challenges in implementation of underground coal gasification project

of 52 /52
Challenges in implementation of Underground Coal Gasification Project

Author: philip-byrd

Post on 31-Dec-2015




1 download

Embed Size (px)


  • Challenges in implementation of Underground Coal Gasification Project

  • The PresentationEnergy Scenario and UCG UCG A Brief ONGCs ExperienceLearningsSum up

  • India16% of Global population

    0.5% of worlds petroleum reserves

    7.1% of coal reserves

    Targeting 8-9% GDP Growth, the CAGR in primary energy demand works out to 4.5%

    India faces a formidable challenge on Energy front

  • INDIA.Has the 4th largest coal reserves in the world (264 Billion Tons)

    Ranks 3rd in coal production (492.95 Million TPA)

    Total Recoverable reserves are only about 20%Underground Coal Gasification is the only way to harness these unrecoverable reserves

  • The PresentationEnergy Scenario and UCGUCG A Brief ONGCs ExperienceLearningsSum up

  • What is Underground Coal Gasification? UCG Process

    Drilling of adjacent bore holes in the coal seam and its linkage Down hole ignition of the coal seamInjection of a pressurised oxidant such as air/oxygen and steam Removal of product gas to surface.

    Underground coal gasification (UCG) Converts coal / lignite in-situ into a gaseous product, commonly known as synthesis gas or syngas.


  • Carbon/coal gasification reactionsPartial CombustionC + O2= 2COexothermic

    CombustionC + O2= CO2 exothermic

    C + CO2= 2COendothermic

    Water-GasC + H2O= CO + H2 endothermic

    HydrogasificationC + 2H2= CH4exothermic

    ShiftCO + H2O= CO2 + H2 exothermic

    ReformationCO + 3H2= CH4 + H2Oexothermic

  • Composition of typical dry UCG product gas with increase of O2 enriched Air


    PowerNitrogenous Fertilizers PetrochemicalsLiquid FuelsProduct usage.Underground Coal Gasification

  • Technology plays an important role UCG processWell configuration and well spacing Different types of wells such as vertical, inclined or horizontal, with intersectionsWells to be completed properly with special high temp. resistant cements, tubular and well headsInjectors & producers need to connected and gasification passage Flame treatedCompression and injection of the air & steam through the set of injector wells for maintaining gasificationProducing, cooling and processing of the produced gas

  • The PresentationEnergy Scenario and UCGUCG A Brief ONGCs ExperienceLearningsSum up

  • UCG Pilot Flow Diagram

  • *1st stage : Site SelectionONGC working with Russian scientists to test UCG technology

    MoUs also signed with coal companies

    Fifteen sites studied Five sites found suitable for UCG

    One site in South Gujarat, prioritized for UCG pilot study

    The site is adjacent to the pit head Power Plant


  • 2nd stage : Detailed geological and Hydro geological studies

    More than 20 boreholes drilled

    Detailed Geological and Geo-mechanical studies carried out

    Hydrological & Hydrodynamic studies carried out

    HRSS carried out

  • 250X250-Line IntervalLines Covered (FS 06-07)Well for loggingDrilled Bore wellsLines Covered (FS 07-08)Seismic Grid

  • Structure Contour Map of Seam1 (based on 2D HRSS)V 7

  • Structure contour map

  • 3rd stage : Pilot Design

    Pilot lay out firmed up

    Detailed Engineering Design is available

  • The Commercial UCG Station Well Pattern..

  • The PresentationEnergy Scenario and UCG UCG A Brief ONGCs ExperienceLearningsSum up

  • UCG is a site specific technologyData required for proper site selection is not usually available with the mining companiesLarge amount of data like the hydro-geological data, seismic data, geo-mechanical data etc. has to be generated All these data generation can tend to delay the time schedule of the project, if not accounted for properly

  • *FFFFV-07V-07Use of seismic as an exploratory tool vis a vis borehole drilling

  • UCG process is technology dependentProcess wells in a UCG panel involves a combination of vertical and horizontal wells which need to intersect to make a gasification passageHigh degree of accuracy Drilling challenge to drill horizontal sections of more than 100 meters through coal / lignite at shallow depthProducers and injectors need to be interlinked and flame treated

    Syngas that is produced is at a high temperature of around 2000 C and needs to be cooled down before processing The clean up process will change with the end usage and is not similar to the one for conventional HC gas

    Project is technologically dependent - ready on the shelf solutions are not availableClaimed to be available with only selected few

  • UCG & EconomicsNo authentic publication of figures in literature for carrying out cost economics

    Sale of Syngas considered on energy basis (rate / BTU) will give the project a technological disadvantage

    Costing of a UCG Project and economic calculations thereof are a challenge

    A pilot must be considered as an R&D investment to boost the development of UCG in India

  • Regulations Gazette notification Issued in July 2007UCG can be end uses for the act Guidelines for UCG Issued in July 2009Provision for nomination of coal blocks to National coal companiesThe applicant company should have minimum net worth of Rs. 200 croresThe applicant company should have collaboration /tie up with the proven technology providersThe normative time limit Explored Blocks - 36 monthsUnexplored Blocks -24 months +36 monthsPenalty for slippage in meeting time limit

  • Flow diagram of UCG Commercial PlantStart UCG is site specific technology It requires pilot testing before commercialisationLinc Energy Chinchila Pilot(1999 - 2003)Restarted Commercial operations in 2007 and reached up to Demo in 2009A demo plant has to be consideredbefore commercialisationGovt. coal companies given preference forNomination of Blocks

  • The PresentationEnergy Scenario and UCG UCG A Brief ONGCs ExperienceLearningsSum up

  • The energy requirements of India are expected to grow by CAGR of 4%. Coal will continue to occupy centre-stage of India's energy scenario

    UCG is the only feasible technology to harness energy from deep unmineable coal seams, in an economically and environmentally clean way

    ONGC has embarked on a highly prestigious project of UCG and is poised to demonstrate the UCG technology in the near future

    Summing up

  • ContThe complexity of UCG makes it technologically dependent where still ready on the shelf solutions are not available. The technology required for drilling, linkage, flame treatment and hot gas clean up is claimed to be available with only selected few

    Costing of a UCG Project and economic calculations thereof are a challenge

    The present statutory regulations require further refinement

  • RecommendationsPreference for award of coal blocks should also be given to other coal companies who can demonstrate the technology early

    Provision of a pilot and a demo plant has to be made in a UCG Project, which if successful should be followed by a commercial venture. This will necessitate increasing the normative time for commercialization of UCG in the guidelines

    Since UCG is a complex underground process, which is yet to be commercialised in India, it requires support of GoI in the form of relaxation in policies and a lucrative economic package. This will help in faster development of UCG Technology in India

  • Geological Section of Vastan (Dip)DD:249.7DD:342DD:280.5DD : 249.7 mDD : 342.0mDD : 280.5 m

  • Composition of typical dry UCG product gas (Calorific Value 13.6MJ/Nm3)(Spanish Trial-Gasification with Oxygen) (Angrenskaya Gasification with Air Injection)(Calorific Value 3.5 MJ/Nm3)

  • Product Gas Composition

    CompositionWet Gas, % WtDry Gas, % WtCO213.8319.37CH41.381.94CO5.347.48H2S0.080.10H210.4514.63N240.1156.16H2O28.580C2H40.230.2O200

  • Flow sheet of gasifier, UCG pilot

  • Earlier Field Trials

    UCG has been tested in many different experimental tests in many countries.

    The Former Soviet Union executed over 50 years of research on UCG, field tests and several commercial projects, including an electric power plant in Angren, Uzbekistan that is still in operation today after 47 years.

    The U.S. carried out over 30 pilots between 1975 and 1996, testing bituminous, sub-bituminous, and lignite coals.

    Since 1991,China has executed at least 16 tests, and has several commercial UCG projects for chemical and fertilizer feedstocks.

    In 2000, Australia began a large pilot (Chinchilla) which produced syngas for 3 years before a controlled shut-down and controlled restart.

    At present, multiple commercial projects are in various stages of development in the U.S., Canada, South Africa, India, Australia, New Zealand and China to produce power, liquid fuels, and synthetic natural gas.

  • Development of a Generalized Simulation Model Factors to be considered

    Drying of porous mediaDevolatilisation or pyrolysis of coalGasification reactions of char with oxygen, carbon dioxide, steam and hydrogenGas phase reactions combustion, water-gas shift and methanationGas flow turbulent and laminarHeat transfer conduction, convection and radiationWater flow through porous mediaPhysical and thermal degradation of solidsSite layout and geophysics

  • Downstream Application of the Syngas:Dimethyl Ether (DME) can be used : For Power Generation, As LPG Substitute, As Transportation fuel, As Chemical feedstock etc.Methanol to Olefins (MTO) Coal gasification route can be extended to manufacturing olefins from methanol (called MTO). Coal to Liquid Petroleum (CTL) The project involves direct conversion of coal to syngas, from which hydrogen will be separated to be further processed along with coal to produce liquid hydrocarbon (Fischer Tropsch process). This liquid hydrocarbon will be refined / distilled like in a typical refinery to produce gasoline and diesel, naphtha etc. Waxes are the byproduct of this process.

  • Downstream Application of the Syngas:Ammonia / Urea N2+3H2 2NH3 2NH3 + CO2 CO(NH2)2 +H2O Methanol for Gasoline Blending CO + 2H2 CH3OH

    Dimethyl Ether (DME) MeOH Synthesis CO + H2 CH3OH MeOH Dehydration2CH3OH CH3OCH3 + H2O Water Gas ShiftH2O + CO H2 + CO2 Net Reaction:3H2 + 3CO CH3OCH3 + CO2

  • Process efficienciesEfficiency of processes for electricity production

    ProcessEfficiencyIGCC ~45.0%Conventional coal~37.0 %

    UCG-CO2 separation39.8 %

    Oxygen UCG46.5 %

    Air UCG45.4 %

  • The gasification occurs within a bubble in an aquifer the gas pressure inside the bubble prevents the water from quenching the reactions.

    Due to the elevated temperature of the gas, water evaporates into the bubble and it is only the flow of water through the surrounding solids that prevents the gas bubble from expanding excessively, a situation that can lead to loss of gas into the surrounding strata.

    The location and size of the bubble will depend on factors such as the gas pressure, temperature and water inflow rates.

    Release of volatiles from the coal is likely to cause hot regions due to combustion of the volatiles, causing localized drying. Conversely, in cold regions it is likely that water will seep into the void and reactions will be extinguished.

    Concept of UCG Process

  • While char combustion is possible in the void, it is unlikely that it will be sustained due to all oxygen being consumed before it can contact the char surfaces.

    Most char will be consumed by steam and carbon dioxide gasification reactions, with steam dominating due to the high moisture levels.

    As these reactions are endothermic, they require that the char must be kept hot for reaction rate to be maintained. This requires locally high gas temperatures and heat transfer through radiative or convective means,

    The driving force for a sustainable UCG process will be the combustion of volatiles and gasification product gases by the injected oxygen.

    Concept of UCG Process

  • Shift conversion:CO + H2O CO2 + H2 + 42.3 KJ/ Kmole The rxn is used to adjust H2/ CO ratio in the feed gas for methanation/ hydrogenation rxns. Also used in reforming rxn of CH4. and NH3 production.Methanation/ Hydrogenation reactions: is used to produce additional CH4 from H2 and the oxides of carbon in case of SNG production.CO + H2 CH4 + H2OSteam reforming:CH4 + H2O CO + H2- 206 KJ/ KmoleCH4 + 2 H2O CO2 + H2- 167 KJ/ moleThe CH4 is reformed under specific CO/ H2 ratio thru shift conversion of CO

  • Potential of UCG Syngas ~64.17 TCMWhat UCG can offer for India 303 Billion Tons (Coal+Lignite Reserves)47 Billion Tons(Minable Reserves)256 Billion Tons (Unminable Reserves)25.7 Billion Tons(Reserves amenable to UCG)

  • Indias Energy Mix (Requirement)Total 306 kgoeTotal 1125 kgoeSource: Integrated Energy Policy, Govt. of India, Planning commission, New Delhi Oil consumption to grow by CAGR 4.0%Gas consumption to grow by CAGR 6.1%

  • Underground Coal Gasification

    Underground coal gasification (UCG) is the in-situ conversion of coal into combustible gases (CO, H2 & CH4)

    A complex process involvingchemical reactions heat and mass transfercomplex flow dynamics &growing cavity dimensions.

    Advantages over conventional process areLow dust and noiseNo ash handling at power stationsNo coal stocking and transportationLarger coal resource exploitationConverts sulphur (S) to H2S and nitrogen (N) to NH3 instead of SO2 and Nox

    DisadvantagesSurface subsidenceAquifer water contamination

  • Revival of Interest in UCGEarly part of last century -there was lot of interest in UCG especially in erstwhile USSRSubsequently, huge natural gas reserves were discovered in Russia-interest in UCG died outSurge in demand for energy as well as prices of crude oil has renewed interest in UCG all over the worldRecently, Australia and South Africa have carried successful tests. In China and other parts of the world several projects are planned/ being carried out

  • *ONGC an Indian State Enterpriseand an integrated Oil & Gas Corporate with interests in E&P, Refining, LNG, Power, Petrochemicals & New sources of energy

    a reliable energy solution provider for the country

    In pursuit of new Energy Sources CBM: Coal Bed MethaneUCG: Underground Coal Gasification

  • Synergies between Oil & Gas and UCG

  • Commercial UCG StationV-7V-1V-13V-8V-14V-2V-3V-4V-5V-6V-15V-16V-17V-18V-9V-10V-11V-12Plan to produce 2 BCM Syngas fromtwo gasifiers per year

  • SuggestionsInclusion of Pilot and demo plant to be considered in the overall scheme thereby increase in time limit for commercialisation

    Preference for award of coal blocks be given to companies who can demonstrate the technology early

    Lucrative economic package by the GoI will help faster development of UCG Technology in India

    **As we know coal consists of 50% carbon by weight and 70% by volume. During partial combustion in presence of oxygen, the coal converts into cabon monoxide and produces cabon di-oxide during total combustion. At higher temperature and pressure, the carbon reacts with cabon di-oxide produces carbon monoxide. When steam is injected over hot coal it coverts into cabon monoxide and hydrogen. Hydrogen reacts with hot coal forms methane and cabon monoxide reacts with hydrogen converts into methane.To generate more cabon monoxide and methane, it is required to inject oxygen and steam instead of air***1 Ton of Lignite can produce about 1700 KWH of electric energy.1 Ton of Lignite can produce 1.2 bbl of Synthetic diesel ! Ton of coal can produce about 2800 m3 of Syn Gas.