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HIGH PRESSURE NH3-REFORMING AND COMBINED REFORMING OF NH3 AS CO-FEED FOR HYDROCARBON/CO2-REFORMING

20250051157 ยท 2025-02-13

    Inventors

    Cpc classification

    International classification

    Abstract

    The present invention relates to a specific process for the reforming of ammonia, wherein the process comprises (i) providing a reactor containing a catalyst comprising a metal M1 selected from the group consisting of Ni, Co, or Ni and Co; (ii) preparing a feed gas stream comprising NH.sub.3; (iii) feeding the feed gas stream prepared in (ii) into the reactor provided in (i) and contacting the feed gas stream with the catalyst, wherein contacting is performed at a pressure of 1 to 50 bara, and at a temperature of 400 to 1,100 C.; (iv) removing an effluent gas stream from the reactor, the effluent gas stream comprising H.sub.2 and N.sub.2.

    Claims

    1.-15. (canceled)

    16. A process for the reforming of ammonia, wherein the process comprises (i) providing a reactor containing a catalyst comprising a metal M1 selected from the group consisting of Ni, Co, or Ni and Co; (ii) preparing a feed gas stream comprising NH.sub.3; (iii) feeding the feed gas stream prepared in (ii) into the reactor provided in (i) and contacting the feed gas stream with the catalyst, wherein contacting is performed at a pressure of 1 to 50 bara, and at a temperature of 400 to 1,100 C.; (iv) removing an effluent gas stream from the reactor, the effluent gas stream comprising H.sub.2 and N.sub.2.

    17. The process of claim 16, wherein the feed gas stream prepared in (ii) comprises from 200 to 20,000 ppmv of H.sub.2O.

    18. The process of claim 16, wherein the total amount of NH.sub.3, N.sub.2, and H.sub.2 comprised in the feed gas stream prepared in (ii) is in the range from 90 to 100 wt.-%.

    19. The process of claim 16, wherein the process is for the reforming of ammonia and hydrocarbons, wherein the feed gas stream prepared in (ii) further comprises one or more hydrocarbons, and one or more of CO.sub.2 and H.sub.2O, and wherein the effluent gas stream removed in (iv) further comprises CO.

    20. The process of claim 19, wherein the feed gas stream prepared in (ii) further comprises CO.sub.2, H.sub.2O, and one or more hydrocarbons.

    21. The process of claim 19, wherein the one or more hydrocarbons are selected from the group consisting of alkanes and mixtures thereof.

    22. The process of claim 19, wherein contacting is performed at a pressure in the range of from 10 to 50 bara.

    23. The process of claim 19, wherein the feed gas stream prepared in (ii) comprises from 0.1 to 75 vol.-% of NH.sub.3.

    24. The process of claim 19, wherein the feed gas stream prepared in (ii) comprises from 10 to 70 vol.-% of the one or more hydrocarbons.

    25. The process of claim 16, wherein the feed stream is fed into the reactor at a gas hourly space velocity in the range of from 500 to 16,000 h.sup.1.

    26. The process of claim 19, wherein the effluent gas stream removed in (iv) displays a stoichiometry number R in the range of from 0.1 to 3, wherein R is defined according to formula (I): R = c ( H 2 ) - c ( CO 2 ) c ( CO 2 ) + c ( CO ) , ( I ) wherein c (H.sub.2), c (CO.sub.2), and c (CO) stand for the molar concentration of H.sub.2, CO.sub.2, and CO in the effluent gas stream, respectively.

    27. The process of claim 26, wherein the stoichiometry number R is in the range of 0.5 to 3.

    28. The process of claim 16, wherein the catalyst contained in the reactor provided in (i) further comprises Al and O.

    29. The process of claim 28, wherein the catalyst contained in the reactor provided in (i) comprises Ni as the metal M1, wherein the catalyst further comprises Mg.

    30. The process of claim 28, wherein the catalyst contained in the reactor provided in (i) comprises Co as the metal M1, wherein the catalyst further comprises La.

    Description

    DESCRIPTION OF THE FIGURES

    [0136] FIG. 1 displays the results of NH.sub.3-reforming from Example 4 employing the Ni-based catalyst of Example 1 at 30 bar and GHSV of 8000 h.sup.1 including 5000 ppmv H.sub.2O in the NH.sub.3 feed. In the figure, the conversion of ammonia in % is plotted along the ordinate and the temperature in C. is plotted along the abscissa. The measured conversion rates are indicated as medium grey circles, wherein the equilibrium conversion rate at that temperature is indicated as dark grey squares.

    [0137] FIG. 2 displays the results of NH.sub.3-reforming from Example 4 employing the Co-based catalyst of Example 2 at 30 bar and GHSV of 8000 h.sup.1 including 5000 ppmv H.sub.2O in the NH.sub.3 feed. In the figure, the conversion of ammonia in % is plotted along the ordinate and the temperature in C. is plotted along the abscissa. The measured conversion rates are indicated as medium grey circles, wherein the equilibrium conversion rate at that temperature is indicated as dark grey squares.

    [0138] FIG. 3 displays the results of NH.sub.3-reforming from Example 4 employing the Ni-based catalysts with PGM and transition metal promotion at GHSV of 2000.sup.1, 30 bar and 10000 ppmv of H.sub.2O in the NH.sub.3 feed.

    [0139] FIG. 4: shows on the left the side view for the arrangement for determining side crushing strength 1 (SCS1), in the middle the side view for the arrangement for determining side crushing strength 2 (SCS2), and on the right the side view for the arrangement for determining side crushing strength 3 (SCS3).

    EXPERIMENTAL SECTION

    [0140] The present invention is further illustrated by the following examples.

    Reference Example 1: Determination of the Side Crushing Strength

    [0141] The side crushing strength was determined on a semi-automatic tablet testing system So-taxST-50 WTDH. The side crushing strength was measured with a constant speed of 0.05 mm/s. A range of from 0 to 800 N could be tested. For each measurement, the orientation of the sample was adjusted with a horizontal rotating table and fine adjustment has been made manually. Further, several measurement parameters were adjustedif applica-bledepending on the orientation and properties of the sample, such as the mass, the height/thickness, the diameter and strength at rupture. The gained data were evaluated with the scientific program q-doc prolab (version 4fsp2 (4.10)). Tablets having a four-hole cross-section were tested, whereby three positions being perpendicular to each other were probed allowing determination of the side crushing strength 1, side crushing strength 2 and side crushing strength 3. The relative standard deviation for crushing strength 1, 2, and 3 was 7.48%.

    [0142] As can be seen in FIG. 1, side crushing strength 1 refers to a position of the tablet in the semi-automatic tablet testing system where the sample stands on two cylindrical segments sided by a flute on the rotating table, side crushing strength 2 refers to a position where the sample stands on one cylindrical segment on the rotating table, and side crushing strength 3 refers to a position where the holes are in parallel to the direction of the force applied on the sample during the test.

    Reference Example 2: Determination of the Side Crushing Strength

    [0143] The side crushing strength was determined on a tablet testing system (Typ BZ2.5/TS1S, Zwick). The side crushing strength was measured using a punching tool. The side crushing strength was recorded as soon as the sample broke. For each measurement, the orientation of the sample was adjusted manually on a horizontal table. The punching tool was arranged to punch from above. Further, several measurement parameters were adjusted-if applica-ble-depending on the orientation and properties of the sample, such as the mass, the height/thickness, the diameter and strength at rupture. Tablets having a four-hole cross-section were tested, whereby three positions being perpendicular to each other were probed allowing determination of the side crushing strength 1, side crushing strength 2 and side crushing strength 3. As can be seen in FIG. 1, side crushing strength 1 refers to a position of the tablet in the semi-automatic tablet testing system where the sample stands on two cylindrical segments sided by a flute on the rotating table, side crushing strength 2 refers to a position where the sample stands on one cylindrical segment on the rotating table, and side crushing strength 3 refers to a position where the holes are in parallel to the direction of the force applied on the sample during the test.

    Example 1: Preparation of a Catalyst Comprising Ni

    [0144] The catalyst comprising Ni was prepared following the process described in example E1 of WO 2013/068905 A1.

    [0145] An aqueous solution of Nickel nitrate (14% Ni concentration) was used instead of the pul-verulent nickel nitrate hexahydrate. The various ingredients were mixed to a paste which was extruded. The extrudates were crushed and sieved to a target fraction having a particle size of from 200 to 900 m after drying and low temperature calcination.

    [0146] The sieved powder was then mixed with graphite 2.8 weight.-% (Asbury Graphite 3160) and 5.5 weight-% cellulose (Arbocel BWW 40). The resulting mixture was tableted to moldings having a four-hole cross-section as shown in FIG. 1 of WO 2020/157202 A. For calcination, the moldings were heated in an annealing furnace to a temperature of 1,030 to 1,050 C. which was held for 4 hours.

    [0147] The nickel content of the calcined moldings was 15.5 weight-%, the magnesium content 14.0 weight-%, the aluminium content was 29.5 weight-%.

    Example 2: Preparation of a Catalyst Comprising Co

    [0148] The catalyst comprising Co was prepared according Example 1 of WO 2020/157202 A1.

    Example 3: Preparation of Ni-Based Catalyst Including PGM or Transition Metal ProMotion

    [0149] The catalysts comprising Ni and platinum group metal or transition metal promotion were prepared following the process described in example E1 of WO 2013/068905 A1. A part of the Ni-salt was substituted by an Fe-salt (here: Fe(NO.sub.3).sub.3 (H.sub.2O).sub.9, degree of substitution 40 at.-% based on the Ni-content). Alternatively, a part of the Ni-salt (here: Ni-nitrate) was substituted by a Ru-salt (here Ru(NO)(NO.sub.3).sub.3 solution, 19,7% Ru conc., degree of substitution 5 at. % based on the Ni-content). The respective metal salt mixtures were mixed with the hydrotalcite and suitable amounts of water to prepare an extrudable paste. This paste was extruded in the next step. The subsequent heat treatments of the resulting extrudates were identical to example 1 (example E1 of WO2013/068905 A1).

    [0150] The procedures accordingly afforded a Ni+Fe supported catalyst and a Ni+Ru supported catalyst, respectively.

    Example 4: Catalytic Tests in NH.SUB.3.-Reforming Under High Pressure

    [0151] The catalysts obtained according to Examples 1-3 were reduced under a mixture of an increasing concentration (with increasing temperature) of 5-50 vol.-% H.sub.2 in inert gas (Ar or N.sub.2) at temperatures of 450-650 C. for the Ni-catalysts and of 450-850 C. for the Co-catalyst. The catalytic NH.sub.3-reforming tests were conducted under p (NH.sub.3) of 30 bar. To the NH.sub.3 feed, a fraction of 5000-10,000 ppmv of H.sub.2O is added. Further, the catalysts were tested at GHSV of 2,000 and 8,000 h.sup.1 and temperatures of 350-650 C. The conversion of NH.sub.3 as function of the temperature at the corresponding GHSVs at 30 bar are shown in Table 1. Furthermore, the results for the samples of Examples 1 and 2 at a GHSV of 8,000 h.sup.1 including 5,000 ppmv H.sub.2O visualized in FIGS. 1 and 2, and the results of the samples of Examples 1 and 3 at a GHSV of 2,000 h.sup.1 including 10,000 ppmv H.sub.2O are displayed in FIG. 3.

    TABLE-US-00001 TABLE 1 Conversion results of the catalysts according to Examples 1-3 under high pressure reforming of NH.sub.3. Ex. 3 Ex. 1 Ex. 3 Ex. 1 Ex. 2 (Ni + Ru) (Ni) (Ni + Fe) (Ni) (Co) 10,000 ppmv H.sub.2O 5,000 ppmv H.sub.2O Temp p(NH.sub.3) GHSV = 2,000 h 1 GHSV = 8,000 h 1 350 30 1.50 0.50 0.60 0.28 0.08 450 30 15.03 6.41 8.65 3.66 1.30 500 30 36.27 18.40 25.80 10.53 3.76 550 30 68.44 40.65 58.07 25.18 9.37 600 30 93.43 71.78 91.48 49.42 13.00 650 30 98.30 94.52 98.44 79.42 32.88

    [0152] As may be taken from the catalyst testing results indicated in Table 1 and displayed in FIG. 1, the ammonia reforming reaction conducted with the Ni-catalyst from Example 1 achieves increasing conversion rates with increasing temperature, wherein at 650 C., the conversion rate almost achieves the equilibrium conversion rate at that temperature. In FIG. 2, the results obtained from ammonia reforming using the Co-catalyst from Example 2 are displayed. Again, growing conversion rates are achieved with increasing temperature, although the conversion rate at 650 C. is not nearly as high as the conversion rate obtained when employing the Ni-catalyst as shown in FIG. 1.

    [0153] Finally, the results from catalyst testing of the Ni-catalyst from Examples 1 and 3 which were conducted at lower GHSV and with higher amounts of steam are displayed in FIG. 3. As may be taken from the results, under those conditions, the Ni-catalyst from Example 1 achieves almost equilibrium conversion at 650 C. Furthermore, when promoted with Ru or Fe, the ammonia conversion rate increases more rapidly, and the conversion rates for the promoted catalysts achieves almost equilibrium conversion rates already at 600 C. for the achieving a conversion rate of over 98% at 650 C.

    Example 5: Simulation of the Combined Reforming of NH.SUB.3 .and Hydrocarbons with or without CO.SUB.2

    [0154] Due to the high activity of the catalysts at the corresponding conditions (20 bar, high temperatures), catalytic performance at the equilibrium conditions is expected when residence times are selected accordingly. For investigating this, simulations were conducted using the software Aspen Plus V11. Tables 2 and 3 shows the inlet and outlet concentration for various cases of the combined reforming of NH.sub.3 and, e.g. hydrocarbons (here: CH)/CO.sub.2 under dry conditions. As may be seen from the results in Tables 2 and 3, the incremental increase of the NH, as co-feed leads to an increase of the R-value due to the additional H.sub.2 created by the NH.sub.3-reforming.

    TABLE-US-00002 TABLE 2 Inlet concentrations used for the simulations in Example 5. H.sub.2O CO.sub.2 CH.sub.4 NH.sub.3 20 bar CO.sub.2/C S/C [vol.-%] [vol.-%] [vol.-%] [vol.-%] Simulation 1 0.43 2.5 63.64 10.91 25.45 0 Simulation 2 0.43 1.5 51.22 14.63 34.15 0.00 Simulation 3 0.43 1.5 48.78 13.94 32.52 4.76 Simulation 4 0.43 1.5 46.14 13.18 30.76 9.91 Simulation 5 0.43 1.0 41.18 17.65 41.18 0.00 Simulation 6 0.43 1.0 37.43 16.04 37.43 9.09 Simulation 7 0.43 1.0 35.81 15.35 35.81 13.04

    TABLE-US-00003 TABLE 3 Simulations of the outlet concentrations in Example 5 based on thermodynamic limitations and calculation of the corresponding R-values. T CO CO.sub.2 H.sub.2 H.sub.2O CH.sub.4 NH.sub.3 N.sub.2 20 bar [ C] [vol.-%] [vol.-%] [vol.-%] [vol.-%] [vol.-%] [vol.-%] [vol.-%] R Sim. 1 850 13.93 8.46 44.83 29.49 3.28 0 0 1.62 900 15.84 7.40 47.26 27.85 1.65 0 0 1.71 950 17.08 6.63 48.38 27.16 0.75 0 0 1.76 Sim. 2 850 18.49 7.61 46.37 20.67 6.86 0 0 1.49 900 21.18 6.11 50.38 18.30 4.04 0 0 1.62 950 23.03 5.04 53.00 16.77 2.16 0 0 1.71 Sim. 3 850 17.36 6.89 47.05 20.21 6.88 0.023 1.58 1.66 900 19.98 5.53 51.08 17.80 4.09 0.020 1.51 1.79 950 21.81 4.56 53.74 16.22 2.21 0.017 1.46 1.87 Sim. 4 850 16.14 6.14 47.82 19.70 6.89 0.034 3.27 1.87 900 18.69 4.93 51.86 17.24 4.13 0.029 3.12 1.99 950 20.48 4.06 54.56 15.61 2.25 0.024 3.01 2.06 Sim. 5 850 21.80 6.77 45.69 15.34 10.41 0.000 0.00 1.36 900 24.83 5.00 50.52 12.82 6.82 0.000 0.00 1.53 950 27.02 3.76 54.17 10.89 4.16 0.000 0.00 1.64 Sim. 6 850 19.16 5.66 47.00 15.02 10.17 0.031 2.96 1.67 900 22.06 4.20 51.77 12.42 6.73 0.027 2.79 1.81 950 24.18 3.16 55.38 10.44 4.15 0.023 2.66 1.91 Sim. 7 850 18.03 5.20 47.61 14.85 10.06 0.038 4.22 1.83 900 20.86 3.87 52.34 12.23 6.68 0.033 3.99 1.96 950 22.95 2.91 55.92 10.23 4.14 0.028 3.81 2.05

    [0155] The results from the simulation displayed in Tables 2 and 3 thus demonstrate the concept of the combined reforming approach (NH.sub.3+HC+CO.sub.2+H.sub.2O) in manipulating and steering the R-value of a final syngas composition. The increase of the R number can possibly start at 0.1 (from a combined reforming including very-dry conditions of reforming, less H.sub.2O and more CO.sub.2/HC) to reach, e.g., R values between 1 and 1.5 for Fischer-Tropsch-like reactions or one-step DME. But also a syngas with an R number >2 is possible.

    [0156] The same holds for the combined reforming of NH.sub.3 and HC/CO.sub.2 under dry conditions, possibly starting at R values of 0.5 to finally reach a R >2 upon increasing the NH.sub.3 amount. So, basically any R-value between 0.1-2.5 is possibly adjusted by the amount of NH.sub.3 co-dosing to the HC/CO.sub.2/H.sub.2O gas mixture.

    Example 6: Catalytic Testing

    [0157] Catalytic tests were performed on a single reactor test unit. This unit allowed for test conditions in a broad temperature and pressure range up to 1100 C. and 20 bar (gauge). As gas feeds carbon dioxide (also designated as CO.sub.2-in), methane (also designated CH.sub.4-in), nitrogen (also designated as N.sub.2-in), ammonia (also designated as NH.sub.3-in) and argon (also designated as Ar-in) were provided and online controlled by mass flow controllers (MFCs). Water (also designated as H.sub.2O-in) was added as steam to the feed stream by an evaporator con-nected to a water reservoir. Analysis of the product gas composition was carried out by online-gas chromatography using argon as internal standard. Gas chromatographic analyt-ics allowed the quantification of hydrogen, carbon monoxide, carbon dioxide, methane, ammonia, nitrogen and C2 components. For the catalytic test, the catalytic material was split (0.5 to 1.0 mm) and 15 ml of the split were then tested as a catalyst. As catalyst, a mixed metal oxide comprising Ni and Mg according to example E1 of WO 2013/068905 A1 was used. The sample was placed in the isothermal zone of the reactor using a ceramic fitting. The given temperature describes the temperature of the oven.

    [0158] The results of the catalytic testing are described in following table. Phase 1+2 and 3+4 rep-resent different kinds of biogas without and with, respectively, NH.sub.3 co-feeding for the adjustment of the R-value.

    TABLE-US-00004 TABLE 4 Results of the catalytic testing. In each phase the pressure was adjusted to 20 bar (gauge). Phase T GHSV CH.sub.4-in CO.sub.2-in H.sub.2O-in NH.sub.3-in Ar-in N.sub.2-in R [#] [ C] [h.sup.1] [mol.-%] [mol.-%] [mol.-%] [mol.-%] [mol.-%] [mol.-%] value 1 950 8000 28.5 14.1 43.1 0 5 9.3 1.5 2 950 8000 28.5 14.1 43.1 13.5 0.8 0 2.1 3 950 6000 23.0 17.0 34.0 0 3 23 0.95 4 950 6000 23.0 17.0 34.0 23.0 3 0 1.95 GHSV: gas hourly space velocity

    [0159] As can be seen from the results shown in table 4, the process according to the present invention, wherein a Ni and/or Co containing catalyst is used, allows reforming of ammonia for providing a syngas stream, especially in a combined reforming approach of NH.sub.3 and hydrocarbons. In particular, a synthesis gas can be produced which matches the R-value of a corresponding down-stream application (e.g. MeOH production, DME production or Fischer-Tropsch process).

    Cited Prior Art

    [0160] WO 2013/068905 A [0161] WO 2013/118078 A [0162] WO 2020/157202 A1 [0163] Int. J. of Hydr. and Energ., 2020, 45, 8965-8974 [0164] Int. J. of Hydr. and Energ., 2014, 39, 35, 19990-19999 [0165] Top Catal (2016) 59:1438-1457 [0166] WO 2021/175785 A1 [0167] Catal. Sci. Technol., 2020, 10, 5027-5035