Skip to main content

Have Bosch Cleaned up Their Act?

Diesel engines have had a tough time of late, what with all the lying and cheating from VW and others caught up in the Dieselgate scandal.  It was with some skepticism then that I read the news that Bosch (who were central to Dieselgate) are claiming to have solved the problem of diesel NOx emissions.

Unlike gasoline (petrol) engines, the diesel drivetrain uses injection of the fuel to initiate combustion, and they time this so that it operates at a high thermal efficiency.  This gives diesel powered cars and trucks excellent fuel economy, but comes at the expense of air quality, with diesel being prone to the formation of soot and NOx.  Maintaining high fuel efficiency while keeping down emissions has been a key challenge for diesel automobiles, and was what drove VW to criminally conceal the true on-road emissions of their vehicles.

Now Bosch are making bold claims that they've made a breakthrough in diesel technology that can meet strict EU emissions standards, saving the diesel automobile.  This breakthrough doesn't involve any new engine hardware though, and instead appears to focus on optimising the operating conditions for various stages of the engine and the exhaust system.  What isn't being discussed is how this new control system influences engine efficiency - remembering that the emissions vs efficiency trade-off is what put diesels on the chopping block to begin with.  Their failure to mention the effect on engine power and torque is what makes me doubt that this is truly a breakthrough; it feels more like a PR exercise from a company with a checkered past trying to promote a technology in which they are heavily invested.


Popular posts from this blog

Australia's Clean Air Myth

I've been thinking a lot about air quality in Australia recently as I wrote up my submission in response to Victoria's Air Quality Statement, which will help shape a future air quality strategy for this state.  The Clean Air Statement presents a rosy picture for air quality in Victoria - our air is repeatedly described as "great" and "very good" - and this leaves the impression that air pollution is not a current health danger to Victorians.  Anecdotally, I have seen this attitude adopted by Australians around the country, who ask me why I need to research air quality in Australia and tell me that we already breathe clean air.  It is true that our air is cleaner than many of our neighbours, but this doesn't mean that it is healthy.  Air pollution in China, for instance, is one of the biggest handbrakes on development in what may soon be the world's biggest economy, and it is meaningless to compare it to Australia.

So, how big is Australia's air …

Is Someone Cheating on the Montreal Protocol?

The Montreal Protocol regulates emissions of ozone depleting substances.  It is ratified by every nation and bans the use of chemicals including chlorofluorocarbons (CFCs), long lived substances which break down the stratosphere's protective ozone layer.  The international treaty has led to decreasing atmospheric levels of CFCs, and the ozone layer is beginning to recover.  It is now being reported, however, that atmospheric levels of one CFC (trichlorofluoromethane, CFC-11) have slowed their rate of decrease, attributed to a new CFC-11 source from Asia.

The origin of these new CFC-11 emissions are unclear, and will be difficult to pinpoint.  They may be from clandestine use of the banned substance, but could also arise from leaky CFC-11 stockpiles.  An international effort to investigate this issue now appears warranted, since it threatens to undo much of the good work of the Montreal Protocol.

CFCs are not the only threat to the ozone layer.  Recent studies have shown that the o…

New Zealand's Toxic Methyl Bromide Problem

Concerns are mounting in New Zealand around the continued use of methyl bromide for fumigation.  Methyl bromide is a highly effective fumigant, but it is also depletes the ozone layer and is harmful to human health.  Under the Montreal Protocol for the regulation of ozone depleting substances, use of methyl bromide is banned for all but a few exempt quarantine purposes. This ban has seen measured atmospheric levels of this substance drop from about 10 to 8 parts per trillion. In New Zealand, however, methyl bromide usage is soaring, with a 2020 deadline to eliminate methyl bromide emissions looming.

One of the biggest exemptions for methyl bromide use is in fumigating logs for export. China and India are the main destinations and both prefer methyl bromide treatment as a bio-security measure. New Zealand is a significant exporter of logs to China and India, and in recent years has grown to become one of the biggest users of methyl bromide worldwide. The NZ government have a 2020 deadl…