Flight map, points with methane concentrations over 3 ppm*m are marked. And that's a lot!
Imagine that you have a landfill that smokes and stinks from time to time. This is due to the fact that various gases are formed during the decay of organic matter. In this case, not only methane is formed, but also completely toxic gases, therefore, solid waste landfills sometimes need to be examined.
This is usually done on foot with a wearable methane detector, but in practice it is very difficult, time consuming and generally not really needed by landfill owners.
But it is necessary for the city government, municipal authorities, regions, etc., where the landfill or authorized landfill is located, environmentalists and ordinary people who want to breathe clean air.
The service of automated measurement of the level of methane using drones is in great demand in Europe.
We, with our partners from the company , carried out joint work in this direction and obtained an interesting result.
What is regulated?
The regulatory framework for solid waste landfills - instructions for the design, operation and reclamation of landfills for municipal solid waste (approved by the Ministry of Construction of the Russian Federation on November 2, 1996), sanitary rules SP 2.1.7.1038-01 "Hygienic requirements for the construction and maintenance of landfills for solid household wasteβ (approved by the Decree of the Chief State Sanitary Doctor of the Russian Federation of May 30, 2001 No. 16), the concept of solid household waste management in the Russian Federation MDS 13-8.2000 (approved by the Decree of the Board of the Gosstroy of the Russian Federation of December 22, 1999 No. 17) , SanPiN 2.1.6.1032-01. 2.1.6. Atmospheric air and indoor air, sanitary air protection. Hygienic requirements for ensuring the quality of atmospheric air in populated areas (approved by the Chief State Sanitary Doctor of the Russian Federation on May 17.05.2001, XNUMX).
The maximum allowable concentrations for this set of documents are as follows:
Substance
MPC, mg / m3
Maximum one-time
Average daily
Dust non-toxic
0,5
0,15
Hydrogen sulfide
0,008
β
Carbon monoxide
5,0
3,0
Nitric oxide
0,4
0,06
Mercury metal
β
0,0003
Methane
β
50,0
Ammonia
0,2
0,04
Benzene
1,5
0,1
Trichloromethane
β
0,03
4-carbon chloride
4,0
0,7
Chlorobenzene
0,1
0,1
Typical biogas composition:
Substance
%
Methane, CH4
50 β 75 Feet
Carbon dioxide, CO2
25 β 50 Feet
Nitrogen, N2
0 β 10 Feet
Hydrogen, H2
0 β 1 Feet
Hydrogen sulfide, H2S
0 β 3 Feet
Oxygen, O2
0 β 2 Feet
Biogas is released up to 12-15 years, and after the second year - mainly only methane or only carbon dioxide (or a mixture of both).
How to look for leaks now
To find places of release of methane at landfills, the work of crawlers is used. They take a hand-held gas analyzer (in the common people - "sniffer") and another thing that looks like an umbrella, the crawler chooses a place on the landfill. He installs a small dome there and waits for a certain concentration of gas to accumulate under the dome. Measures the level of concentration using a gas analyzer and records the readings of the device. After that, he moves to another point for the next measurement. And so on.
The process is quite simple, but very inefficient in terms of the number of measurements taken per unit of time. Let's add here the human factor and the hellish working conditions of the lineman, who is forced to walk around the stinking training ground for hours (probably still using personal protective equipment).
Drone to help us
At the end of 2018, at the INTERGEO 2018 exhibition (Frankfurt), we got acquainted with the Pergamum technology and their experience in flying drones over landfills. The guys began to use a drone with a remote laser methane detector installed on it to search for leaks. A logger was installed on board the drone, which records all the detector readings. Upon completion of the flight, the information from the logger is transferred to the computer in the form of tabular data for analysis. If somewhere there is an excess of methane concentration, the drone is sent to this point again to photograph the leak site.
By that time, the guys from Pergamum had already made a number of overflights of solid waste landfills, and they realized that it was quite simple to fly legally. This resulted in the following process:
- Such overflights by drones are usually agreed within two weeks after compliance with legal formalities: obtaining the permission of the owner of the territory, approved by the aviation authorities and the administration of the flight plan area. An application for the establishment of a local flight regime is sent to the zone center (AC) three to five days before the start of work, the flight plan is sent the day before the start of work. On the day of the start of work, you need to call the SC two hours in advance, before takeoff you need to call all the responsible authorities. Responsible authorities are determined according to the general map "Airspace of the Russian Federation" (VP RF). It seems that changes will come out soon, and it will be possible to fly at altitudes up to 150 meters within line of sight.
- Each time the flight begins with measuring the direction and speed of the wind, atmospheric pressure. If the wind speed is more than four meters per second, then they do not fly, because the result is unpredictable: you can detect a leak in the wrong place (it will physically blow it to the other side).
- The drone operator on site minimizes the number of turns and calculates a flight time of approximately 25 minutes. In general, it is possible to reduce the flight time from 5 to 20%, depending on weather conditions.
- It is better to start flights from the leeward side so that the scanning takes place downwind.
- The flight height of the drone sufficient to search for leaks is 15 meters.
- If there is permission for aerial photography, then you can photograph the place of release with a thermal imager and in the visible range.
Compared to the work of crawlers - a breakthrough! But there was a significant drawback in the operation of the detector used by Pergamum for overflights: the absence of a communication channel between the detector and the operator during the flight. Information about leaks could only be obtained after the drone landed.
Pergamum + CROC + SPH
By the time they got to know Pergamum, CROC had just received an on-board computer for the DJI Matrice 600 drone, which could also broadcast telemetry via DJI LightBridge 2. Pergamum was immediately interested in the product and offered to make a downlink integration for their product, the LMC remote methane detector for the drone.
As a result, a joint development of CROC (Russia), Pergam-Engineering (Russia) and SPH Engineering (Latvia, UGCS software manufacturer) appeared - the LMC G2 DL (Laser Methane Copter Generation 2 with Downlink) complex. This is the second generation of the hardware and software system for detecting methane (CH4) leaks.
The solution includes a DJI Matrice 600 drone with a take-off weight of 11 kilograms, equipped with a remote laser methane detector and an on-board computer. The new software allows you to accurately register the flight path at a given height and at the required speed, instantly respond in case of detection of a methane leak, accurately localize the place and take timely measures.
Now the process is like this:
1. In order not to miss even a small piece of the polygon, the flight plan is created in the UgCS software. It takes minutes. At the same time, you can do it in a warm office and not freeze yourself ... hands.
Drone flight plan in UgCS software.
2. Next, the operator prepares the drone at the take-off point at the training ground. And through the mobile application UgCS launches the flight.
The concentration is normal.
Leak detected.
3. Further, thanks to our on-board computer, the readings of the methane detector are sent online to the mobile application. At the same time, the on-board computer records all readings from the device on the SD card in case of loss of communication with the ground.
4. All exceedances of the methane concentration level can be immediately marked on the map. You no longer waste time on post-processing to localize the leak.
5. Profit!
CROC ecologist's comment:
There is no law that a landfill should officially record any leaks, but methane is a greenhouse gas, and we have banned greenhouse gases for 20 years. There is the Kyoto Protocol, and within the framework of the Clean Air project, which belongs to the Ecology national project, there will most likely be a law on quotas. And these quotas will be traded. And every company needs to understand if they have the ability to minimize or control emissions.
The supervisory authority is Rosprirodnadzor. The landfill itself is an engineering structure, that is, it must pass the Glavgosexpertiza. There is production and environmental control. The frequency of this control is set depending on the hazard and for each specific landfill. Suppose a laboratory comes every three months and measures something - usually water, soil, air. Good landfills themselves arrange pipelines for landfill gas and use this gas for their own needs. Usually there is from 40 percent of methane. If it explodes, there will be destroyed communications, possibly human casualties, a powerful release ... And then a criminal case will be opened against the owner. And nobody is interested in it. A drone in the same Krasnoyarsk, for example, is very economically justified. Two people plus a guard with a gun (seriously - there are bears), an all-terrain vehicle that breaks down every 20-40 km, accommodation, northern daily allowances.
Drones can be used in many places. Burn static on a trolley, irrigate a field, drop a raft to a drowning man, fly through a fire and find all the people, track poachers or look for hemp plantations, take inventory in a warehouse - it's all you want. And in general, everything that your imagination will allow. We are interested in new challenges, and we can and want to try to solve your problem. Well, if you have the task of finding leaks, I have a pilot project for the most interesting one. Mail - [email protected].
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Source: habr.com