BEST PRACTICE IN VAM PROCESSING What is VAM? Why is VAM an issue? Ranchi 9-10 March 2017 Richard Mattus What is VAM? Why is VAM an issue? Why is VAM a ”climate opportunity”? Technologies for processing VAM Proven technologies so far Successful installations Guide lines for feasibility

COAL MINING, METHANE and VAM When coal is formed, so is methane. When coal is excavated, methane is released Methane in air is explosive at 5 – 15 % Methane is drained prior to and after excavation Heavy ventilation to dilute emitted CH4: Concentrations typically below 1 % Good margin to 5%, so safety problem solved! .. very large flows of ventilation air means very large CH4 emissions .. .. which has turned out to be a powerful GreenHouse Gas.

VAM is a major single source of emissions. VAM GreenHouse EFFECT on global warming 1 million t CO2e VAM is a major single source of emissions. ½ million cars = Coal fired Power plant 300 MWth = Coal mine VAM 1 000 000 m3/h, 0.8% (50 000 t CH4/yr) 1 million cows =

One thin bubble of atmosphere Atmosphere thickness to the Earth is like the skin to the apple

One thin bubble of atmosphere Increase of CO2 content increases average atmospheric temperature.

One thin bubble of atmosphere

CO2 in atmosphere can retain a bit of the sun’s heat.

Methane can retain a lot!

Global Methane Emissions - by source (ANTHROPOGENIC) CO2 CH4 Global Warming Power 1 25* Life time in atmosphere (years) 20 000 – 50 000 12 Source: GHG emissions 2012, IEA, International Energy Agency * Based on 100 yrs comparison Second most important greenhouse gas Much more powerful greenhouse gas than CO2 Short life time in atmosphere, so emission reductions will have a quick, positive impact Generates energy when abated (oxidized)

Global Warming Potential – CH4 vs CO2 Methane is a very powerful GHG. Especially short term! 100 years 20 years CO2 CH4 12 years 12 years 20 20 Acc to IPCC (5th Assessment Report, 2014): Compared on 100 yr basis; Methane 25 times more powerful Compared on 20 yr basis; Methane 72 times more powerful

Impact of major emission reduction – CH4 vs CO2 Reducing VAM emissions quickly has a powerful positive impact. Fossile Power Plant Coal mine Vent Shaft GW impact Time CO2 CH4 Major emission reduction (by for example 90%) 12 yrs

TECHNOLOGIES FOR PROCESSING VAM CONDITIONS: Very large volumes of air with extremely low CH4 content. ~1 000 000 Nm3/hr <1% to <<1% TECHNOLOGY SPECIFICS ISSUES COMMENTS COMBUSTION AIR with VAM as supplementary fuel For power plants, (turbines, boilers) Very large air volumes. Hard to find large user nearby a ventilation shaft. LEAN GAS TURBINES Have managed to come down to 2-3%. Typically combined with drainage gas. Very large air volumes. So far only lab scale installations reported. CONCENTRATORS Increase CH4 concentration. Technical difficulties. Very large air volumes. No successful installations or trials officially reported yet. RTO, Regenerative Thermal Oxidizers Need only 0.2% CH4 for self sustaining oxidation process. No major issues for experienced suppliers. Proven technology for VAM with several long time installations. RCO, Regenerative Catalytic Oxidizers Catalyst lowers the temp needed for oxidation. Catalyst can be “poisoned” by e.g. S. Catalyst needs at some point to be exchanged. Several RCO solutions in trial. No success officially reported yet. Recuperative Thermal Oxidation Passes pollutant (CH4) by an open flame. Most traditional industrial oxidizer. Very costly to operate. No serious attempts due to low financial feasibility. INDUSTRIAL OXIDIZERS

VAM PROCESSING AND CARBON CREDITS 1997 Kyoto Conference - Agreement to reduce emissions and to introduce mechanism of Carbon Credits 2009 Copenhagen Conference Failure to extend Kyoto Protocole 1992 Rio Conference - Agreement to establish the UN Framework Convention on Climate Change, UNFCCC Official launch of Kyoto related Carbon Credits 2015 Paris Agreement CARBON CREDITS TRADING VARIOUS ETS (Emission Trading Schemes) EU ETS CARBON CREDITS TRADED 2015 2017 2012 2007 2009 2001 1997 1994 1992 LARGE SIZE VAM Power plant, GaoHe China LARGE SIZE VAM INSTALLATION Power plant, WestVAMP, Australia Abatement, hot water, SongZao, China UK trial at British Coal A few months Australian trial at BHP A full year Abatement demo 1½ year CONSOL, US VAM PILOT Abatement, McElroy, US Abatement/hot water, China Abatement, JWR, US VAM PROCESSING

COMMERCIAL SIZE VAM PROCESSING DaTong 375 000 Nm3/h ZhengZhou 60 000 Nm3/h CONSOL Energy 60 000 Nm3/h McElroy, 180 000 Nm3/h VAM Power Plant GaoHe 1 080 000 Nm3/h VAM Power Plant WestVAMP 250 000 Nm3/h JWR 60 000 Nm3/h

COMMERCIAL SIZE VAM PROCESSING IN OPERATION BY 2017 McElroy, 180 000 Nm3/h Since 2012 VAM Power Plant GaoHe 1 080 000 Nm3/h Since 2015 Closures due to : Moving of mining activities Failing values of carbon credits

RTO technology - How does it work?

Energy Principle of RTO reaction Reaction Temperature Like all VOC gases, methane oxidize at 850-900oC to form water and CO2. And release Energy!

VOC Oxidation Rate 100% Oxidation Rate 1000 °C Temperature

Single can RTO No catalyst operate at natural oxidizing temperature RTO FUNCTION: Heat center cross section of ceramic bed to 1000oC. Pass ventilation air through, heating media, oxidizing all VAM in air passing the hot zone. Change direction of flow, making hot zone remain in center bed section. 20oC 1000oC 60oC No catalyst operate at natural oxidizing temperature

Single can RTO Flow down Flow up

Oxidation in a combustion chamber instead of in the ceramic bed. 2 Can (or more) RTO Main difference between the single can RTO and 2 can or multiple can RTO’s: Oxidation in a combustion chamber instead of in the ceramic bed.

RTO installations typically consists of multiple modular RTO units.

PURE VAM ABATEMENT Min 0.2% CH4 to keep oxidizing going . If higher, the excess can be utilized..

CONVERTING ENERGY OF VAM INTO USEFUL ENERGY Min 0.2% CH4 to keep oxidizing going . If higher, the excess can be utilized as Heating/cooling or as electricity.

Indications of VAM project economics GUIDE LINES The project economics of a VAM processing installation will largely depend on; Total costs for investment, operation and maintenance. Average VAM concentration of the ventilation air being processed. The value of reducing the emissions.

VAM Energy Recovery with RTO’s as boiler units GUIDE LINES VAM Energy Recovery with RTO’s as boiler units 0.2 % methane needed to maintain oxidation. Energy of concentrations above 0.2 % can be recovered. Example: 800 000 m3/h 72 MW(th) 21 MW(el) 1 % CH4 (at 30% efficiency) Example: 800 000 m3/h 36 MW(th) 10 MW(el) 0.6 % CH4 (at 30% efficiency)

Cogeneration of electricity and heating – plus cooling GUIDE LINES Cogeneration of electricity and heating – plus cooling ~ Cooling water from electricity generation drives absorption chiller Example: 800 000 m3/h 1% methane 72 MW(th) 21 MW(el) 19 MW(el) + 38 MW(cool)

Hot water from VAM (thermal energy) GUIDE LINES 0.3% 0.6% 0.9% Heat straight from bed. Water at 70 - 150oC 3 MW 11 MW 18 MW - - For each 250 000 Nm3/h of ventilation air - - - Secondary heat-exchanger. Water at 70oC 1 MW 8 MW 15 MW Water at 150oC - 2 MW 10 MW Heat Exchanger

Electricity from VAM (electrical energy) GUIDE LINES 0.3% 0.6% 0.9% Heat straight from bed. Water at 70 - 150oC 3 MWth = ½ -1 MWe 11 MWth 3 -4 MWe 18 MWth 5 - 6 MWe - - For each 250 000 Nm3/h of ventilation air - - - For large size plants, conversion from thermal to electrical energy can be expected to be around 30%, and lower for smaller plants.

Calculations of CO2e from VAM processing GUIDE LINES Examples: 250 000 Nm3/h @ 0.9 % VAM comes to 240 000 tonnes of CO2e 125 000 Nm3/h @ 0,9 % VAM comes to 120 000 t CO2e 125 000 Nm3/h @ 0,3 % VAM comes to   40 000 t CO2e VAM conc’n Nm3/h vent air 0.3 % 0.6 % 0.9 % 125 000 40 80 120 250 000 160 240 500 000 320 480 1 000 000 640 960 Annual emission reductions in thousand tons of CO2e

VAM project economics indications GUIDE LINES VAM project economics indications CONCLUSIONS for reasonable/good pay back: VAM concentrations should be min ½ percent Carbon Credits should be minimum EUR 10/t CO2e

Overall OPTIMIZATION of CH4 - CMM and VAM emissions Very high volumes. Very low concen-trations. Low CH4 < 1% High CH4 >30% High CH4 Main Coal Mine Vent Shaft Coal Excavation

Overall OPTIMIZATION of CH4 - CMM and VAM emissions For optimization if motivated by VAM energy utilization. Low CH4 < 1% Gas Engines High CH4 >30% VAM processing Main Coal Mine Vent Shaft Coal Excavation

CONCLUSIONS CH4 & VAM and CARBON CREDITS(Climate Change perspective) CH4 is a very powerful GHG, especially short term Short atmospheric life time of CH4 means quick, positive effect on climate change VAM represents a major single emission source of GHG VAM PROCESSING Experienced RTO suppliers can provide proven VAM processing solutions There will be more suppliers and more technical solutions to VAM processing For best feasibility of VAM projekts, look for: VAM concentrations of ~½ % or more Possibility to enrich the ventilation air (into VAM processing) to min ½% Possibilities to utilize thermal energy close to ventilation shaft (cooling?) Look for good value of reducing VAM emissions (Carbon Credits or similar) Optimize your overall emission strategy between processing of drainage gas and VAM Richard.Mattus@gmail.com