The way co-production of ammonia and methanol
(57) Abstract:The invention relates to methods of co-production of ammonia and methanol. The way co-production of ammonia and methanol includes desulfurization, two-step conversion of methane, a high-temperature conversion of carbon monoxide, the cleaning gas from the carbon dioxide absorption hot solution of potash, the synthesis of methanol under a pressure of 5 MPa and synthesis of ammonia under a pressure of 30 MPa, while the cleaning gas from the carbon dioxide lead directly after high-temperature conversion of carbon monoxide to a residual content of carbon dioxide of 0.48 to 0.5% vol. with the subsequent synthesis of methanol at a flow scheme for low-temperature copper-containing catalyst (e.g. DN-8-2) under pressure of 5 MPa at a temperature of 200 - 300°C and at a ratio of N2: WITH = 22.5 : 1, after separation of the methanol gas komprimiert and sent to the ammonia synthesis on the circulation diagram. The implementation of this method can reduce the total content of inert impurities (argon + methane) in the fresh synthesis gas from 1.5 to 0.75%, that reduces the number of blows. Poison the catalyst in the synthesis of ammonia, oxides of carbon are present in trace amounts. 1 Il. The invention I produce ammonia and methanol. Most of these schemes operate on a similar principle. There is a project co-production of ammonia and methanol, according to which from the converted gas initially get methanol. Thus due to the recycling of carbon monoxide concentration in the gas is reduced. Next, the residual carbon monoxide are oxidized by oxygen in the air and hydronaut to methane. The gas mixture was purified of carbon dioxide, is fed to the ammonia synthesis (see Chem. Econ. Eng. Rev. 1972, vol. 4, N 11, p. 32 - 34). According to another scheme, a mixture of carbon oxides and hydrogen is passed at a temperature of 160 - 300oC and a pressure of 5 to 15 MPa through the catalyst layers. The catalyst is placed in multiple, consecutive, the reactors. The gas circulation by reducing the concentration of carbon monoxide in the exhaust gases, which then converts it to steam. After cleaning gas from carbon dioxide and methane residual hydrogen is used to produce ammonia (see U.S. Pat. 67675, 1973 [NDP]). Also developed a scheme with a slightly different principle. According to this method, natural gas komprimiert, cleaned of sulfur compounds, is mixed with steam and fed into a tubular furnace for conversion. After that, the converted gas is cooled in the heat exchange is Lennie gases are mixed in the mixer, komprimiert to pressure synthesis and sent to the column, where the catalyst carry out the synthesis of methanol. Nephrolithotripsy in diffusers gas stream is mixed with the heated air and direct in the shaft reactor where the conversion of the residual hydrocarbons. After that, the gas is further scheme for the synthesis of ammonia (ed. St. N 1197997, class C 01 3/38, 1985 [the USSR], ed. St. N 1407898, class C 01 3/38, 1988 [USSR]). As a prototype accept the scheme co-production of ammonia and methanol, in which the synthesis gas to ammonia synthesis goes through the following stages: purification from sulfur compounds, the conversion of excess carbon monoxide, compression, purification from carbon dioxide and methanol synthesis. To ensure deep processing of carbon oxides and get gas enriched with hydrogen, methanol synthesis maintain a high ratio of H2:CO in fresh (5:1) and the circulation (14:1) gas (see Karavaev M. M. and others - Attn. prom., 1965, No. 4, S. 74-91).A distinctive feature of all these schemes is the presence of circulating synthesis gas for methanol synthesis, which leads to purging and loss of process gas, and subsequent fine purification of gases on artnik impurities in the gas, going for the synthesis of ammonia, and as sledstvie, reducing blowdown and losses of raw materials.The basis of the proposed scheme takes standard scheme ammonia production capacity of 1360 tons of ammonia per day. But compared to the standard in the proposed scheme, there is no stage low-temperature conversion of carbon monoxide and mahanirvana. Instead, offer after high-temperature conversion of CO to do the cleaning gas from the carbon dioxide absorber hot solution of potash to a residual content of CO2in Gaza 0.48-0.50 vol.%. Then the gas is sent not to the hydrogenation to methane, and the first stage of compression to a pressure of 5 MPa, followed by the synthesis of methanol at a temperature of 200-300oC. Synthesis of methanol is performed in the absence of circulating synthesis gas in a flow diagram. The ratio of H2: CO in the gas in the synthesis of methanol reaches 22.5:1. Synthesis is carried out at low temperature copper-containing catalyst for low pressure, for example DN-8-2. The composition of the catalyst, the molar fraction: CuO: ZnO: Cr2O3:MnO:MgO:Al2O3:BaO=1:0.3:(0.15-0.2):(0.05-0.1):(0.05-0.1): (0.25-0.3): 0.05 (see Kurylev A. Y., Tarasov, L. A. the Effect of promoters on the rate of recovery of low-temperature Katalizator. 13-15. Dept. in VINITI N 2685 - B95 from 5.10.95,, Barkovsky A. I., Kurylev A. Y., L. Tarasov A., Anokhin Century. N. The effect of promoters on the activity of low-temperature catalyst for methanol synthesis. Materials of the scientific - technical conference of NIRTO Novomoskovsk, 7 - 9 December 1994, Part 1, pages 34 - 35. Dept. in VINITI N 2685 - B95 from 5.10.95 year). After methanol synthesis gas is returned to stage the standard scheme of the synthesis of ammonia (daimonia gas until the pressure of the synthesis and the synthesis of the circulation scheme).The drawing shows a circuit diagram for implementing the proposed method.Natural gas is compressed in the compressor 1 to a pressure of 2.7 MPa and carry out the desulfurization in the adsorber 2, then the gas is sent to a two-step conversion of methane 3 and 4. After that, the converted gas containing, vol.%: N2- 20.49, Ar - 0.26, H2- 58.33, CO - 12.98, CO2- 7.59, CH4- 0.35, is a high-temperature conversion of carbon monoxide 5 at a temperature of 270oC and a pressure of 2.7 MPa. Further, the gas content, vol.%: N2- 18.64, Ar - 0.23, Hz - 62.08, CO - 2.79, CO2- 15.92, CH4- 0.32, - sent for purification from carbon dioxide 6, after which the gas has the following composition,%: N2- 22.07, Ar - 0.28, H2- 73.48, CO - 3.31, CO22 - 0.48, CH4 lack of H2after synthesis of methanol to stoichiometry in the synthesis of ammonia, and is sent to the syngas compressor. After the first stage of compression 7 gas with a pressure of 5 MPa, containing about.%: N2- 21.91, Ar - 0.28, H2- AT 73.69, CO - 3.27, CO2- 0.48, CH4- 0.38, heated to 200oC in the heat exchanger 8 and is directed in column 9 for the synthesis of methanol under a pressure of 5 MPa at a temperature of 200 - 280oC on the low-temperature copper-containing catalyst with a bulk velocity of 20000 h-1. After cooling to 40oC in the heat exchanger 10 and the separation of methanol 11 gas having a composition, vol.%: N2- 24.82, Ar - 0.31, H2- 74.44, CH4- 0.43, send to the second and subsequent stages 12 compressing the synthesis gas to 30 MPa. After each stage of compression set separators for selecting the condensed during compression of the fluid containing methanol. The gas then goes to the ammonia synthesis 13 on the circulation diagram. After the ammonia synthesis gas is cooled in the refrigerator 14, then in the separator 15 separates the production of ammonia.Research conducted by flowing the synthesis of methanol at temperatures from 200 to 300oC on the low-temperature copper-containing catalyst DN-8-2.with temperature 220oC, oxides of carbon is completely converted into methanol. Output of crude methanol in the temperature range 240 - 280oC remains practically unchanged and amounts to about 4.5% vol. from the total amount of synthesis gas leaving the column for methanol synthesis. The content of methanol in the raw ranges from 91 to 95%. At a temperature of 300oC output raw a few decreases to about 4. %), and the methanol content can be reduced to 87%. Therefore, the most appropriate to carry out the process at a temperature of 240 - 280oC (catalyst DN-8-2).In the proposed scheme, the content of inert impurities (argon and methane) gas, going to the ammonia synthesis, decreases in 2 times due to the lack of stage mahanirvana, and poison the catalyst in the synthesis of ammonia, oxides of carbon are present in trace amounts. In addition, with the increase in natural gas consumption by 10% compared to the standard scheme of the synthesis of ammonia is possible to obtain the same amount of ammonia, which according to the standard scheme, and up to 90,000 tons per year of crude methanol from the methanol content up to 95%. The way co-production of ammonia and methanol, including desulfurization, two-step conversion of methane, a high-temperature conversion oceanium 5 MPa and synthesis of ammonia under a pressure of 30 MPa, characterized in that the cleaning gas from the carbon dioxide lead directly after high-temperature conversion of carbon monoxide to a residual content of carbon dioxide of 0.48 to 0.5% vol. with the subsequent synthesis of methanol at a flow scheme for low-temperature copper-containing catalyst (e.g. DN - 8 - 2) under pressure of 5 MPa at a temperature of 200 - 300oAnd the ratio of N2: WITH = 22,5 : 1, after separation of the methanol gas komprimiert and sent to the ammonia synthesis on the circulation diagram.
FIELD: heat power and chemical industries, applicable in production of ammonia.
SUBSTANCE: in the method for steam generation at production of ammonia from hydrocarbon gases, saturation of the hydrocarbon gas after desulfurization and/or process air fed to the secondary reforming is effected due to the use of the flue gas of a tube furnace at a temperature of 160 to 580C, preferably within 220 to 480C, by means of water recirculation.
EFFECT: reduced consumption of energy due to reduction of the total amount of generated steam, reduced consumption of feed water, and recovered gases dissolved in the process condensate.
4 cl, 1 dwg
FIELD: heat power and chemical industries, applicable in production of ammonia.
SUBSTANCE: in the method for steam generation at production of ammonia from hydrocarbon gases the mean-pressure steam used for the process of steam reforming and/or for the compressor drives is subjected to humidification by injection of the process condensate or feed water, and the obtained humidified steam is overheated by the heat of the flue gas in a unit of the heat-using equipment of the reforming tube furnace.
EFFECT: reduced consumption of energy due to reduction of the amount of generated steam and reduced of the amount of generated steam and reduced consumption of feed water; provided additional cleaning of the process condensate and recovering of gases dissolved in it in the process of steam humidification in the mass transfer device.
2 cl, 1 dwg
FIELD: inorganic synthesis catalysts.
SUBSTANCE: invention provides ammonia synthesis catalyst containing ruthenium as active ingredient supported by boron nitride and/or silicon nitride. Catalyst can be promoted by one ore more metals selected from alkali, alkali-earth metal, or rare-earth metals. Ammonia synthesis process in presence of claimed catalyst is also described.
EFFECT: increased temperature resistance of catalyst under industrial ammonia synthesis conditions.
4 cl, 6 ex
FIELD: chemical industry; production of ammonia.
SUBSTANCE: the invention is pertaining to the process of synthesis of ammonia, in particular to improvement of the process of cleanout synthesis of the gas added into the catalytic reactor for substitution of the reacted synthesis gas. The method of synthesis of ammonia provides for compression of the synthesis gas containing hydrogen and nitrogen in a many-stage centrifugal compressor. On the first stage of this compressor the synthesis gas is compressed up to the pressure making from approximately 800 up to 900 pounds per a square inch - (56-63)·105 Pa, withdraw from this stage and cool, and also dehydrate by a contact to a liquid ammonia in a dehydrator. Then the cooled and dehydrated synthesis gas is fed back in the compressor and bring it on the second stage. The installation for realization of this process contains a centrifugal compressor supplied with the synthesis gas outlet, that connects the synthesis gas discharge outlet from the first stage of the compressor with the synthesis gas inlet in the dehydrator, and also an intermediate inlet of the synthesis gas connecting by a hydraulic link the inlet of the second stage of the compressor with the synthesis gas discharge (outlet) from the dehydrator. Due to the intermediate cooling and a dehydration the compressor rate is lowered, and due to favorable effect of the dehydrator on the last two stages of the compressor a significant saving of the consumed power is also achieved. The additional saving of the consumed power is possible due to decreased need of chill in the closed contour of the synthesis process.
EFFECT: the invention ensures a significant saving of the consumed power for the synthesis process in the installation.
13 cl, 1 dwg
FIELD: industrial inorganic synthesis.
SUBSTANCE: process comprises passing nitrogen and hydrogen-containing synthesis gas stream through three stacked catalyst beds, wherein catalyst is based on iron with magnetite as principal constituent, which is reduced during the process until catalytically active form of alpha-iron is produced. Above-mentioned synthesis gas stream is obtained by combining stream directly supplied onto first catalyst bed with another stream, which is preheated via indirect heat exchange with products exiting first and second catalyst beds, whereupon product is recovered. Method is characterized by that gas under treatment is passed through middle catalyst bed at volume flow rate between 0.65 and 2.00 value of volume flow rate, at which gas under treatment is passed through upper catalyst bed, volume ratio of middle catalyst bed to upper catalyst bed lying preferably between 0.5 and 1.5.
EFFECT: increased yield of product.
2 cl, 1 dwg, 1 tbl