CN104152199B - Technology for preparing natural gas through sulfur resistant methanation by coal-prepared synthesis gases - Google Patents

Abstract

The invention relates to a technology for preparing natural gas through sulfur resistant methanation by coal-prepared synthesis gases, which is characterized in that coal-prepared synthesis gases is subjected to secondary sulfur resistant transformation and methanation reaction on a molybdenum-based bifunctional catalyst, then is eluted by methanol at low temperature to remove acidic gas, and finally, the Ni-based methanation catalyst is used for performing secondary methanation reaction on unreacted CO and H2 to obtain the excellent natural gas product. The technology for preparing natural gas has the advantages of simple process flow, less equipment investment, low comprehensive energy consumption and excellent natural gas product.

Description

A kind of producing synthesis gas from coal carries out the technique that methanation in presence of sulfur prepares natural gas

Technical field

The invention belongs to a kind of natural gas from coal technique, more particularly, to a kind of producing synthesis gas from coal carries out methanation in presence of sulfur preparation The technique of natural gas.

Background technology

China has rich coal, the Energy Situation of oil-poor and few gas, and the wherein consumption proportion of natural gas is average far below the world Level.In recent years, increasing sharply with China's natural gas demand, domestic natural gas insufficiency of supply-demand is gradually increased, and then limits Make the stable and rapid development of Chinese national economy.Natural gas from coal is the technology producing natural gas with coal for raw material, can Coal to be converted clean fuel ch for ease of long-distance sand transport₄, it is to optimize domestic energy resource structure, alleviate natural gas supply and demand lance Shield and the important channel realizing coal high-efficiency clean conversion.

Methanation is the core technology of natural gas from coal, specially co, the co in synthesis gas₂And h₂In uniform temperature, pressure With synthesizing methane under catalyst action.At present, industrial methanation technology is mainly by German Shandong is strange, dimension worn by Top of Denmark rope and Britain Grasp etc. fewer companies, above-mentioned technology is all using the loading type nickel-based catalyst that catalytic performance is excellent, but the presence of this catalyst is anti- Coke formation difference and the shortcoming of not resistant to sulfur, therefore need to adjust h/c in synthesis gas to 3 about before methanation, sulphur is removed to simultaneously Below 0.1ppm.For meeting the requirement to synthesis gas for the nickel-base catalyst, industrial natural gas from coal technique is provided with before methanation Sulphur-resistant conversion unit and depickling gas cell, concrete technology flow process is shown in Fig. 1.Although natural gas from coal is coal cleaning and optimizes profit Optimal selection, but limited by methanation nickel-base catalyst, above-mentioned industry natural gas from coal technology still suffers from problems: (1) low-temp methanol is washed so that synthesis gas must be through " hot (conversion)-cold (methyl alcohol is washed)-heat (methanation)-cold (cooling compression) ", temperature Degree repeatedly arrives -40 DEG C of wide variation through 300～400 DEG C, considerably increases equipment investment, energy ezpenditure and operating cost；(2) Individually sulphur-resistant conversion unit not only increases equipment investment and energy consumption, and because the thermal discharge of water-gas shift is less, works as conjunction When becoming temperature degree and water vapour content that fluctuation occurs, it is frequently encountered the too low phenomenon of transformation temperature so that having in synthesis gas Machine sulphur can not be fully converted to inorganic sulfur, and then affects follow-up sulphur recovery efficiency；(3) methane turns to strong exothermal reaction, industry Above by supplementing vapor and up to 5 times multi cycle gas, synthesis gas is diluted, considerably increases recycle unit investment and follow Ring energy consumption.Therefore, for overcoming problem present in existing natural gas from coal technology, and respond the call that national energy-saving reduces discharging, open The new natural gas from coal technology sending out that technological process is simple, equipment investment is few, comprehensive energy consumption is low and gas product is excellent a kind of Have great importance.

Molybdenum base catalyst for methanation in presence of sulfur is with mos₂For activated centre, not only the sulfur content no maximum in synthesis gas is wanted Ask, and due to having and sulfur-resistant transformation catalyst identical active component, there is sulphur-resistant conversion simultaneously and methanation in presence of sulfur is dual Function, becomes the study hotspot of lot of domestic and foreign mechanism and scientific research institutions.Patent cn103480362a discloses a kind of load The preparation method of type catalyst for methanation in presence of sulfur, with mo, w and v as active component, co, ni, la and k are auxiliary agent for this invention, with al₂o₃Or zro₂For carrier, be prepared for catalyst for methanation in presence of sulfur by the precipitation method, this catalyst have preparation process simple and The good advantage of sulfur tolerance.Patent cn103495421a is prepared for a kind of magnesium aluminate spinel load by kneading method or infusion process Cobalt molybdenum catalyst for methanation in presence of sulfur, this catalyst can use in the pressure limit of 0～6mpa, and catalyst strength and stability are good Good.Patent cn10343326a discloses a kind of zro₂The high stability catalyst for methanation in presence of sulfur of load, by step impregnation method Successively by y₂o₃And mo₂o₃It is carried on zro₂On carrier, wherein y₂o₃Part can be by mgo, cao and/or cr₂o₃Substitute, this catalyst Higher methanation reaction activity and high stability is shown in high hydrogen sulfide atmosphere.

In view of problem present in existing methanation technology, if it is natural mo base bifunctional catalyst to be applied to coal system So that sulphur-resistant conversion and methanation reaction one step complete in gas technology, then remove through low-temp methanol wash-out and obtain final product after sour gas Gas product, not only saves the equipment investment of converter unit and energy consumption, avoids " malaria " present in existing process Problem, and because methanation reaction is the reaction of volume-diminished so that the treating capacity that low-temp methanol is washed substantially reduces.Above-mentioned special By the optimization to mo base catalyst composition, auxiliary agent species, kind of carrier and preparation method, its purpose is to improve to profit mostly Catalyst heat endurance and reduction preparation cost, but the activity of its catalyst and methane selectively are still relatively low.Inventor herein Further study show that, when carrying out conversion and methanation under bifunctional catalyst, inevitably there is methanation, steam simultaneously Conversion and three reactions of Reversed Water-gas Shift occur, and all containing substantial amounts of co in the synthesis gas of existing Coal Gasification Technology preparation₂, Co in the synthesis gas of crushed coal pressure gasifying mostly adopting especially in natural gas from coal technology₂Volume content up to more than 28%, And co after transformed and methanation₂Content can increase further, substantial amounts of co₂The generation of transformationreation against the current can be led to so that co Conversion ratio substantially reduce, through low-temp methanol wash-out except after sour gas, still suffer from product gas in a large number unconverted co and h₂Gas, have impact on the quality of natural gas, limits its industrial applications.

Content of the invention

The purpose of the present invention is that a kind of technological process of exploitation is simple, equipment investment is few, comprehensive energy consumption is low and gas product Excellent producing synthesis gas from coal carries out the technique that methanation in presence of sulfur prepares natural gas.

The present invention is that producing synthesis gas from coal first carries out sulphur-resistant conversion and methanation reaction on molybdenum base bifunctional catalyst simultaneously, Then remove sour gas through low-temp methanol wash-out, finally by ni methylmethane catalyst to unreacted co and h₂Carry out two grades Methanation reaction obtains excellent gas product.

For reaching above-mentioned purpose, inventor herein is by catalyst preparation many times, activity rating, theoretical calculation and soft Part is simulated, and has grasped the reaction rule of synthesis gas sulphur-resistant conversion and methanation in presence of sulfur on molybdenum base bifunctional catalyst, has obtained Gas component with a large amount of basic datas of reaction condition, and combine natural gas from coal Engineering Design experience for many years it is proposed that Gasification generate synthesis gas carry out two-stage methanation in presence of sulfur reaction first, and by select suitable reaction conditions for example temperature, pressure, Air speed and WGR etc., not only make the methane content in methanation in presence of sulfur product gas greatly improve, and by h₂/ co adjust to Between 3.0～3.3；The product gas of methanation in presence of sulfur remove sour gas (co through low-temp methanol wash-out₂+h₂S) after, in nickel catalyst Carry out two grades of methanation reactions in the presence of agent, after cooled and gas-liquid separation more than methane volumetric content >=96% natural gas Product.Compared with existing industry methanation process, the converter unit that methanation in presence of sulfur technique proposed by the present invention need not be independent, stream Journey is simpler, reduces equipment investment and the energy consumption of conversion, and reduces reaction because methane turns to volume, so that low temperature first The equipment investment that alcohol is washed and energy consumption are greatly reduced, and have great industrial value and potentiality.

The invention discloses a kind of producing synthesis gas from coal carries out the technique that methanation in presence of sulfur prepares natural gas, its concrete technology road Line is:

(1) synthesis gas after dedusting and oil removing first passes through the outlet of input and output material heat exchanger ii and methanation in presence of sulfur reactor ii Gas heat exchange, then work off one's feeling vent one's spleen through input and output material heat exchanger i and methanation in presence of sulfur reactor i after heat exchange, and from top after mix with water vapour Portion enters methanation in presence of sulfur reactor i, carries out first order methanation in presence of sulfur and sulphur-resistant conversion is anti-on molybdenum base bifunctional catalyst Should, work off one's feeling vent one's spleen and first reclaim heat through high-pressure waste-heat boilers i, and after input and output material heat exchanger i and synthesis gas heat exchange, remove resistant to sulfur methane Change reactor ii；

(2) reaction gas coming from methanation in presence of sulfur reactor i enters methanation in presence of sulfur reactor ii from top, double in molybdenum base Carry out second level methanation in presence of sulfur and sulfur-tolerant water gas shift on function catalyst, work off one's feeling vent one's spleen and first pass through high-pressure waste-heat boilers ii recovery Heat, then through input and output material heat exchanger ii and synthesis gas heat exchange, after being cooled down by air cooler i further, enter gas-liquid separation Tank i carries out gas-liquid separation, and condensate liquid is discharged from knockout drum i bottom, and gas phase enters low-temp methanol after discharging from separation tank top Wash system, remove carbon dioxide and the hydrogen in gas through low-temp methanol wash-out after, the methanation being sent to equipped with ni base catalyst is anti- Answer device i；

(3) wash, from low-temp methanol, the gas coming first to carry out through working off one's feeling vent one's spleen of input and output material heat exchanger iv and methanator ii Heat exchange, then after input and output material heat exchanger iii works off one's feeling vent one's spleen heat exchange with methanator i, enter methanator from top I, carries out first order methanation reaction under the catalytic action of ni methylmethane catalyst, works off one's feeling vent one's spleen and first passes through waste heat boiler iii Reclaim heat, and wash after the gas converting heat coming with low-temp methanol through input and output material heat exchanger iii, enter methanator from top In ii, carry out second level methanation reaction in the presence of ni methylmethane catalyst, the co in synthesis gas converts completely since then For ch₄Gas, methanator ii works off one's feeling vent one's spleen first through input and output material heat exchanger iv and the gas from rectisol system Heat exchange, after then cooling down through air cooling ii and water cooler, enters knockout drum ii and carries out gas-liquid separation, and condensate liquid is from knockout drum ii Bottom discharge, and knockout drum ii top row goes out gas product, sends into natural gas line after drying compression.

Synthesis gas as above is obtained through Shandong strange crushed coal pressure gasifying technology, and its synthesis gas consists of h₂37～40%, Co 17%～20%, co₂28～33%, ch₄8%～12%, n₂0.1～0.4%.

Molybdenum base bifunctional catalyst quality as above consists of: active component moo₃10～35wt%, auxiliary agent aoxidizes Thing 2～20wt%, carrier 50～85wt%；Wherein auxiliary agent is one or more of co, la, ce, zr, fe, ni and k, and excellent Select co, la, ce, zr；Carrier is γ-al₂o₃、sio₂, magnesium aluminate spinel, zro₂、ceo₂-al₂o₃Complex carrier and al₂o₃-zro₂ Complex carrier, and preferred magnesium aluminate spinel, ceo₂-al₂o₃Complex carrier and al₂o₃-zro₂Complex carrier；Active component passes through leaching Stain method, coprecipitation or sol-gal process are carried on carrier, and infusion process refers to patent 102463118a or cn103495421a, Coprecipitation refers to patent cn103480362a, and sol-gal process refers to patent cn101733115a.

Methanation in presence of sulfur reactor i and methanation in presence of sulfur reactor ii as above is fixed bed adiabatic reactor.

In methanation in presence of sulfur reactor i import as above, vapor and the volume ratio of synthesis gas are 0.1～0.3, mix After conjunction, inlet gas temperature is 270～300 DEG C, and temperature of working off one's feeling vent one's spleen is 500～600 DEG C of reaction pressures is 2.0～7.0mpa, and reaction is empty Speed is 2000～8000h^-1.

Methanation in presence of sulfur reactor ii inlet gas temperature as above is 270～300 DEG C, temperature of working off one's feeling vent one's spleen is 450～ 550 DEG C, reaction pressure is 2.0～7.0mpa, and reaction velocity is 2000～8000h^-1.

Low-temp methanol as above is washed and is made up of desulfurizing tower and decarbonizing tower, and operation temperature is -20～-60 DEG C, operation pressure Power 2.0～7.0mpa, the sulphur in gas after washing through low-temp methanol takes off to 0.01～0.1ppm, co₂Volume content takes off to 0.3～ 0.8v%.

Ni base catalyst used in methanator i and ii as above is the mcr-2x methanation of Top's rope A kind of wide temperature range type methanation of catalyst, davy company ceg-lh methanation catalyst or the exploitation of Dalian Physical and Chemical Inst. is urged Quality in terms of oxide for the catalyst of one of agent, wherein Dalian Physical and Chemical Inst. exploitation consists of: activearm Divide nio 10～75%, auxiliary agent la₂o₃0.1～15% and carrier al₂o₃-zro₂Surplus, auxiliary agent is lanthana or lanthana and nickel The composition of lanthanum compound, carrier is composition, its preparation process and the bar that aluminum oxide is formed with zirconium oxide with nickel aluminide Part refers to patent cn102029162.

Methanator i and methanator ii is fixed bed adiabatic reactor as mentioned above.

The inlet gas temperature of methanator i is 270～300 DEG C, and temperature of working off one's feeling vent one's spleen is 450～620 DEG C, reaction pressure For 2.0～7.0mpa, reaction velocity is 2000～8000h^-1；

The inlet gas temperature of methanator ii is 250～300 DEG C, and temperature of working off one's feeling vent one's spleen is 290～350 DEG C, reaction pressure Power is 2.0～7.0mpa, and reaction velocity is 2000～8000h^-1.

The volume through above-mentioned technique and reacted natural gas for the synthesis gas as above consists of: ch₄96～98%, co₂0.2～0.5, h₂0.5～2%, n₂0.6～1.2%, c_2～60.3～0.5%.

Compared with prior art, the present invention has substantive distinguishing features to the present invention and marked improvement is:

(1) sulphur-resistant conversion and methanation in presence of sulfur are merged by the producing synthesis gas from coal methanation in presence of sulfur technique of present invention exploitation, with Existing industry natural gas from coal technique is compared, and decreases single sulphur-resistant conversion unit, saves investment and the fortune of conversion equipment Row cost.

(2) traditional coal process for producing natural is that synthesis gas is washed and methanation finally prepared sky through sulphur-resistant conversion, low-temp methanol So gas, and the present invention first carries out low-temp methanol wash-out after sulphur-resistant conversion and methanation in presence of sulfur and removes sour gas, due to methanation For deduction son reaction, the gas flow minimizing about 20% after methanation in presence of sulfur and sulphur-resistant conversion, reduce the equipment that low-temp methanol is washed Size and energy consumption.

(3) present invention set up two methanators being filled with nickel-base catalyst after low-temp methanol is washed so that by In co₂Partly unreacted co and h that excessive and inverse water-gas shift leads to₂Completely, the methane content in product gas is up to for conversion More than 96%, take full advantage of sulphur-resistant conversion and the advantage of methanation bifunctional catalyst, the shortcoming that compensate for this catalyst.

(4) in methanation in presence of sulfur due to gas in have the substantial amounts of co excellent in heat energy power₂With the vapor supplementing, energy Enough effectively control methanation in presence of sulfur bed reaction temperatures, need not follow the dilution of gas；Through methanation in presence of sulfur and remove sour gas After body, due to containing substantial amounts of ch in gas₄Gas, and co and h₂Relatively low Deng available gas ratio, therefore in methanation Move heat without circulating air.Therefore, the present invention is significantly reduced recycle compressor compared with industrial natural gas from coal and puts into and circulate Energy consumption.

(5) resistant to sulfur change and methanation in presence of sulfur are merged by the present invention, because the strong exothermal reaction of methanation is so that resistant to sulfur becomes Changing temperature increases, it is to avoid lead to not because temperature is too low during independent sulphur-resistant conversion realize organic sulfur turning to inorganic sulfur Change and affect the problem of sulfur recovery.

Brief description

Fig. 1 is prior art producing synthesis gas from coal methanation synthetic natural gas technique.

Fig. 2 is producing synthesis gas from coal methanation in presence of sulfur synthetic natural gas new technology

As illustrated, 1 is methanation in presence of sulfur reactor i, 2 is methanation in presence of sulfur reactor ii, and 3 is methanator i, 4 is methanator ii, and 5 is rectisol system, and 6 is knockout drum i, and 7 is knockout drum ii, and 8 is that air is cold But device i, 9 is aerial cooler ii, and 10 is waste heat boiler i, and 11 is waste heat boiler ii, and 12 is waste heat boiler iii, and 13 are into and out expecting Heat exchanger i, 14 are into and out expecting heat exchanger ii, and 15 are into and out expecting heat exchanger iii, and 16 are into and out expecting heat exchanger iv, 17 is water cooler.

Specific embodiment

The proposition of present invention process and condition is all to numerous mo base sulfur resistant catalysts and ni methylmethane chemical industry catalysis Propose on the basis of agent screening, in implementation process, catalyst model can be provided if the industrial catalyst present invention, if The catalyst invented from other, the present invention can provide its composition or source.

Below by specific embodiment, the specific embodiment of the present invention is described in further detail, but should be by This is interpreted as that the scope of the present invention is only limitted to above-described embodiment.

Embodiment 1

In the present embodiment, methanation in presence of sulfur reactor i is identical with the catalyst used in methanation in presence of sulfur reactor ii, Its oxide mass consists of moo₃25wt%-co₂o₃+zro₂15wt%/ceo₂-al₂o₃The catalyst of 60wt%, active component moo₃With auxiliary agent co₂o₃+zro₂It is carried on carrier ceo by way of dipping₂-al₂o₃On, concrete preparation method and technique are shown in Cn102463118a embodiment 5；Nickel-base catalyst in methanator i and methanator ii adopts Top's rope Mcr-2x catalyst.Using above-mentioned catalyst, its specific technical process and condition are as follows:

(1) after dedusting and oil removing, volume consists of h₂39%th, co 19.6%, co₂31.5%th, ch₄9.5% and n₂0.4% Synthesis gas first pass through input and output material heat exchanger ii and working off one's feeling vent one's spleen of methanation in presence of sulfur reactor ii and carry out heat exchange, then change through input and output material Hot device i and methanation in presence of sulfur reactor i heat exchange of working off one's feeling vent one's spleen reaches 270 DEG C, and from top entrance resistant to sulfur methane after mix with vapor Change reactor i, vapor is 0.30 with the mol ratio of synthesis gas, in pressure 4.5mpa and air speed 8000h^-1Reaction condition under, In support type moo₃25wt%-co₂o₃+zro₂15wt%/ceo₂-al₂o₃One-level resistant to sulfur is carried out on 60wt% bifunctional catalyst Methanation and sulfur-tolerant water gas shift, temperature is to reclaim heat through high-pressure waste-heat boilers i after 600 DEG C of elder generation of working off one's feeling vent one's spleen, and through turnover After material heat exchanger i reaches 270 DEG C with synthesis gas heat exchange, remove methanation in presence of sulfur reactor ii；

(2) reaction gas coming from methanation in presence of sulfur reactor i enters methanation in presence of sulfur reactor ii from top, in pressure 4.5mpa and air speed 8000h^-1Reaction condition under, in support type moo₃25wt%-co₂o₃+zro₂15wt%/ceo₂- al₂o₃Second level methanation in presence of sulfur and sulfur-tolerant water gas shift are carried out on 60wt% bifunctional catalyst, temperature is 550 works off one's feeling vent one's spleen First pass through high-pressure waste-heat boilers ii and reclaim heat, then through input and output material heat exchanger ii and synthesis gas heat exchange, and pass through air cooling further Device i enters knockout drum i after being cooled down and carries out gas-liquid separation, and condensate liquid is discharged from knockout drum i bottom, separates tank top row The gas phase going out enters rectisol system, removes co by low-temp methanol wash-out under conditions of -40 DEG C and 4.5mpa₂And h₂s Afterwards, wherein h₂S is removed to 0.03ppm, and co₂It is removed to volume content 0.5%, be sent to the methane equipped with nickel-base catalyst Change reactor i；

(3) first work off one's feeling vent one's spleen with methanator ii through input and output material heat exchanger iv from the gas that low-temp methanol is washed and changed After heat, then reached after 270 DEG C by input and output material heat exchanger iii and methanator i heat exchange of working off one's feeling vent one's spleen, from top entrance equipped with In the methanator i of mcr-2x catalyst, in pressure 4.5mpa and air speed 5000h^-1Under the conditions of to carry out one-level methanation anti- Should, temperature is that 620 DEG C work off one's feeling vent one's spleen first passes through waste heat boiler iii recovery heat, and through input and output material heat exchanger iii and low-temp methanol After the gas converting heat washed reaches 250 DEG C, enter equipped with mcr-2x methanator ii from top, in pressure 4.5mpa and sky Fast 5000h^-1Under the conditions of carry out two grades of methanation reactions, the co in synthesis gas is fully converted to ch since then₄Gas, temperature is 350 DEG C implication first through input and output material heat exchanger iv and the gas converting heat from rectisol system, then through aerial cooler ii and Enter knockout drum ii after water cooler cooling, condensate liquid is discharged from the bottom of knockout drum ii, and knockout drum ii top row goes out i.e. For gas product, after drying and compression, send into natural gas line.

The gas product composition synthesizing in the unstripped gas of the present embodiment and at reaction conditions for details see attached table 1.

Embodiment 2

In the present embodiment, methanation in presence of sulfur reactor i is identical with the catalyst used in methanation in presence of sulfur reactor ii, Its oxide mass consists of moo₃30wt%-co₂o₃+fe₂o₃+ nio 20wt%/ceo₂-al₂o₃The catalyst of 50wt%, lives Property component moo₃With auxiliary agent co₂o₃+fe₂o₃+ nio is carried on carrier ceo by way of dipping₂-al₂o₃On, concrete preparation method See cn102463118a embodiment 5 with technique；The nickel-base catalyst of methanator i and methanator ii adopts Top The mcr-2x catalyst of rope.Using above-mentioned catalyst, its specific technical process and condition are as follows:

(1) after dedusting and oil removing, volume consists of h₂40%th, co 20%, co₂31.7%th, ch₄8.0% and n₂0.3% Synthesis gas first passes through input and output material heat exchanger ii and carries out heat exchange with working off one's feeling vent one's spleen of methanation in presence of sulfur reactor ii, then through input and output material heat exchange Device i and methanation in presence of sulfur reactor i heat exchange of working off one's feeling vent one's spleen reaches 275 DEG C, and from top entrance methanation in presence of sulfur after mix with vapor Reactor i, vapor is 0.25 with the mol ratio of synthesis gas, in pressure 4.0mpa and air speed 7500h^-1Reaction condition under, Support type moo₃30wt%-co₂o₃+fe₂o₃+ nio20wt%/ceo₂-al₂o₃One-level is carried out on 50wt% bifunctional catalyst resistance to Sulphur methanation and sulfur-tolerant water gas shift, temperature is to reclaim heat through high-pressure waste-heat boilers i after 583 DEG C of elder generation of working off one's feeling vent one's spleen, and through entering After effluent exchanger i and unstripped gas heat exchange reach 275 DEG C, remove methanation in presence of sulfur reactor ii；

(2) reaction gas coming from methanation in presence of sulfur reactor i enters methanation in presence of sulfur reactor ii from top, in pressure 4.0mpa and air speed 7500h^-1Reaction condition under, in support type moo₃30wt%-co₂o₃+fe₂o₃+ nio 20wt%/ceo₂- al₂o₃Second level methanation in presence of sulfur and sulfur-tolerant water gas shift are carried out on 50wt% bifunctional catalyst, temperature is 537 works off one's feeling vent one's spleen First pass through high-pressure waste-heat boilers ii and reclaim heat, then through input and output material heat exchanger ii and synthesis gas heat exchange, and pass through air cooling further Device i enters knockout drum i after being cooled down and carries out gas-liquid separation, and condensate liquid is discharged from knockout drum i bottom, separates tank top row The gas phase going out enters rectisol system, removes co by low-temp methanol wash-out under conditions of -35 DEG C and 4.0mpa₂And h₂s Afterwards, wherein h₂S is removed to 0.04ppm, and co₂It is removed to volume content 0.55%, be sent to the methane equipped with nickel-base catalyst Change reactor i；

(3) first work off one's feeling vent one's spleen with methanator ii through input and output material heat exchanger iv from the gas that low-temp methanol is washed and changed After heat, then reached after 275 DEG C by input and output material heat exchanger iii and methanator i heat exchange of working off one's feeling vent one's spleen, from top entrance equipped with In the methanator i of mcr-2x catalyst, in pressure 4.0mpa and air speed 6000h^-1Under the conditions of to carry out one-level methanation anti- Should, temperature is that 601 DEG C work off one's feeling vent one's spleen first passes through waste heat boiler iii recovery heat, and through input and output material heat exchanger iii and low-temp methanol After the gas converting heat washed reaches 255 DEG C, enter equipped with mcr-2x methanator ii from top, in pressure 4.0mpa and sky Fast 6000h^-1Under the conditions of carry out two grades of methanation reactions, the co in synthesis gas is fully converted to ch since then₄Gas, temperature is 324 DEG C implication first through input and output material heat exchanger iv and the gas converting heat from rectisol system, then through aerial cooler ii and Enter knockout drum ii after water cooler cooling, condensate liquid is discharged from the bottom of knockout drum ii, and knockout drum ii top row goes out i.e. For gas product, after drying and compression, send into natural gas line.

The gas product composition synthesizing in the unstripped gas of the present embodiment and at reaction conditions for details see attached table 1.

Embodiment 3

In the present embodiment, methanation in presence of sulfur reactor i is identical with the catalyst that methanation in presence of sulfur reactor ii is used, its Quality consists of moo₃35wt%-co₂o₃+ko₂2wt%/zro₂The catalyst of 63wt%, active component moo₃With auxiliary agent co₂o₃+ ko₂It is carried on carrier zro by way of dipping₂On, concrete preparation method and technique are shown in cn103495421a embodiment 14；First The nickel-base catalyst of alkylation reactors i and methanator ii adopts the ceg-lh catalyst of davy.Using above-mentioned catalyst, Its specific technical process and condition are as follows:

(1) after dedusting and oil removing, volume consists of h₂40%th, co 20%, co₂30.3%th, ch₄9.5% and n₂0.2% Synthesis gas first passes through input and output material heat exchanger ii and carries out heat exchange with working off one's feeling vent one's spleen of methanation in presence of sulfur reactor ii, then through input and output material heat exchange Device i and methanation in presence of sulfur reactor i heat exchange of working off one's feeling vent one's spleen reaches 280 DEG C, and from top entrance methanation in presence of sulfur after mix with vapor Reactor i, vapor is 0.20 with the mol ratio of synthesis gas, in pressure 3.5mpa and air speed 7000h^-1Reaction condition under, Support type moo₃35wt%-co₂o₃+ko₂2wt%/zro₂One-level methanation in presence of sulfur and resistance to is carried out on 63wt% bifunctional catalyst Sulphur transformationreation, temperature is to reclaim heat through high-pressure waste-heat boilers i after 583 DEG C of elder generation of working off one's feeling vent one's spleen, and through input and output material heat exchanger i with After unstripped gas heat exchange reaches 280 DEG C, remove methanation in presence of sulfur reactor ii；

(2) reaction gas coming from methanation in presence of sulfur reactor i enters methanation in presence of sulfur reactor ii from top, in pressure 3.5mpa and air speed 7000h^-1Reaction condition under, in support type moo₃35wt%-co₂o₃+ko₂2wt%/zro₂63wt% is double Second level methanation in presence of sulfur and sulfur-tolerant water gas shift are carried out on function catalyst, temperature is that 521 DEG C work off one's feeling vent one's spleen first passes through high pressure Waste heat boiler ii reclaims heat, then through input and output material heat exchanger ii and synthesis gas heat exchange, and cooled down by air cooler i further Enter knockout drum i afterwards and carry out gas-liquid separation, condensate liquid is discharged from knockout drum i bottom, separate the gas phase discharged tank top and enter Enter rectisol system, under conditions of -45 DEG C and 3.5mpa, co is removed by low-temp methanol wash-out₂And h₂After s, wherein h₂S takes off Remove to 0.05ppm, and co₂It is removed to volume content 0.60%, be sent to the methanator i equipped with nickel-base catalyst；

(3) first work off one's feeling vent one's spleen with methanator ii through input and output material heat exchanger iv from the gas that low-temp methanol is washed and changed After heat, then reached after 280 DEG C by input and output material heat exchanger iii and methanator i heat exchange of working off one's feeling vent one's spleen, from top entrance equipped with In the methanator i of mcr-2x catalyst, in pressure 3.5mpa and air speed 7000h^-1Under the conditions of to carry out one-level methanation anti- Should, temperature is that 584 DEG C work off one's feeling vent one's spleen first passes through waste heat boiler iii recovery heat, and through input and output material heat exchanger iii and low-temp methanol After the gas converting heat washed reaches 260 DEG C, enter equipped with mcr-2x methanator ii from top, in pressure 3.5mpa and sky Fast 7000h^-1Under the conditions of carry out two grades of methanation reactions, the co in synthesis gas is fully converted to ch since then₄Gas, temperature is 319 DEG C implication first through input and output material heat exchanger iv and the gas converting heat from rectisol system, then through aerial cooler ii and Enter knockout drum ii after water cooler cooling, condensate liquid is discharged from the bottom of knockout drum ii, and knockout drum ii top row goes out i.e. For gas product, after drying and compression, send into natural gas line.

The gas product composition synthesizing in the unstripped gas of the present embodiment and at reaction conditions for details see attached table 1.

Embodiment 4

In the present embodiment, methanation in presence of sulfur reactor i is identical with the catalyst that methanation in presence of sulfur reactor ii is used, its Quality consists of moo₃13wt%-zro₂14.5wt%/γ-al₂o₃The catalyst of 72.5wt%, active component moo₃And auxiliary agent zro₂It is carried on γ-al by way of co-precipitation₂o₃On, concrete preparation method and technique are shown in cn103480362a embodiment 7； Nickel-base catalyst quality in methanator i and methanator ii consists of nio 40wt%-la₂o₃7wt%- al₂o₃43wt%-zro₂7wt%, concrete preparation method and step are shown in cn102029162a embodiment 5.Using above-mentioned catalyst, Its specific embodiment and condition are as follows:

(1) after dedusting and oil removing, volume consists of h₂37%th, co 20%, co₂30.7%th, ch₄12% and n₂0.3% conjunction Become gas to first pass through input and output material heat exchanger ii and carry out heat exchange with working off one's feeling vent one's spleen of methanation in presence of sulfur reactor ii, then through input and output material heat exchanger I and methanation in presence of sulfur reactor i heat exchange of working off one's feeling vent one's spleen reaches 285 DEG C, and anti-from top entrance methanation in presence of sulfur after mix with vapor Answer device i, vapor is 0.15 with the mol ratio of synthesis gas, in pressure 3.0mpa and air speed 6500h^-1Reaction condition under, negative Load type moo₃13wt%-zro₂14.5wt%/γ-al₂o₃Carry out on 72.5wt% bifunctional catalyst one-level methanation in presence of sulfur and Sulfur-tolerant water gas shift, temperature is to reclaim heat through high-pressure waste-heat boilers i after 571 DEG C of elder generation of working off one's feeling vent one's spleen, and through input and output material heat exchanger i Reach after 285 DEG C with unstripped gas heat exchange, remove methanation in presence of sulfur reactor ii；

(2) reaction gas coming from methanation in presence of sulfur reactor i enters methanation in presence of sulfur reactor ii from top, in pressure 3.0mpa and air speed 6500h^-1Reaction condition under, in support type moo₃13wt%-zro₂14.5wt%/γ- al₂o₃Second level methanation in presence of sulfur and sulfur-tolerant water gas shift are carried out on 72.5wt% bifunctional catalyst, temperature is 507 DEG C goes out Implication first passes through high-pressure waste-heat boilers ii and reclaims heat, then through input and output material heat exchanger ii and synthesis gas heat exchange, and pass through further Air cooler i enters knockout drum i after being cooled down and carries out gas-liquid separation, and condensate liquid is discharged from knockout drum i bottom, separates tank deck The gas phase that portion discharges enters rectisol system, removes co by low-temp methanol wash-out under conditions of -60 DEG C and 3.0mpa₂With h₂After s, wherein h₂S is removed to 0.02ppm, and co₂It is removed to volume content 0.40%, be sent to equipped with nickel-base catalyst Methanator i；

(3) first work off one's feeling vent one's spleen with methanator ii through input and output material heat exchanger iv from the gas that low-temp methanol is washed and changed After heat, then reached after 285 DEG C by input and output material heat exchanger iii and methanator i heat exchange of working off one's feeling vent one's spleen, from top entrance equipped with Nio 40wt%-la₂o₃7wt%-al₂o₃43wt%-zro₂In the methanator i of 7wt% catalyst, in pressure 3.0mpa With air speed 6500h^-1Under the conditions of carry out one-level methanation reaction, temperature be 569 DEG C work off one's feeling vent one's spleen first pass through waste heat boiler iii reclaim Heat, and reach after 265 DEG C through the gas converting heat that input and output material heat exchanger iii is washed with low-temp methanol, enter equipped with nio from top 40wt%-la₂o₃7wt%-al₂o₃43wt%-zro₂In 7wt% methanator ii, in pressure 3.0mpa and air speed 6500h^-1Under the conditions of carry out two grades of methanation reactions, the co in synthesis gas is fully converted to ch since then₄Gas, temperature is 312 DEG C Implication first through input and output material heat exchanger iv and the gas converting heat from rectisol system, then through aerial cooler ii and water Enter knockout drum ii after cooler cooling, condensate liquid is discharged from the bottom of knockout drum ii, and knockout drum ii top row goes out is Natural gas line is sent into after gas product, drying and compression.

The gas product composition synthesizing in the unstripped gas of the present embodiment and at reaction conditions for details see attached table 1.

Embodiment 5

In the present embodiment, methanation in presence of sulfur reactor i is identical with the catalyst that methanation in presence of sulfur reactor ii is used, its Quality consists of moo₃13wt%-co₂o₃+ceo₂14.5wt%/γ-al₂o₃The catalyst of 72.5wt%, active component moo₃With Auxiliary agent co₂o₃+zro₂+ceo₂It is carried on carrier γ-al by way of co-precipitation₂o₃On, concrete preparation method and technique are shown in Cn103480362a embodiment 5；Nickel-base catalyst quality in methanator i and methanator ii consists of nio 75wt%-la₂o₃7wt%-al₂o₃15wt%-zro₂3wt%, concrete preparation method and step are shown in cn102029162a embodiment 4.Using above-mentioned catalyst, its specific technical process and condition are as follows:

(1) after dedusting and oil removing, volume consists of h₂37.3%th, co 20%, co₂30.4%th, ch₄12% and n₂0.3% Synthesis gas first passes through input and output material heat exchanger ii and carries out heat exchange with working off one's feeling vent one's spleen of methanation in presence of sulfur reactor ii, then through input and output material heat exchange Device i and methanation in presence of sulfur reactor i heat exchange of working off one's feeling vent one's spleen reaches 290 DEG C, and from top entrance methanation in presence of sulfur after mix with vapor Reactor i, vapor is 0.10 with the mol ratio of synthesis gas, in pressure 2.0mpa and air speed 6000h^-1Reaction condition under, Support type moo₃13wt%-co₂o₃+ceo₂14.5wt%/γ-al₂o₃One-level resistant to sulfur is carried out on 72.5wt% bifunctional catalyst Methanation and sulfur-tolerant water gas shift, temperature is to reclaim heat through high-pressure waste-heat boilers i after 557 DEG C of elder generation of working off one's feeling vent one's spleen, and through turnover After material heat exchanger i reaches 290 DEG C with unstripped gas heat exchange, remove methanation in presence of sulfur reactor ii；

(2) reaction gas coming from methanation in presence of sulfur reactor i enters methanation in presence of sulfur reactor ii from top, in pressure 2.0mpa and air speed 6000h^-1Reaction condition under, in support type moo₃13wt%-co₂o₃+ceo₂14.5wt%/γ- al₂o₃Second level methanation in presence of sulfur and sulfur-tolerant water gas shift are carried out on 72.5wt% bifunctional catalyst, temperature is 496 DEG C goes out Implication first passes through high-pressure waste-heat boilers ii and reclaims heat, then through input and output material heat exchanger ii and synthesis gas heat exchange, and pass through further Air cooler i enters knockout drum i after being cooled down and carries out gas-liquid separation, and condensate liquid is discharged from knockout drum i bottom, separates tank deck The gas phase that portion discharges enters rectisol system, removes co by low-temp methanol wash-out under conditions of -50 DEG C and 2.0mpa₂With h₂After s, wherein h₂S is removed to 0.06ppm, and co₂It is removed to volume content 0.70%, be sent to equipped with nickel-base catalyst Methanator i；

(3) first work off one's feeling vent one's spleen with methanator ii through input and output material heat exchanger iv from the gas that low-temp methanol is washed and changed After heat, then reached after 290 DEG C by input and output material heat exchanger iii and methanator i heat exchange of working off one's feeling vent one's spleen, from top entrance equipped with Nio 75wt%-la₂o₃7wt%-al₂o₃15wt%-zro₂In the methanator i of 3wt% catalyst, in pressure 2.0mpa With air speed 6000h^-1Under the conditions of carry out one-level methanation reaction, temperature be 569 DEG C work off one's feeling vent one's spleen first pass through waste heat boiler iii reclaim Heat, and reach after 270 DEG C through the gas converting heat that input and output material heat exchanger iii is washed with low-temp methanol, enter equipped with nio from top 75wt%-la₂o₃7wt%-al₂o₃15wt%-zro₂In 3wt% methanator ii, in pressure 2.0mpa and air speed 6000h^-1Under the conditions of carry out two grades of methanation reactions, the co in synthesis gas is fully converted to ch since then₄Gas, temperature is 309 DEG C Implication first through input and output material heat exchanger iv and the gas converting heat from rectisol system, then through aerial cooler ii and water Enter knockout drum ii after cooler cooling, condensate liquid is discharged from the bottom of knockout drum ii, and knockout drum ii top row goes out is Natural gas line is sent into after gas product, drying and compression.

The gas product composition synthesizing in the unstripped gas of the present embodiment and at reaction conditions for details see attached table 1.

Embodiment 6

In the present embodiment, methanation in presence of sulfur reactor i is identical with the catalyst that methanation in presence of sulfur reactor ii is used, its Quality consists of moo₃23wt%-co₂o₃+zro₂+ceo₂7wt%/γ-al₂o₃The catalyst of 70wt%, active component moo₃With Auxiliary agent co₂o₃+zro₂+ceo₂It is carried on carrier γ-al by way of co-precipitation₂o₃On, concrete preparation method and technique are shown in Cn103480362a embodiment 2；The nickel-base catalyst of methanator i and methanator ii adopts the ceg-lh of davy Catalyst.Using above-mentioned catalyst, its specific technical process and condition are as follows:

(1) after dedusting and oil removing, volume consists of h₂40%th, co 19.3%, co₂30.4%th, ch₄10% and n₂0.3% Synthesis gas first passes through input and output material heat exchanger ii and carries out heat exchange with working off one's feeling vent one's spleen of methanation in presence of sulfur reactor ii, then through input and output material heat exchange Device i and methanation in presence of sulfur reactor i heat exchange of working off one's feeling vent one's spleen reaches 295 DEG C, and from top entrance methanation in presence of sulfur after mix with vapor Reactor i, vapor is 0.20 with the mol ratio of synthesis gas, in pressure 7.0mpa and air speed 5500h^-1Reaction condition under, Support type moo₃23wt%-co₂o₃+zro₂+ceo₂7wt%/γ-al₂o₃One-level resistant to sulfur is carried out on 70wt% bifunctional catalyst Methanation and sulfur-tolerant water gas shift, temperature is to reclaim heat through high-pressure waste-heat boilers i after 542 DEG C of elder generation of working off one's feeling vent one's spleen, and through turnover After material heat exchanger i reaches 295 DEG C with unstripped gas heat exchange, remove methanation in presence of sulfur reactor ii；

(2) reaction gas coming from methanation in presence of sulfur reactor i enters methanation in presence of sulfur reactor ii from top, in pressure 7.0mpa and air speed 5500h^-1Reaction condition under, in support type moo₃23wt%-co₂o₃+zro₂+ceo₂7wt%/γ- al₂o₃Second level methanation in presence of sulfur and sulfur-tolerant water gas shift are carried out on 70wt% bifunctional catalyst, temperature is 481 DEG C of outlet Gas first passes through high-pressure waste-heat boilers ii and reclaims heat, then through input and output material heat exchanger ii and synthesis gas heat exchange, and pass through sky further Cooler i enters knockout drum i after being cooled down and carries out gas-liquid separation, and condensate liquid is discharged from knockout drum i bottom, separates tank top The gas phase discharged enters rectisol system, removes co by low-temp methanol wash-out under conditions of -55 DEG C and 7.0mpa₂And h₂s Afterwards, wherein h₂S is removed to 0.01ppm, and co₂It is removed to volume content 0.3v%, be sent to the methane equipped with nickel-base catalyst Change reactor i；

(3) first work off one's feeling vent one's spleen with methanator ii through input and output material heat exchanger iv from the gas that low-temp methanol is washed and changed After heat, then reached after 295 DEG C by input and output material heat exchanger iii and methanator i heat exchange of working off one's feeling vent one's spleen, from top entrance equipped with In the methanator i of ceg-lh catalyst, in pressure 7.0mpa and air speed 5500h^-1Under the conditions of to carry out one-level methanation anti- Should, temperature is that 531 DEG C work off one's feeling vent one's spleen first passes through waste heat boiler iii recovery heat, and through input and output material heat exchanger iii and low-temp methanol After the gas converting heat washed reaches 260 DEG C, enter equipped with ceg-lh methanator ii from top, in pressure 7.0mpa and sky Fast 5500h^-1Under the conditions of carry out two grades of methanation reactions, the co in synthesis gas is fully converted to ch since then₄Gas, temperature is 304 DEG C implication first through input and output material heat exchanger iv and the gas converting heat from rectisol system, then through aerial cooler ii and Enter knockout drum ii after water cooler cooling, condensate liquid is discharged from the bottom of knockout drum ii, and knockout drum ii top row goes out i.e. For gas product, after drying and compression, send into natural gas line.

The gas product composition synthesizing in the unstripped gas of the present embodiment and at reaction conditions for details see attached table 1.

Embodiment 7

In the present embodiment, methanation in presence of sulfur reactor i is identical with the catalyst that methanation in presence of sulfur reactor ii is used, its Quality consists of moo₃27wt%-co₂o₃+la₂o₃The catalyst of 8wt%/magnesium aluminate spinel 65wt%, active component moo₃With help Agent co₂o₃+la₂o₃It is carried on carrier magnesium aluminate spinel by way of dipping, concrete preparation method and technique are shown in Cn103495421a embodiment 14；Nickel-base catalyst in methanator i and methanator ii adopts davy's Ceg-lh catalyst.Using above-mentioned catalyst, its specific technical process and condition are as follows:

(1) after dedusting and oil removing, volume consists of h₂40%th, co 20%, co₂28%th, ch₄11.6% and n₂0.4% conjunction Become gas to first pass through input and output material heat exchanger ii and carry out heat exchange with working off one's feeling vent one's spleen of methanation in presence of sulfur reactor ii, then through input and output material heat exchanger I and methanation in presence of sulfur reactor i heat exchange of working off one's feeling vent one's spleen reaches 300 DEG C, and anti-from top entrance methanation in presence of sulfur after mix with vapor Answer device i, vapor is 0.20 with the mol ratio of synthesis gas, in pressure 6.0mpa and air speed 5000h^-1Reaction condition under, negative Load type moo₃27wt%-co₂o₃+la₂o₃Carry out one-level resistant to sulfur methane on 8wt%/magnesium aluminate spinel 65wt% bifunctional catalyst Change and sulfur-tolerant water gas shift, temperature is to reclaim heat through high-pressure waste-heat boilers i after 527 DEG C of elder generation of working off one's feeling vent one's spleen, and changes through input and output material After hot device i and unstripped gas heat exchange reach 300 DEG C, remove methanation in presence of sulfur reactor ii；

(2) reaction gas coming from methanation in presence of sulfur reactor i enters methanation in presence of sulfur reactor ii from top, in pressure 6.0mpa and air speed 5000h^-1Reaction condition under, in support type moo₃27wt%-co₂o₃+la₂o₃8wt%/magnesium aluminate spinel Second level methanation in presence of sulfur and sulfur-tolerant water gas shift are carried out on 65wt% bifunctional catalyst, temperature is 467 DEG C of elder generation of working off one's feeling vent one's spleen Heat is reclaimed by high-pressure waste-heat boilers ii, then through input and output material heat exchanger ii and synthesis gas heat exchange, and pass through air cooler i further Enter knockout drum i after being cooled down and carry out gas-liquid separation, condensate liquid is discharged from knockout drum i bottom, separate tank top and discharge Gas phase enter rectisol system, by low-temp methanol wash-out except co under conditions of -45 DEG C and 6.0mpa₂And h₂After s, Wherein h₂S is removed to 0.02ppm, and co₂It is removed to volume content 0.6v%, be sent to the methanation equipped with nickel-base catalyst Reactor i；

(3) first work off one's feeling vent one's spleen with methanator ii through input and output material heat exchanger iv from the gas that low-temp methanol is washed and changed After heat, then reached after 300 DEG C by input and output material heat exchanger iii and methanator i heat exchange of working off one's feeling vent one's spleen, from top entrance equipped with In the methanator i of ceg-lh catalyst, in pressure 6.0mpa and air speed 5000h^-1Under the conditions of to carry out one-level methanation anti- Should, temperature is that 507 DEG C work off one's feeling vent one's spleen first passes through waste heat boiler iii recovery heat, and through input and output material heat exchanger iii and low-temp methanol After the gas converting heat washed reaches 260 DEG C, enter equipped with ceg-lh methanator ii from top, in pressure 6.0mpa and sky Fast 5000h^-1Under the conditions of carry out two grades of methanation reactions, the co in synthesis gas is fully converted to ch since then₄Gas, temperature is 300 DEG C implication first through input and output material heat exchanger iv and the gas converting heat from rectisol system, then through aerial cooler ii and Enter knockout drum ii after water cooler cooling, condensate liquid is discharged from the bottom of knockout drum ii, and knockout drum ii top row goes out i.e. For gas product, after drying and compression, send into natural gas line.

The gas product composition synthesizing in the unstripped gas of the present embodiment and at reaction conditions for details see attached table 1.

Embodiment 8

In the present embodiment, methanation in presence of sulfur reactor i is identical with the catalyst used in methanation in presence of sulfur reactor ii, Its oxide mass consists of moo₃20wt%-co₂o₃+ce₂o₃12wt%/γ-al₂o₃The catalyst of 68wt%, active component mo₂o₃With auxiliary agent co₂o₃+ce₂o₃It is carried on carrier γ-al by way of collosol and gel₂o₃On, concrete preparation method and technique See cn101733115a embodiment 4；Nickel-base catalyst in methanator i and methanator ii adopts Top's rope Mcr-2x catalyst.Using above-mentioned catalyst, its specific technical process and condition are as follows:

(1) after dedusting and oil removing, volume consists of h₂38%th, co 19%, co₂32.1%th, ch₄10.5% and n₂0.4% Synthesis gas first passes through input and output material heat exchanger ii and carries out heat exchange with working off one's feeling vent one's spleen of methanation in presence of sulfur reactor ii, then through input and output material heat exchange Device i and methanation in presence of sulfur reactor i heat exchange of working off one's feeling vent one's spleen reaches 280 DEG C, and from top entrance methanation in presence of sulfur after mix with vapor Reactor i, vapor is 0.20 with the mol ratio of synthesis gas, in pressure 5.5mpa and air speed 4000h^-1Reaction condition under, Support type moo₃20wt%-co₂o₃+ce₂o₃12wt%/γ-al₂o₃One-level resistant to sulfur methane is carried out on 68wt% bifunctional catalyst Change and sulfur-tolerant water gas shift, temperature is to reclaim heat through high-pressure waste-heat boilers i after 516 DEG C of elder generation of working off one's feeling vent one's spleen, and changes through input and output material After hot device i and unstripped gas heat exchange reach 280 DEG C, remove methanation in presence of sulfur reactor ii；

(2) reaction gas coming from methanation in presence of sulfur reactor i enters methanation in presence of sulfur reactor ii from top, in pressure 5.5mpa and air speed 4000h^-1Reaction condition under, in support type moo₃20wt%-co₂o₃+ce₂o₃12wt%/γ- al₂o₃Second level methanation in presence of sulfur and sulfur-tolerant water gas shift are carried out on 68wt% bifunctional catalyst, temperature is 461 DEG C of outlet Gas first passes through high-pressure waste-heat boilers ii and reclaims heat, then through input and output material heat exchanger ii and synthesis gas heat exchange, and pass through sky further Cooler i enters knockout drum i after being cooled down and carries out gas-liquid separation, and condensate liquid is discharged from knockout drum i bottom, separates tank top The gas phase discharged enters rectisol system, removes co by low-temp methanol wash-out under conditions of -60 DEG C and 5.0mpa₂And h₂s Afterwards, wherein h₂S is removed to 0.01ppm, and co₂Be removed to volume content 0.7v%, after be sent to methanation equipped with nickel-base catalyst Reactor i；

(3) first work off one's feeling vent one's spleen with methanator ii through input and output material heat exchanger iv from the gas that low-temp methanol is washed and changed After heat, then reached after 280 DEG C by input and output material heat exchanger iii and methanator i heat exchange of working off one's feeling vent one's spleen, from top entrance equipped with In the methanator i of ceg-lh catalyst, in pressure 5.5mpa and air speed 4000h^-1Under the conditions of to carry out one-level methanation anti- Should, temperature is that 481 DEG C work off one's feeling vent one's spleen first passes through waste heat boiler iii recovery heat, and through input and output material heat exchanger iii and low-temp methanol After the gas converting heat washed reaches 260 DEG C, enter equipped with ceg-lh methanator ii from top, in pressure 5.5mpa and sky Fast 4000h^-1Under the conditions of carry out two grades of methanation reactions, the co in synthesis gas is fully converted to ch since then₄Gas, temperature is 302 DEG C implication first through input and output material heat exchanger iv and the gas converting heat from rectisol system, then through aerial cooler ii and Enter knockout drum ii after water cooler cooling, condensate liquid is discharged from the bottom of knockout drum ii, and knockout drum ii top row goes out i.e. For gas product, after drying and compression, send into natural gas line.

The gas product composition synthesizing in the unstripped gas of the present embodiment and at reaction conditions for details see attached table 1.

Embodiment 9

In the present embodiment, methanation in presence of sulfur reactor i is identical with the catalyst used in methanation in presence of sulfur reactor ii, Its oxide mass consists of moo₃15wt%-co₂o₃+la₂o₃The catalyst of 10wt%/magnesium aluminate spinel 75wt%, activearm Divide moo₃With auxiliary agent co₂o₃+la₂o₃It is carried on carrier al by way of collosol and gel₂o₃-zro₂On, concrete preparation method and work Skill is shown in cn101733115a embodiment 6；Nickel-base catalyst in methanator i and methanator ii adopts Top's rope Mcr-2x catalyst.Using above-mentioned catalyst, its specific technical process and condition are as follows:

(1) after dedusting and oil removing, volume consists of h₂38%th, co 18.4%, co₂32%th, ch₄11.5% and n₂0.1% Synthesis gas first passes through input and output material heat exchanger ii and carries out heat exchange with working off one's feeling vent one's spleen of methanation in presence of sulfur reactor ii, then through input and output material heat exchange Device i and methanation in presence of sulfur reactor i heat exchange of working off one's feeling vent one's spleen reaches 280 DEG C, and from top entrance methanation in presence of sulfur after mix with vapor Reactor i, vapor is 0.20 with the mol ratio of synthesis gas, in pressure 5.0mpa and air speed 3000h^-1Reaction condition under, Support type moo₃15wt%-co₂o₃+la₂o₃Carry out one-level resistant to sulfur first on 10wt%/magnesium aluminate spinel 75wt% bifunctional catalyst Alkanisation and sulfur-tolerant water gas shift, temperature is to reclaim heat through high-pressure waste-heat boilers i after 508 DEG C of elder generation of working off one's feeling vent one's spleen, and through input and output material After heat exchanger i and unstripped gas heat exchange reach 280 DEG C, remove methanation in presence of sulfur reactor ii；

(2) reaction gas coming from methanation in presence of sulfur reactor i enters methanation in presence of sulfur reactor ii from top, in pressure 5.0mpa and air speed 3000h^-1Reaction condition under, in support type moo₃15wt%-co₂o₃+la₂o₃10wt%/magnesium aluminate spinel Second level methanation in presence of sulfur and sulfur-tolerant water gas shift are carried out on 75wt% bifunctional catalyst, temperature is 455 DEG C of elder generation of working off one's feeling vent one's spleen Heat is reclaimed by high-pressure waste-heat boilers ii, then through input and output material heat exchanger ii and synthesis gas heat exchange, and pass through air cooler i further Enter knockout drum i after being cooled down and carry out gas-liquid separation, condensate liquid is discharged from knockout drum i bottom, separate tank top and discharge Gas phase enter rectisol system, by low-temp methanol wash-out except co under conditions of -20 DEG C and 5.0mpa₂And h₂After s, Wherein h₂S is removed to 0.1ppm, and co₂It is removed to volume content 0.8v%, the methanation being sent to equipped with nickel-base catalyst is anti- Answer device i；

(3) first work off one's feeling vent one's spleen with methanator ii through input and output material heat exchanger iv from the gas that low-temp methanol is washed and changed After heat, then reached after 280 DEG C by input and output material heat exchanger iii and methanator i heat exchange of working off one's feeling vent one's spleen, from top entrance equipped with In the methanator i of mcr-2x catalyst, in pressure 5.0mpa and air speed 3000h^-1Under the conditions of to carry out one-level methanation anti- Should, temperature is that 461 DEG C work off one's feeling vent one's spleen first passes through waste heat boiler iii recovery heat, and through input and output material heat exchanger iii and low-temp methanol After the gas converting heat washed reaches 260 DEG C, enter equipped with mcr-2x methanator ii from top, in pressure 5.0mpa and sky Fast 3000h^-1Under the conditions of carry out two grades of methanation reactions, the co in synthesis gas is fully converted to ch since then₄Gas, temperature is 305 DEG C implication first through input and output material heat exchanger iv and the gas converting heat from rectisol system, then through aerial cooler ii and Enter knockout drum ii after water cooler cooling, condensate liquid is discharged from the bottom of knockout drum ii, and knockout drum ii top row goes out i.e. For gas product, after drying and compression, send into natural gas line.

The gas product composition synthesizing in the unstripped gas of the present embodiment and at reaction conditions for details see attached table 1.

Embodiment 10

In the present embodiment, methanation in presence of sulfur reactor i is identical with the catalyst used in methanation in presence of sulfur reactor ii, Its oxide mass consists of moo₃10wt%-co₂o₃5wt%/al₂o₃-zro₂The catalyst of 85wt%, active component moo₃With Auxiliary agent co₂o₃It is carried on carrier al by way of co-precipitation₂o₃-zro₂On, concrete preparation method and technique are shown in Cn101733115a embodiment 3；Nickel-base catalyst in methanator i and methanator ii adopts Top's rope Mcr-2x catalyst.Using above-mentioned catalyst, its specific embodiment and condition are as follows:

(1) after dedusting and oil removing, volume consists of h₂37.6%th, co 17.3%, co₂33%th, ch₄12% and n₂0.1% Synthesis gas first passes through input and output material heat exchanger ii and carries out heat exchange with working off one's feeling vent one's spleen of methanation in presence of sulfur reactor ii, then through input and output material heat exchange Device i and methanation in presence of sulfur reactor i heat exchange of working off one's feeling vent one's spleen reaches 280 DEG C, and from top entrance methanation in presence of sulfur after mix with vapor Reactor i, vapor is 0.20 with the mol ratio of synthesis gas, in pressure 4.5mpa and air speed 2000h^-1Reaction condition under, Support type moo₃10wt%-co₂o₃5wt%/al₂o₃-zro₂Carry out on 85wt% bifunctional catalyst one-level methanation in presence of sulfur and Sulfur-tolerant water gas shift, temperature is to reclaim heat through high-pressure waste-heat boilers i after 500 DEG C of elder generation of working off one's feeling vent one's spleen, and through input and output material heat exchanger i Reach after 280 DEG C with unstripped gas heat exchange, remove methanation in presence of sulfur reactor ii；

(2) reaction gas coming from methanation in presence of sulfur reactor i enters methanation in presence of sulfur reactor ii from top, in pressure 4.5mpa and air speed 2000h^-1Reaction condition under, in support type moo₃10wt%-co₂o₃5wt%/al₂o₃-zro₂85wt% is double Second level methanation in presence of sulfur and sulfur-tolerant water gas shift are carried out on function catalyst, temperature is that 450 DEG C work off one's feeling vent one's spleen first passes through high pressure Waste heat boiler ii reclaims heat, then through input and output material heat exchanger ii and synthesis gas heat exchange, and cooled down by air cooler i further Enter knockout drum i afterwards and carry out gas-liquid separation, condensate liquid is discharged from knockout drum i bottom, separate the gas phase discharged tank top and enter Enter rectisol system, under conditions of -30 DEG C and 2.0mpa, co is removed by low-temp methanol wash-out₂And h₂After s, wherein h₂S takes off Remove to 0.9ppm, and co₂It is removed to volume content 0.7v%, be sent to the methanator i equipped with nickel-base catalyst；

(3) first work off one's feeling vent one's spleen with methanator ii through input and output material heat exchanger iv from the gas that low-temp methanol is washed and changed After heat, then reached after 280 DEG C by input and output material heat exchanger iii and methanator i heat exchange of working off one's feeling vent one's spleen, from top entrance equipped with In the methanator i of mcr-2x catalyst, in pressure 2.0mpa and air speed 2000h^-1Under the conditions of to carry out one-level methanation anti- Should, temperature is that 450 DEG C work off one's feeling vent one's spleen first passes through waste heat boiler iii recovery heat, and through input and output material heat exchanger iii and low-temp methanol After the gas converting heat washed reaches 260 DEG C, enter equipped with mcr-2x methanator ii from top, in pressure 2.0mpa and sky Fast 3000h^-1Under the conditions of carry out two grades of methanation reactions, the co in synthesis gas is fully converted to ch since then₄Gas, temperature is 300 DEG C implication first through input and output material heat exchanger iv and the gas converting heat from rectisol system, then through aerial cooler ii and Enter knockout drum ii after water cooler cooling, condensate liquid is discharged from the bottom of knockout drum ii, and knockout drum ii top row goes out i.e. For gas product, after drying and compression, send into natural gas line.

The gas product composition synthesizing in the unstripped gas of the present embodiment and at reaction conditions for details see attached table 1.

Subordinate list 1

Claims (14)

1. a kind of producing synthesis gas from coal carries out methanation in presence of sulfur and prepares the technique of natural gas it is characterised in that comprising the steps:

(1) synthesis gas after dedusting and oil removing is first passed through input and output material heat exchanger ii and is changed with working off one's feeling vent one's spleen of methanation in presence of sulfur reactor ii Heat, then work off one's feeling vent one's spleen through input and output material heat exchanger i and methanation in presence of sulfur reactor i after heat exchange, and enter from top after mixing with water vapour Enter methanation in presence of sulfur reactor i, molybdenum base bifunctional catalyst carries out first order methanation in presence of sulfur and sulfur-tolerant water gas shift, goes out Implication first reclaims heat through high-pressure waste-heat boilers i, and after input and output material heat exchanger i and synthesis gas heat exchange, goes methanation in presence of sulfur anti- Answer device ii；

(2) reaction gas coming from methanation in presence of sulfur reactor i enters methanation in presence of sulfur reactor ii from top, difunctional in molybdenum base Carry out second level methanation in presence of sulfur and sulfur-tolerant water gas shift on catalyst, work off one's feeling vent one's spleen and first pass through high-pressure waste-heat boilers ii recovery heat Amount, then through input and output material heat exchanger ii and synthesis gas heat exchange, after being cooled down by air cooler i further, enter knockout drum i Carry out gas-liquid separation, condensate liquid is discharged from knockout drum i bottom, and gas phase enters low-temp methanol and washes after discharging from separation tank top and is System, remove carbon dioxide and the hydrogen in gas through low-temp methanol wash-out after, is sent to the methanator equipped with ni base catalyst i；

(3) wash, from low-temp methanol, the gas coming first to be changed with working off one's feeling vent one's spleen of methanator ii through input and output material heat exchanger iv Heat, then after input and output material heat exchanger iii works off one's feeling vent one's spleen heat exchange with methanator i, enter methanator i from top, Carry out first order methanation reaction under the catalytic action of ni methylmethane catalyst, working off one's feeling vent one's spleen first passes through waste heat boiler iii and return Receive heat, and wash after the gas converting heat coming with low-temp methanol through input and output material heat exchanger iii, enter methanator ii from top In, carry out second level methanation reaction in the presence of ni methylmethane catalyst, the co in synthesis gas is fully converted to since then ch₄Gas, working off one's feeling vent one's spleen of methanator ii is first changed with the gas from rectisol system through input and output material heat exchanger iv Heat, after then cooling down through air cooling ii and water cooler, enters knockout drum ii and carries out gas-liquid separation, condensate liquid is from knockout drum ii's Bottom is discharged, and knockout drum ii top row goes out gas product, sends into natural gas line after drying compression；

Described synthesis gas is obtained through Shandong strange crushed coal pressure gasifying technology, and its synthesis gas consists of h₂37～40%, co 17%～ 20%th, co₂28～33%, ch₄8%～12%, n₂0.1～0.4%.

2. a kind of producing synthesis gas from coal carries out the technique that methanation in presence of sulfur prepares natural gas as claimed in claim 1, and its feature exists Consist of in described molybdenum base bifunctional catalyst quality: active component moo₃10～35wt%, auxiliary agent oxide 2～ 20wt%, carrier 50～85wt%；Wherein auxiliary agent be one or more of co, la, ce, zr, fe, ni and k, carrier be γ- al₂o₃、sio₂, magnesium aluminate spinel, zro₂、ceo₂-al₂o₃Complex carrier or al₂o₃-zro₂Complex carrier.

3. a kind of producing synthesis gas from coal carries out the technique that methanation in presence of sulfur prepares natural gas as claimed in claim 2, and its feature exists It is co in described auxiliary agent, la, ce or zr.

4. a kind of producing synthesis gas from coal carries out the technique that methanation in presence of sulfur prepares natural gas as claimed in claim 2, and its feature exists It is magnesium aluminate spinel, ceo in described carrier₂-al₂o₃Complex carrier or al₂o₃-zro₂Complex carrier.

5. a kind of producing synthesis gas from coal carries out the technique that methanation in presence of sulfur prepares natural gas as claimed in claim 1, and its feature exists It is fixed bed adiabatic reactor in described methanation in presence of sulfur reactor i and methanation in presence of sulfur reactor ii.

6. a kind of producing synthesis gas from coal carries out the technique that methanation in presence of sulfur prepares natural gas as claimed in claim 1, and its feature exists In described methanation in presence of sulfur reactor i import, vapor and the volume ratio of synthesis gas are 0.1～0.3, inlet gas after mixing Temperature is 270～300 DEG C, and temperature of working off one's feeling vent one's spleen is 500～600 DEG C of reaction pressures is 2.0～7.0mpa, reaction velocity is 2000～ 8000h^-1.

7. a kind of producing synthesis gas from coal carries out the technique that methanation in presence of sulfur prepares natural gas as claimed in claim 1, and its feature exists It is 270～300 DEG C in described methanation in presence of sulfur reactor ii inlet gas temperature, temperature of working off one's feeling vent one's spleen is 450～550 DEG C, reaction Pressure is 2.0～7.0mpa, and reaction velocity is 2000～8000h^-1.

8. a kind of producing synthesis gas from coal carries out the technique that methanation in presence of sulfur prepares natural gas as claimed in claim 1, and its feature exists Wash in described low-temp methanol and be made up of desulfurizing tower and decarbonizing tower, operation temperature is -20～-60 DEG C, operating pressure 2.0～ 7.0mpa.

9. a kind of producing synthesis gas from coal carries out the technique that methanation in presence of sulfur prepares natural gas as claimed in claim 1, and its feature exists In described wash through low-temp methanol after sulphur in gas take off to 0.01～0.1ppm, co₂Volume content takes off to 0.3～0.8v%.

10. a kind of producing synthesis gas from coal carries out the technique that methanation in presence of sulfur prepares natural gas as claimed in claim 1, and its feature exists Ni base catalyst used in described methanator i or methanator ii is the mcr-2x methane of Top's rope Change catalyst, davy company ceg-lh methanation catalyst or catalyst are that the quality in terms of oxide consists of: active component Nio 10～75%, auxiliary agent la₂o₃0.1～15% and carrier al₂o₃-zro₂Surplus, auxiliary agent is lanthana or lanthana and nickel lanthanum The composition of compound, carrier is the composition that aluminum oxide is formed with zirconium oxide with nickel aluminide.

11. as claimed in claim 1 a kind of producing synthesis gas from coal carry out the technique that methanation in presence of sulfur prepares natural gas, its feature exists It is fixed bed adiabatic reactor in described methanator i and methanator ii.

12. as claimed in claim 1 a kind of producing synthesis gas from coal carry out the technique that methanation in presence of sulfur prepares natural gas, its feature exists Inlet gas temperature in methanator i is 270～300 DEG C, and temperature of working off one's feeling vent one's spleen is 450～620 DEG C, and reaction pressure is 2.0 ～7.0mpa, reaction velocity is 2000～8000h^-1.

13. as claimed in claim 1 a kind of producing synthesis gas from coal carry out the technique that methanation in presence of sulfur prepares natural gas, its feature exists Inlet gas temperature in methanator ii is 250～300 DEG C, and temperature of working off one's feeling vent one's spleen is 290～350 DEG C, and reaction pressure is 2.0 ～7.0mpa, reaction velocity is 2000～8000h^-1.

A kind of 14. producing synthesis gas from coal as described in any one of claim 1-13 carry out the work that methanation in presence of sulfur prepares natural gas Skill is it is characterised in that the described synthesis gas volume through above-mentioned technique and reacted natural gas consists of: ch₄96～98%, co₂0.2～0.5, h₂0.5～2%, n₂0.6～1.2%, c_2～60.3～0.5%.