Hydrogen – part of a greener use for forestry residues

OPINION: Toyota NZ has recently been showcasing its hydrogen fuel cell electric car the Toyota Mirai in Nelson. These cars are more commonly seen on the streets of Los Angeles than here in New Zealand, but the sight of one on our roads shows that the global industry is moving towards providing a range of offerings beyond the battery electric cars that we commonly see.

In fact, the real challenge in front of us is how we will power the trucks and bulldozers that do the heavy work in our supply chains and construction industry. In Europe, the early adopters of hydrogen fuel cell engines are the fleets of inner-city buses with engines that run on electricity produced from the chemical reaction of hydrogen binding with oxygen producing an on-street emission of only water.

In New Zealand, the Government is backing the future of hydrogen by assisting with funding the establishment of hydrogen refuelling stations along the length of State Highway 1. The first South Island station is set to be built this year.

However, regional hubs like Nelson will have to wait several years to see their own station under construction. Just like the construction of cycleways led to a boom in cycle sales, the establishment of a refuelling network will pave the way for companies moving to the new energy source. There is even a New Zealand truck manufacturer readying a 54-tonne heavy goods vehicle for market that is powered using fuel cell electric technology.

Although hydrogen is a very lightweight gas it packs a lot of energy, having three times the energy as the same weight of diesel. It can be compressed or liquefied, with the former option being used for vehicles. The tank pressures are very high, and an enormous amount of development has gone into producing tanks that meet vehicle safety standards.

A particularly relevant question for our region, is how new fuels such as hydrogen will be made. Typically, the path to hydrogen is through using electricity to separate the hydrogen from oxygen in water. However, much of New Zealand has limited capacity within its lines network to provide the quantity of energy required for future hydrogen demand.

There are also limits to our network generation capacity at peak loading times. Meanwhile, we are seeing farms being bought and covered in solar panels for hydrogen production which doesn’t seem like the ideal use of land.

This is where there may be an opportunity for wood residues to produce hydrogen. To produce hydrogen from wood, the wood residues are heated in an environment free of oxygen, and this produces a mix of methane and hydrogen. The hydrogen is separated off, and the methane can be used to power the process, or even converted to biodiesel through another process. More >>

Source: Stuff