`Low-Cost and Small-Size SOFC for Home `

Arranged by T. HOMMA
1.National Policy
2.Local Government Policy
3.Trends in SOFC Development
4.Research on FC Related Elementary Technology
5.Development of PEFC Elementary Technologies
6.Elementary Research of DMFC
7.PEFC Demonstration
8.FCV Forefront
9.Construction and Achievement of Hydrogen Station
10.Development of Reforming, Hydrogen Production and Purification
11.Technology for Hydrogen Storage and Transportation
12.Hydrogen Related Technologyn

1.National Policy
(1) Participation in US FutureGen Program
@Japanese government decided policy to participate US FutureGen program of large-scale CO2 recovery and storage (CCS). It is one in Bush's series of initiatives for climate change, hydrogen fuel and air cleanup, and it is project of 10 years and 1 billion dollar budget. Japan shares cost of 10 million yen and makes technical advice, and it receivs in return license for domestic use of the technology. This is a multi-national cooperative program, and the purposes are to establish a high-efficiency power generating system using coal and to demonstrate underground disposal of CO2. The scheme and process are as follows. Oxygen and water vapor are introduced into a coal gasification furnace for purification of the gas, and after removing sulfur and particulates, the gas is separated into hydrogen and CO2 by adding water vapor into the gas of main components, hydrogen and CO. Hydrogen is used in FC and turbines for power generation, and then CO2 is recovered and stored underground. The coal consumption rate is 2,000 ton/day and 273 MW prototype generating plant using this amount of hydrogen will be constructed. Decision of the site will be done in 2007, and the plant will start the operation until 2012. [The Denki Shimbun (electricity) Jan. 9, 2007]

(2) Ministry of Economy, Trade and Industry
@The ministry will start examination of concrete policy for promoting propagation of the next generation car fuel. Four items are listed up, and they are biomass fuel, clean diesel engine, electric cars plus the next generation batteries and FC plus hydrogen. On each item technical tasks and infrastructure for the propagation will be discussed. Discussion meeting will be held among the minister and tops of car and oil industries at the beginning, and three working groups will be organized for each item of fuel and power sources as below. Concrete tasks will be studied on expert level, and interim reports will be completed by June of 2007. The report will be presented to the advisory board on economy and finance to reflect them in fundamental policies of the government.
@The three working groups are (1) biomass fuel, cellulose utilization technology plus octane value, (2) clean diesel fuel (CDF), and (3) electrified cars, the next generation batteries, FC and hydrogen. [The Nikkan Jidosha Shimbun (automobile) Jan. 23, 2007, The Nikkan Kogyo Shimbun (business and technology) Jan. 24, 2007, The Mainichi Shimbun, The Denki Shimbun (electricity) and The Nikkan Kogyo Shimbun (Jan. 25, 2007.)

(3) NEDO
@New Energy and Industrial Technology Development Organization (NEDO) decided foreign subsidized institutes in international cooperative research for promoting R&D of FC. In this R&D 15 foreign research institutes in 9 countries will participate R&D of production and storage of hydrogen together with Japanese 9 institutes. R&D will be done for 14 months and the total budget is about 300 million yen. [The Nikkei Sangyo Shimbun (economy and industry) Jan. 25, 2007].

(4) FCCJ
@FCCJ made propositions on development targets and evaluation methods of automobile and stationary PEFC. It intends to formalize the endurance test method and to laterally evaluate possibility of new technology by making databases of the endurance test results. It aims at increasing operating temperature and decreasing atmospheric humidity both for automobile and stationary FC. The followings are the targets. Automobile; Target cost of electrolyte membrane below 1,000 yen/m2, cell temperature -30 - 90oC (in 2012), -30 - 120oC (final target); relative humidity 30% (in 2015 - 20), no humidification (final target), electrolyte membrane resistance; 0.05 ohm cm2 at -20oC, below 0.0125 ohm cm2 at 120oC and 35% relative humidity (tentative) ; catalytic activity (cathode) 3 times ( in 2010) 10 times (2015 - 20) in comparison with standard catalytic activity; total platinum catalyst per generating power 0.3 g/kW (in 2010) 0.1 g/kW (in 2015 - 20)0 g/kW (final)
@Stationary (as an image); about 70oC, 100% humidity, 40,000 hour operating time, and start and stop 4,000 times (2008) 80 - 85oC, about 65% relative humidity, 50,000 hours and 4,000 times (2012), 80 -90oC, 30 - 40% relative humidity, 90,000 hours and 4,000 times (after 2015)
@The followings are also proposed; materials stability tests, such as hot water immersion test of electrolyte membrane (thermal endurance) and exposure test to H2O2 gas (chemical endurance), together with structural stability test methods, such as freeze and melting cycle test, humidity cycle test and compression and creep cycle test. [The Chemical Daily Feb. 1, 2007]
2.Local Government Policy
@On January 29, 2007 Kyoto City announced that it succeeded in hydrogen production from biomass, such as garbage and wasted paper. Taking this opportunity the city intends to realize FC power generation using biomass by 2010 in collaboration with a biomass research group consisting of 6 plant makers and Osaka Gas Co., Ltd., Kyoto University and Ministry of Environment. In the experiment garbage and paper were mixed with glycerin made from wasted frying oil, and the mixture was fermented in a methane ferment vessel for 20 days. The formed biomass was recovered and reacted with water vapor and oxygen to produce hydrogen by self-heating reforming. From 1 ton of general garbage removing cans, bottles and PET bottles, about 250 kWh electric energy was obtained. The city has a plan of constructing a plant for biogas in a garbage disposal site in Fushimi ward where replacement of the present facility is planned in 2013. In this facility 30,000 kWh, equivalent to consumption for 3,000 homes per day, is anticipated. [The Mainichi Shimbun and The Nikkan Kogyo Shimbun (business and technology) Jan. 30, 2007]
3.Trends in SOFC Development
(1) CEPRI and AIST
@Central Electric Power Research Institute (CEPRI) and National Institute for Advanced Industrial Science and Technology (AIST) developed SOFC operating in a low temperature range from 500 - 650oC and its electric efficiency achieved is over real-use level. The cells are cylindrical (3 mm in outer diameter and 3 cm in length of generating part) and the power density of 1.06 W/cm2 was recorded by using hydrogen fuel. The air electrodes of SOFC developed are made of porous ceramics, and silver nano-particles (the particle diameter 10 - 100 nm) are uniformly dispersed. The porous ceramic is immersed in mixture of silver nitrate, citric acid and ethylene glycol, and then it is sintered at 800oC. By this process activity of dissociating oxygen to oxide ion and electron is improved even in the low temperature range, they said. Any special equipment is not needed for dispersing the silver particles. The stacks were assembled by piling up the cells. The research group intends to develop it for home and as dispersed power sources. [The Nikkei Sangyo Shimbun (economy and industry) Jan. 18, 2007]

(2) Toho Gas Co., Ltd.
@The company made trial new type SOFC modules operating at 500oC and they demonstrated the power density over 0.5 W/cm2. In these modules the cells of small tube developed by AIST (above) were piled up. The electrolyte is ceria base ion conducting ceramics. The trial modules are made of 6 stripe type tubes (2 mm in diameter and about 5 cm in length) and total 36 single cells are assembled. The power output per module is 10 - 20 W. Combining multiple modules demonstration of several hundred W level output will be done by 2009, and the company intends to complete development of home-use and business-use stationary SOFC systems in 2011 - 2012. [The Nikkan Kogyo Shimbun (business and technology) Jan. 19, 2007]

(3) J Power
@The company (Electric Power Development Co., Ltd.) would start ambient atmosphere SOFC of 150 kW scale since Jan. 26, 2007. Construction for installation in its Chigasaki research center was completed and it is now in the final preparation for starting the test. The main purposes of the test are SOFC system formation and examination of long-term reliability. The targets of the power generating operation are DC output power efficiency of 45% (LHV) and total over 10,000 hour operation. The period is assumed by March of 2008. The used SOFC is a new structure SOFC consisting of stripe type cylindrical cell tubes developed by Mitsubishi Heavy Industries, and both ends of cylindrical cell tube are supported to improve the endurance. Fuel is supplied by simple one-through structure to reduce cost in the future. [The Denki Shimbun (electricity) Jan. 23, 2007]
@The operating test of the above SOFC system was started on Jan. 26, 2007. [The Asahi Shimbun Jan. 27, 2007]

(4) Osaka Gas Co., Ltd. and Kyocera, Corp.
@On Jan. 25, 2007 Osaka Gas Co., Ltd. announced that it developed home-use SOFC cogeneration systems of 700 W output in collaboration with Kyocera Corp. Down-sizing of the components and improvement in stacking cells, down-sizing of the power generating system was succeeded (95 cm height, 35 cm depth and 54 cm width). The electric efficiency is 45% (at AC output, LHV), and the efficiency of the exhausted heat recovery is over 30%. About 70% of electric demand for small homes can be covered, and 60,000 - 70,000 yen can be reduced in expense for electricity and heat per year, they said. They are aiming at commercialization in 2008 fiscal year, and they also expected that the price would be 500,000 - 600,000 yen by making full use of the ceramic technology. [The Yomiuri Shimbun, The Asahi Shimbun, The Nihon Keizai Shimbun, The Denki Shimbun (elecrtricity), The Nikkei Sangyo Shimbun (economy and industry), The Nikkan Kogyo Shimbun (business and technology), The Dempa Shimnbun (radio wave) The Kyoto Shimbun, The Fuji Sankei Business Eye and The Chemical Daily Jan. 26, 2007]
4.Research on FC Related Elementary Technology
@A research group in Chiba University observed a new phenomenon. When oxygen atoms adsorbed on ruthenium fine particles, which is promising as catalyst for the next generation FC, order in ruthenium surface layer disappears. In the experiment oxygen is adsorbed on the flat surface of ruthenium single crystal, and its x-ray diffraction is observed by using high intensity synchrotron orbital resonance (SOR) at a large SOR facility "Spring 8." Disorder is found to the depth of 1.5 nm, which is equivalent to 6 atomic layers. When oxygen atom adsorbs on ruthenium surface, disorder forms in the surface layer and characteristics of ruthenium changes down to relatively deep layers, so that the catalytic activity decreases. It was known that the catalytic activity of fine particles with large surface area is low due to disorder in the surface structure. This "size effect" was a task previously. Since analysis of atomic arrangement in ruthenium surface layer was succeeded, it is expected to find optimum design. The surface disorder is not observed for metals, such as gold, copper, nickel etc. The disorder is characteristic of noble metals, which have activity even for fine particles of diameter below 3 nm. Since now platinum, which has similar activity, will be studied in detail. [The Nikkan Kogyo Shimbun (business and technology) Jan. 10, 2007]
5.Development of PEFC Elementary Technologies
(1) Toray Corp.
@The company will start hydrocarbon electrolyte business in 2009 in its earliest anticipation. By making full use of its structure controlling technology of nm level, the company succeeded in improvement of endurance and realizing performance to be used in PEFC for FCV. From a viewpoint that there is a strong relation between polymer structure and intermolecular affinity, the company uses the relation for improving mechanical characteristics and endurance in dry and wet cycles. Furthermore, aiming at non-crosslinking and non-reinforcement hydrocarbon electrolyte membrane, the company introduced its original higher order control concept of nm level into polymer design of higher order structure and film making technology. As the results, spring-like structure can be introduced between polymer chains to get high mechanical strength, flexibility and plasticity at the same time. Thus in comparison with fluorocarbon membrane, tensile strength, elongation at breaking point and elastic modulus were improved respectively by 2.7, 1.3 and 10. Moreover, tear strength was much improved and endurance in dry and wet cycles became in the level of fluorocarbon membrane, and hydrogen permeability reduced to 1/10. Over 20 times improvement in endurance was observed at OCV test. It was said that proton conductivity and electric power performance in PEFC were the same as the fluorocarbon and that thermal stability partly exceeds the fluorocarbon membrane. The company is programming since now demonstration of high endurance, optimization of polymer structure and film making process, performance improvement under low temperature and low humidity conditions for automobiles. Over 1,000 hour stability was observed in an accelerated test. The company found possibility to reduce the price below 1/10. [The Chemical Daily Jan. 18, 2007]

(2) Japan Vilene Co., Ltd.
@The company comes to fields of porous materials of gas diffusion for PEFC and filters for stationary PC. The gas diffusion porous materials are new porous materials consisting of carbon powder, synthetic resin and unwoven cloth, and it is good in power generating performance under high temperature and low humidity condition because of highly fine structure. The materials fulfill requirements of flexibility and mechanical endurance. Because it is different from carbon paper made of high cost carbon fibers, the low cost of 1,000yen/cm2 is in sight as gas diffusion layer (GDL). The materials developed by the company are made of resin superior in endurance to oxidation, binder of carbon particles and unwoven cloth as supports. The materials are both flexible and tough, so that the materials can be made by roll process at low cost. In comparison with carbon paper the material have high allowance in density control and design. The company succeeded in power generation at 90oC under low humidity condition. The materials are especially suitable to FCV. The company will start supply as samples in February of 2007 and it will install trial mass production facility in the before half of 2007 fiscal year. It will make development coping with power generation.
@On the other hand, the filter is for removing gas and particulates, which degrade the stacks. It is base material for air conditioners of automobiles. In cooperation with the holding company, Freudenberg, will make standard goods and supply them as samples. [The Chemical Daily Jan. 30, 2007]
6.Elementary Research of DMFC
@Kuraray Co., Ltd. succeeded in improvement of maximum power generating performance by 2 and by 1.3 in comparison with fluorocarbon membrane and their conventional one respectively. The success was gotten by technology of largely reducing methanol crossover. It is superior in flexibility and mechanical endurance, and moreover its ion conductivity is higher than fluorocarbon membrane. When it is used in portable equipment, it contribute to short start-up time.
@By utilizing the unique technology of polymer design, synthesis and handling of the company, it improves hydrogen ion permeability. For this purpose the company controls polymer nano-level structure to control scale and arrangement of hydrogen ion channel and it also developed controlling technology of polymer swelling by developed film handling technology to greatly reduce methanol crossover. Thus the company realized reduction of swelling ratio to 1/23 for the film of 30 micron m and 0% methanol leakage. Furthermore when it changes from dry state to wet state, it takes halftime to stabilize ion conductivity compared with fluorocarbon membrane. This is thought to be effective in start-up time of DMFC portable equipment in open-air environment. On the other hand, this halogen free film is flexible and adherence of the film with the electrode layer is improved to overcome problem of hydrocarbon membrane. Thus superior mechanical and chemical stabilities are realized. Because establishment of mass production by roll process comes in sight, the company begins sample supply to several companies. Coping with high concentration methanol, the company is preparing production to meet increasing demand. [The Nikkei Sangyo Shimbun (economy and industry) and The Chemical Daily Jan. 26, 2007]
7.PEFC Demonstration
(1) New Energy Foundation
@On Jan. 18, 2007 the foundation completed an operation report of PEFC at 175 sites for 1 year in the first period of large-scale demonstration of home-use PEFC starting in 2005. According to the report, energy saving achieved is 15.3%, and oil equivalent to 11 cans (18 L capacity) of kerosene was saved per one home in average. Reduction in CO2 was 1,400 g per year compared with thermal power generation as the tope datum, and that of 175 sites average was 850 g. [The Nikkan Kogyo Shimbun (business and technology), The Chemical Daily Jan. 19, 2007, The Nikkan Jidosha Shimbun (automobile) Jan 20, 2007 and The Nikkei Sangyo Shimbun (economy and industry) Jan. 23, 2007]

(2) Nippon Oil Corp.
@On Jan. 22, 2007 its Hokkaido Branch announced installation of kerosene-fueled home-use PEFC at a house in Sapporo city of Hokkaido. The electric power is 950 W and the fuel is kerosene specific to PEFC. [The Hokkaido Shimbun Jan. 23, 2007]

(3) Osaka Gas Co., Ltd. etc.
@Osaka Gas Co., Ltd., Toshiba FC Systems Inc. and Chofu Seisakusho developed PEFC cogeneration systems in which hydrogen is directly used, and the systems are designed for apartment houses A hot water tank is unified with FC, so that it is compact and the unit is 500 W output. This FC system will be installed at an apartment house in Osaka and in this system the exhausted heat is primarily used for air conditioning. The demonstration will be made by supplying hydrogen with pipes from a hydrogen producing equipment. With the air conditioner air can be dehumidified by exhausted heat at 60oC, and thus the recovered heat from PEFC can be used. Because hydrogen is used directly, the efficiency is high; the electric efficiency is 40 - 46%. The fuel utilization ratio is 99%, and surplus hydrogen in partial load is fired by catalytic combustion to heat water for realizing high temperature water storage. The start-up time is less than 5 min., and when the catalytic burner is heated, it is less than 1 min. It was reported that the efficiency in hot water storage is 46% and that for dehumidification is 40%, while the overall efficiency is 81%. By unification with the hot water storage of 50 L the depth, width and height of the unit are 450, 700 and 1250 mm respectively. Since the package is slim, it can be set in a pipe shaft. The energy saving effect for whole apartment houses as a model is estimated to be reduced by 8.3% in compared with conventional systems connected with an electric grid and installed with a boiler. [The Nikkan Kogyo Shimbun (business and technology) Jan. 30, 2007]

(4) Idemitsu Kosan Co., Ltd.
@The company developed a business-use 5 kW scale modified system (proto 2) and will begin its field test aiming at the start within this year. It is expected to introduce them in restaurants and convenience stores, where electric consumption is high. With data and know-how accumulated in demonstration made till now, high performance and long life of desulfurizing reagent and reforming catalyst are target, while modified systems of both types specified to kerosene and LP gas will be tested in the fields for examining tasks for real use. [The Chemical Daily Feb. 2, 2007]
8.FCV Forefront
@DHL Japan introduced one FCV "F Cell" made by Daimler-Chrysler in 2006 and it runs 4,300 km per month without any troubles. In this FCV cylinders of hydrogen compressed at 350 atmospheres is installed. The maximum range for one charge per a day is 150 km. The rear sheets are modified for parcels. [The Nikkan Kogyo Shimbun (business and technology) Jan. 17, 2007]
9.Construction and Achievement of Hydrogen Station
@Showa-Shell Oil Co., Ltd. and Iwatani International Corp. announced on Jan. 18, 2007 that accumulated charging amounted to 2,000 cars in "JHFC Ariake Hydrogen Station" operated by the both companies in cooperation. Liquid hydrogen charging and compressed hydrogen charging both are possible and for both cases the charging time per one car is less than 10 min. The operation was started in June of 2003. [The Nikkan Kogyo Shimbun (business and technology) and The Chemical Daily Jan. 23, 2007 and Jan. 31, 2007.]
10.Development of Reforming, Hydrogen Production and Purification
(1) JRCM etc.
@It was published that technology for efficient hydrogen production from large amount of methane formed in cakes oven gas (COG) in iron industry was established in a project participated by government, industry and academic sector. This project is carried out by JRCM (R&D center of metallic materials) Nihon Steel Corp., Teikoku Oil Co., Ltd., JFE Steel Corp., National Institute for Advanced Industrial Science and Technology and 7 universities including Kyoto University. The purpose of the project is to increase hydrogen by over 2 by the following 3 items. The first one is research of catalysts and reaction designing technology for highly efficient hydrogen production reaction by reforming (reforming by oxygen introduction). The second is highly efficient oxygen separation system using mixed conductors. The third is highly efficient hydrogen production technology (a membrane reactor) by unification of the above technologies. The project team established each individual goal. The test of a bench plant for examination of total process was made by using catalysts for dry gasification and hydrogen reforming. By the test, hydrogen amplification ratio of 3.1 - 5.6 was achieved. By test for real use made in the final fiscal year (This 5 year project started in 2001 fiscal year.) The followings are realized. The hydrogen production cost is less than 12 yen/ Nm3 assuming 170 ton/d production. Adding costs of compression, shipment, transportation and hydrogen station the retail price is less than 60 yen/Nm3, which is in the same level as the present price for on-site supply. The evaluation report will be completed in March of 2007 in a sub-committee of advisory board on industrial structure in METI. [The Chemical Daily Jan. 11, 2007]

(2) Hokkaido University
@An assistant professor of research center for catalytic chemistry of Hokkaido University, Prof. Fukuoka et al developed a catalyst for simply removing CO in reformed gas from natural gas. Platinum particles were put into 3 nm size of pore in honeycomb structure of silicon dioxide, and they found that in this structure oxygen molecules are dissociated to oxygen atoms and reacts with CO at 40oC to CO2. Hitherto CO was removed with similar catalyst, but high temperature over 150oC was necessary, so that cooling of produced hydrogen is needed. By using the newly found catalyst cooling becomes unnecessary. The research group begins negotiation with a functional materials producing company to search for possibility of business. [The Nikkei Sangyo Shimbun (economy and industry) Jan. 12, 2007]

(3) Nippon Oil Corp.
@The company developed catalyst for highly efficient water vapor reforming of kerosene. Ruthenium is finely dispersed with cerium oxide as co-catalyst. By testing it in a commercial equipment it was found that the catalyst was stable and no degradation was found after 5,000 hour testing. There are many carbon bonds in kerosene and it contains aromatic hydrocarbon and sulfur oxides, so that high performance and long life of catalyst are hard. High activity for dissociating carbon bonds and sulfur endurance to reduce sulfur effect at its minimum are needed. In new FC development Ebara-Ballard Corp. is charged in kerosene specified FC, while Nippon Oil Corp. is charged in a hydrogen reforming equipments using kerosene with the highly efficient water vapor reforming catalyst. The total system was developed in the cooperation of the two companies. The obtained hydrogen is of necessary purity. Un-reacted kerosene was not found at the outlet of the reformed gas, so that conversion ratio of kerosene was achieved 100%. They will continue research for high efficiency and low cost. [The Chemical Daily Jan. 31, 2007]
11.Technology for Hydrogen Storage and Transportation
@National Institute for Advanced Industrial Science and Technology carries out portable FC and its hydrogen generation system using hydrolysis of ammonia borane (AB; NH3BH3). This substance contains 19.6wt% hydrogen and has a property of generating hydrogen by heating. In comparison with sodium boride hydride (SBH), its feature is safety because it is stable in water. SBH tends to react with water, and usually magnesium hydroxide is added (10 - 20%) for stabilization. In this point AB is stable and easy to be handled. At present noble metal catalyst is used, but they intend to develop highly active catalyst while reducing the amount of noble metal by loading it on various carriers. They also intend to find new catalysts. It is also planned to develop catalyst, which is inactive or of low activity in hydrolysis and hydrogen formation but active in cathode reaction. By these they intend to realize hydrogen producing devises for small FC, in which hydrogen production can be controlled by demand. Use of phthalocyanine metal compounds of nickel etc. is considered, and regeneration of boron compounds is also examined for reuse of formed boron compounds. Thus real use of AB fueled FC is aimed at. [The Chemical Daily Jan. 7, 2007]
12.Hydrogen Related Technology
@Sumitomo Denko Steel Wire Corp., Ltd. (Itami city) developed "stainless steel wire for spring" which is endurable to hydrogen brittleness. It is in the same level of strength and anticorrosion as general stainless steel SUS 304 for spring. Nitrogen and manganese are added to SUS 304 and austenite phase is formed for stabilization. It has high wear resistance before hydrogen storage and a little decrease in the resistance was observed after hydrogen storage. Stainless steel of endurance to hydrogen brittleness was thus developed. High value of 490 MPa was observed at 400 atmospheres after hydrogen storage. The company promotes its sales as valves for adjusting hydrogen high pressure in FC systems, materials endurable in hydrogen environment etc. [The Tekko Shimbun (iron and steel) Jan. 15, 2007 and The Nikkei Sangyo Shimbun (economy and industry) Jan. 29, 2007]

------------ This edition is made up as of February 2, 2007. ---------------