Towngas - or the Hong Kong and China Gas Company - said on Monday it has developed a new hydrogen extraction system that can supply almost pure hydrogen through its existing pipeline network as a greener alternative to diesel for heavy vehicles, such as buses, while obviating the need to transport the gas by truck.

Towngas supplies a 50 percent hydrogen mix through its pipelines for household use.

But the company said the new technology would allow it to extract almost 100 percent of the hydrogen from the gas mix in its pipelines, which could then be used to refuel hydrogen vehicles at a filling station similar to fuel pumps at petrol stations, without the need to transport the gas by road.

“The refilling station is just like the LPG taxi refilling station. [Drivers] can just charge up the hydrogen tank inside the vehicles,” Towngas’s general manager of gas production Stephen Chan said.

Don Cheng, the general manager of commercial, industrial marketing, and sales at Towngas, said hydrogen is particularly advantageous for heavy vehicles as refuelling is quick.

“For passenger cars, there's already battery cars," Cheng said, adding that it's a proven technology that's already been running on Hong Kong's roads for a number of years.

"There's no problem about the utilisation,” he said.

“But for heavy vehicles, the battery .. is much bigger. You need a longer time to charge it.”

When asked about the safety of pure hydrogen extraction and fuelling, Chan said there would be a monitoring system very similar to the one that monitors town gas.

“We already have 160 years of experience in using hydrogen-rich gas. There is no difference. People have to be trained, competent and do it safely.”

Chan assured the public that there would be regular gas leak detection to ensure the integrity of its fuelling system.

Towngas said it had been negotiating with different transport operators and expects the first hydrogen buses to be on the streets by the end of this year.