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Development of Granular Catalysts and Natural Gas Combustion Technology for Small Gas Turbine Power Plants

80Gas TurbiIn ation for at leastratures over 1200 K (McCarty et al 1999)Material developmentthe keyto possess high mechanical strength and the ability to initiate methane oxidation in leanmixtures at low temperatures 620-720 K antain stable oxidation during long time atemperatures above 1200 K (Dalla Betta et al, 1995; Dalla Betta Rostrup-Nielsen, 1999)Today catalysts for gas turbines are prepared in the form of monoliths from foil made ofresistant alloys with deposited porousand the active componebased on platinum andy or palladium(Dalla Betta et al, 1995a: McCarty et al 2000; Carronit al 2003) However, application of such catalysts requires many prolrelated to the high temperature of gas typical for modern gasprolonged periods of time(total operation time of modern GTPPs reaches 100000 hoursupports able thermal corrosion, especially in the presence ofvapor

It results in thetalyst destruction, peeling of the support and loss of noble metals dility isOne of thehes to solve this problem is based on develecatalystsulated supports and design of a catalytic package for GTPP combustion chamberwhich would provide minimum emissions of NOx, CO and HC at moderate temperaturespresent our results on development and study of alternativef 400-500 kw power with regenerative cycle, intended for decentralized powerThe small power of these turbisults in reduced catalyst loading and makesexisting industrial faciliti2 Selection of catalysts for application in gas turbine combustorsthe least readidizable hydrocarbon Therefore, it is necessary to produce catalystspable of initiating methane oxidationinimum possible temperatures andthstandinIt is very difficult to find catalysts meeting requirements ofactivity at lowustors generallythe loatalyst which converts fuel at higher temperatures(Tin approx 700C T a secondmperature(350C Tin < 450Cof CH4 must be(Carroni et al 2002)ell known that catalysts based on noble metals750C because of a high volatility of the noble metals(Arai et al 1986of palladium asthe active component in the high-temperature oxidation of methane is most piThisbecause palladium has a high specific activity in this reaction( Burch Hayes, 1995; LeeTrimm, 1995)and a relatively low volatility in comparison with other noble metals,as

Development of Granular Catalysts and Natural Gas Combustion TechnologyThe temperature cycle mode consisted of four cycles of gas combustion, catalyst cooling andd inlet temperature 580-600 C The valrheight of the catalytic package was 300 mm The dynamics of changes in the activity ofdifferent catalysts are presented in Fig 4990x6080100120Time on stream hFig 4 methanevS operation time in CCC at GHSV: 14, 900-15, 100 h-l and a67-68 Uniform catalyst package loaded with: (1)Mn-AlO(Tin-600C): (2)Mn-La-Al2O3Ii-600°C;(3)PdMn-La-AlO3(Tm-575-580°CThe data presented in Fig 4 indicate that the catalysts Mn-AlO3, Mn-La-Al2O and PdMn-La-Al2O differ both by their activity and stability For example, the activity of the MnAl2O catalyst gradually decreased as evidenced by gradual increase of the methane andtration at the CCC outlet, The methdecreased from 99

6% to 979ring the first 50-54 h on stream Then the catalyst activity stabilized and did not change in) At the end of the experiment the methanees the outlet temperatures and emissions of CH4 and Co during natural gascombustion over Mn-Al2O catalysts with different fractional compositions at GHSV15,000 h-L It was shown that the methane combustion efficiency over large catalyst granulesth the external ring diameter 15mm was lowNote that under similar CCC operation conditionsoplication of catalyst granules withmal diameter 75se of the methane emission and30-fold decrease of the co emission In both caCC efficiency also depended orontact time TheV=15,000 h-1)to 042 s(GHSV00 h-l)affected more significantly the efficiency of CCC loaded with the catalyst withmaller internal and external diameters of the granules(75er fractiothe catalyst bed These dane mass transfer of thereaction products to/ from the catalyst surfacetially affects the total cCin methane combustion at the inlet temperaa e hsarC At this temperature

Gas Turbiproceeds mainly on thesurface and the contribution of hen with the increase of the catalysts geometrical surfaceee with the work(Hayashi et al, 1995) where the authorsdependences ofbutions of heterogeneous and homogeneoxidation reactions on the monolithic Pt-Pd catalyst on the inlet temperature, pressure andthe catalyst channel density, Placing the catalysts with small cells(200 cpsi)in the front parttheth with larger channels(100 cpsi), especially at temperature 700the homogeneous oxidation reaction was prevailingFrac- Gair, GNGHSVXCHAppm ppm ppm194309149006785779867920917328102150243115006705676779039269057351110850652295s94891921480059062363898989879435150271006105706047399960662962814850090562591790903897504344olume flow ratencentrations of CHi co and NO X othermocouples placed along the catalyst bed at different distances from the CCC inlet: T1-25 mm;: T:Table 6 Parameters of methane combustion over Mn-AlzO3 catalysts with differentfractionalpositiodecrease wadramatpared to the Mn-Al2O3talyst( Fig 4) The methane conversion over Mn-La-Alodecreased from 99

5% to 993%(Fig 4, curve 2)and from 997% to 99AlzO catalyst that showed similar values at 600 Cerature 575C than the mn -Laerature The NO,concentration at the outlet of the catalyst package did not exceed 0-2 ppm on all theThus, the obtained results demonstrate that the activity of the Pd-Mn-La-AlO3higher than that of thehile, the stability of thisas comparable to that of Mn-La-Al2O being determinhexaaluminate phatalyst based on Mn oxide These results of the catalysts testing under the above conditionset al 2002: Tf Mn-aluminaearthetals allowed a considerable inof thermal stability of the catalysts due to the

Development of Granular Catalysts and Natural Gas Combustion TechnologySmall grbine powe9formation of manganese-te phase(Yashnik et al 2006: T'sikoza et al, 2002)of the air-natural gas mixture(Yashnik et al, 2006)The pressure drop on the full height of the catalyst bed for unifoding of the catalystsAlO Mn-La-AlO3espectively These valrof the total pressure whichure 5 shows the effect of the air/fuel equiratio on the outlet temperature andmethane conversion over the catalyst package loaded with the Mn-La-AlzO3 catalyst Thevariation of a between 62 and 7 2 showed that its decrease (enrichment of the fuel-airmixture with methane) resulted in a growth of the temperature at the outlet of the catalystbed and, consequently, increase of the methaneion For inwhendecreased from 7 to 62, the methane conversion increased from 99

3% to 9993% and thegrew from 937 to 9g2 C at GHSV= 15,000 h-1, Howably leaddeactivation therefore alternatithe methanehamber Several methods for stepwise combustion of hydrocathe gtPP CCcive been implemented American comCatalytica(Dalla Betta Tsurumi, 1993)andestinghouse Electric Corp (Young Carl, 1989)suggested feeding the fuel-air mixture tot if the surface reaction in the channel with a catalyst takes place in the diffusion - controlledegime, adiabatic heating to themperature does not occur because the heat istransferred to the inert channelmonolith, The fuel-air mixture exiting the inertchannels is burnt at the exit of theth catalystFig 5 Dependence of methane conversion(filled symbols) and catalyst temperature at theCCC outlet (open symbols) during methambustion in CCC loaded with Mn-La-AlO3talyst on a GHSv 15, 000 h-1, Tin-600

Gas TurbiIn patents(Dalla Betta Tsurumi, 1993; Pfefferle, 1997) it was suggestth different levels of activity to carry out combustion in the kinetically coegime The catalytic activity is regulated by varying the concentration of the noble metalmost often Pa) in the range of 5-20 wt or the nature of the active component (noble metal,transition metal oxides) Itso suggested (Dalla Betta Velasco, 2002)to use a two-stagethic catalyst combined from catalytic systems with different thermal stabilities Atalyst with low ignition temperaturne whereas a catalyst resistant to the action of high temperatures is placed at the exitests of ccc with cortwo-stage catalyst packaguggestedlysts with then but different fractionalhe Pd-Mn-La-AlO3talyst as an example we studied the effect of the catalyst bed fractional void volume on theCC, The n052a catalyst laver with 60erical granules withfractional void volume 0

42 was placed near the outlet of the package The total pdntration in the catal%The application of the spherical catalyst at the CCC outlet made it possible to achieve over9% combustion efficiency(Fig 6)and decrease the methane concentration from 85 ppmnts the methane and Co profiles along the reactor length Onesee that more than 90% of methaxidized at themum CO concentration is observed in this region, Furtheand CO to concentrations below 10 ppm is observed mostly at 280-340 mm from the inlet of∵,,80100120140Time on stream hFig 6 Methane conversion time in CCC for different catalyst packages: ( 1)-Al Os, rings(Tin=575-580C, GHSV= 15, 100 h-l,aPd-Mn-La-Al2O, rings and spheres (Tiombined catalyst package: Mn-La-AlyO3, rings, and-Mn-La-Al2O3, spheres

sma as turbine lawar alysts aand Natural Gas Combustion Technology300550100150200250300350Reactor length, mmFig 7 Profiles of methane and COrations along the reactor length duringbined catalyst package Pd-Mn-La-Al2O3: 280 mm ofrings and 60 mm of spherical granules (Tin=580C, GHSV= 12,500 hd The layer of thistalyst has a higher deand higher geometricalThen, we determined the role of catalyst activity in the total CCC efficiency We carried outtests on a combined catalyst package consisting on Mn-La-AlzO(rings)and Pd-Mn-LaAlzO3(spheres) and compared the methane conversion with the results of the previous testtotal pd content in cccmuch loabout 0

1 wt because most of the catalystckage consisted of the Mn-La-Al O catalyst The activity of this catalyst (Tso CH4)lower than that of Pd-Mn-La-AlzOs Table 3) However, the substitution of the more activeof the total pd content (fase the methanebustion efficiompared to the previous test( Fig 6, curv2)where the total Pd content was 06 wt % Thus, increase of the efficiency of the use of thelyst granules even at a relatively short length of the CCC results in a noticeablecement of the overall CCC efficiency at a low total Pd loadingHowever, such CCC design produced a larger pressure drop than the uniform catalystkahe layer of the spherical Pd-Mn-La-Al2O3s catal20 and 13 mbarThe tests of CCC with a combined two-stage catalyst package at lower inlet temperathowed that the inlet temperature decrease from 580 to 470 c decreased the methanecombustion effcv The methanekage Pd-Mn-La-AlO3ngs)/Pd-Mn-La-Al2O3(decreased from o 93% to 99% with methane and cocentrations increasing to 37 and 150 ppm, respectively The methane conversiocatalyst package Mn-La-AlzO(rings)/Pd-Mn-La-Al2Os(spheres)at the inlet temperature

Gas Turbi470 C was only 994% with methane and CO concentrations 90 and 220 Ppm, respectivelyThe increase of the methane combustion efficiency at low inlet temperature was made54 Tests of ccc with col2 wt %o PeMost of the package consisted of Mn-La-Al2O catalystBoth catalysts were shaped as 75 mm x 75 mm x 25 mm rings Pd-Mn-La-Alg O catalystin the form of 4-5 mm spherical granules was placed in the downstream part of the catalystof the catalyst Iats was 40/240/60mm Similarly to the teststwo-stage packages, the ratio of the heights of ring and spherical granules was 280/60mmThe tests were carried out at the inlet temperature 470 o C, GHSv= 10,000 h-1 and52Under such conditions the temperature at the outlet zone of the catalyst package remainedat about 950 oCmperature profile along the CCc length In the inlet zone filled withhe Pd-Ce- Os catalyst at 25 mm from the inlet the feed is heated from 470 to 580

c duecatalytic combustion of methane The latter temperature is sufficiently high for effectivefunctioning of the main12O catalyst bed Further temperature growth from 580950C takes place on this catalystThe profiles of the methane and Cog the CCC length are show8b The methane concentration profile shows a sharation fall in the inlet zonewhere the Pd-Ce-AlzO catalyst is located The main decrease of thetration from1% to 170 ppm takes place in the zone of the maint Mn-La-AlO(40-280 mThen at the CCC exit in the layer of the spherical Pd-Mn-La-Al2O catalyst the residualamounts of methane burn from 170 to 0-10 ppm concentrations The concentration of theintermediate initially grows Then, when most methane is oxidized, then also decreases from 300 to 40in the Mn-La-Al2O3 bed Finally, residualCO is burned in the spherical Pd-Mn-La-Al2O3 catalyst tom concentrations TheThus, the use of the three-stage combined catalyst package including a thin layer of theactive palladium-ceria catalyst located at the CCC entrance before the main oxidbed allows us to increase the CCC efficiency for methane combustion and obtain requiredane emission value of 10 ppm at low inlet temperature 470 C This additionalprovides the initial methane6 Modeling of methane combustion processes in a catalytic combustp

ackages used in modeling are schematically presented in Fig 3 Forcalculation of the catalyst package perforeactor The calculation of the terture profiles and methane conversioned at variation of catalyst methane oxidation activity and geometry of catalysttio of bed lengths of different catalysts in the package, temperature, pressurend gas space velocity in the combustor

sma as turbine lawar alysts aand Natural Gas Combustion TechnologyReactor length, mm求288天50100150200250300350Reactor length,Fig, 8 Profiles of temperature(a)and methaneO concentrations (b along the reactorngth during combustion of natural gas on a combined catalyst package Pd-Mn-La-Ce-Al2O3(Tin-470C, GHSV- 10,000 h-I, a-5

2The reaction rate was calculated using Eqs (1)and(2)the methane concehich thetally (in this case it is equal to l bar), n is efficiency factor(dimensionless), kothe pre-exponential factor of the kinetic constant(s-), E is the activation energy mol-l)the univeral gas constant molK ), e is the fractional void volume in the catalyst bed(dimensionl

and Natural Gas Combustion Technologydetermined by studying the interaction of the metals with oxygen at 730-1730 C(McCartaL, 1999) It is these properties of palladium that attract researchers' interestbehavior in the methane oxidation reaction It is well known that, up to 800%C, palladiumexists as Pdo which undergoes reduction to palladtal as the temperature is furthertion is reversible up to ca 900C, so a decrease in temperature leads to thereoxidation of Pd to PdO in air As a consequence, the temperature dependence of theis(Farrauto et al 1992) There is stillon its surface, or Pd particles covered by Pdo -is the most active species in combustion((Mc Carty, 1995; Burch, 1996; Su et al 1998a; Su et al 1998 b; Lyubovsky Pfefferle, 1998,pfaffupporting of palladium on a substrate, primarily y- or a-Al O3 or Al]O modified withthe activity and thermal stability ofponent andegation stabilityBaldwin Burch, 1990; Groppi et al, 1999, Ismagilov et al, 2003,a,2003,LDeganello, 2003; Yue et al

, 2005)ternative catalytic systems for methane combustion are catalysts based on hexaaluminatesand transition metal oxides Hexaaluminates are the class of compounds with a generalformula ABAl12-O19, where A is a rare- earth or alkaline-earth metal, such as la and bnd B is a transition metal with an atomic radius comparable to the radius of aluminove 1200C, and this is why they are very stable up to hightemperatures The specific surface area of hexaaluminates and, accordingly, their activity inmethane oxidation depend on the preparation method( Choudhary et al 2002) Howespective of their specific surface area, the hexaaluminates are much less active than thepalladium catalysts In view of this, there have been attempts to enhance the catalyticactivity of hexaaluminates by introdPd gang et al, 1999)k(Yashniktal2006roducing 05 wt Pd inthexaaluminateMn, Mg)LaAlnO1g resulted in a significant increase in the catalyst ac

Gas Turbi3 Synthesis of granular catalysts for methane combustionat the boreskoy institute ofCatalysis(Shepeleva et al, 1991; Ismagilov et al, 1991, Koryabkina et al, 1991; Koryabkinaet aL, 1996) prepared in the form of spheres and rings Their characteristics are presented inPropertyRing-shapedDiameter mnI Pore volume(H-O), cm3/g045Specific surface area, m2/gCrushing strength under static conditions, kg/cm2PhaseY-Al2O340%X-Al2O3Table 1 Physicochemical properties of the spherical and ring shaped aluminasPd-Ce-Al2O3, The catalprepared on the ring-shaped support andd12% CeO, and 2 wt Pd It wapport withd(NO )z solution Before being loaded with palladium, the alumina support modified witlm was calcined at 600"C After supporting of palladium, it wasnally calcined at1000C The pilot catalyst batch was designatedMn-Al2Oj The catalyst was prepared on the ring- shaped support by the incipient wetnesselution it contained 1 wt %manganese oxides in terms of mno trate(Mn(NO)2-6H20)mpregnation of the support with an aqueoustemperature was 900 C

It was similar in composition to the commercial catalystfor this reason, its pilot batch is hereafter designated IKT-12-40AMnr-La-Al2O3 This catalyst was prepared on the ring-shaped support by successivecipient-wetness impregnation of alumina with lanthanum andolutions using the procedure described in (Yashnik et al, 2006) It contained 8-11 wt %ons of MnO and 10-12 wt lanthanum in termsand lanthanasuffichigh catalytic activityand stability of the catalyst(Yashnik et al, 2006) The calcination temperature was 1000Cthan the temperature used in our previous study (rashnik et al, 2006)and was equalto the onset temperature of hexaaluminate phase formation This allowed us to increase theof the sample The pilot catalyst batchprepared on the ring-shaped support bywetnessles were dried and calcined at 400%C Thereafter the samples were loaded withpalladium nitrate solution by impregnation Final calcination was carried out at 1000C Theesulting catalyst contained 8-1l wt Mn in terms of MnO2, 10-12 wt La in terms203, and was 065 wt Pd The pilot batch of the catalyst was designated IK-12-62-2

Development of Granular Catalysts and Natural Gas Combustion Technologymall grbine powe83alystsngadditionally containing lanthanum and palladium,igated how theirphysicochemical and catalytic properties depend on their chemical composition, the activeonent and modifier(manganese, lanthanum, palladium,hexaaluminate phasetents, the chemical nature of Mn and Pd precursors, the calcination temperature, and theactive component introduction method (ashnik et al 2006; Tsikoza et al 2002 Tsikoza efal, 2003) Measuring the catalytic activity of catalyst samples in methane oxidation allowede properties are listed in Tablsupport(IK-12-60-2, IKT-12-40A, IK-12-61, IK-1Institute of CatalysisThe results of these tests are presented in Table 3 The catalyst IK-12-60-2 retained its highr 100 h: then temperature ign) was 240C, and the reaction productswere almost free of co and NO, Thethese catalysts, Tresidual CO and NOx contents were higher than with lK-12-60-2However, the initial activity of the catalyst IK-12-61 did not decrease, but even graduallyeased during testing: in 200 h, Tign falls from 365 to 350 C, the NO concentration in thereaction products remaintemperature of the methane-air mixture almost by 100C and thede service lifeteststhat all catalysts are tolerant to high temperatures (up to 930C)and to thethe reaction medare and the methane-air combustionefficiency remained unchanged at least over 100 h of testingThe investigation of the physicochemical properties of the initial samples(Table 2 )showedJ-2, the active component Pdo is finely dispersed and this alloyinitiate combustion of the methane-air mixtlow temperatureslysts based on MnIK-12-62-2)contain thekaaluminate phase, which is known to be resistant to high temperatures

The durabilitytests altered the structural and textural characteristics of the catalysts (table 4) Over the first50 h of testing, the specific surface area and pore volume of the IK-12-60-2 catalyst decreasedbecause of the coarsening of alumina parand the onset of a-AlzO formation via the 6-Al2O3-a-Al2O3 phase transition under prolonged heating The active component Pdond the degree ofegreeation than the Pd-Ce catalyst Some changesthe phase composthe catalysts occur because of the formation of high-temperaturees, namely, a-Al2O3 and a(Mn, Al)Al O4 solid solution in IKT-12-40A andxaaluminate in lK-12-61 and IK-12-62talytic activity of the hexaaluminate-based samples in the CI00-h-long testing was similar to the activity of the fresh catalysts: T5o is 470-480C for thetalyst IK-12-61 and 363-380C for IK-12-62-2 at GHSV=1000 h-1(Fig 1) The activityhe catalysts Pd-Ce-Al-O and MnOx -AlzO3 decreased slightly and Tso increased by 50"c

84Gas TurbiChemicalPhaseength,Catalyst tempe- sition, composition m2/g cme/grature,°wt%Pd-2K12602100040262450A480)IKT-12Mixture of (0+ y)90Mn-69 Al2O3,Al2O380023400MnzO3Al-oMnLaAlo1gK126221000traces),Y-Al2O3(a =7,937 A), Pdo70" The particle size was derived from the size of coherent-scattering domain region, Relative phaseestimated from peak areas(S arb, units) in diffAl-O, **VE(Nads)is poreN2 adsorption, *x*T, 508 CH4 is temperature of 50% methane conversion on catalyst fraction 0

5-1t GHSv- 1000 l and methane concentration in air equal to 1%Table 2 Physicochemical and catalytic properties of the initial catalysts on spherical andCatalysTest dK-12-6020-1IKT12-40365-35055-34Table 3 Resultstalyst durability tests in natural gas combustion at 930Ctesting unit at the Boreskov Institute of CatalysisThe catalytic activity of the hexaaluminate-basedles in the chon reaction afteratalysts: T5o is 470-480C for thecatalyst IK-12-61 and 363-380C for IK-12-62-2 at GHSV- 1000 h-1(Fig 1) The activiof the catalysts Pd-Ce-Al2Os and MnOx-AlzO decreased slightly, and T50 increased by

sma as turbine lawar alysts aand Natural Gas Combustion TechnologyTestduration, hPhase compositionIK-12602508-AlO a-Al2O3do(-300A,S018Pd(300A,S=120AlO a-AlzO3CeO2(-200A,S3KT-1240A100a-Al2O3, y-Al2O3-based solidIn, Al)Al2O 4AIK-1261MnLaAln O19(S37=240),41018MnLaAln O1(S37 250)LaAlO a-Al-O3MnLaAlo1g400

13LaAlO, a-AlO3IK-12-62-2|5MnLaAlO19(S3,=230)MnLaAlnO1%(S37" 230)A0(>400ATable 4 Physicochemical properties of the catalysts after durability tests in natural gasombustion

emperature, CFig 1turevol % CHV=1000l) on the catalysts:I-1261:▲- initial,;· after30h■-aftr50h;◆- after 100 h testing inCHa combustion at 930 C: IK-12-62-2itia; o- after 50 h: o after 100 hKinetic studies of methane catalytic oxidationKinetic studies of methane catalytic oxidation were performed in a flow reactor Thereaction ordith respect to methane was found to be equal to 1 In kinetic calculations,used activity data for the 05-10 mm size fractions of the catalysts in methane oxidationat GHSV=1000, 24000, and 48000 h-1

The results obtained by data processing in the plugflow approximation are presented in Table 5 The obtained kinetic parameters were usedfurther for modeling of methane combusticIK-12-60IKT-12-402K-12622Table 5, Kinetic parameters of the total methane oxidation reaction5 Experimental studies of natural gas combustioncatalytic combustionstion were carried out in a stainless-steel tubic combustion chamber(CCC) with an internal diameter of 80 mm The CCCschematically shown in Fig 2 The volume of the catalytic package was 1

sma as turbine lawar alysts aand Natural Gas Combustion TechnologyMIXTUREElectnc heater0200PRODUCTSg 2 Schematic view of the catalytic combustion chamber: T-1 to T-4 thermocouples,mpling 1-5: gas sampfueselected to be close to theameter in the operating regime of full-power GtPP(a=64-6 8)

The inlet temperaturehe fuel-air mixture (Tin)wasbetwd600°C, the temperat( Tex)was 900-985C, the GHSv of the fuel-air mixture was 8500-15, 000 hNatural gas was introduced into the combustion chamber after reaching the light-offmperature Due to the natural gas combustion, the temperature in the catalyst bedcreased and reached the values close to the desired onesThe temperaturemode was corrected by smooth variation of the air and natural gas flWhen the desired temperature regime wasd,temperatures along the length of theafter the pilot-plant tests A reference manometer was usedtalyst bed The gas phase composition at the CCC outlet was analyzed using a"Kristall-2000 M gas chromatograph Thebes were also analyzed in paraECOM-AC

Gas TurbiThe catalytic packages studied are schematically presented in Fig 3aped high temperature resistantture catalysts with different granule shape According to the results ofmodeling, the methanuld increase with changng cylinder sphere However, the use of spherical catalyst for entire reactor ispossible due to a high pressure drop Therefore, the reactor consists of two sectionstreamection with spherical catalyst having lower fractional void volume This combinationith a short bed of spherical catalyst provides rather high methane combustionfficiency a3 two ring shapedsts with different catalytic activity In this case, a short bedeam sectionresistant oxide catalthe downstream section provides high efficiency of methaneombustion thisotal pd loadingn increase of methane combiefficiency at a low inlet temperatur4 three catalysts with different catalytic activity and fractional void volume

The highlymperature resistant catalyst in the larger middand low fractional void roet spherical Pd-Mn-Al-O catalyst with a low Pd-contentcombustion The bicomregarding the residual traces1234CHa+ airCH+airCHa+ air CH,+ airFig 3, Schemes of uniform (1)and structured (2-4)loading of the reactor and phegranulated catalyst (Yashnik et al, 2009, Ismagilov et al, 2010)52 Tests of the catalytic combustion chamber with uniform catalyst packageFirst, we testeddthe natural gas-airIre sueanalyze the perspectives of using manganese-alumina catalystsnd evaluate their catalytic properties in natural gas combustion by such parameters asoutlet temperature and emission of hydrocarbons Mn-AlOs, Mn-La-Al2Os and Pd-Mn-La-AlO catalysts shapedested for 72-120 h in a temperature cycle mode