Ultra low sulphur myth
The Tata Energy Research Institute (TERI) is reopening the diesel versus CNG debate in Delhi. Several reports in the media have been quoting the institute to say that ultra-low sulphur diesel (ULSD) is better that CNG to solve Delhi's air pollution problem economically. TERI got the lieutenant governor of Delhi to release its study "Delhi's Transport and the Environment: shaken but not stirred' amid great fanfare.
The most striking aspect of this study and the consequent public attention on ULSD is the timing of it. All this has happened just as the Delhi government and bus operators in Delhi became serious about implementing the Supreme Court order on CNG. It is clear that lobbies are hard at work to scuttle the move that threatens their entrenched business interests. After the court's March 26, 2001 order, there was a flurry to place orders for CNG buses and conversion kits. This has obviously irked the pro-diesel lobby and CNG's detractors have begun working overtime to create confusion and delay implementation.
The question to ask is: why is TERI raking up the controversy at this juncture. And why is the institute using measurements from one study done on one bus in London in 1997 to challenge the court decision? Why is it ignoring a range of studies since 1998 which prove that CNG is far cleaner than diesel technology? Why it took TERI so long to release this old and disproved study is anyone's guess. "This is nothing but a deliberate and ham-handed effort to subvert and sabotage the critical court order that will go a long way to protect public health,' says Sunita Narain, director of the Centre for Science and Environment.
TERI is clearly throwing around half-baked research and misinformation. The institute's study rests its opposition to CNG on the results of one set of measurements conducted on one bus of the London Transport Buses in 1996/1997. The study claims to have found that a Euro II-compliant diesel engine running on ULSD (with 0.005 per cent sulphur) and fitted with continuously regenerating traps (CRT, which control particulate emissions) achieves emission results better than CNG buses. Since its publication, the study has come under serious scrutiny by several agencies that find it flawed in terms of the methods used. A 1998 study by the Expert Reference Group, commissioned by the Australian government, has been presented in the court by Fali Nariman, counsel for the Tata Engineering and Locomotive Company. This, too, is based on the London study. TERI conveniently forgot to inform the people of a 2000 report by the Australian Council for Scientific and Industrial Research Organisation, which debunks the London study and states that CNG and LPG are the best options for combating air pollution and global warming.
The only other evidence that the pro-diesel lobby has been able to summon is a