OPERATION & MAINTENANCE OF POWER PLANTS
F
or the past year or so, instrument suppliers such as Opsis have received many requests for quotations from operators of waste incinerators,
notably for instruments measuring the concentrations of total mercury and dioxins in the emissions to air. Te successful suppliers have also seen a lot of orders for such instrumentation over the past year, and Opsis is no exception. It also means that these suppliers have been working hard to produce and install all ordered equipment, in many cases with a deployment deadline during the Autumn of 2023. What brought all this along?
NEW REGULATIONS Industrial emissions within the European Union are governed by the Industrial Emissions Directive, the IED. It is a framework directive largely relying on industry-specific reference documents on best available techniques, BREFs. Te BREFs are revised regularly to keep the directives up to date with new and improved techniques on emissions control. By example, the BREF for waste incinerators (WI) was revised during the 2010s and a new version became effective in December 2019.
Te expectations on industrial emissions
control are in practice expressed in BREF conclusion documents, BATCs, accompanying the BREFs. Accordingly, there was also a new WI-BATC released in late 2019. Some of the new conclusions were “associated emission levels” (AELs) on total mercury and dioxins in the emissions to air, both types of compounds being very toxic and bad for the environment. Te AELs are mostly expressed in
intervals, where the lowest number is a best achievable performance if implementing state-of-the-art techniques, and the highest number is a minimum requirement. By example, the AEL for total mercury (THg, the sum of elementary mercury and its compounds) stated by the new WI-BATC is “< 5-20 µg/m3
” as a daily average expressed
in standardised cubic metres. Accordingly, THg emissions can be kept below 5 µg/m3 using best available techniques and should as a minimum effort be kept below 20 µg/m3
An Opsis total mercury monitoring system under installation
release of the new WI-BREF, that is by the end of 2023.
CONTINUOUS MONITORING Mercury emission limits and mercury monitoring is nothing new, but it was first in the 2019 version of the WI- BATC that requirements on continuous monitoring were introduced. Tere are exemptions, but a notable number of waste incineration facilities still faced the need for acquiring new and continuously operating monitoring equipment meeting the standards prescribed by the WI- BATC. Tis of course meant a cost for the industry and like many other costs with no immediate financial return on investment, it took some time before the orders started to be placed. However, with a rapidly approaching implementation deadline, we have seen a steadily increasing flow of new THg instruments being delivered across Europe in 2023.
. It is then up to the competent national authorities to impose appropriate emission limits on the individual industries. Following the IED, the new standards must be implemented through national legislation and the industry must comply with this not later than four years from the
LONG-TERM SAMPLING Te new WI-BATC also came with new requirements on dioxins emissions monitoring. “Dioxins” is a simplified expression, the actual compounds are named “polychlorinated dibenzo-p- dioxins and -furans” and the like, but let’s call them all dioxins for simplicity. In contrast to for example mercury, dioxins are relatively complex substances and there is no viably available technology for detection and quantification in real time. Te approach is instead to gather a sample of the emissions. Te sampling is done with the same flow rate as inside the
flue gas duct (“isokinetic sampling”) and runs continuously for two to four weeks. After the end of the sampling period, the exposed sample container is sent to a laboratory where total amount of dioxins is established using gas chromatography and mass spectrometry. Dividing the lab result with the total volume that passed the container yields the average dioxins concentration in the emissions during the sampling period.
Te long-term sampling is to be
repeated every month. With an up to four-week sampling period, the dioxins sampling can approach continuous monitoring although with a very low time resolution. Tere is also notable delay in reporting given the time it takes to ship and process the exposed sample at the laboratory, and to compile the dioxins emissions report. However, it is still a matter of close-to continuous monitoring of the dioxins emissions to air.
AND THE WINNER IS... So, who has gained the most from the new regulations on mercury and dioxins emissions monitoring? Well, they have meant good business for several instrument suppliers but that’s merely a side effect. In the long run, the real winner is the European environment and everyone living there, now being less and less exposed to toxic mercury and dioxins.
Bengt Löfstedt is with Opsis.
www.opsis.se
www.engineerlive.com 17
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52
