8/9/2019 Coal Flaring
1/27
September 2007
Harworth Power Ltd
CMM Flaring
8/9/2019 Coal Flaring
2/27
Harworth Power
Part of UK Coal PLC -Ex Nationalised British Coal
UK Coal 4000 employees, 14Mt capacity, surface and deep mines
VAM oxidation technology trialled on an operating coal mine
CMM utilised in boilers since the 1960s
CMM utilised in gas turbines and gas engines since 1991
CMM utilised in high efficiency gas engines since 2000 (30MWe installed)
CMM destructed in enclosed flares since 2004 (7 flares installed)
Part of the UK ETS since 2001, 2.3Mt CO2e verified (3.9Mt total)
Separate unit specialising in assisting mines maximise capture, qualityand utilisation engineers deployable to assist in design and
implementation
Typical capture rates 40% - 60% of coal face district gas
Typical gas quality 30% to 50% methane
All gas is utilised in generators, boilers or flared
2
8/9/2019 Coal Flaring
3/27
Key Issues in Flaring of CMM
Gas is NOT utilised but destroyed
Safety
Capital Cost
Operating Cost
Equipment Delivery Will the Government allow gas to be flared rather than
utilised?
Ideal scenario in the US distributed remote gas sourceswithout realistic or economic means us using heat,electricity or low quality gas near the well head.
3
8/9/2019 Coal Flaring
4/27
Coal to CMM Flaring
4
8/9/2019 Coal Flaring
5/27
Coal Mining General Data
KellingleyColliery
ThoresbyColliery
WelbeckColliery
HarworthColliery
StillingfleetMine
Depth (m) 900 750 700 850 700
Tonnage (Mt) 1.455 Mt 0.829 Mt 0.868 Mt Mothballed Mine Closed Mine
Seam Thickness 2.1 1.85 1.85 2 3
Gas M3/tonne 5.3 5.2 5.0 6.2
Gas Typical FlowRate (l/s)
400 600 250 - 350 350 - 450 650 850 950
Gas TypicalConcentration
40 50% 30 40% 35 45% 45 55% 80%
Utilization /destruction
2x 20,000 lb/hrdry sat steam
boilers
3x 1.4MWe gasengine generators
1x 2,000 Nm3/hrenclosed flare
2x 1.4MWe gasengine generators
1x 2,000 Nm3/hrenclosed flare
2x 20,000 lb/hrdry sat steam
boilers
2x 1.4MWe gasengine generators
2 x 2,000 Nm3/hrenclosed flare
2x 20,000 lb/hrdry sat steam
boilers
5x 1.4MWe gasengine generators
1x 2,000 Nm3/hrenclosed flare
18MWe CCGT
4x 3MWe gasengine generators
5
8/9/2019 Coal Flaring
6/27
Overview
Gas Flaring.Technology:Destruction of drained methane gas through combustion in
a gas flare. 2000 Nm3
/hr destruction capacity per flare.
Benefits:A low capex cost technology with a short manufacture and installation lead time.Simple, low cost and reliable to operate, gas flaring offers a very high potential for significant GHG reduction.Low maintenance requirements.Installation Requirements:80 litres/s pure methane flow at 20% purity or above,Methane drainage infrastructure already in place, Suitable flame arrestor technology installed to prevent flame propagation into the mine.Mine Suitability:A disciplined drainage approach ensuring that methane isonly drained above 20% purity.
6
8/9/2019 Coal Flaring
7/27
Flare P&I Diagram
2000 Nm3/hr methane destruction capacity
>27% CH4 for reliable flare start
Flare will operate down to 20% CH4
Automatic control
Internet Remote Monitoring and Control
Skid mounted for ease of installation
7
8/9/2019 Coal Flaring
8/27
Importance of Gas Purity
Gas will not burn or explode outside of the flammablerange
Gas will not allow an existing flame to propagate into themine outside of the flammable range
Multiple failsafe concentration transducers automatically
stop supply of gas to extraction pumps and flare Careful consideration of system T90 reaction period
Only effective means of protection against lightning as an
ignition source
8
8/9/2019 Coal Flaring
9/27
Flammability of Methane / Air at Atmospheric Pressureand Temperature
The flammability of mixtures of Methane and Air
C
Capable of formingflammable
mixtures with airper se.
FlammableRegion
Coward Diagram
20
15
10
5
0
B
E
F
D
Not capable offorming
flammable
mixtures with air
Oxygen
Concentration
255 10 15 20Methane Concentration
9
8/9/2019 Coal Flaring
10/27
Hierarchy of Explosion Prevention and Mitigation
1. Prevent formation of flammable atmosphere measureconcentration and stop flow
2. Prevent exposure of ignition source to flammableatmosphere necessary for destruction / combustion
3. Prevent propagation through flammable mixture use ofequipment/burner design, flame arresters and valves
4. Dissipate energy bursting discs / relief valves / vents
5. Prevent of release of explosion energy vessel and
pipework design
10
8/9/2019 Coal Flaring
11/27
Flame Propagation in Pipework
Flame Speed
Point ofIgnition
50 x Pipe Diameters
Direction of flame propagation
Deflagration
Detonation
Overdriven DetonationChoked flame speed (Mach 1)
M = 1
x
11
8/9/2019 Coal Flaring
12/27
Specific Flare Safety Features
Safety risk assessments carried out fordesign and operation to prevent flashback
HAZOP Hazardous Area Classification Flame Arrester suitability assessment Multiple redundancy and safety features Gas quality monitoring and oxygen inter-
trip PLC controlled with certain high integrity
functions duplicate hard wired
Burner velocity design to preventflashback
Temperature sensing to prevent flamearrester burn through
Purge for start-up
12
8/9/2019 Coal Flaring
13/27
September 2007
Thank you
Neil ButlerTechnical Director
44-7798-571612
8/9/2019 Coal Flaring
14/27
USA Coal Mine Methane Conference
The modern high temperature flareSt Louis, 26thSeptember 2007
www.clarke-energy.com
8/9/2019 Coal Flaring
15/27
Cla rk e Ener gy supp l i es, i nst a l ls and m a in t a ins HAASE f lar es
15www.clarke-energy.com
8/9/2019 Coal Flaring
16/27
Cheap and d i r t y v e rsus st a te -o f - t he -a r t
60% CH4destruction
99.9% CH4destruction
16www.clarke-energy.com
8/9/2019 Coal Flaring
17/27
HAASE f l a re t yp es h i gh t em pe ra tu re con t i nuou s du t y an d l o w t e m p er a t u r e e m er g e n cy
0.3s retention
99.9% CH4 destruction
CH4 down to 25% or lowerwith propane assist atignition
Turn down 5:1 or greater
HT type LT type 2 LT type 1
www.clarke-energy.com17
8/9/2019 Coal Flaring
18/27
HAASE l i n i ng 1 0 y ear gu a ran t ee
18www.clarke-energy.com
8/9/2019 Coal Flaring
19/27
Cold s ide l i n in g f i x ing
19www.clarke-energy.com
8/9/2019 Coal Flaring
20/27
Germ an and UK regu la t i ons
TA-Luft UK
NOX 200 mg/m3 150 mg/m3
CO 100 mg/m3 50 mg/m3
Temperature 1,200oC (1830oF) 1,000oC (2200oF)
(Reference 3% O2by vol. in exhaust gas)
www.clarke-energy.com20
8/9/2019 Coal Flaring
21/27
21www.clarke-energy.com
Natu r a l l y ven t i l at ed and f an ven t i l at ed
20MW
27MW
10:1 turndownfan assisted
8/9/2019 Coal Flaring
22/27
4 x 4 5 0 0 m 3/ h + 2 x 15 00 m 3/ h ( 1 @ 1 0 : 1 t u r n d ow n )
10:1turndown
Total
105MW
22www.clarke-energy.com
l fl ( l ) d
8/9/2019 Coal Flaring
23/27
HAASE lean gas flare (pilot) down to 10%methane
23www.clarke-energy.com
T l l d l f
8/9/2019 Coal Flaring
24/27
Telecontrol system can record values forcarbon credits
On-site-control Remote control
24www.clarke-energy.com
8/9/2019 Coal Flaring
25/27
Hat f ie ld Co l l i e ry 4 x Roots blower delivering
880Nm3/h (each) at -500mbarg to
-100mbarg delivery
2 x Roots blower delivering1660Nm3/h (each) at -100mbarg to
+200mbarg delivery
25www.clarke-energy.com
8/9/2019 Coal Flaring
26/27
The HAASE st a te o f t he a r t h i gh t em pe ra tu re f l a re in su m m ar y ;
99.9% CH4 destruction Down to 25% CH4 , or lower with propane
assistance at ignition
Turn down ratio 5:1 standard, 10:1 or greateroptional
10 year lining guarantee Exceeds German TA Luft requirements
www.clarke-energy.com26
8/9/2019 Coal Flaring
27/27
Thank you!Clarke Energy distributes GE Energy Jenbacher and HAASE best in class products supplying, installing and maintaining
www.clarke-energy.com