1. Objective of R&D
International Clean Energy Network Using Hydrogen Conversion (WE-NET)
aims at contribution to solving global environmental problems by means
of large-scale and effective utilization of clean and renewable energies
such as hydraulic, solar, and wind which are available widely on the
earth. Its purpose is also to establish technologies capable of introducing
an international energy network utilized in wide fields such as hydrogen
production from these energies, conversion of hydrogen as necessary,
transportation, storage, generation of power, fuel for transportation,
and town gas, in order to satisfy energy demands, and to develop core
elementary technology as well as preparation conceptual design of the
total system.
Phase I of WE-NET scheduled for six years from FY 1993 aims at establishment
of basic technologies for hydrogen production, hydrogen transportation
and storage, and utilization of hydrogen, by means of necessary investigation,
basic researches, and studies for elementary technologies, in order
to obtain information necessary for the optimum design of the total
system and establish technologies necessary for the design and construction
of a pilot plant.
Phase II of WE-NET scheduled for five years from FY 1999 aims at establishment
of basic technologies for hydrogen production, hydrogen transportation and storage,
and utilization of hydrogen, by means of necessary investigation, basic researches,
and studies for elementary technologies, in order to obtain information necessary
for the optimum design of the total system and establish technologies necessary
for the design and construction of a pilot plant.
In addition, studies for technologies adaptable to the project in future
are intended to be carried out in parallel with the above to be properly
reflected on every research and development items.
The results obtained in R&D of Phase I will be reflected on realization
of the plans of Phase II. Fig. 1 shows the schematic illustration of
WE-NET.
2. Items and targets of R&D
R&D for Phase IIhas been carried out in the following 12 tasks.
2.1 Task 1 Study of System Evaluation
The aim of surveys and studies is to study an optimal scenario for introduction
of hydrogen energy and formulate a strategy for its introduction. Also
a research coordination council will be organized and held to coordinate
research activities under the WE-NET Project.
2.2 Task 2 Study of Safety Measures
We will conduct experiments ( liquid hydrogen spillage and evaporaion experiment
and hydrogen explosion experimentand ) By these studies, we will establish
the method to evaluate the effect of the postulated accident with high
accuracy. And we will further survey safety related information and
will study to make the safety design standard.
2.3 Task 3 Review and Investigation for International Cooperation
We will carry out activities to develop international understanding of the
WE-NET and promote exchange of technical information in order to develop
the WE-NET project.
2.4 Task 4 Development of Power Generation Technology
We will develop of a single-cylinder hydrogen combustion diesel engine rated
100kW for co-generation system. This engine having about 45% efficiency
at terminal and more than 85% total efficiency(higher heating value
basis) shall be free of any emission of environmental pollution.
2.5 Task 5 Development of Hydrogen Vehicule Systems
We will develop of elemental technology for fuel system of fuel cell powered
vehicle which being expected a hydrogen supply from a hydrogen refueling
station. And we will do the technical execution of running system of
hydrogen vehicle which being combined with a hydrogen refueling system
and the estimation of energy efficiency of the whole system.
2.6 Task 6 Development of PEFC Utilizing Pure Hydrogen
We will develop of element technology for the fuel cell power generation system
which meets the utilization of pure hydrogen and achieves about 45%
electrical efficiency at the AC sending terminal (higher heating value
basis), shall be established and a stationary type 30kW class generation
system shall be demonstrated.
2.7 Task 7 Development of Hydrogen Refueling Stations
We will develop demonstration system which has hydrogen refueling capacity
of 30 Nm3/h corresponding to 1/10 of practical scale and verify the
system performance through technical demonstration combined with hydrogen
vehicle system for the purpose of establishment of essential and systematizing
technology for hydrogen refueling station.
2.8 Task 8 Development of Hydrogen Production Technology
We will develop large-scale cell lamination (electrode area 2,500 cm2) by using
two hydrogen production methods (electroless plating method and hot
press method). The target of current density is over 1A/cm2 and the
target of energy efficiency is over 90%. And we will develop the cells
(electrode area 1,000 cm2) for hydrogen stations. Moreover, we will
develop solid high polymer electrolytes resistant to high temperatures.
2.9 Task 9 Development of Hydrogen Transportation and Storage Technology
We are going to conduct elemental tests of insulation structure and to establish
the data base of thermal insulation performance. And we will develop
element technologies of liquid hydrogen pump. Moreover, we will collect
basic data of aerodynamic design and seal design for hydrogen compressor.
2.10 Task 10 Development of Cryogenic Materials Technology
The goals are to test material properties under liquid hydrogen environments
and to develop elemental technology related to optimized welding material
and welding method. Moreover, the material characteristic database will
be enhanced.
2.11 Task 11 Development of Hydrogen Absorbing Alloys for Small
Scale Transportation and Storage System
The target is to develop hydrogen absorbing alloys having the following performance.
- Effective hydrogen storage capacity : more than 3wt%
- Temperature for hydrogen desorption : less than 100℃
- Duarability : hydrogen storage capacity more than 90% of the initial
capacity after 5,000-cycle use
2.12 Task 12 Investigation and Study of Innovation & Leading
Technology
It is aimed at giving valuable suggestions and proposals to the direction
of the WE-NET project and contributing to the research and development
through feasibility study, as well as further research if necessary,
of such innovative, leading and conventional technologies.
3. Summary of FY 1999 Results
3.1 Task 1 Study of System Evaluation
We assessed the capacity and economical efficiency of systems for supplying
soda-electrolysis by-product hydrogen and coke-oven by-product hydrogen
that are considered promising sources of hydrogen supply from short-
and medium-range points of view. And we assessed the economical efficiency
of a stand-alone wind power and fuel cell combined power generation
system that replaces diesel power generation by wind power generation
and stores part of electric energy produced by the wind power unit
in the form of hydrogen through water electrolysis and uses it as
fuel for power generation by the fuel cell unit whenever wind conditions
are unfavorable.
3.2 Task 2 Study of Safety Measures
In order to analyze the cause of accident, we investigated the conceptual
design of hydrogen supply station that is being studied at task 7
in WE-NET project as a model case. We sorted out the relation between
the latent incidents for the accident initiation and the measures
corresponding to them and studied items that are needed to consider
for safety design. Then we investigated available databases that show
various safety-related information in order to execute quantitative
risk assessment.
3.3 Task 3 Review and Investigation for International Cooperation
To develop understanding of the WE-NET project, we gave presentations
of the WE-NET activities at the international conferences. And we
carried out research cooperation in the International Energy Agency
(IEA) As measures to promote information exchange, we carried out
Overseas Survey, Survey on Hydrogen Project in EC, Update of WE-NET
Web Site, Video Production on Hydrogen Safety. And because of the
rsearch of standardization of hydrogen energy technologies, guidelines
about legislation and rules in Japan were compiled based on referring
to the "Sourcebook for Hydrogen Applications" which was prepared in
the United States and Canada. And we coped with activity of ISO/TC197.
3.4 Task 4 Development of Power Generation Technology
As development of element technologies,we developed injection valve,exhaust
gas condenser and Gas-Liquid separator,turbocharger and expansion
turbine. As development of element test,we analyzed self ignition
combustion test,combustion control test by laser ignition,lubrication
test of piston ring and cylinder liner,simulation of the cylinder
inside phenomena of the hydrogen diesel engine.As development of single-cylinder
test machine, we examined basic plan of fuel and working gas supply
facilities,gas circulating line,layout plan of building for laboratory
and equipments,design and investigation of single-cylinder test engine.
3.5 Task 5 Development of Hydrogen Vehicule Systems
We analyzed safety of hydrogen absorbing alloys.Mini-scale tanks
filled with hydrogen and hydrogen absorbing alloys were prepared and
they were subjected to impact rupture test in order to evaluate behaviors
of hydrogen and the alloys released into the air as a result of rupture
of hydrogen absorbing alloy tank filled with hydrogen caused by collision
or others.And we investigated measuring method of fuel consumption
rate of hydrogen fuel cell powered vehicles.
3.6 Task 6 Development of PEFC Utilizing Pure Hydrogen
The three operating methods (Hydrogen recovery and recycle operation,Anode
outlet line closed operation,Anode recycle operation)were examined,
as the suitable operating method for the high hydrogen utilization
operation.
3.7 Task 7 Development of Hydrogen Refueling Stations
We studied the general system of hydrogen refueling station. We also
investigated desirable specification for main component equipment
of the station, such as hydrogen production equipment with reformer,
polymer electrolyte water electrolysis hydrogen production equipment,
hydrogen absorbing alloy tank and hydrogen dispenser unit, assuming
aspects of set-up and operation in each hydrogen refueling station
to make the total design of the station system.
3.8 Task 8 Development of Hydrogen Production Technology
As well as implementing development of large-scale cell lamination
(electrode area 2,500 cm2, 10 cells) by using two hydrogen production
methods (electroless plating method and hot press method), work was
started in tandem with task 7 on developing cells (electrode area
1,000 cm2) for hydrogen stations. Moreover, in continuation from the
previous year, conceptual design was carried out on optimum conditions
in hydrogen production on a practical scale, and the impact on hydrogen
production cost was examined. In research on solid high polymer electrolytes
resistant to high temperatures, numerous types of high polymer electrolytes
were bonded and assessment of characteristics was carried out. Furthermore,
review was carried out on the latest literature concerning water electrolysis.
3.9 Task 8 Development of Hydrogen Production Technology
We established the data base of thermal insulation performance, strength
at liquid hydrogen temperature for many kinds of insulation structures.
And the liquid hydrogen pump was revised and revolving test was conducted
at LH2 temperature environment. Then, standard performance of rotor
and pump were obtained. As to develop high-performance hydrogen compressor,
we conducted researches on challenges of aerodynamic design and seal
design and formulated development plan.
3.10 Task 10 Development of Cryogenic Materials Technology
Various mechanical properties were evaluated with respect to the
base metal and weld metal in temperatures ranging from extremely low
(4K) to room temperature. With respect to material evaluation in liquid
hydrogen environments that had been difficult to perform in the past,
new equipment was designed and installed and the evaluation was implemented
having established evaluation test technology. As a result, it was
found that while the base metal maintained sufficiently high tenacity
in liquid hydrogen environments, the weld metal showed high embrittlement
susceptibility with respect to low temperature embrittlement and hydrogen
embrittlement in liquid hydrogen environments thus indicating need
for improvement. On the other hand, with respect to hydrogen environment
embrittlement in low temperature hydrogen gas atmosphere (150K to
room temperature), SUS304L showed high embrittlement susceptibility.
A cryogenic material database was formed utilizing material data accumulated
in WE-NET and overseas reference data.
3.11 Task 11 Development of Hydrogen Absorbing Alloys for Small Scale Transportation
and Storage System
Thorough our investigation, we have successfully developed a multi-component
V-based alloy which has the largest effective capacity of hydrogen
under the practical pressure and temperature ranges. The V-Ti-Cr-Mn
alloy dissociates 2.64 mass% hydrogen from 273 K (0℃) and 3.3
MPa to 373 K (100 ℃) and 0.01 MPa.373 K (100 ℃) and 0.01
MPa. And we prepared wide-ranging compositions of ternary Mg-Ca-Ni
alloys (39 samples) in order to develop sophisticated Mg-Ca-Ni systems
hydrogen absorbing alloys and to make a breakthrough by discovering
new ternary Mg-Ca-Ni intermetallic compound with new crystalline structure.
And we have developed catalytically enhanced complex aluminum hydrides.
And we reviewed and summarized new carbon materials such as graphite,
carbon nano-tubes and graphite nano-fibers.
3.12 Task 12 Investigation and Study of Innovation & Leading
Technology
We received 8 new technology proposals. We evaluated the 8 proposals
for feasibility studies, and selected 3 proposals for FY 1999 feasibility
studies at the committee. And based on the new technology trends found
by the researches and studies conducted to date, we examined the promising
technology which should be reflected in the WE-NET project, and selected
the items of which the fundamental research should be commenced at
the Phase II. Selected item was magnetic refrigeration for liquefaction
of hydrogen.
4. Future Development
Research, basic investigation, study of elementary technologies, and other
investigations will be carried out continuously to FY 1999 to obtain
necessary information for the optimum design of the total system,
in order to confirm establishment of technologies required to design
and construct a pilot plant.
 |
