June 11, 2013


Meeting the Challenge of Stable Green Electricity Supply with Powdered Hydrogen Compound Fuel: Earth Project Co.

Keywords: Environmental Technology Newsletter Renewable Energy 

JFS Newsletter No.129 (May 2013)
"Towards a Sustainable Japan -- Corporations at Work" (No. 103)

"I want to accelerate the shift away from an energy structure based on fossil fuels and nuclear power generation by providing a stable supply of renewable energy." Motivated by such thoughts, Takashi Shiraiwa became the president of Earth Project Co., an eco-solutions planning company, in April 2012.

Mission of Earth Project Co.

"The era of mass production and mass disposal is ending. We are in the midst of a transition towards an era that will require a business model focused on sustainability and connectedness. Recent trends including energy issues are also showing signs of structural transition from centralization to decentralization." Shiraiwa perceived the current situation as a time for creative transition and set up a mission for the company -- the Earth Project Company's role is to provide projects and products that will contribute to society.

To achieve its mission, the company has set up three basic guidelines for marketing its products and solution services. 1) Communicate advanced technology clearly and comprehensively. 2) Accumulate successful cases and give them visual shape. 3) Aim at global-scale practical application.

Focusing on Electricity Generation from Hydrogen Fuel

Earth Project focuses on electricity generation from hydrogen fuels in accordance with the following concepts.


In Japan, the Great East Japan Earthquake in March 2011 and the subsequent nuclear accident at Tokyo Electric Power Company's Fukushima Daiichi nuclear power plant triggered a very active discussion on energy issues. One major focus of the discussion is the potential for a shift towards more decentralized energy production and away from centralized production based on fossil fuels and nuclear power.

The major sources of decentralized energy are renewables such as solar and wind power. However, these sources have disadvantages, notably unstable energy output due to their dependence on weather conditions. "Hydrogen power generation" systems can overcome this difficulty, and such systems are expected to facilitate the shift towards more widespread use of renewable energy to the point where it accounts for at least 20 to 30 percent of total generation.

From the viewpoint of the global environment, all countries will have to basically curb their emission of carbon dioxide (CO2). The time has come for concrete action to realize a low carbon society. We have no time to lose, as the impact of CO2 emissions will accelerate global warming, leading to extreme climate and the destruction of ecosystems in many countries.

Electricity generation from hydrogen does not involve or emit CO2 in any way, therefore, it could be an optimum locally-distributed energy supply system suitable for modern times. Decentralized energy production could become one of the pillars of energy policy in the future.


Working on an Innovative Energy Supply System using SBH Hydrogen Fuel

As one approach to electricity generation from hydrogen, Earth Project is engaged in the development and commercialization of a hydrogen fuel system utilizing sodium boro-hydride (SBH) in cooperation with Tokyo University of Science and Hydric Power Systems Co., where Shiraiwa sits on the board of directors.

In attempting to achieve the practical application of electricity generation from hydrogen fuel, conventional methods of handling hydrogen as a gaseous substance raise costs. As a gas, hydrogen has a very low energy density, and must be compressed or liquefied to increase its density. Also, infrastructure specific to hydrogen storage and transportation is required for distribution, meaning that expensive hydrogen stations must be built.

It takes huge investments to clear these hurdles, and so electricity generation from hydrogen has seemingly fallen behind other renewable energy sources such as solar, wind and biomass power. Moreover, the enormous amount of investment for hydrogen tends to result in a centralized electricity supply system similar to current systems for nuclear and thermal power generation.

A new way to solve these problems is technology that can provide a hydrogen source in the form of a solid powder. In this technology, borax, a natural mineral powder, chemically combines with hydrogen to produce a compound in powder form, which can be used as a fuel with an energy density 2500 times greater than hydrogen in gaseous form. This powdered hydrogen compound fuel for the SBH system can be handled safely, as it can be packed into cartridges that allow for easy transportation, storage and electricity generation.

The generator tailored to the SBH system generates electricity for the heat emitted by a hydrolysis reaction in the SBH powdered fuel. The same amount of fuel can generate about two times more electricity compared to a gasoline engine generator. Moreover, after electricity generation, the spent SBH fuel can be used many times over as a recyclable energy source; specifically, sodium metaborate (NaBO2), a by-product associated with releasing hydrogen, can be reprocessed into sodium borohydride (NaBH4), the original fuel of the SBH system.

The SBH system emits no CO2 whatever. Most fuel batteries currently on the market generate electricity through reactions using hydrogen obtained from reformed natural gas, and this process discharges CO2. On the other hand, the SBH system uses no carbon at all.

Thus the SBH system can potentially realize low-cost, decentralized energy production and supply without any special infrastructure, because this system uses hydrogen in the form of SBH powder, an innovative fuel medium that is easily stored and transported.

Test Run of Fuel Cell Vehicle Succeeds

A research team led by Nobukazu Hoshi, an associate professor in the Faculty of Science and Technology, Tokyo University of Science, announced on January 22, 2013, that they had succeeded in completing a test run of a fuel-cell electric vehicle (FCV) that runs on SBH powder fuel. This was the first big step toward practical application of an SBH system.

Movie of experiment by the research team of Tokyo University of Science

As explained above, the sodium borohydride used in an SBH system is a solid substance at ordinary temperatures and generates electricity using heat from a hydrolysis reaction. In this process, the sodium metaborate (NaBO2) generated after releasing hydrogen bonds easily to a catalyst, inhibiting the continuation of the hydrolysis reaction.

However, the research team has solved problems inherent to this reaction by introducing a method utilizing a centrifuge and succeeded with the FCV test run.

FCVs are one of the hot items being developed by vehicle manufacturers. Currently, one common approach is to install a high-pressure hydrogen tank in vehicles as a fuel storage component. However, it is difficult to install these tanks in compact cars due to limited space. Application of the SBH system, which does not need a high-pressure hydrogen tank, will open the way for compact FCVs without any major infrastructure investment.

Before widespread practical use of SBH systems is realized, there remain issues of by-product collection and energy efficiency improvement through returning by-products to replenish fuel using a hydrogenation process. We will continue to monitor how Earth Project meets these challenges and how it overcomes these problems.

Written by Nobuhiro Tanabe