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I agree in principle about sustainable energy but the best way I can think to answer the point about nuclear power is to give a real life illustration. Bare with me, this might turn into a ramble.
I used to work as an automotive consultant, specialising in the field of vehicle exhaust emissions, and have done work for Ford Motor Company, Burmah Castrol, Jaguar, Land Rover etc, so I know what I'm talking about.
Back in the late 70s and early 80s people were (rightly) getting more concerned about Urban pollution and impact of motor vehicles on that. Now at that time, there were if you like two approaches. One approach, favoured by the US was to use exhaust gas after treatment. The other approach, favoured by European engineers, was to concentrate on engine technology so that engines did not emit the pollutants to start with (or at least severely reduce them and use minimal exhaust gas after treatment).
The major causes of concern were (are) Carbon Monoxide (CO) total hydrocarbons (THC - basically unburnt fuel) and Oxides of Nitrogen (mostly NO but also some NO2 so collectively referred to as NOx). Note that this "list" of polltants did not include CO2 because it was not and never will be a pollutant (despite what you may hear).
The "US" approach used the three way catalytic converter (commonly called a "catalyst" although that's technically incorrect). This works by reducing NOx to Nitrogen and Oxygen, the Oxygen (along with any other Oxygen left over from the combustion process) is used to Oxidise CO into CO2, and THC into CO2 and water. It is a very effective technology. However, there is s downside (of course). This is that for the "catalyst" to work, it needs to be "fed" a very precise ratio of gases. It is what is know as the stoichiometric air/fuel ratio which for gasoline is about 14.7:1 be mass. If the air/fuel ratio is too rich (too much fuel) there will be insufficient oxygen in the exhaust gas to oxide the CO and THC (although practically all the NOx will be reduced). If the air/fuel ratio is too "lean" (not enough fuel) the free oxygen will combine with the CO and THC but the NOx will not get reduced.
The "European" approach was to develop engines which produced very little pollution before any exhaust gas after treatment. I won't go into all the technical details but the theory and processes were well understood but not yet practically applied. Basically it involves very finely atomised droplets of fuel mixed by creating high levels of turbulence with the combustion chamber to make an engine which would run on very high air/fuel ratios, without missiring and with sufficient excess air to effectively "quench" the formation of NOx. This technology was called "Lean Burn" technology and hundreds of millions were being invested.
However, the environmentalists won the day with their argument that we could have lower emissions NOW, by adopting US style exhaust gas after treatment, rather than wait a few years for Lean Burn to become a reality. So, almost over night Lean Burn was abandoned and now all cars have three way cataylitic converters.
Why does this bother me? Because, as I stated earlier, for the catalytic converter to work with all three pollutants, it has to fueled at stoichiometric air fuel ratio of 14.7 under ALL conditions. On part throttle, where all of us do most of our driving, any engine can (and used to) run "leaner" - more like 16 or 17:1. So all cars, use more fuel and hence produce more CO2 - approx 10%) than they need to, in order to reduce the polutant gases.
Had Lean Burn research not been effectively stopped by environmentalists wanting a "quick fix", we could all now be driving cars with the same levels of reduced polution but at air fuel ratios in excess of 20:1. That is to say about 50% less fuel (and therefore CO2).
So, before we say "Lets build loads of nuclear power stations, worldwide, NOW", with all the associated problems that might lead too, we'd better be damn sure we are doing the right thing and for the right reasons.
Right now, there is a lot of research going on into other forms of renewable energy (that's my lean burn analogy) and if we adopt nuclear (US style exhaust gas after treatment analogy) NOW becuase of the hysteria about AGW, then that research will stop. We could end up with mountains of radiactive waste, ecological disasters and terrorists getting hold of enriched plutonium or whatever.
We need to be concerned about the use of fossil fuels, and we need to find alternatives becasue they will run out in time and/or become very expensive to recover. BUT at the same time we need to put a break on the AGW hysteria so that we have enough time to develop other technolgies and not rush down the "nuclear path".
Just my twopence worth of course. |
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Author: Jenn
26-11-2019 04:27:29
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