Oil & Natural Gas Projects
Exploration and Production Technologies
Catalytic Methane Decomposition for CO2-Free Hydrogen Production
This project was funded through DOE's Natural Gas and Oil Technology Partnership
Program. The program establishes alliances that combine the resources and experience
of the Nation's petroleum industry with the capabilities of the national laboratories
to expedite RD&D of advanced technologies for improved natural gas and oil
production and processing.
The goal is to develop a catalyst for methane (CH4) decomposition for the high-yield
production of hydrogen (H2) and solid carbon without the production of the greenhouse
gas carbon dioxide (CO2).
Idaho National Laboratory (INL)
Idaho Falls, ID
Salt Lake City, UT
Methane decomposition for the production of H2 and solid carbon is being accomplished
by experimental system modifications and approvals to allow for overnight catalyst
testing, catalyst optimization for the purpose of increasing hydrogen yields,
extended catalyst testing for up to one full week of continuous hydrogen production
using promising catalysts developed in this study, energy and mass balance calculations
using a process simulation code such as ASPEN Plus to estimate energy conversion
efficiencies and compare those with steam reforming, and technology transfer
To realize a greenhouse gas-free hydrogen economy, CO2 must be sequestered or
not produced. This catalytic route offers a promising path for economical, environmentally
sound production of hydrogen without production of CO2.
Through DOE's Downstream Environmental program funding of the project Proton
Exchange Reactive Membranes for Conversion of Light Alkanes to Clean Liquid
Fuels, INL developed a stable and efficient catalyst for converting CH4 to H2
without the generation of CO2. This catalytic process could provide a significant
advance in the development of the hydrogen economy utilizing natural gas CH4
without the production of greenhouse gases.
This research explores direct catalytic decomposition of CH4 to make H2 and
solid carbon. Solid carbon particles that are produced flow out of the catalyst
bed and are collected in downstream filter equipment. The catalyst was produced
using a mix of proprietary metal salts that were deposited within a common high-surface
area with microporous support.
Without optimization of the catalyst, reactor, or process conditions, CH4 conversions
over 50% were obtained with a corresponding high H2 yield. Higher conversions
are expected with system optimization. The catalyst was found to have stable
activity in tests as long as 30 hours in a continuous-flow, packed-bed experimental
test stand. Tests were performed at atmospheric pressure, at temperatures of
500-700 C., and at industrially relevant space velocities of up to 2.5 grams
(g) of CH4 per g of catalyst per hour. Catalysts for this process are comparable
to standard industrial catalyst costs. In the absence of the catalyst, the reaction
does not take place. Reactor and associated unit operation capital costs are
expected to be low, since the reactor and separations are simple and do not
require development of new technologies.
The project tasks are planned to accomplish the following:
- Experimental system modifications and approvals to allow for long-term catalyst
- Catalyst optimization for the purpose of increasing H2 yields.
- Extended catalyst testing for continuous H2 production using promising catalysts
developed during previous studies.
- Energy and mass balance calculations using a process simulation code such
as ASPEN Plus to estimate energy conversion efficiencies and compare those
with steam methane reforming.
- Technology protection, communication, and transfer for the purpose of transferring
the technology to industry.
An initial ASPEN numerical model of the reaction process has been set up. Thermodynamic
analysis shows that this reaction requires less energy per mole of H2 than traditional
steam methane reforming commonly used to make H2. The reaction is equilibrium-limited,
with maximum H2 concentrations constrained to 75 mol % at 600° C., increasing
to 96 mol % at 800° C. Experimental work has focused on a metal modified
zeolite catalyst. To date, the catalyst has demonstrated 70 mol % hydrogen in
the reactor effluent at 700° C. and stable catalyst activity for 30 hours-the
entire test duration.
Hydrogen yield as a function of time on stream (TOS) was explored at different
reaction temperatures. At 600-700° C. the production of H2 was relatively
stable, but at 800° C., a marked decrease was apparent. In addition to H2,
other reaction products included benzene and higher aromatics. For the TOS utilized,
the catalyst retained a high portion of its initial surface area and micropore
volume. Transmission electron microscopy analyses showed a homogenous covering
of the zeolite surface with carbonaceous deposits.
Catalyst samples were regenerated in flowing air at 600° C. After regenerating
the catalyst, activity was recovered; however, some loss was apparent on the
catalyst utilized at the highest reaction temperature. This loss of activity
after regeneration is ascribed to carbonaceous deposits that remained on the
catalyst surface after regeneration and was confirmed by temperature programmed
oxidation studies. The carbonaceous species deposited on the catalyst surface
were more condensed as the reaction temperature increased. The carbonaceous
deposits on the catalyst sample utilized to produce H2 at 600° C. had desorbed
completely under oxidation at 600° C.
As part of the project, additional research is needed in catalyst optimization,
process optimization, reactor development, and carbon analysis. In addition,
market analysis for the high-quality carbon product and economic analysis of
the processes must be performed.
Current Status (October 2005)
Additional funding for this project was received in August 2004. This project
will explore the catalyst discovered in the Proton Exchange Reactive Membranes
project for the production of hydrogen and solid carbon by the decomposition
of methane. The Cooperative Research and Development Agreement with Ceramatec
Inc. is being modified to cover this new scope of work under this project.
Publications are being prepared and will be submitted for peer review after
protection of the technology is assured by patent coverage.
Project Start: August 10, 2004
Project End: August 9, 2005
Anticipated DOE Contribution: $125,000
Performer Contribution: $32,000 (20.4% of total)
NETL - Kathleen Q. Stirling (Kathy.Stirling@netl.doe.gov or 918-699-2008)
INL - Daniel M. Ginosar (Daniel.Ginosar@inl.gov or 208-526-9049)
Catalyst test system for decomposition of CH4 to H2 without producing CO2.
Reactor effluent concentrations at 700° C.