Is liquefied petroleum gas (LPG) more environmental friendly than diesel or gasoline?

This is a matter of great concern for the Guangzhou city committee on transport when an investigation report by five local people's congress deputies has concluded with enough evidence that LPG causes more air pollution than diesel.

This southern city has already invested 2.4 billion yuan in replacing 80 percent of the city's buses powered by diesel with LPG-fuelled ones. So the committee has stated that it will continue with its scheme to replace the remaining buses running on diesel with LPG as the latter is on the State list of clean energy, and the LPG scheme has been evaluated by experts and examined by environmental protection department.

However, the transport committee has no evidence to show that LPG is a clean energy. The report by the five deputies says that the organic particles emitted by LPG-run buses are a bit lower than diesel buses, but the oxynitride, carbon compound, sulphur compound and other pollutants they discharge are all higher than diesel-run buses. The hydrocarbon emitted is 127 times higher.

If the deputies are correct, what the local transport committee has done is not just a waste of public money. It has also caused more pollution by making the wrong decision. Their investigation also suggests that LPG is much more costly than diesel.

Searching online reveals that debate has been continuing in the past six years since 2003 when Guangzhou city government decided to use LPG as a clean energy alternative for the public buses and taxis. Some experts and officials even within the city government have time and again challenged LPG as a clean alternative to diesel.

The question is why the scheme was launched and so much money spent without further study to ascertain whether LPG was really a clean alternative.

Given modern technology, it should not be a difficult problem. From the response of the transport authorities to the deputies' report, it is very easy to tell that the transport authorities have no intention of doing the job. If they were serious about the debate that has been going on for years and the challenge to their decision, they should have done the job before implementing the scheme.

We do not know whether these five deputies including some experts who have supported their investigation will take further action to press for a responsible reply from the transport authorities. Neither do we know how the city authorities will respond.

But we are sure that a conclusion is needed on whether LPG is a clean energy alternative. This may need to be done by national authorities, after a thorough investigation by environmental experts, as it is of national significance.

If LPG is not certified as clean energy, then the investigation should turn to why the Guangzhou transport committee pushed it as a clean alternative and whether there is any scandal behind it.

(China Daily 10/26/2009 page4)