CA1197098A

CA1197098A - Carbonaceous materials and methods for making hydrogen and light hydrocarbons from such materials

Info

Publication number: CA1197098A
Application number: CA000398346A
Authority: CA
Inventors: Jack L. Blumenthal; Maksymilian Burk
Original assignee: TRW Inc
Current assignee: Northrop Grumman Space and Mission Systems Corp
Priority date: 1981-03-27
Filing date: 1982-03-15
Publication date: 1985-11-26
Also published as: JPH0463913B2; WO1982003380A1; NL8220132A; ZA821679B; PL235658A1; IT8267385A0; IL65225A; EP0074394A4; IL65225A0; BR8207244A; IT1191176B; EP0074394A1; JPS58500445A

Abstract

ABSTRACT OF THE DISCLOSURE
Carbonaceous materials comprising major amounts of carbon, and minor amounts of hydrogen and ferrous group metal components, particularly nickel and cobalt, react with steam at low temperatures, and produce commercially attractive quantities of such gases as hydrogen, methane, carbon oxides and other light hydrocarbons.

Description

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NEW CARBONACEOUS MATERIALS AND METHODS FOR MAKING
~YDRO~EN AND LIGHT HYDROCARBONS FROM
SUCH MATERIALS
This invention relates to new processes for making hydrogen, oxides of carbon, methane, other ligh-t hydrocarbons, and mixtures oE two or more oE these products by reacting carbon-aceous materials comprising carbon, ferrous group metal comp-onents, and hydrogen with steam. These processes produce commercially attractive product yields in commercially attractive IQ temperature ranges.
The invention also relates to new carbonaceous materials comprising carbon, hydrogen, and ferrous group metal components, particularly nickel and cobalt. To make these new carbonaceous materials, we react a gaseous mixture that includes carbon mon-oxide and hydrogen with one or more ferrous group ~etal components.
Canadian Patent No. 1~136,413, November, 1982, discloses a broad class of carbonaceous materials that include the new carbonaceous materials of this invention. That patent also discloses methods for making our new carbonaceous materials.
BRIEF DESCRIPTION OF_THE DRAWINGS

FIGURE 1 illustrates the range of steam reactivities with several different carbonaceous materials including those of the invention herein;
FIGURE 2 illustrates the effect that the temperature of carbon deposition exerts on the composition of product gases m~de by steam ~asification of the new carbonaceous materials o~ the inven-tion herein;
FIG~RE 3 sets forth data obtained from steaming a nickel-based carbonaceous material at 650C at three different pressures, ~0 namely 1 a-tmosphere, 4.4 atmospheres and 7.8 atmospheres;

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~IGUFU ~ shows that the new carbonaceous material of this invention can cycle many tilings between the carbon-rich states entering the stecml siEi~ntion process of the invention, and the carbon-lean states resulting tron~ th-` steam gasiEication processes of the inventLon;
L`[GIrR~ 5 is a scanning electron micrograph oE a cobalt-containing ( .Il'~On(lCCOUS Eiber;
l[GURE 6 pLots the percent carbon gasified as a Eunction of time at eacl~ of three temperatures;
FtCURE 7 shows a comparison of measured steam-carbon reaction J llroducts with equilibrium calculations at 600C;
FIGURE 8 shows that the overall gasification rate is primarily a Eunction of steam feed rate as a result of the processes operating close to equilibrium conditions;
FIG~RE 9 is a block diagram showing some of the advantages of a !i preferred embodiment of the new process for producing methane or other synthetic natural gas, and electric power, from coal;
FIGURE 10 shows one embodiment of a reactor for gasifying the carbonaceous materials of the invention under fluid bed conditions with steam; and 'l) FIGURE 11 shows,in block diagram, a material ancl heat balanced system Eor the conversion of the carbonaceous materials to methane, ass~lmlng steam carbon equilibrium at 550C and 200 psig.

The new carbonaceous materials include a ma~or amount oE carbon, and millor amounts oE hydrogen, and one or more ferrous group metal components.
") I`ho new carbonaceous materials include from about 55 percent by wieght to about ~)c~ percent by weight of carbon, and preferably from about 75 percent by w~lul~t to about 95 percent by weight. The ferrous group metal components coln~:~it;ute an amo~lnt in the range of about one percent to about 44 percent, preferably in the range of about 25 percent to aDout 5 percent by wei~ht, of thecarbonaceous rnaterial. At tllese high carbon-to-metal ratios, tiie carbonaceousmaterials react readily with steam to produce large, cornrl-ercially attractive quantities of hydrogen, methane, and/or other ligl-t hydrocarDons in 5 commercially attractive temperature ranges. I~loreover, our carDonaceous materials exhibit excellent fluidity in fluid bed reactors, where these carbonaceous materidls are reacteci with steam. Tnese carbonaceous materials also include hydrogen in anlounts ranging from a~out 0.1 to about 1.0 percent byweii;nt. Measured ~y low temperature gas aasorption methods, the carDonaceous 0 rnatericlls have total surface areas in t~e range of about l~(i to about 300 sc~uare rrleters pcr c,ram of carbonaceous material, ana pore volumes in the range of about 0.3 to aDout 0.6 milliliters (ml) per gram of carbonaceous material.
The ferrous group ~netai components in our new carDonaceous materials are selected from the group consisting of nickel, cobalt, nickel alloys, and coDalt 5 alloys, and mixtures of th~se metals and alloys. Broadly, iron constitutes no more than about 30 percent by weight, and preferably no more than about 10 percent Dy weight, of the ferrous group n,etal component content of our new carbonaceous materials. Nickel and cobalt constitute at least 70 percent by weight of the ierrous ~roup metal component content in our carbonaceous 20 materials.
Our new carbonaceous materials, prepared by tne deposition processes referred to hereafter, typically include several phases. The major phase includes about 95'ib to about 99.9~ carbon by wei~ht, and hydrogen in an amount of about 0.1 percent to about I percent. The balance, if any, is one or more of the25 ferrous group metal components set forth aDove. Dispersed throu~hout this major phase are ferrous group metal component-rich minor phases cornprising at least about 5CI percent by wei~ht of such metals as explained and as limited above. The remainder of the rninor phases is principally carbon, but may include some hydrogen.
Made by our preferred deposition methods, our new carDonàcèous rr~aterials appear fibrous under the hign magnification of a transmission or scarlnir-~ electron microscope. Figure 5 is a scannin~, electron micrograpll of a cobalt-containing carbonaceous fiDer. Tnis fiDrous carDonaceous rnate!ial contains more than about 90 percent by weight carDon, and includes at least ~'~

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aDout 5 percent by weight of cobalt-rich minor phases of the kina describea aoove, as indicated at the arrow in FIG. 5.
Broadly, the methoas for makine, our new carbonaceous materiaJs comprise aepositing carbon from carbon monoxide-containing gas mixtures over S one or more ferrous group metal initiators. In the process of carbon oeposiIion, ferrous metal is transferred from the inititor to our carDonaceous material ana bec~rrles an integral part of these materials as described above. Tne ferrous group rnetal starting materials, called initiators in the deposition reaction todistinguish them from ferrous group metal components in our new carbonaceous 0 materials, can De supportea or unsupported ferrous group rr~etals, ores, alloys or mixtures of such species.
The deposition processes take place at pressures in the range of aDout I
to about 100 atmospheres or more, and at temperatures in the range of aoout 30GC to about 700O~ inere tne ferrous group metal component includes more 15 than about 70 percent by weight nickel, and the carbon deposition temperature is in the ran~,e of about 3~ûOC to about 500C, the carbonaceous material is especially suitable for making methane by reaction with steam. At deposition temperatures above about ~50C, and especially where the ferrous group metal component is more than a~out 70 percent by weight cobalt, the carbonaceous 20 material is especially suitaDle for making hydrogen by reaction with steam.
Our new carbonaceous rnaterials are highly reactive with steam at pressures in the range from a~out 1 to about 100 atmospheres or more and al temperatures in the range of about 500C to about 750C. From Ihese steaming reactions, we obtain product gas mixtures that include hydrogen, carDon 25 monoxide, carbon dioxide, methane and other light hydrocarbons. The ~uantities of each gas produced in the steaming reactions depena on the nature of the carbonaceous material and the temperature and pressure at which the steam ~asiEication taKes place. In particular, carbonaceous rr,aterials formed at temperatures in the range of about 300C to aDout 500C, especially those 30 Eormea in this temperature range from niclcel alone or from ferrous group rnetal components containing at least about 70 percent by weight nic~el, tend to produce suL~stantial quantities of methane in the steam gasification reactions of this inventior). ~y contrast, carbonaceous materials formed at temperatures above about 55~C, especially those carbonaceous materials formed aDove tnis 3S temperature from cobalt alone or from ferrous group metal components -containing at least about 70 percent by weignt cobalt, tend to probuce substantial quantities of hydrogen in tne steam gasification reactions of t~is i nven t ion .
Where the n,olar ratio of steam fed to carDon gasified is at least a~out ~, S ~and therefore exceeds the amount required for therrnodynamic equilil~rium), and thc steam ~asification pressure is in the range of about 1 to about 1() atlnospheres, the gasification reaction tends to produce hydrogen in large qllantities, especially where the carbonaceous material is cobalt-based. Wnere the molar ratio of steam fed to carbon gasifieci is less than a~out 3, and the 0 steam gasification pressure is in tne range of aDout lG to about 1()0 atmospheres, (and therefore nearly equals the amount requirea for thermodynamic equilibrium), the gasification reaction tencls to produce methane in large quantities, especially where the carbonaceous material is nickel-based.
The gaseous products initially formea in the steaming reactions of this 15 invention can be converted to gas mixtures richer in hydrocarbons, hydrogen, or both, by lowering the temperature of the gaseous products and contacting these products witn either fresh or partially reacted carbonaceous material in the ran~,e of about 300C to about 5ù0C, and by adjusting the pressure and steam feed rate to produce the desired gases, as explained below.
~ Our new carbonaceous n-aterials serve distinctly different purposes in the initial steam gasification process of this invention and in the subsequent, Jower temperature conversion reaction of the gasification products from the steaming reactions. In the steaming reactions, our new carbonaceous materials participate as reactants. In the subsequent conversion of the steam gasification25 products to either hydrogen-rich or hydrocarbon-rich product gas mixtures at temperatures below the steam gasification ternperatures our carbonaceous rnaterials serve as a catalyst.
The carbon monoxide-containing gas mixtures used in the deposition processes for making our new carbonaceous materials can be low pressure or high 30 pressure producer or synthesis gases. Such gas mixtures may include substantial cluantities of nitrogen and carbon dioxicle, but must contain little or no sulfur compounds such as i~yarogen sulfide, carbon disulfide or sulfur dioxide. If necessary, carl~on monoxide-containing gas mixtures are pretreatea by ~<nown methods for removing sulfur-containing gases before carbon deposition begins.
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Carbol~ deposition removes some of the carbon from the carbon monoxide-containin~ gas mixtures at nearly 100 percent thermal efficiency since tne heat of reaction may remain as sensible heat in the carbon monoxiae-(Iepleted fuel gas strearn. The reaction heated, carbon monoxide-deplete(l gas S mixture frorn tne carbon deposition reaction is a good fuel source ior generating combined cycle electric power.
A surprising and unexpected aspect of our methoas for steal~, gasification of the new carbonaceous materials is that where such carDonaceous materials contain iron as the chief ferrous rnetal component, such carbonaceous 0 materials have quite low rates of reactivity with steam at temperatures in tnerange of about $00C to arJout 6CuC. Steam gasification, of such carbonaceous materials at temperatures above about 700C is adversely affected by the side reaction of the iron component with steam, ana gasification ceases long before all of the carDon is gasified. By contrast, our new carDonaceous materials, whicn IS contain suDstantial amounts of nickel, coDalt, nickel alloys, coDalt alloys and mixtures thereoE, have high reaction rates with steam, and do not sufEer from deactivating side reactions. Figure ~ illustrates the range of steam reactivities with several different carDonaceous materials, including those of our invention.To ob~ain the datd illustrated in the grapn in FIG. 1, we passed gas 20 mixtures comprising 85 percent carbon monoxide and 15 percent hydrogen over small samples of iron, nickel and coDalt initiators until tlle carDon-to-metal ratio of each sample reached four or more. We then s~eam gasified 0.5-grarn samples of each carbonaceous material at progressively increasing ternperatures, ana measured the rate of production of the dry gasification products formed. As ~5 ~IG. 1 shows, the reactivities of these carbonaceous materials with stearn varied ~reatly. The cobalt-containing carbonaceous material gasified rapidly at 500C.
L)y contrast, the iron-based carbonaceous material was inactive until the temperature reached 800C. Accordingly, the nickel and cobalt-based carbollaceous materials are far more attractive for commercial manufacture of 30 hy~lrogen and rnethane, particularly Decause the steam/carbonaceous material reactions are enclothermic, and must be driven by indirect heat transfer. At teloperatures in the range of aDout 500C to about 600OC, where our nickel-basec~ and cobalt-based carbonaceous materials readily steam gasify, indirect heat transfer is easily efEected by state of the art techniques. At 800C and 35 hiE~ller, indirect heat transfer is difficult to achieve and costly as well.
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Figure 2 illustrates tt~e effect that the temperature of carbon deposition exerts on the cornposition of product gases made by steam gasification of the new carbonaceous materiaJs oI our invention. To show this effect, we preparea two different coDalt-based carbonaceous materials by depositing carDon from a 5 mixture comprising 85 percent carbon rnonoxide anà 15 percent hyarogen at atmospheric pressure. We prepared both carbonaceous materials by reaction with cobalt powder, forrning one sample at 450~ and the other at 650~ e continued the deposition reaction until we obtained a carbon-to-coDalt weight ratio of ten. We then reacted each sample with steam at 550C ana 0 atmosph~ric pressure. As FIG. 2 shows, the carDonaceous material deposited at 65t~oc proauced far more hydrogen in the steam gasification reaction ~nen cid the cobalt-based carbonaceous material produced at 450C. Indeed, after rernoving the carbon dioxide formed auring stearn gasification, the carbonaceous material formed at $50C produces nearly pure hydrogen upon steaming at 15 550C.
The data in Tables 1 and 2 show differences in final prouuct gas composition where the products of steam-carbon gasification of carbonaceous reactants containinE different ferrous group metals further react at temperatures below the carbon gasification point of about 500C. In Table 1, a 20 carbonaceous material comprising about 90 percent carbon and about 9 percent nickel, prepared Dy carbon deposition on nickel powder, at about 450C, catalyzed the furtner conversion of a typical steam-carbon gasification mixture of carbon monoxide, hydrogen and steam at 400C and about 1 atmosphere pressure in a steady flow reactor. As Table 1 shows, nearly all of the carbon 25 monoxide was converted to methane and carbon dioxide, with very little additional gasification of solid carbon (0.04 gram out of 0.83 gram in 203 minutes).
Table 2 relates to an identical run, with one exception: Tne carDonaceous material contained cobalt instead of nic~el (about 90 percent 30 carbon, and about 9 percent cobalt). These data show that co~alt-Dased carDonaceous material is less effective in converting the gas mixture to methanethan the nickel-based material (27.2 percent rnetnane for nickel-basea; 9~5 perccnt, for cobalt-based), but more effective in shiftin~ to hydrogen (49.8 percent hydro~en from coDalt-based material; 27.0 percent for nickel-based 35 material).

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Pressure has no significant effect on the rate at which stea~"
~asification o~ our carbonaceous materials proceeds, but does affect tne composition of the product gases obtained. Figure 3 and Table 3 set forth aata obtained from steaming a nickel-Dased carbonaceous material at 650OC at three different pressures, namely one atmosphere, 4.4 atmospheres, and 7.8 atmospheres. ~3ie conducted all these runs in small, fluidized bed~ steady flow reactors at a constant steam feed rate of 23 standard cubic centimeters per millute per grarn of carDon initially in the reactor. Figure 3 shows ~hat the carbon gasification rate was nearly linear until su~stantially all the carbon was ~asified. ,~loreover, this rate did not vary appreciably with pressùre. ~y contrast, tl-e product composition set forth in Table ~ did cnange substantiallydepending on the pressure. As the pressure rose from one atmosphere to 7.
atmospheres, the methane concentration tripled, the carbon monoxi~e concentration decreased by a factor of two, the hydrogen concentration 5 decreased from about 53 percent to about 43 percent, and the carbon dioxiae concentration rose froln about 21 percent to about 31 percent.

Figure 4 shows that our new carbonaceous materials can cycle many times between the carb,on-rich states entering the steam gasification process of20 our invention, and the carbon-lean states resulting from the steam gasification processes of our invention. To illustrate this point, we prepared a one gram sample of a carbonaceous material comprising about 90 percent carbon and about 9 percent cobalt by depositing carbon from a gas mixture comprising about 8 percent carbon monoxide and about 15 percent hydrogen at 45UC anà one 25 atmosphere pressure. We steam gasified this carDonaceous material at 550C
and one atmosphere pressure until we had gasified about 45 percent of its carboncontent. We then returned the residue to the deposition reaction, and resumecl deposition until the carbon content l ad attained the pre-~asification levels. ~e repeatecl this cycle of carbon deposition and steam gasification nine tirnes, and 30 obtained the data set forth in FIG. 4. Figure 4 shows that the rate of steam gasification did not vary significantJy from one cycle to the o~her.
The followin~ examples show that the cobalt-basecl carDonaceous materials of our invention react readily with steam at low temperatures to produce comrrlercially attractive (luantities of gas mixtures comprising hydrogen, 35 carbon oxides, and methane, at a rate of at least a~out 0.2 moles of caroon Unable to recognize this page.

7~3~8 -~asifieb per mole of carDon present per hour when stearm is fed to the reaction at the tate of about 1.0 mole per hour per mole of carbon present at a temperature of about 55Goc ancl at a pressure of about I atmosphere.
lnto a horizontal tube reactor we placed 0.5 gram of reduced cobalt 5 oxide powder, and Ied to the reactor a stream of 200 standard cubic centimeters per minute of a gas mixture cornprisiny 85 percent carbon monoxide and 15 percent hydrogen at 450C and I atmosphere pressure. We continuea this procedure until 3.3 grams of cart)onaceous material formed.
\~je removed the carbonaceous material formed, and determined that the 0 carbonaceous rnaterial comprised about 87 percent carbon, about 1;~ percent cobalt, ano about I percent hydrogen. \I~e divided these materials into three one gram samples, and placed each sample in turn in a small, vertical~ fixed bea reactor with the sarnple suspended between quartz wool plugs. We placea the reactor in a tur~e furnace which controlled the reactor temperature throu~ahout lS tne steam gasification process. We fed steam to the reactor at atmospheric pressure and at a rate of 20.~ standard cubic centimeters per rninute, holding the ternperature at 5~5C durin~a the first run. We measured the volume of dry product gasses formea with a wet test meter, and determined the composition of the mixture by gas chromatography. We condensed and periodically weighed tne 20 unreacted steam. We continued each run until no further gas formed. We repeated these runs two adaitional times, once at 550C, and once at ~00C~
Tables 4, 5, and 6 present the outlet gas composition, the Yolume of product gas, the cumulative percent carbon gasified as a function of time and the average carbon balances obtained in these runs.
Figure 6 plots the percent carbon gasified as a function of time at eacn temperature. The carbon gasification rates, showr~ rby the slopes of the iines in FIG. 6, were nearly constant until nearly alJ the carbon in the samples gasifiea.
Th& gasification rates increased slightly with temperature, primarily because of&quilibrium considerations. As reaction temperature increased, the amount of 30 carbon gasi~ied per mole of steam fed to the reactor rose at equilibrium. As 1 able 7 an(l FIG. 7 show, these runs operated at near- equiliDrium conclitions.The run represented by Table 7 occurred at 5500C and the run representea by F IC;. 7 oCCurred at 6G(iC.
Frorn the slopes of the lines shown in FIG. 6, we aerivea tne overall 35 carbon gasification rates at the conditions of temperature, pressure and stean-feed rate used. For exarnple, at 55GC, ~ percent of the ori~inal cari)on gasified in one hour, meaninl~a that the carr~on ~asification rate was 0.2~ moles of r Unable to recognize this page.

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TABLE 7. CQMPARISON OF MEASURED STEAM-CARBOPI
REACTIQN PRODUCTS ~IITI~ EQUILIBRIUM

(87~ C - 13X ~o) ~UIL lElRtU~
CO~POSI~ l~N 14EASUREI) i~ 5'jO~ ~1 550 DR~' BAS 15 ~ ~S

H2 ~2 . 9S 52 . 215 C2 3~ . S~

CO 1 1 . 3 _ _ _ _ _ _ 1 ATM PRESSUR~

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_ carbon gasified per hour per mole of carbon initially in the reactor. The steam feed rate in this run was 0.752 moles of steam per hour per mole of carbon initially placed in the reactor. E,ecause our processes operate close to equilibriurn conditions~ the overall carbon gasification rate is primarily a S function of the steam feed rate, as FIG. 8 shows. There, the steam utilization at 60dOC is near equilibrium throughout the run.
Figure 9 is a block diagram showing some of the advanta~es of a preferrcd embodiment of our new processes for producing methane, or other synthetic natural gas, and electric power, from coal. In FIG. 9, coal from source 0 I passes on path 2 to coal gasîfication and clean-up zone 3. There, the coal is converted to a gaseous mixture of nitrogen, carbon monoxide, carbon dioxi~e and hydrogen, and the ash, sulfur and water content of the mixture is reduced toacceptable levels by known methods. One advantage of our processes is that we can make synthetic natural gas by reacting coal with air instead of oxy~en.
15 Unlike other synthetic gas manufacturing processes, our processes are compatible with feed stocks containing substantial amounts of nitrogen and carbon dioxide. The cold, clean product gas then passes along path 4 to carbon deposition zone 5 where formation of our carbonaceous materials by deposition over one or more ferrous group metal initiators takes place. Some of the fuel 20 gas may pass along path 6 directly to power generation zone 7, if desired, for combustion with air to generate base load and/or peaking power~ l~epleled fuel gas passes on path 8 to zone 7 for conversion to power in the same way.
Catalytically-actiYe carbon rich carbonaceous material passes on path 9 to steam gasification ~one 10 for reaction with steam to produce carbon 25 monoxide, carbon dioxide, hydrogen, methane or possibly other light hydrocarbons, as desired. Carbon lean carbonaceous material is returned on path 11 to carbon deposition zone 5. Nearly all of the heating value of the carbonaceous material can be converted to methane or hydrogen in our steam gasification processes.
Following the process steps outlined in FIG 9, we can withdraw, save from about 25 percent to about 50 percent of the initial heating value from a carbon monoxide/hydrogen-containing fuel gas in the form of carbon, then use the depleted fuel gas as an energy source to generate electric power Ot to produce power quality steam. The withdrawn carbon, which is embodiea in our 35 new carbonaceous materials, can be steam gasiiEied to convert from about 40 ; -~
.

~7~3~8 percent to about 80 percent of the carbor~ to hydrogen, carbon oxides, methane, and other light hydrocarbons. The carbon-depleted carbonaceous materials can be enriched in carbon by further carbon deposition from carbon monoxide/hydrogen gas mixtures such as the fuel ~as referred to above, using theS carbon-lean carbonaceous material from the steam gasification.
Figure 10 shows one embodiment of a reactor for gasifying our carbonaceous materials under fluid bed conditions with steam. Our carbonaceous materials enter reactor 101, which has a high length-to-diameter ratio, on path 102, and pass downwardly under fluiaizing conditions on path 102 toward the 0 bo~tom of reactor 101. Superheated steam enters reactor 101 along path 103 andpasses upwardly into contact with the descending carbonaceous materials. Hot combustion gasses enter reactor 101 in pipes, separate from the carbonaceous material, and pass through path 103 to provide the heat required for reaction ofsteam with the carbonaceous materials. Carbon monoxide, hydrogen, methane 15 and other gasses formed in hot reactor zone A pass upwardly through ccoler zone B, where shift methanation reactions take place, but no further carbon ~asifies.Product gasses exit reactor 101 on path 105, are cooled in cooling means 106, and then passed through bag house 107, where unreacted carbon is captured for return to reactor 101. Methane-rich gas passes from bag house 107 on path 10 20 for removal of carbon dioxide and other conventional polishing steps.
Ferrous group metal component-rich material exits reactor 101 at the bottom, on path 108, and may be returned, if desired, to a carbon deposition reaCtQr.
Figure 11 shows, in block diagram, a material and heat balanced system for the conversion of our carbonaceous materials to methane, assuming steam-

2~ carbon equilibrium at 550C: and 200 psig. Carbonaceous material passes fromstorage zone 201 on path 202 to reactor 203. Steam enters reactor 203 on path 204 and contacts the carbonaceous materials for production of methane, carbon monoxide, hydrogen and other gases. This gas mixture exits the reactor 20ne on path 205, passes through superheater 206, and then, on path 207, to zone 20 30 where carbon dioxide and water are remo~!ed. From zone 208, product gas passes on path 209 to polishing methanator 210, from which the produc~ methane gas emerges on path 211.
Some of the product gas on path 205 is drawn of f on path 212, passed to radiant boiler 213 in combination with air added on path 214, and then fed 35 indirectly in pipes into reactor 203 on path 214 to provide added heat there.

]8. ~ ~7~8 These gases leave reactor 203 on path 222, pass through superheater 218, and boiler 219.
In one broad aspect, the invention contemplates a carbonaceous material comprising carbon in an amount from about S5~ by weight to about 98~ by weight, hydrogen in an amount from about 0.1% to about 1~ by weight, and at least one ferrous group metal component selected from the group consisting of nickel, cobalt, nickel alloys, and cobalt alloys, tne ferrous group metal component containing not L0 more than about 30% by weight of iron.
The invention further contemplates a stea~ gasification process for producing a stream of gas selected from the group of hydrogen-rich and methane rich gases which comprises re-acting a carbonaceous material having a ferrous group metal component containing at least 70~ by weight of a metal select-ed from the group consisting of cobalt and nickel and not more than 30~ b~ weight iron.with steam, with the steam gasification temperature being between about 500C to about 750C and the steam gasification pressure being between about 1 to about 100 atmospheres.
In another embodiment, the invention contemplates a steam gasification process for producing a product gas rich in meth-ane or in hydrogen which comprises re.acting a carbonaceous material having a ferrous group metal component containing not more than 30% by weight iron, at a temperature between about 500C to about 750C, with sufficient steam to gasify at least some of the carbon in the carbonaceous material. The process is further characterized in that either the hydrogen yield is increased by feeding steam to the reaction at a molar ratio of steam fed to carbon gasified of a-t least about 3 with the steam gasification pressure between about 1 to about 10 atmospheres, and with the ferrous group metal component comprising at least 70~ by weight cobalt, or the methane yield is increased by feed-ing steam to the reac-tion at a molar ratio oF steam fed to car-bon gasified of less -than about 3 wi-th the steam gasification pressure between about 10 to about 100 atmospheres and with the ferrous group metal component comprising at least 70% by weight nickel.

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In a further embodiment, the invention is a steam gasification process for producing a methane-rich gas stream from a low heating value fuel gas containing carbon monoxide and hydrogen which comprises the steps of reacting in a s-team gasification zone a carbon-enriched carbonaceous material having a ferrous group metal component containing at least 70~ by weight nickel and not more than 30~ by weight iron with a sufficient amount of steam to maintain a molar ratio of steam Eed to carbon gasified of less than about 3, the steam qasification temperature being between abou-t 550C to about 700C and the steam gasification pressure being between about one to about ten atmospheres, gasifying from about ~0~ to about 80~ of the carbon in the carbon-enriched carbonaceous ma-terial whereby a carbon-lean carbonaceous material is produced, re-acting in a carbon deposition zone the carbon-lean carbonaceous material with the fuel gas at a temperature between about 350C to about 500C to deposit additional carbon on the carbon-lean carbonaceous material to form carbon-enriched carbonaceous material which can be further reacted with steam, and recycling the carbon-enriched carbonaceous material from the carbon deposition zone to the steam gasification zone. The depleted fuel gas then is used as an energy source to generate electric power or to produce steam.

Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A steam gasification process for producing a stream of gas selected from the group of hydrogen-rich and methane-rich gases comprising reacting a carbonaceous material having a ferrous group metal component containing at least 70% by weight of a metal selected from the group consisting of cobalt and nickel and not more than 30% by weight iron with steam, with the steam gasification temperature being between about 500°C to about 750°C and the steam gasification pressure being between about 1 to about 100 atmospheres.

2. The process of Claim 1 wherein said gas stream is hydrogen-rich and said ferrous group metal components are cobalt and iron, a sufficient amount of steam is present to maintain a molar ratio of steam to carbon gasified of at least about 3, and the steam pressure being between 1 and 10.

3. The process of Claim 1 wherein said gas stream is methane-rich and said ferrous group metal components are nickel and iron, a sufficient amount of steam is present to maintain a molar ratio of steam to carbon gasified of less than about 3, and the steam pressure being between 10 and 100.

4. A process as set forth in Claim 2, further comprising gasifying about 40% to about 80% of the carbon in said carbonaceous material whereby a carbon-lean carbon-aceous material is produced, and reacting said carbon-lean carbon-aceous material with a gaseous mixture including carbon monoxide and hydrogen at a temperature between about 550°C
to about 700°C to deposit additional carbon on said carbon-lean carbonaceous material to form a carbon-enriched carbon-aceous material which can be further reacted with steam.

5. The process as set forth in Claim 2, wherein the carbonaceous material comprises from about 55% to about 98% by weight carbon, from about 1% to about 44% by weight ferrous group metal component, and from about 0.1% to about 1.0% by weight hydrogen.

6. The process as set forth in Claim 5, wherein the carbonaceous material includes a major phase and a minor phase, said major phase comprising from about 95% to about 99.9% by weight carbon, from about 0.1% to about 1%
by weight hydrogen, and the balance, if any, is the ferrous group metal component; said minor phase being nodules which are dispersed throughout the major phase and are intimately associated with and at least partly bonded to the carbon in said major phase, said minor phase comprising carbon and at least about 50% by weight ferrous group metal component.

7. The process as set forth in Claim 2, wherein the ferrous group metal component is selected from the group consisting of cobalt, cobalt alloys, and mixtures thereof.

8. The process as set forth in Claim 2, wherein said ferrous group metal component contains less than about 10% by weight iron.

9. The process as set forth in Claim 5, wherein said ferrous group metal component constitutes an amount from about 5% to about 25% by weight of said carbonaceous material.

10. The process as set forth in Claim 2, further comprising contacting the product gas from said gasification reaction with fresh or partially reacted carbonaceous material and with steam at a temperature between about 300°C to about 500°C.

11. The process of Claim 2, further comprising gasifying from about 40% to about 80% of the carbon in said carbon-enriched carbonaceous material whereby a carbon-lean carbonaceous material is produced, reacting in a carbon deposition zone said carbon-lean carbonaceous material with said fuel gas at a temperature between about 550°C to about 700°C to deposit additional carbon on said carbon-lean carbonaceous material to form carbon-enriched carbon-aceous material which can be further reacted with steam, recycling said carbon-enriched carbonaceous material from the carbon deposition zone to the steam gasification zone, and utilizing the depleted fuel gas as an energy source to generate electric power or to produce steam.

12. The process as set forth in Claim 11 further comprising contacting the product gas from said gasifi-cation reaction with carbon-enriched or carbon-lean carbo-naceous material and with steam at a temperature between about 300°C to about 500°C.

13. The process as set forth in Claim 11 wherein She carbonaceous material comprises from about 55% to about 98% by weight carbon, from about 1% to about 44% by weight ferrous group metal component, and from about 0.1% to about 1.0% by weight hydrogen.

14. The process as set forth in Claim 13 wherein the carbonaceous material includes a major phase and a minor phase, said major phase comprising from about 95% to about 99.9% by weight carbon, from about 0.1% to about l%
by weight hydrogen, and the balance, if any 9 is the ferrous group metal component; said minor phase being nodules which are dispersed throughout the major phase and are intimately associated with and at least partly bonded to the carbon in said major phase, said minor phase comprising carbon and at least about 50% by weight ferrous group metal component.

15. The process as set forth in Claim 11 further comprising initially forming said carbon-enriched carbo-naceous material by contacting at least one ferrous group metal initiator selected from the group consisting Or cobalt, cobalt alloys, and mixtures thereof, with a fuel gas including carbon monoxide and hydrogen at a temperature between about 550°C to about 700°C, said carbon-enriched carbonaceous material having from about 25% to about 50% of the initial heating value Or said fuel gas in the form of carbon and separately said carbon-enriched carbonaceous material from said fuel gas.

16. The process as set forth in Claim 11 wherein the ferrous group metal components is selected from the group consisting of cobalt, cibalt alloys, find mixtures thereof.

17. The process as set forth in Claim 11 wherein said ferrous group metal component contains less than about 10% by weight iron.

18. The process as set forth in Claim 3, wherein said ferrous group metal component constitutes an amount from about 5% to about 25% by weight of said carbonaceous material.

19. A process as set forth in Claim 3,further comprising gasifying about 40% to about 80% of the carbon in said carbonaceous material whereby a carbon-lean carbo-naceous material is produced, and reacting said carbon-lean carbonaceous material with a gaseous mixture Including carbon monoxide and hydrogen at a temperature between about 350°C to about 500°C to deposit additional carbon on said carbon-lean carbonaceous material to form a carbon-enriched carbonaceous material which can be further reacted with steam.

20. The process as set forth in Claim 3, wherein the carbonaceous material comprises from about 55% to about 98% by weight carbon, from about 1% to about 44% by weight ferrous group metal component, and from about 0.1% to about 1.0% by weight hydrogen.

21. The process as set forth in Claim 20 wherein the carbonaceous material includes a major phase and a minor phase, said major phase comprising from about 95% to about 99.9% by weight carbon, from about 0.1% to about 1%
by weight hydrogen, and the balance, if any, is the ferrous group metal component; said minor phase being nodules which are dispersed throughout the major phase and are intimately associated with and at least partly bonded to the carbon in said major phase, said minor phase comprising carbon and at least about 50% by weight ferrous group metal component.

22. The process as set forth in Claim 3, wherein the ferrous group metal component is selected from the group consisting of nickel, nickel alloys, and mixtures thereof.

23. The process as set forth in Claim 3, wherein said ferrous group metal component contains less than about 10% by weight iron.

24. The process as set forth in Claim 20 wherein said ferrous group metal component constitutes an amount from about 5% to about 25% by weight of said carbonaceous material.

25. The process as set forth in Claim 3, further comprising contacting the product gas from said gasifi-cation reaction with fresh or partially reacted carbonaceous material at a temperature between about 300°C
to about 500°C.

26, A steam gasification process for producing methane-rich gas stream from a low heating value fuel gas containing carbon monoxide and hydrogen comprising reacting in a steam gasification zone a carbon-enriched carbonaceous material having a ferrous group metal component containing at least 70% by weight nickel and not more than 30% by weight iron with a suffi-cient amount of steam to maintain a molar ratio of steam fed to carbon gasified of less than about 3, the steam gasification temperature being between about 550°C to about 700°C and the steam gasification pressure being between about one to about ten atmospheres, gasifying from about 40% to about 80% of the carbon in said carbon-enriched carbonaceous material whereby a carbon-lean carbonaceous material is produced, reacting in a carbon deposition zone said carbon-lean carbonaceous material with said fuel gas at a temperature between about 350°C to about 500°C to deposit additional carbon on said carbon-lean carbonaceous material to form carbon-enriched carbonaceous material which can be further reacted with steam, recycling said carbon-enriched carbonaceous material from the carbon deposition zone to the steam gasi-fication zone, and utilizing the depleted fuel gas as an energy source to generate electric power or to produce steam.

27. The process as set forth in Claim 26 further comprising contacting the product gas from said gasifi-cation reaction with carbon-enriched or carbon-lean carbo-naceous material at a temperature between about 300°C to about 500°C.

28. The process as set forth in Claim 26 wherein the carbonaceous material comprises from about 55% to about 98% by weight carbon, from about 1% to about 44% by weight ferrous group metal component, and from about 0.1 to about 1.0 percent by weight hydrogen.

29. The process as set forth in Claim 28 wherein the carbonaceous material includes a major phase and a minor phase, said major phase comprising from about 95% to About 99.9% by weight carbon, from about 0.1% to about 1%
by weight hydrogen, and the balance, if any, is the ferrous group metal component; said minor phase being nodules which are dispersed throughout the major phase and are intimately associated with and at least phase bonded to the carbon in said major phase, said minor phase comprising carbon and at least about 50% by weight ferrous group metal component.

30. The process as set forth in Claim, 26 further comprising initially forming said carbon-enriched carbo-naceous material by contacting at least one ferrous group metal initiator selected from the group consisting of nickel, nickel alloys, and mixtures thereof, with a fuel gas including carbon monoxide and hydrogen at a temperature between about 350°C to about 500°C, said carbon-enriched carbonaceous material having from about 25% to about 50% of the initial heating value of said fuel gas in the form of carbon, and separating said carbon enriched carbonaceous material from said fuel gas.

31. The process as set forth in Claim 26 wherein the ferrous group metal component is selected from the group consisting of nickel, nickel alloys and mixtures thereof.

32. The process as set forth in Claim 26 wherein said ferrous group metal component contains less than about 10% by weight iron.

33. The process as set forth in Claim 26 wherein said ferrous group metal component constitutes an amount from about 5% to about 25% by weight of said carbonaceous material.

34. A steam gasification process for producing a product gas rich in methane or in hydrogen comprising reacting a carbonaceous material having a ferrous group metal component containing not more than 30% by weight iron, at a temperature between about 500°C to about 750°C, with sufficient steam to gasify at least some of the carbon in the carbonaceous material, said process being further characterized in that either:
(a) the hydrogen yield is increased by feeding steam to the reaction at a molar ratio of steam ted to carbon gasified of at least about 3, the steam gasifi-cation pressure is between about 1 to about 10 atmospheres, and said ferrous group metal component comprises at least 70% by weight cobalt; or (b) the methane yield is increased by feeding steam to the reaction at a molar ratio of steam fed to carbon gasified of less than about 3, the steam gasifi-cation pressure is between about 10 to about 100 atmo-spheres, and said ferrous group metal component comprises at least 70% by weight nickel.

35. The process us set forth in Claim 34 wherein tile carbonaceous material comprises from about 55% to about 98% by weight carbon, from about 1% to About 44% by weight ferrous group metal component. and from about 0.1% to about 1.0% by weight hydrogen.

36. The process as set forth in Claim 35 wherein the carbonaceous material includes a major phase and a minor phase, said major phase comprising from about 95% to about 99.9% by weight carbon, from about 0.1% to about 1%
by weight hydrogen, and the balance, if any, is the ferrous group metal component; said minor phase being nodules which are dispersed throughout the major phase and are intimately associated with and at least partly bonded to the carbon in said major phase, said minor phase comprising carbon and at least about 50% by weight ferrous group metal component.

37. The process as set forth in Claim 34 wherein said ferrous group metal component contains less than about 10% by weight iron.

38. The process as set forth in Claim 35 wherein said ferrous group metal component comprises from about 5%
to about 25% by weight of said carbonaceous material.

39. The process as set forth in Claim 34 wherein the methane yield is further increased by contacting the product gas from said gasification reaction with fresh or partially reacted carbonaceous material at a temperature between about 300°C to about 500°C.

40. The process as set forth in Claim 34 wherein the hydrogen yield is further increased by contacting the product gas from said gasification reaction with fresh or partially reacted carbonaceous material and with steam at temperature between about 300°C to about 500°C.

41. A steam gasification process for producing a hydrogen-rich gas stream from a low heating value fuel gas containing carbon monoxide and hydrogen comprising reacting in a steam gasification zone a carbon-enriched carbonaceous material with a sufficient amount of steam to maintain a molar ratio of steam fed to carbon gasified of at least about 3, said carbon-enriched carbonaceous material comprising from about 75% to about 95% by weight carbon, from about 5% to about 25% by weight ferrous group metal component containing at least 70% by weight cobalt and not more than about 10% by weight iron, and from about 0.1% to about 1.0% by weight hydrogen, and said carbon-enriched carbonaceous material including a major phase and a minor phase, said major phase comprising from about 95% to about 99.9% by weight carbon, from about 0.1% to about 1% by weight hydrogen, and the balance, if any, is the ferrous group metal components, said minor phase being nodules which are dispersed throughout the major phase and are intimately associated with and at least partly bonded to the carbon in said major phase, said minor phase comprising carbon and at least about 50% by weight ferrous group metal component, the steam gasification temperature being between about 550°C to about 700°C and the steam gasification pressure being between about I to about 10 atmospheres, gasifying from about 40% to about 80% of the carbon in said carbon-enriched carbonaceous material whereby a carbon-lean carbonaceous material is produced, reacting in a carbon deposition zone said carbon-lean carbonaceous material with said fuel gas at temperature between about 550°C to about 700°C to deposit additional carbon on said ca bon-lean carbonaceous material to form carbon-enriched carbonaceous material which can be further reacted with steam, recycling said carbon-enriched carbonaceous material from the carbon deposition zone to the steam gasi-fication zone, and utilizing the depleted fuel gas as an energy source to generate electric power or to produce steam.

42. A steam gasification process for producing methane-rich gas steam from a low heating value fuel gas containing carbon monoxide and hydrogen comprising reacting in a steam gasification zone a carbon-enriched carbonaceous material with a sufficient amount of steam to maintain a molar ratio of steam fed to carbon gasified of less than about 3, said carbon-enriched carbonaceous material comprising from about 75% to about 95% by weight carbon, from about 5% to about 25% by weight ferrous group metal component containing at least 70% by weight nickel and not more than about 10% by weight iron, and from about 0.1% to about 1.0% by weight hydrogen, and said carbon-enriched carbonaceous material including major phase and a minor phase, said major phase comprising from about 95% to about 99% by weight carbon, from about 0.1% to About 1,0% by weight hydrogen, and the balance, if any, is the ferrous group metal component, said minor phase being nodules which arc dispersed throughout the major phase and are intimately associated with and at least partly bonded to the carbon in said major phase, said minor phase comprising carbon and at least about 50% by weight ferrous group metal component, the steam gasification temperature being between 550°C to about 700°C and the steam gasification pressure being between about 1 to about 10 atmospheres,

Claim 42 - cont'd..
gasifying from about 40% to about 80% of the carbon in said carbon-enriched carbonaceous material whereby a carbon-lean carbonaceous material is produced, reacting in a carbon deposition zone said carbon-lean carbonaceous material with said fuel gas at a temperature between about 350°C to about 500°C to deposit additional carbon on said carbon-lean carbonaceous material to form carbon-enriched carbonaceous material which can be further reacted with steam.
recycling said carbon-enriched carbonaceous material from the carbon deposition zone to the steam fication zone, and utilizing the depleted fuel gas as an energy source to generate electric power or to produce steam.

43. A carbonaceous material comprising carbon in an amount from about 55% by weight to about 98% by weight; hydrogen in an amount from about 0.1%
to about 1% by weight; and at least one ferrous group metal component selected from the group consisting of nickel, cobalt, nickel alloys, and cobalt alloys, said ferrous group metal component containing not more than about 30% by weight of iron.

44. A carbonaceous material comprising a major phase that includes from about 95% to about 99.9% by weight carbon, from about 0.1% to about 1% by weight hydrogen, and the balance, if any, a ferrous group metal component selected from the group consisting of nickel, cobalt, nickel alloys, and cobalt alloys, and minor phases dispersed in said major phase consisting of nodules comprising carbon and at least 50% by weight of at least one ferrous group metalcomponent selected from the group consisting of nickel, cobalt, nickel alloys and cobalt alloys wherein iron constitutes less than about 30% by weight of the ferrous metal component.

45. A carbonaceous material comprising carbon, hydrogen, and at least one ferrous group metal component selected from the group consisting of nickel, cobalt, nickel alloys and cobalt alloys, said ferrous group metal component containing not more than about 30% by weight of iron, said ferrous group metal component being dispersed throughout the carbon and intimately associated with and at least partly bonded to the carbon, said carbon having a steam gasification rate at about 550°C and about 1 atmosphere pressure of at least about 0.2 mole per hour per mole of carbon present in said carbonaceous material where steam ?
fed to said gasification at a rate of about 1.0 mole per hour per mole of carbonpresent in said carbonaceous material.

46. The carbonaceous material of claim 43, claim 44 or claim 45 in which the ferrous group metal component is nickel.

47. The carbonaceous material of claim 43, claim 44 or claim 45 in which the ferrous group metal component is cobalt.

48. The carbonaceous material of claim 43, claim 44 or claim 45 wherein the ferrous group metal component in said carbonaceous material contains less than about 10% by weight of iron.

49. The carbonaceous material of claim 43, 44 or 45 wherein the ferrous group metal component constitutes an amount from about 5% to about 25% by weight of said carbonaceous material.

50. The carbonaceous material of claim 43 formed by depositing carbon from a gas mixture comprising carbon monoxide and hydrogen in the presence of a ferrous group metal initiator.

51. The carbonaceous material of claim 44 formed by depositing carbon from a gas mixture comprising carbon monoxide and hydrogen in the presence of a ferrous group metal initiator.

52. The carbonaceous material of claim 45 formed by depositing carbon from a gas mixture comprising carbon monoxide and hydrogen in the presence of a ferrous group metal initiator.

53. The carbonaceous material of claim 50, 51 or 52, wherein said carbon deposition is carried out at a temperature in the range of about 300°C to about 700°C
and at a pressure of at least about 1 atmosphere.

54. The carbonaceous material of claim 50, 51 or 52, wherein said carbon deposition takes place at a temperature of at least about 550°C, in the presence of cobalt and at a pressure of at least about one atmosphere.

55. The carbonaceous material of Claim 50, 51 or 52 wherein said deposition takes place at a temperature of less than about 500°C, in the presence of nickel and at a pressure of at least about 1 atmosphere.

56. The carbonaceous material of claim 50, 51 or 52 wherein said ferrous group metal initiator is supported.

57. The carbonaceous material of claim 43, 44 or 45 wherein said material is fibrous and has a total surface area, measured by gas absorption, in the range of about 100 to about 300 square meters per gram of carbonaceous material.

58. The carbonaceous material of claim 43 further comprising a support for said material.

59. The carbonaceous material of claim 44 further comprising a support for said material.

60. The carbonaceous material of claim 45 further comprising a support for said material.

61. A continuous steam gasification process for producing a high heating value gas stream containing methane and hydrogen from a low heating value fuel gas containing carbon monoxide and hydrogen comprising the steps of:
(a) reacting in a steam gasification zone a fibrous carbon-enriched carbonaceous material with steam at a temper-ature of from about 500°C to about 750°C and a pressure of from about 1 to about 100 atmospheres to gasify at least about 40%
of the carbon in the fibrous carbon-enriched carbonaceous material to produce (i) a high heating value gas stream contain ing methane and hydrogen and (ii) a fibrous carbon-lean carbonaceous material, the fibrous carbon-enriched carbonaceous material comprising from about 55% to about 98% by weight carbon, from about 1% to about 44% by weight ferrous group metal component, and from about 0.1% to about 1% by weight hydrogen, the ferrous group metal component containing at least 70% by weight nickel, cobalt and combinations thereof and not more than 30% by weight iron, the fibrous carbon-enriched carbonaceous material including a major phase and a minor phase, the major phase comprising from about 95% to about 99.9% by weight carbon, from about 0-1% to about 1% by weight hydrogen, and the balance, if any, being the ferrous group metal component, the minor com-ponent being nodules which are dispersed throughout the major phase and are intimately associated with and at least partly bonded to the carbon in the major phase, the minor phase com-prising carbon and at least 50% by weight ferrous group metal component;
(b) withdrawing the high heating value gas stream and the fibrous carbon lean carbonaceous material from the steam gasification zone;
(c) reacting in a carbon deposition zone the withdrawn fibrous carbon-lean carbonaceous material with the low heating value fuel gas at a temperature of from about 300° to about 700°C to deposit carbon on the fibrous carbon-lean carbonaceous material to form (i) the fibrous carbon-enriched carbonaceous material and (ii) depleted low heating value fuel gas;

(d) recycling carbon-enriched carbonaceous material from the carbon deposition zone to the steam gasification zone; and (e) lowering the temperature of the withdrawn high heating value gas stream and contacting it with the fibrous carbon-enriched carbonaceous material at a temperature of 300 to 500°C for increasing the heating value of the high heating value gas stream.

62. The process of Claim 61 wherein the withdrawn high heating value gas stream having a lowered temperature is contacted with steam and the fibrous carbon-enriched carbona-ceous material at a temperature of 300 to 500°C for increasing the heating value of the high heating value gas stream.

63. The process of Claim 61 wherein the withdrawn high heating value gas stream having a lowered temperature is contacted with steam and the fibrous carbon-lean carbonaceous material at a temperature of 300 to 500°C for increasing the heating value of the high heating value gas stream.

64. The process of Claim 61 in which the temperature in the steam gasification zone is from about 500 to about 600°C.

65. The process of Claim 61 wherein the low heating value fuel gas is formed by burning coal with air.

66. The process of Claim 61 including the step of withdrawing depleted low heating value fuel gas from the carbon deposition zone and utilizing the withdrawn low heating value fuel gas to generate electrical power or to produce steam.

67. A continuous steam gasification process for producing a high heating value gas stream containing methane and hydrogen from a low heating value fuel gas containing carbon monoxide and hydrogen comprising:

(a) reacting in a steam gasification zone a fibrous carbon-enriched carbonaceous material with steam at a tempera-ture of from about 500°C to about 750°C and a pressure of from about 1 to about 100 atmospheres to gasify at least about 40%
of the carbon in the fibrous carbon-enriched carbonaceous material to produce (i) a high heating value gas stream contain-ing methane and hydrogen and (ii) a fibrous carbon-lean carbona-ceous material, the fibrous carbon-enriched carbonaceous material comprising from about 55% to about 98% by weight carbon, from about 1% to about 44% by weight ferrous group metal component, and from about 0.1% to about 1% by weight hydrogen, the ferrous group metal component containing at least 70% by weight nickel, cobalt, and combinations thereof and not more than 30% by weight iron, the fibrous carbon-enriched carbonaceous material including a major phase and a minor phase, the major phase comprising from about 95% to about 99.9% by weight carbon, from about 0.1% to about 1% by weight hydrogen, and the balance, if any, being the ferrous group metal component, the minor component being nodules which are dispersed throughout the major phase and are intimately associated with and at least partly bonded to the carbon in the major phase, the minor phase com-prising carbon and at least 50% by weight ferrous group metal component;
(b) withdrawing the high heating value gas stream and the fibrous carbon-lean carbonaceous material from the steam gasification zone;
(c) reacting in a carbon deposition zone the with-drawn fibrous carbon-lean carbonaceous material with the low heating value fuel gas at a temperature of from about 300°C
to about 700°C to deposit carbon on the fibrous carbon-lean carbonaceous material to form (i) the fibrous carbon-enriched carbonaceous material and (ii) depleted low heating value fuel gas;
(d) recycling carbon-enriched carbonaceous material from the carbon deposition zone to the steam gasification zone;
and (e) lowering the temperature of the withdrawn high heating value gas stream and contacting it with the fibrous carbon-lean carbonaceous material at a temperature of 300 to 500°C for increasing the heating value of the high heating value gas stream.

68. The process of Claim 67 in which the temperature in the steam gasification zone is from about 500 to about 600°C.

69. The process of Claim 67 wherein the low heating value fuel gas is formed by burning coal with air.

70. The process of Claim 67 including the step of withdrawing depleted low heating value fuel gas from the carbon deposition zone and utilizing the withdrawn low heating value fuel gas to generate electrical power or to produce steam.

71. A continuous steam gasification process for producing a high heating value methane-rich gas stream from a low heating value fuel gas containing carbon monoxide and hydrogen comprising:
(a) reacting in a steam gasification zone a fibrous carbon-enriched carbonaceous material with steam at a tempera-ture of from about 500°C to about 750°C, a pressure of from about 10 to about 100 atmospheres, and a molar ratio of steam fed to carbon gasified of less than about 3 to gasify at least about 40% of the carbon in the fibrous carbon-enriched carbonaceous material to produce (i) a high heating value methane-rich gas stream and (ii) a fibrous carbon-lean carbonaceous material, the fibrous carbon-enriched material comprising from about 55% to about 98% by weight carbon, from about 1% to about 44% by weight ferrous group metal component, and from about 0.1% to about 1% by weight hydrogen, the ferrous group metal component being selected from the group consisting of nickel, cobalt, iron, and combinations thereof, at least 70% by weight of the ferrous group metal component being nickel, the fibrous carbon-enriched carbonaceous material including a major phase and a minor phase, the major phase comprising from about 95% to about 99% by weight carbon, from about 0.1% to about 1% by weight hydrogen, and the balance, if any, being the ferrous group metal component, the minor component being nodules which are dispersed throughout the major phase and are intimately associated with and at least partly bonded to the carbon in the major phase, the minor phase comprising carbon and at least 50% by weight ferrous group metal component;
(b) withdrawing the high heating value methane-rich gas stream and the fibrous carbon-lean carbonaceous material from the steam gasification zone;
(c) reacting in a carbon deposition zone the withdrawn fibrous carbon-lean carbonaceous material with the low heating value fuel gas at a temperature of from about 300 to about 500°C
to deposit carbon on the fibrous carbon-lean carbonaceous material to form (i) the fibrous carbon-enriched carbonaceous material and (ii) depleted low heating value fuel gas; and (d) recycling carbon-enriched carbonaceous material from the carbon deposition zone to the steam gasification zone.

72. The process of Claim 71 comprising the steps of lowering the temperature of the withdrawn high heating value gas stream and contacting it with the fibrous carbon-enriched carbonaceous material at a temperature of 300 to 500°C for increasing the heating value of the high heating value gas stream.

73. The process of Claim 71 comprising the steps of lowering the temperature of the withdrawn high heating value gas stream and contacting it with steam and the fibrous carbon-enriched carbonaceous material at a temperature of 300 to 500°C
for increasing the heating value of the high heating value gas stream.

74. The process of Claim 71 comprising the steps of lowering the temperature of the withdrawn high heating value gas stream and contacting it with the fibrous carbon-lean carbonaceous material at a temperature of 300 to 500°C for increasing the heating value of the high heating value gas stream.

75. The process of Claim 71 comprising the steps of lowering the temperature of the withdrawn high heating value gas stream and contacting it with steam and the fibrous carbon-lean carbonaceous material at a temperature of 300 to 500°C for increasing the heating value of the high heating value gas stream.

76. The process of Claim 71 wherein the low heating value fuel gas is formed by burning coal with air.

77. A continuous steam gasification process for producing a high heating value hydrogen-rich gas stream from a low heating value fuel gas containing carbon monoxide and hydro-gen comprising:
(a) reacting in a steam gasification zone a fibrous carbon-enriched carbonaceous material with steam at a tempera-ture of from about 500°C to about 650°C, a pressure of from about 1 to about 10 atmospheres , and a molar ratio of steam fed to carbon gasified of at least about 3 to gasify at least about 40% of the carbon in the fibrous carbon-enriched carbona-ceous material to produce (i) a high heating value hydrogen-rich gas stream containing hydrogen and (ii) a fibrous carbon-lean carbonaceous material, the fibrous carbon-enriched carbonaceous material comprising from about 55% to about 98% by weight carbon, from about 1% to about 44% by weight ferrous group metal component, and from about 0.1% to about 1%
by weight hydrogen, the ferrous group metal component being selected from the group consisting of nickel, cobalt, iron, and combinations thereof, at least 70% by weight of the ferrous group metal component being cobalt, the fibrous carbon-enriched car-bonaceous material including a major phase and a minor phase, the major phase comprising from about 95% to about 99.9% by weight carbon, from about 0.1 to about 1% by weight hydrogen, and the balance, if any, being the ferrous group metal component, the minor component being nodules which are dispersed throughout the major phase and are intimately associated with and at least partly bonded to the carbon in the major phase, the minor phase comprising carbon and at least 50% by weight ferrous group metal component;
(b) withdrawing the high heating value hydrogen-rich gas stream and the fibrous carbon-lean carbonaceous material from the steam gasification zone;
(c) reacting in a carbon deposition zone the with-drawn fibrous carbon-lean carbonaceous material with the low heating value fuel gas at a temperature of above about 550°C
to deposit carbon on the fibrous carbon-lean carbonaceous material to form (i) the fibrous carbon-enriched carbonaceous material and (ii) depleted low heating value fuel gas; and (d) recycling carbon-enriched carbonaceous material from the carbon deposition zone to the steam gasification zone.

78. The process of Claim 77 comprising the steps of lowering the temperature of the withdrawn high heating value gas stream and contacting it with the fibrous carbon-enriched carbonaceous material at a temperature of 300 to 500°C for increasing the heating value of the high heating value gas stream.

79. The process of Claim 77 comprising the steps of lowering the temperature of the withdrawn high heating value gas stream and contacting it with steam and the fibrous carbon-enriched carbonaceous material at a temperature of 300 to 500°C
for increasing the heating value of the high heating value gas stream.

80. The process of Claim 77 comprising the steps of lowering the temperature of the withdrawn high heating value gas stream and contacting it with the fibrous carbon-lean carbonaceous material at a temperature of 300 to 500°C for increasing the heating value of the high heating value gas stream.

81. The process of Claim 77 comprising the steps of lowering the temperature of the withdrawn high heating value gas stream and contacting it with steam and the fibrous carbon-lean carbonaceous material at a temperature of 300 to 500°C for increasing the heating value of the high heating value gas stream.

82. The process of Claim 77 wherein the low heating value fuel gas is formed by burning coal with air.

83. The process of Claim 77 wherein the ferrous group metal component comprises iron.

84. The process of Claim 83 in which the ferrous group metal component comprises up to 10% by weight iron.