Landfills eyed after success of biogas plan

PUBLISHED : Saturday, 26 January, 2008, 12:00am
UPDATED : Saturday, 26 January, 2008, 12:00am

Methane from the Tseung Kwan O landfill could in future be converted for household and commercial use, environment officials said yesterday.

They said the Environmental Protection Department, Towngas and the landfill operator were studying the feasibility of such a project, but no timetable had been set.

The proposed project for Tseung Kwan O was revealed after success in transferring methane, also known as biogas, through a 19km pipeline from the Ta Kwu Ling landfill near the border to a Towngas plant in Tai Po. The conversion of biogas from Ta Kwu Ling into town gas began in the middle of last year. Town gas is a general term referring to manufactured gas fuels produced for sale to consumers.

The supply of the biogas, now at 6,000 cubic metres per hour, has helped Towngas replace 43,000 tonnes of imported naphtha for town-gas manufacturing, lower costs and tariffs, and cut greenhouse gases by 135,000 tonnes a year, it says.

The transfer was made possible under a tripartite agreement in which Towngas invested HK$150 million for the pipeline and landfill operator Far East Landfill Technologies paid HK$80 million for a gas-processing plant, while the government provided the landfill.

At present, Towngas pays nothing for the biogas, but when usage reaches a certain level it will pay the government and Far East for the methane.

Speaking after the official opening ceremony for the gas plant at the Ta Kwu Ling landfill, Secretary for the Environment Edward Yau Tang-wah said he hoped the project could be extended.

'Landfill gases account for over 10 per cent of total greenhouse gases emitted in Hong Kong. The project can reduce these emissions, as landfill gases are expected to increase over [their] remaining life,' he said.

Most of the landfill gases are now turned into electricity for on-site use or as heating sources for waste treatment.

Using methane from the Tseung Kwan O landfill could be more costly than from Ta Kwu Ling because the former is farther from the Tai Po gas plant, increasing transport costs.

A solution could be to build a Towngas production facility on-site that could convert the methane and pump the town gas directly into existing pipelines, said Ellen Chen Ying-lung, assistant director of the environment department.

Alfred Chan Wing-kin, managing director of Towngas, yesterday said the feasibility of using gases in other landfills was being studied.

James Tam Ping-cheong, director of Swire SITA Waste Services, which owns Far East, said the Tuen Mun landfill also had plenty of potential because the volume of biogas available was double that of Ta Kwu Ling.