Constructionshows
Malcolm Kent, senior technical consultant at the Construction Equipment Association, explains what users and buyers of construction machinery need to be aware of.
2012 promises to be a busy year in the plant sector, as the latest engine emissions control regulations loom.
We are currently in the transition phase between two stages of engine emissions control for all non-road mobile machinery (NRMM) in Europe.
NRMM covers just about every kind of machine with an engine in it except for on-highway vehicles, including machines which are mobile but not self-propelled such as compressors and generator sets.
Timeframe for NRMM implementation
For diesel engines over 130kW (177PS) emissions, Stage IIIB started at the end of 2010, and for engines between 56 and 130kW (76 and 177PS) it started at the end of 2011. For engines between 37 and 56kW (50 and 76PS) Stage IIIB cuts in at the end of 2012 but there is currently no Stage IIIB planned for engines below 37kW. However, machine suppliers are allowed some flexibility in the dates.
Firstly, under the ‘sell-off’ scheme, engines built before the new stage comes into effect can be used in machines built and sold later. This is to allow for the normal lead times of stockholding and manufacturing.
Secondly, there is a ‘flexibility scheme’ written into the law which allows machine manufacturers to build a limited number of machines which have engines from the previous stage several years into the ‘new’ stage. This is to allow them to smooth out their product development work and also to allow smaller manufacturers some additional leeway.
The upshot of all this is that not all machines from day one of 2012 will have Stage IIIB compliant engines in them, even if their power is over 56kW. This could be important when we look at the London Low Emission Zone below.
How machines will change
So what kind of changes are you likely to see on machines?
Well, each engine manufacturer has developed a solution to meet the emission limits of Stage IIIB and they are not all the same. There are pros and cons to each of the solutions on the market but they all meet the regulations. The solutions on the market mainly consist of a combination of some of three technologies, along with electronic engine control:
1. Selective Catalytic Reduction (SCR). This means having a urea tank on the machine which needs regular refilling. SCR reduces the NOx (nitrous oxide) emissions.
2. Diesel Particulate Filter (DPF). These have a filter and a catalyser at the end of the exhaust system, usually where the muffler would be. They need to go through regeneration cycles (either manually or automatically) to burn off the trapped particles. A DPF reduces the emission of particulates – small particles of dirt.
3. Exhaust Gas Recirculation (EGR). This is a system that bleeds off a portion of the exhaust gasses from the engine and feeds it back in to the cylinders with the incoming air. EGR also reduces NOx emissions.
Although only DPFs obviously reduce particulate emissions, the reduction in NOx emissions from the other two can allow other tweaks to be made to engine settings to get the particulate emissions down to the right levels, so not all Stage IIIB engines need a DPF.
There are knock-on effects of some of this, too, beyond the engine itself, such as the need for bigger radiators to take away more heat, and of course, the need to top up the urea tank when the machine needs it.
And the bad news?
Well, new technology doesn’t come cheap and engine manufacturers will need to sell at a cost which will eventually recover the huge investment they have made towards giving us all cleaner air
– although emissions from NRMM have been shown to make only a very small contribution to overall air quality problems.
London Low-Emission Zone for non-road mobile machinery
The Greater London Authority has been working for some time on introducing a LEZ for NRMM, in a similar way to the on-highway LEZ that is in force already. A draft of the proposed regulations circulated in September 2011 includes the following points:
From 1 June 2012, all NRMM at high risk sites would have to meet the Stage IIIA standard. The definition of ‘high risk’ is not included in the draft but is assumed to mean those in sensitive
locations such as next to schools or hospitals. Note that Stage IIIA came into effect between the end of 2005 and the end of 2007, so most machines under 5 years old will comply.
From 1 June 2013, NRMM used on any site in London would be required to meet the Stage IIIA standard. See comments above. By this time most machines under 6 years old will comply.
From 1 June 2014, NRMM used on any site in London would be required to meet the Stage IIIB standard. This is the tough one. As Stage IIIB will only have been in force for 18 months for engines of 37-56kW there will be many machines around that do not comply, even very new ones!
However, recent communications from the GLA tell us that the project has been delayed and the dates above no longer apply. We await further communication towards the end of this year.
The GLA states that retrofitting (to upgrade existing machinery to new emission levels) is an option open to owners; however there are problems with this.
It is possible to buy and install DPFs to reduce particulate emissions and this could really be a useful option up to June 2014. The reason is that the NOx limits did not reduce at Stage IIIA, so Stage II machines from around 2003/4 with a suitable DPF could comply until then.
However the allowable NOx levels have reduced significantly for Stage IIIB, so from 2014 just adding a DPF will probably not do the trick. A study of the effectiveness of retrofitting London buses with NOx reduction equipment concluded it wasn’t worth doing, so there could be a real problem coming up at that time.
Difficulty in achieving compliance
Machines just a couple of years old, or even brand new if the manufacturer has used a Stage IIIA engine under either of the sell-off or flexibility schemes, might not comply, and it could be nigh-on impossible to make them comply.
And how is all this going to be introduced and enforced? The idea is that Local Planning Authorities would write conditions into planning approvals requiring that machinery used on sites complied with the LEZ requirements, and it would then be up to the LPAs to enforce it.
What kind of enforcement, and what kind of penalties could be levied, is not clear at present as the scheme has not been finalised, and it depends on the granting of planning applications.
And what about other cities, will they follow London? We just don’t know. There have been suggestions that other cities are watching to see how it works out before introducing their own schemes. We will have to wait and see on that one. One thing is for sure, emissions legislation is not going to make the lives of contractors any easier!
Source: CEA News Room
