen research.5,6 introduced into the reaction environment and subjected to an The committee finds it plausible that PEM electrolyzer electrical current that causes dissociation, after which the capital costs can fall by a factor of eight -- from $1000/kW in resulting hydrogen and oxygen atoms are put through an the near term to $125/kW over the next 15 to 20 years, conionic transfer mechanism that causes the hydrogen and oxy- tingent on similar cost reductions occurring in PEM fuel gen to accumulate in separate physical streams.
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From page 99... ...
It reduces the cost of producing the HYDROGEN PRODUCED FROM WIND ENERGY hydrogen, which without grid backup would be $10.69/kg The production of hydrogen from renewable energy H2, but it also incurs CO2 emissions from what would othersources is often stated as the long-term goal of a mature wise be an emission-free hydrogen production system. hydrogen-based economy (Turner, 1999)
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From page 100... ...
It fulfills the two main motivations that are Demonstration Plan propelling the current push toward a hydrogen economy, namely, reducing CO2 emissions and reducing the need for There is little mention of hydrogen production from wind hydrocarbon imports. In addition, it is the most affordable throughout the entire June 2003 draft entitled "Hydrogen, renewable technology deployed today, with expectations that Fuel Cells and Infrastructure Technologies Program: Multicosts will continue to decline.
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From page 101... ...
and are limited to midsize-scale operations,10 due to the het erogeneity of biomass, the localized production of biomass, and the relatively high costs of gathering and transporting Biomass Costs and Availability biomass feedstock. Therefore, in addition to the relatively Hydrogen production from biomass is a thermodynami- high feedstock costs, dedicated biomass gasification plants cally inefficient and expensive process, in which approxi- are associated with capital costs that, in the current technolmately 0.2 percent to 0.4 percent of the total solar energy is ogy case, the committee estimates to be $2.44/kg H2, comconverted to hydrogen at a price of currently about $7.05/ pared with about $0.46/kg H2 for large, central station coal kg H2 by gasification in a midsize plant (see Figure 5-2 in gasification (see Figure 5-2)
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From page 102... ...
Thus, cheaper, though less ing systems."13 The technical targets that the DOE has set plentiful, biomass residue could supplant bioenergy crops as for biomass gasification and biomass pyrolysis are ambifeedstock. Using residue biomass would also have a much tious; they include cost reduction from $3.60 to $2.00/kg H2 less significant impact on the environment than would farm- by 2015 for gasification and from $3.80 to $2.40/kg H2 by ing of bioenergy crops.
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From page 103... ...
hydrogen conversion, the high costs of bioenergy crop pro- The committee estimated the cost to produce hydrogen usduction and biomass gasification, and the significant demand ing electricity from solar PV devices to power electrolyzers. for and impact on land use and natural resources for bio- In the current technology case, with a favorable installed cost energy crop farming; and of about $3.28/Wp, the electricity cost is estimated to be about · The engineering of (micro)
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From page 104... ...
The potential research opportunities listed in the preceding subsection for PV solar cells along with elec trolyzers must be actively explored. Challenges and Research and Development Needs Large-scale use of solar energy for a hydrogen economy will Summary require research and development efforts on multiple fronts: All of the current methods and the projected technologies · In the short term, there is a need to reduce the cost of for producing hydrogen from solar energy are much more thin-film solar cells.
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From page 105... ...
. Such low capital costs electrochemical as well as other methods that directly confor electrolyzer units, together with levelized electricity costs vert solar energy to hydrogen should be actively pursued, in the neighborhood of $0.02 to $0.03/kWh, would result in the route of solar electricity generation coupled with use of a competitive hydrogen cost.
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