Hydrogen powered bus takes to the road

Toyota's Fuel Cell Hydrogen Vehicle uses pure hydrogen

The world's first bus service using a regular hydrogen fuel cell will begin on Saturday at a Japanese airport.

A 65-seat bus, manufactured by Toyota and Hino, will transport passengers to and from the Central Japan International Airport (Centrair) near the city of Nagoya in southern Japan, according to sources at Toyota. 

"The airport was built on environmentally friendly principles, such as efficient use of energy and low pollution, so we have been happy to cooperate with Toyota on this project, and we hope we can use more vehicles like this in the future," Yuki Hasegawa, of Centrair's general affairs division, told vnunet.com.

The airport, completed last year, makes extensive use of solar panels and other green concepts.

The new bus is particularly notable because it uses pure hydrogen as fuel. Typically, fuel cells have used hydrogen in an intermediate format, such as methanol, because it is difficult to store and handle in its gaseous state.

In the bus, the gas is absorbed and later released by an alloy honeycomb inside the vehicle's fuel tank.

The fuel cell generates electricity which drives the vehicle's electric motor. The bus also uses a secondary battery for storing and reusing energy generated during braking.

Toyota claims that its pure hydrogen technology is on the verge of surpassing gasoline engines in power density.

Inside the fuel cell engine, hydrogen is combined with oxygen from the air in a chemical reaction which generates 90 kilowatts of electricity. The only waste product is water vapour.

The basic chemistry has been described as the opposite of the common classroom electrolysis experiment which uses electricity to break down water, or compounds dissolved in water, into their component parts.

The new bus generates only half the CO2 emissions of a traditional diesel vehicle, almost all of that during the hydrogen fuel manufacturing stage, where the carbon dioxide released might be easier to capture and store safely.

Toyota acknowledges that developing an infrastructure of what might literally be called 'gas stations' to refill vehicles with hydrogen is crucial to the success of its fuel cell concept, and one of the most difficult hurdles to overcome. 

A special hydrogen filling station at Centrair will fuel the new bus service.

Although Toyota did not provide full details of the new vehicle, a smaller early version had a maximum range of more than 300km and a top speed of more than 150km/h.

The company has carried out several public tests of the vehicle over the past 18 months, but the new airport routes will be the first time it has been put into regular service in place of a traditional bus.