Coal-To-Liquids (CTL) & Fischer-Tropsch Processing (FT)

CCTRIndiana Center for Coal Technology ResearchCoal-To-Liquids (CTL) &Fischer-Tropsch Processing (FT)CCTR Basic Facts File # 1Brian H. Bowen, Marty W. Irwin, Devendra CanchiThe Energy Center at Discovery ParkPurdue UniversityCCTR, Potter Center, 500 Central DriveWest Lafayette, IN il: cctr@ecn.purdue.eduJune 20071Indiana Center for Coal Technology Research

CCTRCTL TECHNOLOGYThere are two main processes:[1] Coal to SynGas & [2] SynGas to FT FuelsWith two major equipment needs:COAL GASIFIER & FT REACTOR[1] Coal to SynGas[2]SynGas to FT ProductsNote: ATR, Autothermal Reformer2Indiana Center for Coal Technology Research

CCTRCOAL FOR THE FT PROCESSThe chemical content and physical parameters of thecoal supply for gasification, prior to the FT processing,will influence the design & operation of the CTL facilityCarbon forms more than 50% by weight & more than70% by volume of coal (this includes inherent moisture).This is dependent on coal rank, with higher rank coalscontaining less hydrogen, oxygen & nitrogen, until95% purity of carbon is achieved at Anthracite rank &above3Indiana Center for Coal Technology Research

CCTRCOAL CONTENTSVolatile matter consists of aliphatic carbon atoms (linked in openchains) or aromatic hydrocarbons (one or more six-carbon ringscharacteristic of benzene series) and mineral matterAsh consists of inorganic matter from the earth’s crust:- limestone,iron, aluminum, clay, silica, and trace elements (concentrations ofless than 1000 ppm [ 0.1% of a rock’s composition] of zinc, copper,boron, lead, arsenic, cadmium, chromium, selenium)4Indiana Center for Coal Technology Research

CCTRTYPICAL PERCENTAGES OF CONTENTINDIANA COAL &ILLINOIS BASIN COALCoal Types (Rank) and Material ContentAnthraciteBituminousLignite2.8 – 16.32.2 – 15.939.0Fixed Carbon 80.5 – 85.744.9 – 78.231.4(% Weight)MoistureAsh9.7 – 20.23.3 – 11.74.2Sulfur0.6 – 0.770.7 – 4.00.4Bulk Density (lb/ft3)50 - 5842 - 5740 - -coal-d 164.htmlIndiana Center for Coal Technology Research5

CCTRCOAL PHYSICAL PARAMETERSEach type of coal has a certain set of physical parameterswhich are mostly controlled by(a) carbon content(b) volatile content (aliphatic or aromatic hydrocarbons) &(c) moisture Aliphatic - designating a group of organic chemical compounds(carbon compounds) in which the carbon atoms are linked in open chains Aromatic - containing one or more six-carbon rings characteristicof the benzene series Hydrocarbons - numerous organic compounds, such as benzene &methane, that contain only carbon & hydrogen6Indiana Center for Coal Technology Research

CCTRCOAL RANKThe degree of 'metamorphism' or coalificationundergone by a coal, as it matures from peatto anthracite, has an important bearing on itsphysical and chemical properties, & is referredto as the 'rank' of the coalVolatile matter, H2 , O2 , NHIGHMoisture ContentCarbon/Energy ContentLow Rank CoalHIGHHigh Rank CoalVolatile matter decreases as rank cation.htm#typesIndiana Center for Coal Technology Research7

CCTRCOAL VOLATILE MATTERVolatile matter is material that is driven off whencoal is heated to 950 C (1,742 F) in the absenceof air under specified conditions - liberated usually asa mixture of short & long chain hydrocarbons,& measured practically by determining the loss of weightConsists of a mixture of gases, low-boiling-pointorganic compounds that condense into oils uponcooling, & l-utilizationIndiana Center for Coal Technology Research8

CCTRSULFUR IN COALAlthough coal is primarily a mixture of carbon (black)& hydrogen (red) atoms, sulfur atoms (yellow) arealso trapped in coal, primarily in two forms. In oneform, (1) the sulfur is a separate particle often linkedwith iron (green, pyritic sulfur) with no connectionto the carbon atoms, as inthe center of the drawing(fools gold). In thesecond form, (2) sulfur ischemically bound to thecarbon atoms (organicsulfur), such as in theupper leftSource: /coal/coal cct2.htmlIndiana Center for Coal Technology Research9

CCTRGASIFICATION BASICS10Indiana Center for Coal Technology Research

CCTRPRODUCTS OF GASIFICATION11Indiana Center for Coal Technology Research

CCTRBEGINNINGS OF THE FT PROCESSThe process was invented in petroleum-poorbut coal-rich Germany in the 1920s, to produceliquid fuels. The invention of the original processwas developed by the German researchersFranz Fischer and Hans Tropsch at theKaiser Wilhelm Institute. It was used byGermany and Japan during World War II toproduce alternative fuels. Germany's annualsynthetic fuel production reached morethan 124,000 barrels per day in 1944(from 25 plants, 6.5 million tons)Source: ls history.htmlIndiana Center for Coal Technology Research12

CCTRFT PROCESS BASICSThe Fischer-Tropsch process uses hydrogen (H2)and carbon-monoxide (CO) to make differenttypes of hydrocarbons with various H2:CO ratiosH2COHydrocarbonsIn a CTL facility the H2 and CO can besupplied from the coal gasifier13Indiana Center for Coal Technology Research

CCTRFT PROCESS BASICSThe original Fischer-Tropsch process is describedby the following chemical equation:(2n 1)H2 nCO CnH(2n 2) nH2OThe initial FT reactants in the above reaction (i.e. CO& H2) can be produced by other reactions such asthe partial combustion of a hydrocarbon or by thegasification of coal or biomass: C H2O H2 COFT reactants can also be produced from methanein the gas to liquids process: CH4 ½O2 2H2 COSource: http://en.wikipedia.org/wiki/Fischer-Tropsch processIndiana Center for Coal Technology Research14

CCTRSYNGAS TO FT REACTOR15Source: Eastman Chemical CompanyIndiana Center for Coal Technology Research

CCTRH2:CO RATIOProportion Converted to HydrocarbonsThe products of FTsynthesis includehydrocarbon chains,oxygenates, water& carbon-dioxideamong others atvarying proportionsdepending on thecatalyst used &reactor conditions.The efficiency ofthe FT reaction iscommonly measuredSynGas H2:CO Molar Ratio Input {(Moles of converted CO &H2)/Totalby the conversionMoles of CO & H2)} to Synthesis Reactor, Fixed Volume of (CO H2)ratio, also known asThe FT process still produces CO2 although substantially the rate of FT reactionsmaller amounts compared with the gasification processSource: TITLE Williams, Larson, Jin, 2006Indiana Center for Coal Technology Research16

CCTRSLURRY- PHASE FT REACTORSteamC1 to C4 Liquefied Petroleum Gas20o CHeight 65 ftWater used forheat transferFT Wax(Liquid Hydrocarbons)Fractionsdecreasingwith boilingpoint70o CC5 to C9 Naphtha and Other ChemicalsC5 to C10 Gasoline120o C170oC10 to C16 Kerosene, Jet fuelCC14 to C20 Diesel Oils270o CSynGas bubbledinto a slurrysuspended withcatalystC20 to C50 Lubricating Oils375o CC20 to C70 Fuel Oil600o C C70 ResidueSyn-gasDiameter 15ftCatalyticHydrocracker17Indiana Center for Coal Technology Research

CCTRFT & CATALYSISThe FT Process is a catalyzed chemical reaction inwhich carbon monoxide and hydrogen are convertedinto liquid hydrocarbons of various formsThe catalyst used (often based on iron or cobalt) is achemical compound that increases the rate of achemical reaction without altering the finalequilibrium (catalysis is purely a kinetic phenomenon).Catalysts reduce the free activation energy whichthen quickens the speed of the reaction‐ M‐ ‐ ‐CO‐‐M MetalCO Carbon MonoxideThe ligand CO (propensityto bonding) exchangeselectrons with the MetalIndiana Center for Coal Technology Research18

CCTRCATALYSTS & PRODUCTSCATALYSTPRODUCTIronLinear alkenes and oxygenatesCobaltAlkanesNickelMethaneRutheniumHigh molecular weight hydrocarbonsRhodium Large amounts of hydrocarbons & little oxygenatesNote: Alkanes are hydrocarbons containing only single covalent bonds.Alkenes are hydrocarbons containing a double covalent bond betweentwo carbon atoms. Oxygenated substances have been infused with oxygen.Oxygenates are usually employed as gasoline additives to reduce CO thatis created during the burning of the fuel19Indiana Center for Coal Technology Research

CCTRCTL GLOBAL PRODUCTION RATES1944 Germany’s production 124,000 B/DNote: B/D Barrels per DaySource: es/ctl/map.xmlIndiana Center for Coal Technology Research20

CCTRPRODUCTS FROM ABARREL OF CRUDE OILOne barrel of crude oilproduces nearly half abarrel of gasolineNumbers are based on average yieldsfor U.S. refineries in 2000. One barrelcontains 42 gallons of crude oil. Thetotal volume of products made is 2.6gallons greater than the original 42gallons of crude oil. This represents‘processing gain’Source: of%20oilIndiana Center for Coal Technology Research21

CCTRWHAT CAN BE PRODUCEDFROM A CTL FACILITY?The final products coming from a CTL facility are decidedupon during the initial stages of plant design22Indiana Center for Coal Technology Research

CCTRU.S. POTENTIAL CTL REGIONS23Indiana Center for Coal Technology Research

Indiana Center for Coal Technology Research 3 CCTR COAL FOR THE FT PROCESS Carbon forms more than 50% by weight & more than 70% by volume of coal (this includes inherent moisture). This is dependent on coal rank, with higher rank coals containing less hydrogen, oxygen & nitrogen, until 95% purity of carbon is achieved at Anthracite rank & above