Method for preparing synthesis gas

Abstract

A continuous process for reforming one or more hydrocarbons into a synthesis gas comprising hydrogen and carbon monoxide, the start-up stage of the process comprising the steps of: (i) providing a reactor comprising a reaction zone comprising a catalyst comprising a mixed oxide comprising cobalt and oxygen; (ii) continuously passing an inert gas stream comprising one or more inert gases through the reaction zone according to (i); (iii) continuously flowing a reactant gas stream into the reaction zone resulting from (ii), wherein 95-100% by volume of the reactant gas stream flowed into the reaction zone consists of one or more hydrocarbons, carbon dioxide, and water; subjecting the reactant gas stream to reforming conditions in the reaction zone; and removing a product stream comprising hydrogen and carbon monoxide from the reaction zone.

Description

[Technical field]

[0001] The present invention relates to a method for the preparation of synthesis gas. Synthesis gas or syngas is a fuel gas mixture consisting mainly of hydrogen, carbon monoxide, and very often some carbon dioxide. Synthesis gas can be produced from many sources, such as natural gas, coal, or biomass, in particular by reaction with steam and carbon dioxide. Syngas is an important resource for the production of hydrogen, ammonia, methanol, and synthetic hydrocarbon fuels. Preparation methods include steam reforming of natural gas or hydrocarbons to produce hydrogen.

[0002] In particular, the present invention relates to a continuous process for reforming one or more hydrocarbons into a synthesis gas comprising hydrogen and carbon monoxide, where a specific start-up stage of said process is applied. The start-up stage of the process is particularly distinguished from the latter in that the general start-up stage comprises passing an inert gas stream through the reaction zone followed by flowing a carbon dioxide-free reactant gas stream into the reaction zone. Carbon dioxide feed is added to the reactant gas stream at a later point in time. In contrast, the process of the present invention avoids such a step, and the reactant gas stream introduced into the reaction zone also comprises carbon dioxide. [Background technology]

[0003] Regarding reforming catalysts in general, WO 2013 / 118078 A1 discloses a hexaaluminate-containing catalyst comprising a hexaaluminate-containing phase containing cobalt and at least one additional element from the group La, Ba, Sr. Besides the hexaaluminate-containing phase, the catalyst may contain 0-50 wt. % of an oxide second phase. Furthermore, a reforming method for converting hydrocarbons is disclosed, characterized in that the catalyst is used at a process temperature above 700° C. and the process pressure is above 5 bar. According to an embodiment, the reforming method is started by introducing a reactant gas stream comprising methane and steam into a reactor at 850° C.

[0004] Furthermore, US 2003 / 176278 A1 relates to metal-exchanged hexaaluminate catalysts that exhibit good catalytic activity and / or stability at high temperatures for extended periods of time while maintaining activity as a combustion catalyst and more generally as an oxidation catalyst, making them highly suitable for use in methane combustion, in particular for use in natural gas-fueled gas turbines. According to the examples, the activity of the catalysts for methane combustion was measured by flowing a mixture of 3% methane in air over the catalyst at a pressure of 517 kPa (75 psi) and a gas hourly space velocity of 17000 / h.

[0005] The conversion to synthesis gas can be influenced, for example, by the temperature of the reaction, i.e. by the temperature of the reactor, the temperature of the catalyst and the temperature of any gas streams, by the gas hourly space velocity and by the composition of any gas streams introduced into the reactor. More specifically, the production cost for reforming of hydrocarbons to synthesis gas can be further improved by using more active selected catalysts, but also by increasing the stability of the catalyst and improving the production cost of the catalyst. Increasing the conversion of hydrocarbons is highly advantageous, since it allows to reduce the size of the reactor and therefore the size of the reforming plant, the amount of catalyst required and the size of the recycle.

[0006] Usually, the start-up procedure for synthesis gas conversion, i.e. reforming, involves a steam reforming step in which no carbon dioxide is introduced into the reactor. However, it has surprisingly been found that the specific sequence of parameters required for the start-up procedure for reforming can have a significant effect on the activity of Co-based catalysts in particular. It is advantageous for the activity of starting a Co-based dry reforming catalyst without a steam reforming step. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] International Publication No. 2013 / 118078 [Patent Document 2] U.S. Patent No. 9,259,712 Summary of the Invention [Problem to be solved by the invention]

[0008] It was therefore an object of the present invention to provide an improved process for the production of synthesis gas comprising hydrogen, carbon monoxide and carbon dioxide in the presence of a catalyst comprising a mixed oxide, in particular comprising cobalt, which provides a low selectivity towards the by-products and side-products of the reaction while simultaneously allowing a high conversion rate towards the starting materials, in particular towards the hydrocarbons, preferably methane, and / or carbon dioxide.

[0009] Surprisingly, it has been found that this problem can be solved if a specific sequence of process steps is implemented in a method for producing synthesis gas in the presence of a catalyst, preferably in particular in the presence of a catalyst comprising a mixed oxide comprising cobalt, resulting in an improved activity of the catalyst. [Means for solving the problem]

[0010] The present invention therefore relates to a continuous process for reforming one or more hydrocarbons into a synthesis gas comprising hydrogen and carbon monoxide, the start-up stage of said process comprising: (i) providing a reactor comprising a reaction zone containing a catalyst comprising a mixed oxide comprising cobalt and oxygen; (ii) continuously passing an inert gas stream comprising one or more inert gases through a reaction zone according to (i); (iii) continuously flowing a reactant gas stream into the reaction zone resulting from (ii), wherein 95-100% by volume of the reactant gas stream flowing into the reaction zone consists of one or more hydrocarbons, carbon dioxide, and water; subjecting said reactant gas stream to reforming conditions in said reaction zone; removing a product stream comprising hydrogen and carbon monoxide from said reaction zone.

[0011] The present invention further relates to a continuous process for reforming one or more hydrocarbons into a synthesis gas comprising hydrogen and carbon monoxide, the start-up stage of said process comprising: (i) providing a reactor comprising a reaction zone containing a catalyst comprising a mixed oxide comprising cobalt and oxygen; (ii) continuously passing an inert gas stream comprising one or more inert gases through a reaction zone according to (i); (iii) continuously flowing a reactant gas stream into the reaction zone resulting from (ii), wherein 95-100% by volume of the reactant gas stream flowing into the reaction zone consists of one or more hydrocarbons, carbon dioxide, and water; subjecting said reactant gas stream to reforming conditions in said reaction zone; removing a product stream comprising hydrogen and carbon monoxide from said reaction zone; wherein during (iii), the reforming conditions in the reaction zone include a setting (iii.1) and a setting (iii.2) that is achieved immediately after setting (iii.1), and setting (iii.1) comprises: (a) the volumetric ratio of hydrocarbon:carbon dioxide:water in the reactant gas stream flowing into the reaction zone; (b) the temperature in the reaction zone; (c) Gas hourly space velocity of the reactant gas streams flowing into the reaction zone differs from setting (iii.2) in at least one of the following:

[0012] Still further, the present invention relates to a continuous process for reforming one or more hydrocarbons into a synthesis gas comprising hydrogen and carbon monoxide, the start-up step of said process comprising: (i) providing a reactor comprising a reaction zone containing a catalyst comprising a mixed oxide comprising cobalt and oxygen; (ii) continuously passing an inert gas stream comprising one or more inert gases through a reaction zone according to (i); (iii) continuously flowing a reactant gas stream into the reaction zone resulting from (ii), wherein 95-100% by volume of the reactant gas stream flowing into the reaction zone consists of one or more hydrocarbons, carbon dioxide, and water; subjecting said reactant gas stream to reforming conditions in said reaction zone; removing a product stream comprising hydrogen and carbon monoxide from said reaction zone; wherein during (iii), the reforming conditions in the reaction zone include a setting (iii.1) and a setting (iii.2) that is achieved immediately after setting (iii.1), and setting (iii.1) comprises: (a) the volumetric ratio of hydrocarbon:carbon dioxide:water in the reactant gas stream flowing into the reaction zone; (b) the temperature in the reaction zone; (c) Gas hourly space velocity of the reactant gas streams flowing into the reaction zone differs from setting (iii.2) in at least one of the following: wherein during (iii), the reforming conditions in the reaction zone further comprise one or more settings (iii.x), each of the settings (iii.x) comprising: (a) the volumetric ratio of hydrocarbon:carbon dioxide:water in the reactant gas stream flowing into the reaction zone; (b) the temperature in the reaction zone; (c) Gas hourly space velocity of the reactant gas streams flowing into the reaction zone (iii.x-1) in at least one of (x is an integer and x>2). [Brief description of the drawings]

[0013] [Figure 1] Carbon dioxide and methane conversion in % for a typical prior art process for producing synthesis gas is shown on the ordinate (left), while the temperature, composition, and gas hourly space velocity GHSV of the gas feed stream are shown on the ordinate (right). The gas time on stream TOS is shown on the abscissa. [Diagram 2]The carbon dioxide and methane conversion in % for the process according to the invention for producing synthesis gas is shown on the ordinate (left), and the temperature, composition and gas hourly space velocity GHSV of the reactant gas streams are shown on the ordinate (right). The gas flow time TOS is shown on the abscissa. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] With respect to the reactor, it is preferred that the reactor provided according to (i) comprises two or more reaction zones. It is further preferred that the reactor provided according to (i) comprises two or more reactors arranged in parallel.

[0015] It is preferred that two or more reaction zones are arranged in parallel, and it is further preferred that two or more reaction zones are arranged in series.

[0016] With regard to the catalyst, it is preferred that the reaction zone according to (i) comprises catalyst arranged as a fixed bed catalyst.

[0017] It is preferred that 99 to 100% by weight, more preferably 99.5 to 100% by weight, and even more preferably 99.9 to 100% by weight of the catalyst is made of the mixed oxide.

[0018] The catalyst may be provided in the reaction zone in any suitable form, for example the catalyst may be a powder, preferably the catalyst is in the form of moldings, more preferably platelets.

[0019] The BET specific surface area of ​​the catalyst, measured as described in Reference Example 1, is 7 to 13 m 2 / g, more preferably 7.5 to 12 m 2 / g, more preferably 8 to 12 m 2 It is preferable that the range is / g.

[0020] Furthermore, the Langmuir specific surface area of ​​the catalyst, measured as described in Reference Example 1, is 9 to 15 m 2 It is preferable that the range is / g.

[0021] With regard to the mixed oxide contained in the catalyst, it is preferred that, calculated as an element, 5 to 10% by weight of the mixed oxide consists of cobalt.

[0022] The cobalt contained in the mixed oxide may be present in an amorphous and / or crystalline phase. It is preferred that the cobalt contained in the mixed oxide is present in one or more crystalline phases, more preferably in at least two crystalline phases, more preferably in at least three crystalline phases, more preferably in three crystalline phases.

[0023] With regard to the mixed oxide contained in the catalyst, it is preferred that the mixed oxide further comprises one or more of lanthanum and aluminium, more preferably lanthanum and aluminium.

[0024] It is preferred that the mixed oxide further contains aluminum. Furthermore, when the mixed oxide further contains aluminum, the weight ratio of cobalt to aluminum in the mixed oxide, calculated as elements, is at least 0.1:1, more preferably in the range of 0.13:1 to 0.3:1, more preferably in the range of 0.15:1 to 0.25:1, more preferably in the range of 0.17:1 to 0.22:1. Furthermore, when the mixed oxide further contains aluminum, it is preferred that the mixed oxide, calculated as elements, comprises 33 to 40% by weight, more preferably 34 to 38% by weight, more preferably 35 to 37% by weight, more preferably 35.5 to 36.5% by weight of aluminum.

[0025] It is preferred that the mixed oxide further contains lanthanum. When the mixed oxide further contains lanthanum, the weight ratio of cobalt to lanthanum in the mixed oxide, calculated as an element, is preferably in the range of 0.2:1 to 0.6:1, more preferably in the range of 0.25:1 to 0.5:1. When the mixed oxide further contains lanthanum, it is preferred that 15 to 25% by weight, more preferably 16 to 23% by weight of the mixed oxide, calculated as an element, is made up of lanthanum.

[0026] For mixed oxides, it is preferred that 80-100% by weight of the mixed oxide is in crystalline form, more preferably 90-100% by weight, more preferably 92-100% by weight.

[0027] It is particularly preferred that the mixed oxide further comprises lanthanum and aluminum. When the mixed oxide further comprises lanthanum and aluminum, the mixed oxide is at least LaCoAl 11 O 19 and a crystalline phase of LaAl(Co)O3.

[0028] According to the invention, the mixed oxide exhibits a peculiarity that can be measured by X-ray diffraction, in particular as described in Reference Example 2. It is therefore furthermore possible to provide a mixed oxide that is composed of lanthanum and aluminium, and at least LaCoAl 11 O 19 and a crystalline phase of LaAl(Co)O3, the mixed oxide further contains a crystalline phase of LaCoAl, as measured by XRD as described in Reference Example 2. 11 O 19 It is particularly preferred that the weight ratio of LaAl(Co)O3 is at least 10:1, more preferably in the range of 10:1 to 25:1.

[0029] When the mixed oxide further comprises lanthanum and aluminium, it is preferred that the mixed oxide comprises the crystalline phase LaAlO3, more preferably the crystalline phase LaAlO3 and the crystalline phase CoAl2O4, more preferably the crystalline phase LaAlO3, the crystalline phase CoAl2O4, and the crystalline phase La(OH)3.

[0030] Furthermore, when the mixed oxide further comprises lanthanum and aluminum, the mixed oxide has the crystalline phase LaCoAl 11 O 19 and the crystalline phase CoAl2O4. 11 O 19 and when it contains the crystalline phase CoAl2O4, LaCoAl, as measured by XRD as described in Reference Example 2. 11 O 19It is preferred that the weight ratio of CoAl2O4 is at least 10:1, more preferably in the range of 12:1 to 30:1.

[0031] The mixed oxide may further comprise other elements of the periodic table of the elements. Thus, the mixed oxide may further comprise one or more of barium, strontium and mixtures thereof.

[0032] It is preferred that the catalyst is heated in one or more of (i), (ii) and (iii), more preferably in one or more of (ii) and (iii), more preferably in (ii) and (iii).

[0033] The conditions for continuously passing the inert gas stream according to (ii) through the reaction zone according to (i) are not subject to any particular restrictions. It is preferred that the catalyst is heated during (ii) to a temperature in the range of 350-450°C, more preferably in the range of 375-425°C.

[0034] The conditions for continuously flowing the reactant gas stream according to (iii) into the reaction zone obtained from (ii) are also not subject to any particular restriction. It is preferred that the catalyst is heated during (iii) to a temperature in the range of 550-980°C, more preferably in the range of 575-975°C, more preferably in the range of 600-950°C.

[0035] Generally, it is preferred that the process is carried out by removing oxygen (O2). In particular, it is preferred that the reaction zone resulting from (ii) is essentially free of oxygen (O2) before the reactant gas stream is flowed into the reactor according to (iii). It is particularly preferred that the reaction zone resulting from (ii) contains 0-0.1% by volume of oxygen (O2), more preferably 0-0.01% by volume, more preferably 0-0.001% by volume of oxygen (O2) before the reactant gas stream is flowed into the reactor according to (iii).

[0036] It is preferred that a reactant stream comprising one or more of hydrocarbons and water, more preferably hydrocarbons and water and containing 0-0.1 vol. %, more preferably 0-0.01 vol. %, more preferably 0-0.001 vol. % carbon dioxide is not flowed into the reaction zone according to (i) prior to (iii).

[0037] Further, it is preferred that a stream consisting of 95-100% by volume, preferably 98-100% by volume, more preferably 99-100% by volume of one or more of hydrocarbons and water, preferably hydrocarbons and water, is not flowed into the reaction zone according to (i) prior to (iii).

[0038] Furthermore, it is preferred that the reaction zone obtained from (ii) and before (iii) is essentially free of one or more of carbon dioxide and oxygen (O2), preferably free of carbon dioxide and oxygen (O2). It is particularly preferred that the reaction zone obtained from (ii) and before (iii) comprises 0-0.1% by volume, more preferably 0-0.01% by volume, more preferably 0-0.001% by volume of one or more of carbon dioxide and oxygen (O2), preferably carbon dioxide and oxygen (O2).

[0039] With regard to the inert gas stream, it is preferred that 95-100% by volume, more preferably 98-100% by volume, more preferably 99-100% by volume of the inert gas stream according to (ii) consists of one or more inert gases.

[0040] The inert gas is not subject to any particular limitation and any suitable inert gas may be used. It is preferred that the one or more inert gases according to (ii) include one or more of nitrogen and argon. Furthermore, it is particularly preferred that the one or more inert gases are nitrogen and argon. Alternatively, it is particularly preferred that the one or more inert gases are nitrogen, preferably technical nitrogen.

[0041] The conditions for passing the inert gas stream according to (ii) through the reaction zone according to (i) are not subject to any particular restrictions. It is preferred to pass the inert gas stream according to (ii) through the reaction zone according to (i) at a gas hourly space velocity (GHSV) of the inert gas stream in the range of 1000 to 10000 / h, more preferably 2000 to 6000 / h, more preferably 3000 to 4000 / h.

[0042] For the reactant gas stream, there are no particular restrictions as to the physical or chemical properties of the hydrocarbon. It is preferred that the hydrocarbon is one or more of methane, ethane, propane and butane, preferably methane.

[0043] It is preferred that in the reactant gas stream resulting from (ii) passed into the reaction zone the volume ratio of hydrocarbon to carbon dioxide is in the range 0.75:1 to 1.25:1, more preferably in the range 0.8:1 to 1.2:1, more preferably in the range 0.9:1 to 1.1:1, more preferably in the range 0.95:1 to 1.05:1.

[0044] It is further preferred that in the reactant gas stream resulting from (ii) passed into the reaction zone the volume ratio of hydrocarbon to water is in the range of from 1.7:1 to 2.9:1, more preferably in the range of from 1.8:1 to 2.8:1, more preferably in the range of from 1.85:1 to 2.75:1.

[0045] It is preferred that 96-100% by volume of the reactant gas stream resulting from (ii) flowing into the reaction zone consists of hydrocarbons, carbon dioxide and water, more preferably 98-100% by volume, more preferably 99-100% by volume, more preferably 99.5-100% by volume.

[0046] There is no particular restriction on the additional components contained in the reactant gas stream. For example, the reactant gas stream flowing into the reaction zone resulting from (ii) may further comprise one or more inert gases, more preferably one or more of nitrogen and argon, as an internal standard for testing purposes. In this context, it is preferred that 1-5% by volume, more preferably 2-5% by volume, more preferably 4.5-5% by volume of the reactant gas stream flowing into the reaction zone resulting from (ii) is composed of one or more inert gases. It is therefore particularly preferred that 95-100% by volume, more preferably 96-100% by volume, more preferably 97-100% by volume, more preferably 99-100% by volume, more preferably 99.5-100% by volume of the reactant gas stream is composed of hydrocarbons, carbon dioxide, water, and one or more inert gases.

[0047] There is no particular restriction on the specific composition of the reactant gas stream obtained from (ii) before passing through the reaction zone. It is preferred that 1-50% by volume of the reactant gas stream obtained from (ii) before passing through the reaction zone, preferably 10-50% by volume, more preferably 30-50% by volume, more preferably 35-45% by volume, more preferably 37-40.5% by volume, consists of hydrocarbons. It is further preferred that 1-50% by volume of the reactant gas stream obtained from (ii) before passing through the reaction zone, preferably 10-50% by volume, more preferably 30-50% by volume, more preferably 35-45% by volume, more preferably 37-40.5% by volume, consists of carbon dioxide (CO2). It is further preferred that 1-50% by volume of the reactant gas stream obtained from (ii) before passing through the reaction zone, preferably 5-35% by volume, more preferably 10-25% by volume, more preferably 12-23% by volume, more preferably 14-21% by volume, consists of water (H2O).

[0048] The reforming conditions in the reaction zone according to (ii) are not subject to any particular restrictions. It is preferred that the reforming conditions in the reaction zone according to (iii) comprise a pressure of the gas phase in the range of 1-50 bar (abs), preferably in the range of 10-40 bar (abs), more preferably in the range of 15-30 bar (abs), more preferably in the range of 17-23 bar (abs), more preferably in the range of 19-21 bar (abs), more preferably in the range of 19.5-20.5 bar (abs). It is further preferred that the reforming conditions in the reaction zone according to (iii) comprise a gas hourly space velocity (GHSV) of the reactant gas stream in the range of 1000-7500 / h, more preferably in the range of 1250-7300 / h, more preferably in the range of 1500-7100 / h, more preferably in the range of 3500-7500 / h, more preferably in the range of 3700-7300 / h, more preferably in the range of 3900-7100 / h. It is further preferred that the reforming conditions in the reaction zone according to (iii) comprise a temperature of the gas phase in the reaction zone in the range of 550-980° C., preferably in the range of 575-975° C., more preferably in the range of 600-950° C. It is therefore particularly preferred that the reforming conditions in the reaction zone according to (iii) comprise a pressure of the gas phase in the range of 19.5-20.5 bar (abs), a Gas Hourly Space Velocity (GHSV) of the reactant gas stream in the range of 3900-7100 / hour, and a temperature of the gas phase in the reaction zone in the range of 600-950° C.

[0049] According to the present invention, it is contemplated that the reforming conditions in the reaction zone, in particular the volumetric ratio of hydrocarbon:carbon dioxide:water in the reactant gas streams flowing into the reaction zone, the temperature in the reaction zone, and the gas hourly space velocity of the reactant gas streams flowing into the reaction zone, may be varied during (iii) to have different settings.

[0050] Thus, the start-up phase of a continuous process for reforming one or more hydrocarbons into a synthesis gas comprising hydrogen and carbon monoxide comprises: (i) providing a reactor comprising a reaction zone containing a catalyst comprising a mixed oxide comprising cobalt and oxygen; (ii) continuously passing an inert gas stream comprising one or more inert gases through a reaction zone according to (i); (iii) continuously flowing a reactant gas stream into the reaction zone resulting from (ii), wherein 95-100% by volume of the reactant gas stream flowing into the reaction zone consists of one or more hydrocarbons, carbon dioxide, and water; subjecting said reactant gas stream to reforming conditions in said reaction zone; removing a product stream comprising hydrogen and carbon monoxide from said reaction zone; wherein during (iii), the reforming conditions in the reaction zone include a setting (iii.1) and a setting (iii.2) that is achieved immediately after setting (iii.1), and setting (iii.1) comprises: (a) the volumetric ratio of hydrocarbon:carbon dioxide:water in the reactant gas stream flowing into the reaction zone; (b) the temperature in the reaction zone; (c) Gas hourly space velocity of the reactant gas streams flowing into the reaction zone It is particularly preferred that the setting (iii.2) differs from the setting (iii.3) in at least one of the following:

[0051] There are no particular limitations on the volume ratio of hydrocarbon:carbon dioxide:water in the reactant gas stream flowing into the reaction zone according to setting (iii.1), the temperature in the reaction zone, and the gas hourly space velocity of the reactant gas stream flowing into the reaction zone. It is preferred that the volume ratio of hydrocarbon:carbon dioxide:water in the reactant gas stream flowing into the reaction zone according to setting (iii.1) is (2.5-2.9):(2.5-2.9):(0.8-1.2), more preferably (2.55-2.8):(2.55-2.8):(0.9-1.1), more preferably (2.6-2.75):(2.6-2.75):(0.95-1.05). It is further preferred that the temperature in the reaction zone according to setting (iii.1) is in the range of 550-980° C., more preferably in the range of 575-975° C., more preferably in the range of 600-950° C., more preferably in the range of 880-920° C., more preferably in the range of 890-910° C., more preferably in the range of 895-905° C. Furthermore, it is preferred that the gas hourly space velocity of the reactant gas stream according to setting (iii.1) is in the range of 1000-7500 / h, preferably in the range of 1250-7300 / h, more preferably in the range of 1500-7100 / h, more preferably in the range of 3700-4300 / h, more preferably in the range of 3800-4200 / h, more preferably in the range of 3900-4100 / h.

[0052] It is preferred that setting (iii.1) is maintained for a time in the range of 1 to 10 hours, more preferably in the range of 3 to 8 hours, more preferably in the range of 4 to 6 hours.

[0053] The volume ratio of hydrocarbon:carbon dioxide:water in the reactant gas stream flowing into the reaction zone according to setting (iii.2), the temperature in the reaction zone, and the gas hourly space velocity of the reactant gas stream flowing into the reaction zone are also not subject to any particular restrictions. It is preferred that the volume ratio of hydrocarbon:carbon dioxide:water in the reactant gas stream according to setting (iii.2) is (2.5-2.9):(2.5-2.9):(0.8-1.2), more preferably (2.55-2.8):(2.55-2.8):(0.9-1.1), more preferably (2.6-2.75):(2.6-2.75):(0.95-1.05). Further, the temperature in the reaction zone according to the setting (iii.2) is preferably in the range of 550 to 980° C., more preferably in the range of 575 to 975° C., more preferably in the range of 600 to 970° C., more preferably in the range of 930 to 970° C., more preferably in the range of 940 to 960° C., and more preferably in the range of 945 to 955° C. Further, the gas hourly space velocity according to the setting (iii.2) is preferably in the range of 1000 to 7500 / hour, more preferably in the range of 1250 to 7300 / hour, more preferably in the range of 1500 to 7100 / hour, more preferably in the range of 3700 to 4300 / hour, more preferably in the range of 3800 to 4200 / hour, and more preferably in the range of 3900 to 4100 / hour.

[0054] It is preferred that setting (iii.2) is maintained for a time in the range of 10 to 50 hours, preferably in the range of 20 to 40 hours, more preferably in the range of 30 to 35 hours.

[0055] When the reforming conditions in the reaction zone during (iii) comprise setting (iii.1) and setting (iii.2), which is achieved immediately after setting (iii.1), it is preferred that the reforming conditions in the reaction zone further comprise setting (iii.3), which is achieved immediately after setting (iii.2), wherein setting (iii.3) comprises (a) the volumetric ratio of hydrocarbon:carbon dioxide:water in the reactant gas stream flowing into the reaction zone; (b) the temperature in the reaction zone; (c) Gas hourly space velocity of the reactant gas streams flowing into the reaction zone differs from setting (iii.2) in at least one of the following:

[0056] The volume ratio of hydrocarbon:carbon dioxide:water in the reactant gas stream flowing into the reaction zone according to setting (iii.3), the temperature in the reaction zone, and the gas hourly space velocity of the reactant gas stream flowing into the reaction zone are also not subject to any particular restrictions. It is preferred that the volume ratio of hydrocarbon:carbon dioxide:water in the reactant gas stream according to setting (iii.3) is (1.7-2.1):(1.7-2.1):(0.8-1.2), more preferably (1.8-1.95):(1.8-1.95):(0.9-1.1), more preferably (1.85-1.9):(1.85-1.9):(0.95-1.05). Further, the temperature in the reaction zone according to the setting (iii.3) is preferably in the range of 550 to 980° C., more preferably in the range of 575 to 975° C., more preferably in the range of 600 to 970° C., more preferably in the range of 930 to 970° C., more preferably in the range of 940 to 960° C., more preferably in the range of 945 to 955° C. Further, the gas hourly space velocity according to the setting (iii.3) is preferably in the range of 1000 to 7500 / hour, more preferably in the range of 1250 to 7300 / hour, more preferably in the range of 1500 to 7100 / hour, more preferably in the range of 3700 to 4300 / hour, more preferably in the range of 3800 to 4200 / hour, more preferably in the range of 3900 to 4100 / hour.

[0057] It is preferred that setting (iii.3) is maintained for a time in the range of 5 to 50 hours, preferably in the range of 10 to 40 hours, more preferably in the range of 20 to 30 hours.

[0058] When the reforming conditions in the reaction zone during (iii) include setting (iii.3) achieved immediately after setting (iii.2), it is preferred that the reforming conditions in the reaction zone further include setting (iii.4) achieved immediately after setting (iii.3), wherein setting (iii.4) comprises (a) the volumetric ratio of hydrocarbon:carbon dioxide:water in the reactant gas stream flowing into the reaction zone; (b) the temperature in the reaction zone; (c) Gas hourly space velocity of the reactant gas streams flowing into the reaction zone differs from setting (iii.3) in at least one of the following:

[0059] The volume ratio of hydrocarbon:carbon dioxide:water in the reactant gas stream flowing into the reaction zone according to setting (iii.4), the temperature in the reaction zone, and the gas hourly space velocity of the reactant gas stream flowing into the reaction zone are also not subject to any particular restrictions. It is preferred that the volume ratio of hydrocarbon:carbon dioxide:water in the reactant gas stream according to setting (iii.4) is (1.7-2.1):(1.7-2.1):(0.8-1.2), more preferably (1.8-1.95):(1.8-1.95):(0.9-1.1), more preferably (1.85-1.9):(1.85-1.9):(0.95-1.05). Further, the temperature in the reaction zone according to the setting (iii.4) is preferably in the range of 550 to 980° C., more preferably in the range of 575 to 975° C., more preferably in the range of 600 to 970° C., more preferably in the range of 930 to 970° C., more preferably in the range of 940 to 960° C., more preferably in the range of 945 to 955° C. Further, the gas hourly space velocity according to the setting (iii.4) is preferably in the range of 1000 to 7500 / hour, more preferably in the range of 1250 to 7300 / hour, more preferably in the range of 1500 to 7100 / hour, more preferably in the range of 6700 to 7100 / hour, more preferably in the range of 6800 to 7100 / hour, more preferably in the range of 6900 to 7100 / hour.

[0060] It is preferred that setting (iii.4) is maintained for a time in the range of 2 to 30 hours, preferably in the range of 5 to 20 hours, more preferably in the range of 10 to 15 hours.

[0061] When the reforming conditions in the reaction zone during (iii) include setting (iii.4) achieved immediately after setting (iii.3), it is preferred that the reforming conditions in the reaction zone include setting (iii.5) achieved immediately after setting (iii.4), wherein setting (iii.5) is (a) the volumetric ratio of hydrocarbon:carbon dioxide:water in the reactant gas stream flowing into the reaction zone; (b) the temperature in the reaction zone; (c) Gas hourly space velocity of the reactant gas streams flowing into the reaction zone differs from setting (iii.4) in at least one of the following:

[0062] The volume ratio of hydrocarbon:carbon dioxide:water in the reactant gas stream flowing into the reaction zone according to setting (iii.5), the temperature in the reaction zone, and the gas hourly space velocity of the reactant gas stream flowing into the reaction zone are also not subject to any particular restrictions. It is preferred that the volume ratio of hydrocarbon:carbon dioxide:water in the reactant gas stream according to setting (iii.5) is (2.5-2.9):(2.5-2.9):(0.8-1.2), more preferably (2.55-2.8):(2.55-2.8):(0.9-1.1), more preferably (2.6-2.75):(2.6-2.75):(0.95-1.05). Further, the temperature in the reaction zone according to the setting (iii.5) is preferably in the range of 550 to 980° C., more preferably in the range of 575 to 975° C., more preferably in the range of 600 to 970° C., more preferably in the range of 930 to 970° C., more preferably in the range of 940 to 960° C., more preferably in the range of 945 to 955° C. Further, the gas hourly space velocity according to the setting (iii.5) is preferably in the range of 1000 to 7500 / hour, more preferably in the range of 1250 to 7300 / hour, more preferably in the range of 1500 to 7100 / hour, more preferably in the range of 6700 to 7100 / hour, more preferably in the range of 6800 to 7100 / hour, more preferably in the range of 6900 to 7100 / hour.

[0063] It is preferred that setting (iii.5) is maintained for a time in the range of 2 to 30 hours, more preferably in the range of 5 to 20 hours, more preferably in the range of 10 to 15 hours.

[0064] When the reforming conditions in the reaction zone during (iii) include setting (iii.5), which is achieved immediately after setting (iii.4), it is preferred that the reforming conditions in the reaction zone further include setting (iii.6), which is achieved immediately after setting (iii.5), wherein setting (iii.6) is (a) the volumetric ratio of hydrocarbon:carbon dioxide:water in the reactant gas stream flowing into the reaction zone; (b) the temperature in the reaction zone; (c) Gas hourly space velocity of the reactant gas streams flowing into the reaction zone differs from setting (iii.5) in at least one of the following:

[0065] The volume ratio of hydrocarbon:carbon dioxide:water in the reactant gas stream flowing into the reaction zone according to setting (iii.6), the temperature in the reaction zone, and the gas hourly space velocity of the reactant gas stream flowing into the reaction zone are also not subject to any particular restrictions. It is preferred that the volume ratio of hydrocarbon:carbon dioxide:water in the reactant gas stream according to setting (iii.6) is (1.7-2.1):(1.7-2.1):(0.8-1.2), more preferably (1.8-1.95):(1.8-1.95):(0.9-1.1), more preferably (1.85-1.9):(1.85-1.9):(0.95-1.05). Further, the temperature in the reaction zone according to the setting (iii.6) is preferably in the range of 550 to 980° C., more preferably in the range of 575 to 975° C., more preferably in the range of 600 to 970° C., more preferably in the range of 930 to 970° C., more preferably in the range of 940 to 960° C., more preferably in the range of 945 to 955° C. Further, the gas hourly space velocity according to the setting (iii.6) is preferably in the range of 1000 to 7500 / hour, more preferably in the range of 1250 to 7300 / hour, more preferably in the range of 1500 to 7100 / hour, more preferably in the range of 3700 to 4300 / hour, more preferably in the range of 3800 to 4200 / hour, more preferably in the range of 3900 to 4100 / hour.

[0066] Setting (iii.6) is preferably maintained for a time in the range of 2 to 30 hours, preferably in the range of 5 to 20 hours, more preferably in the range of 10 to 15 hours.

[0067] When the reforming conditions in the reaction zone during (iii) include setting (iii.6) achieved immediately after setting (iii.5), the reforming conditions in the reaction zone may further include one or more settings (iii.x) achieved immediately after setting (iii.6), wherein each of the settings (iii.x) comprises: (a) the volumetric ratio of hydrocarbon:carbon dioxide:water in the reactant gas stream flowing into the reaction zone; (b) the temperature in the reaction zone; (c) Gas hourly space velocity of the reactant gas streams flowing into the reaction zone (iii.x-1) in at least one of (x is an integer and x>6).

[0068] All cited documents are incorporated herein by reference.

[0069] The unit bar (abs) is 10 5 The pressure in kW is the absolute pressure in mPa.

[0070] The present invention is further illustrated by the following series of embodiments and combinations of embodiments, which can be obtained from the indicated dependencies and back references. In particular, it should be noted that in each instance where a range of embodiments is mentioned in conjunction with a term such as "the method according to any one of embodiments (1) to (4)," it is meant that all embodiments within this range are expressly disclosed to those skilled in the art, i.e., the wording of this term should be understood by those skilled in the art to be synonymous with "the method according to any one of embodiments 1, 2, 3, and 4."

[0071] 1. A continuous process for reforming one or more hydrocarbons into a synthesis gas comprising hydrogen and carbon monoxide, the process comprising the steps of: (i) providing a reactor comprising a reaction zone containing a catalyst comprising a mixed oxide comprising cobalt and oxygen; (ii) continuously passing an inert gas stream comprising one or more inert gases through a reaction zone according to (i); (iii) continuously flowing a reactant gas stream into the reaction zone resulting from (ii), wherein 95-100% by volume of the reactant gas stream flowing into the reaction zone consists of one or more hydrocarbons, carbon dioxide, and water; subjecting said reactant gas stream to reforming conditions in said reaction zone; removing a product stream comprising hydrogen and carbon monoxide from said reaction zone.

[0072] 2. The process of embodiment 1, wherein the reaction zone according to (i) comprises a catalyst arranged as a fixed bed catalyst.

[0073] 3. The process of any one of the preceding claims, wherein the reactor provided according to (i) comprises two or more reaction zones.

[0074] 4. The method of embodiment 3, wherein two or more reaction zones are arranged in parallel.

[0075] 5. The method of embodiment 3 or 4, wherein two or more reaction zones are arranged in series.

[0076] 6. The method of any one of the preceding embodiments, wherein the reactor provided according to (i) comprises two or more reactors arranged in parallel.

[0077] 7. The method according to any one of the preceding embodiments, wherein 99 to 100% by weight, preferably 99.5 to 100% by weight, more preferably 99.9 to 100% by weight, of the catalyst consists of the mixed oxide.

[0078] 8. The method of any one of the preceding embodiments, wherein the catalyst is in the form of a molding, preferably a platelet.

[0079] 9. The BET specific surface area of ​​the catalyst, measured as described in Reference Example 1, is 7 to 13 m 2 / g, preferably 7.5 to 12 m 2 / g, more preferably 8 to 12 m 2The method of any one of the preceding claims, wherein the ionic liquid is in the range of / g.

[0080] 10. The Langmuir specific surface area of ​​the catalyst, measured as described in Reference Example 1, is 9 to 15 m 2 The method according to any one of the preceding embodiments, wherein the ionic liquid is in the range of 1 / g.

[0081] 11. The method of any one of the preceding claims, wherein 5 to 10% by weight of the mixed oxide consists of cobalt, calculated as element.

[0082] 12. The method of any one of the preceding embodiments, wherein the cobalt is present in one or more crystalline phases, preferably in at least two crystalline phases, more preferably in at least three crystalline phases, more preferably in three crystalline phases.

[0083] 13. The method of any one of the preceding embodiments, wherein the mixed oxide further comprises one or more of lanthanum and aluminum, preferably lanthanum and aluminum.

[0084] 14. The method of any one of the preceding embodiments, wherein the mixed oxide further comprises aluminum, and wherein the weight ratio of cobalt to aluminum in the mixed oxide, calculated as element, is preferably at least 0.1:1, more preferably in the range of 0.13:1 to 0.3:1, more preferably in the range of 0.15:1 to 0.25:1, more preferably in the range of 0.17:1 to 0.22:1.

[0085] 15. The method of any one of the preceding embodiments, wherein the mixed oxide further comprises lanthanum, and wherein the weight ratio of cobalt to lanthanum in the mixed oxide, calculated as element, is preferably in the range of 0.2:1 to 0.6:1, preferably in the range of 0.25:1 to 0.5:1.

[0086] 16. The method according to any one of the preceding embodiments, wherein the mixed oxide further comprises lanthanum, and wherein 15 to 25% by weight, preferably 16 to 23% by weight, of the mixed oxide, calculated as element, consists of lanthanum.

[0087] 17. The method according to any one of the preceding embodiments, wherein the mixed oxide further comprises aluminum, and wherein 33 to 40% by weight, preferably 34 to 38% by weight, more preferably 35 to 37% by weight, more preferably 35.5 to 36.5% by weight of the mixed oxide, calculated as element, consists of aluminum.

[0088] 18. The method according to any one of the preceding embodiments, wherein 80-100% by weight, preferably 90-100% by weight, more preferably 92-100% by weight of the mixed oxide is in crystalline form.

[0089] 19. The mixed oxide further comprises lanthanum and aluminum, the mixed oxide being at least LaCoAl 11 O 19 19. The method according to any one of the preceding claims, comprising a crystalline phase of LaAl(Co)O3 and a crystalline phase of LaAl(Co)O3.

[0090] 20. In the mixed oxide, LaCoAl, as measured by XRD as described in Reference Example 2 11 O 19 20. The method of embodiment 19, wherein the weight ratio of LaAl(Co)O3 to LaAl(Co)O3 is at least 10:1, preferably in the range of 10:1 to 25:1.

[0091] 21. The method of any one of the preceding embodiments, wherein the mixed oxide further comprises lanthanum and aluminum, and wherein the mixed oxide comprises crystalline phase LaAlO3, preferably crystalline phase LaAlO3 and crystalline phase CoAl2O4, more preferably crystalline phase LaAlO3, crystalline phase CoAl2O4, and crystalline phase La(OH)3.

[0092] 22. The mixed oxide further comprises lanthanum and aluminum, and the mixed oxide has the crystalline phase LaCoAl 11 O 19and crystalline phase CoAl2O4.

[0093] 23. The mixed oxide further comprises lanthanum and aluminum, and the mixed oxide has the crystalline phase LaCoAl 11 O 19 and crystalline phase CoAl2O4, where LaCoAl, as measured by XRD as described in Reference Example 2, 11 O 19 23. The method according to any one of the preceding embodiments, wherein the weight ratio of CoAl2O4 to CoAl2O4 is preferably at least 10:1, more preferably in the range of 12:1 to 30:1.

[0094] 24. The method of any one of the preceding embodiments, wherein the mixed oxide further comprises one or more of barium, strontium, and mixtures thereof.

[0095] 25. The method of any one of the preceding embodiments, wherein the catalyst is heated in one or more of (i), (ii), and (iii), preferably in one or more of (ii) and (iii), more preferably in (ii) and (iii).

[0096] 26. The method of any one of the preceding embodiments, wherein during (ii), the catalyst is heated to a temperature in the range of 350 to 450°C, preferably in the range of 375 to 425°C.

[0097] 27. The method of any one of the preceding embodiments, wherein during (iii), the catalyst is heated to a temperature in the range of 550 to 980°C, preferably in the range of 575 to 975°C, more preferably in the range of 600 to 950°C.

[0098] 28. The method of any one of the preceding embodiments, wherein the reaction zone resulting from (ii) contains 0-0.1 vol. %, preferably 0-0.01 vol. %, more preferably 0-0.001 vol. % oxygen (O2) prior to flowing the reactant gas streams into the reactor according to (iii).

[0099] 29. The method of any one of the preceding embodiments, wherein a reactant stream comprising one or more of a hydrocarbon and water, preferably a hydrocarbon and water, and comprising 0-0.1 vol. %, more preferably 0-0.01 vol. %, more preferably 0-0.001 vol. % carbon dioxide, is not flowed into the reaction zone according to (i) prior to (iii).

[0100] 30. The process of any one of the preceding embodiments, wherein a stream consisting of 95-100% by volume, preferably 98-100% by volume, more preferably 99-100% by volume, of one or more of hydrocarbons and water, preferably hydrocarbons and water, is not flowed into the reaction zone according to (i) prior to (iii).

[0101] 31. The method according to any one of the preceding embodiments, wherein the reaction zone obtained from (ii) and before (iii) comprises 0-0.1% by volume, preferably 0-0.01% by volume, more preferably 0-0.001% by volume of one or more of carbon dioxide and oxygen (O2), preferably carbon dioxide and oxygen (O2).

[0102] 32. The method according to any one of the preceding embodiments, wherein 95-100% by volume, preferably 98-100% by volume, more preferably 99-100% by volume, of the inert gas stream according to (ii) consists of one or more inert gases.

[0103] 33. The method of any one of the preceding embodiments, wherein the one or more inert gases according to (ii) comprise one or more of nitrogen and argon.

[0104] 34. The method of any one of the preceding embodiments, wherein the one or more inert gases are nitrogen and argon.

[0105] 35. The method according to any one of the preceding embodiments, wherein the one or more inert gases is nitrogen, preferably technical nitrogen.

[0106] 36. The process according to any one of the preceding embodiments, wherein in accordance with (ii), the inert gas stream is passed through the reaction zone in accordance with (i) at a gas hourly space velocity (GHSV) of the inert gas stream in the range of 1000 to 10000 / hour, preferably in the range of 2000 to 6000 / hour, more preferably in the range of 3000 to 4000 / hour.

[0107] 37. The method of any one of the preceding embodiments, wherein the hydrocarbon is one or more of methane, ethane, propane and butane, preferably methane.

[0108] 38. The process of any one of the preceding embodiments, wherein in the reactant gas stream resulting from (ii) passed into the reaction zone, the volume ratio of hydrocarbon to carbon dioxide is in the range of 0.75:1 to 1.25:1, preferably in the range of 0.8:1 to 1.2:1, more preferably in the range of 0.9:1 to 1.1:1, more preferably in the range of 0.95:1 to 1.05:1.

[0109] 39. The method of any one of the preceding embodiments, wherein the volume ratio of hydrocarbon to water in the reactant gas stream passed into the reaction zone resulting from (ii) is in the range of 1.7:1 to 2.9:1, preferably in the range of 1.8:1 to 2.8:1, more preferably in the range of 1.85:1 to 2.75:1.

[0110] 40. The process of any one of the preceding embodiments, wherein 96-100% by volume, preferably 98-100% by volume, more preferably 99-100% by volume, more preferably 99.5-100% by volume, of the reactant gas stream flowing into the reaction zone resulting from (ii) consists of hydrocarbons, carbon dioxide, and water.

[0111] 41. The process of any one of the preceding embodiments, wherein 1 to 50 vol. %, preferably 10 to 50 vol. %, more preferably 30 to 50 vol. %, more preferably 35 to 45 vol. %, more preferably 37 to 40.5 vol. % of the reactant gas stream consists of hydrocarbons prior to passing through the reaction zone resulting from (ii).

[0112] 42. The process of any one of the preceding embodiments, wherein 1 to 50% by volume of the reactant gas stream consists of carbon dioxide (CO2) prior to passing through the reaction zone resulting from (ii), preferably 10 to 50% by volume, more preferably 30 to 50% by volume, more preferably 35 to 45% by volume, more preferably 37 to 40.5% by volume.

[0113] 43. The process of any one of the preceding embodiments, wherein 1 to 50% by volume of the reactant gas stream consists of water (H2O), preferably 5 to 35% by volume, more preferably 10 to 25% by volume, more preferably 12 to 23% by volume, more preferably 14 to 21% by volume, prior to passing through the reaction zone resulting from (ii).

[0114] 44. The process according to any one of the preceding embodiments, wherein the reforming conditions in the reaction zone according to (iii) comprise a pressure of the gas phase in the range of 1 to 50 bar (abs), preferably in the range of 10 to 40 bar (abs), more preferably in the range of 15 to 30 bar (abs), more preferably in the range of 17 to 23 bar (abs), more preferably in the range of 17 to 23 bar (abs), more preferably in the range of 19 to 21 bar (abs), more preferably in the range of 19.5 to 20.5 bar (abs).

[0115] 45. The process according to any one of the preceding embodiments, wherein the reforming conditions in the reaction zone according to (iii) comprise a gas hourly space velocity (GHSV) of the reactant gas stream in the range of 1000 to 7500 / hr, preferably in the range of 1250 to 7300 / hr, more preferably in the range of 1500 to 7100 / hr, more preferably in the range of 3500 to 7500 / hr, more preferably in the range of 3700 to 7300 / hr, more preferably in the range of 3900 to 7100 / hr.

[0116] 46. ​​The process according to any one of the preceding embodiments, wherein the reforming conditions in the reaction zone according to (iii) comprise a temperature of the gas phase in the reaction zone in the range of 550 to 980°C, preferably in the range of 575 to 975°C, more preferably in the range of 600 to 950°C.

[0117] 47. During (iii), the reforming conditions in the reaction zone include a setting (iii.1) and a setting (iii.2) that is achieved immediately after setting (iii.1), where setting (iii.1) is (a) the volumetric ratio of hydrocarbon:carbon dioxide:water in the reactant gas stream flowing into the reaction zone; (b) the temperature in the reaction zone; (c) Gas hourly space velocity of the reactant gas streams flowing into the reaction zone The method according to any one of the preceding embodiments, wherein the setting (iii.2) differs from the setting (iii.3) in at least one of the following:

[0118] 48. The method of embodiment 47, wherein the volume ratio of hydrocarbon:carbon dioxide:water in the reactant gas stream according to setting (iii.1) is (2.5-2.9):(2.5-2.9):(0.8-1.2), preferably (2.55-2.8):(2.55-2.8):(0.9-1.1), more preferably (2.6-2.75):(2.6-2.75):(0.95-1.05).

[0119] 49. The process according to embodiment 47 or 48, wherein the temperature in the reaction zone according to setting (iii.1) is in the range of 550 to 980°C, preferably in the range of 575 to 975°C, more preferably in the range of 600 to 950°C, more preferably in the range of 880 to 920°C, more preferably in the range of 890 to 910°C, more preferably in the range of 895 to 905°C.

[0120] 50. The method according to any one of embodiments 48 to 49, wherein the gas hourly space velocity of the reactant gas stream according to setting (iii.1) is in the range of 1000 to 7500 / h, preferably in the range of 1250 to 7300 / h, more preferably in the range of 1500 to 7100 / h, more preferably in the range of 3700 to 4300 / h, more preferably in the range of 3800 to 4200 / h, more preferably in the range of 3900 to 4100 / h.

[0121] 51. The method according to any one of embodiments 47 to 50, wherein the setting (iii.1) is maintained for a time in the range of 1 to 10 hours, preferably in the range of 3 to 8 hours, more preferably in the range of 4 to 6 hours.

[0122] 52. The method according to any one of embodiments 47 to 51, wherein the volume ratio hydrocarbon:carbon dioxide:water in the reactant gas stream according to setting (iii.2) is (2.5-2.9):(2.5-2.9):(0.8-1.2), preferably (2.55-2.8):(2.55-2.8):(0.9-1.1), more preferably (2.6-2.75):(2.6-2.75):(0.95-1.05).

[0123] 53. The process according to any one of embodiments 47 to 52, wherein the temperature in the reaction zone according to setting (iii.2) is in the range of 550 to 980°C, preferably in the range of 575 to 975°C, more preferably in the range of 600 to 970°C, more preferably in the range of 930 to 970°C, more preferably in the range of 940 to 960°C, more preferably in the range of 945 to 955°C.

[0124] 54. The method according to any one of embodiments 47 to 53, wherein the gas hourly space velocity according to setting (iii.2) is in the range of 1000 to 7500 / h, preferably in the range of 1250 to 7300 / h, more preferably in the range of 1500 to 7100 / h, more preferably in the range of 3700 to 4300 / h, more preferably in the range of 3800 to 4200 / h, more preferably in the range of 3900 to 4100 / h.

[0125] 55. The method according to any one of embodiments 47 to 54, wherein the setting (iii.2) is maintained for a time in the range of 10 to 50 hours, preferably in the range of 20 to 40 hours, more preferably in the range of 30 to 35 hours.

[0126] 56. The method according to claim 1, further comprising setting (iii.3) during (iii) in which reforming conditions in the reaction zone are achieved immediately after setting (iii.2), wherein setting (iii.3) comprises: (a) the volumetric ratio of hydrocarbon:carbon dioxide:water in the reactant gas stream flowing into the reaction zone; (b) the temperature in the reaction zone; (c) Gas hourly space velocity of the reactant gas streams flowing into the reaction zone The method according to any one of embodiments 47 to 55, which differs from setting (iii.2) in at least one of the following:

[0127] 57. The method of embodiment 56, wherein the volume ratio of hydrocarbon:carbon dioxide:water in the reactant gas stream according to setting (iii.3) is (1.7-2.1):(1.7-2.1):(0.8-1.2), preferably (1.8-1.95):(1.8-1.95):(0.9-1.1), more preferably (1.85-1.9):(1.85-1.9):(0.95-1.05).

[0128] 58. The method according to embodiment 56 or 57, wherein the temperature in the reaction zone according to setting (iii.3) is in the range of 550 to 980°C, preferably in the range of 575 to 975°C, more preferably in the range of 600 to 970°C, more preferably in the range of 930 to 970°C, more preferably in the range of 940 to 960°C, more preferably in the range of 945 to 955°C.

[0129] 59. The method according to any one of embodiments 56 to 58, wherein the gas hourly space velocity according to setting (iii.3) is in the range of 1000 to 7500 / h, preferably in the range of 1250 to 7300 / h, more preferably in the range of 1500 to 7100 / h, more preferably in the range of 3700 to 4300 / h, more preferably in the range of 3800 to 4200 / h, more preferably in the range of 3900 to 4100 / h.

[0130] 60. The method according to any one of embodiments 56 to 59, wherein the setting (iii.3) is maintained for a time in the range of 5 to 50 hours, preferably in the range of 10 to 40 hours, more preferably in the range of 20 to 30 hours.

[0131] 61. During (iii), the method further includes setting (iii.4) in which reforming conditions in the reaction zone are achieved immediately after setting (iii.3), wherein setting (iii.4) comprises: (a) the volumetric ratio of hydrocarbon:carbon dioxide:water in the reactant gas stream flowing into the reaction zone; (b) the temperature in the reaction zone; (c) Gas hourly space velocity of the reactant gas streams flowing into the reaction zone The method according to any one of embodiments 56 to 60, which differs from setting (iii.3) in at least one of the following:

[0132] 62. The method of embodiment 61, wherein the volume ratio hydrocarbon:carbon dioxide:water in the reactant gas stream according to setting (iii.4) is (1.7-2.1):(1.7-2.1):(0.8-1.2), preferably (1.8-1.95):(1.8-1.95):(0.9-1.1), more preferably (1.85-1.9):(1.85-1.9):(0.95-1.05).

[0133] 63. The process according to embodiment 61 or 62, wherein the temperature in the reaction zone according to setting (iii.4) is in the range of 550 to 980°C, preferably in the range of 575 to 975°C, more preferably in the range of 600 to 970°C, more preferably in the range of 930 to 970°C, more preferably in the range of 940 to 960°C, more preferably in the range of 945 to 955°C.

[0134] 64. The method according to any one of embodiments 61 to 63, wherein the gas hourly space velocity according to setting (iii.4) is in the range of 1000 to 7500 / h, preferably in the range of 1250 to 7300 / h, more preferably in the range of 1500 to 7100 / h, more preferably in the range of 6700 to 7100 / h, more preferably in the range of 6800 to 7100 / h, more preferably in the range of 6900 to 7100 / h.

[0135] 65. The method according to any one of embodiments 61 to 64, wherein the setting (iii.4) is maintained for a time in the range of 2 to 30 hours, preferably in the range of 5 to 20 hours, more preferably in the range of 10 to 15 hours.

[0136] 66. During (iii), the reforming conditions in the reaction zone further include setting (iii.5) which is achieved immediately after setting (iii.4), wherein setting (iii.5) comprises: (a) the volumetric ratio of hydrocarbon:carbon dioxide:water in the reactant gas stream flowing into the reaction zone; (b) the temperature in the reaction zone; (c) Gas hourly space velocity of the reactant gas streams flowing into the reaction zone The method according to any one of embodiments 61 to 65, which differs from setting (iii.4) in at least one of the following:

[0137] 67. The method according to embodiment 66, wherein the volume ratio of hydrocarbon:carbon dioxide:water in the reactant gas stream according to setting (iii.5) is (2.5-2.9):(2.5-2.9):(0.8-1.2), preferably (2.55-2.8):(2.55-2.8):(0.9-1.1), more preferably (2.6-2.75):(2.6-2.75):(0.95-1.05).

[0138] 68. The process according to embodiment 66 or 67, wherein the temperature in the reaction zone according to setting (iii.5) is in the range of 550 to 980°C, preferably in the range of 575 to 975°C, more preferably in the range of 600 to 970°C, more preferably in the range of 930 to 970°C, more preferably in the range of 940 to 960°C, more preferably in the range of 945 to 955°C.

[0139] 69. The method according to any one of embodiments 66 to 68, wherein the gas hourly space velocity according to setting (iii.5) is in the range of 1000 to 7500 / h, preferably in the range of 1250 to 7300 / h, more preferably in the range of 1500 to 7100 / h, more preferably in the range of 6700 to 7100 / h, more preferably in the range of 6800 to 7100 / h, more preferably in the range of 6900 to 7100 / h.

[0140] 70. The method according to any one of embodiments 66 to 69, wherein the setting (iii.5) is maintained for a time in the range of 2 to 30 hours, preferably in the range of 5 to 20 hours, more preferably in the range of 10 to 15 hours.

[0141] 71. The method according to claim 1, further comprising setting (iii.6) during (iii) in which reforming conditions in the reaction zone are achieved immediately after setting (iii.5), wherein setting (iii.6) comprises: (a) the volumetric ratio of hydrocarbon:carbon dioxide:water in the reactant gas stream flowing into the reaction zone; (b) the temperature in the reaction zone; (c) Gas hourly space velocity of the reactant gas streams flowing into the reaction zone The method according to any one of embodiments 66 to 70, which differs from setting (iii.5) in at least one of the following:

[0142] 72. The method of embodiment 71, wherein the volume ratio hydrocarbon:carbon dioxide:water in the reactant gas stream according to setting (iii.6) is (1.7-2.1):(1.7-2.1):(0.8-1.2), preferably (1.8-1.95):(1.8-1.95):(0.9-1.1), more preferably (1.85-1.9):(1.85-1.9):(0.95-1.05).

[0143] 73. The process according to embodiment 71 or 72, wherein the temperature in the reaction zone according to setting (iii.6) is in the range of 550 to 980°C, preferably in the range of 575 to 975°C, more preferably in the range of 600 to 970°C, more preferably in the range of 930 to 970°C, more preferably in the range of 940 to 960°C, more preferably in the range of 945 to 955°C.

[0144] 74. The method according to any one of embodiments 71 to 73, wherein the gas hourly space velocity according to setting (iii.6) is in the range of 1000 to 7500 / h, preferably in the range of 1250 to 7300 / h, more preferably in the range of 1500 to 7100 / h, more preferably in the range of 3700 to 4300 / h, more preferably in the range of 3800 to 4200 / h, more preferably in the range of 3900 to 4100 / h.

[0145] 75. The method according to any one of embodiments 71 to 74, wherein the setting (iii.6) is maintained for a time in the range of 2 to 30 hours, preferably in the range of 5 to 20 hours, more preferably in the range of 10 to 15 hours.

[0146] 76. During (iii), the method further includes one or more settings (iii.x) in which reforming conditions in the reaction zone are achieved after setting (iii.6), wherein each of the settings (iii.x) comprises: (a) the volumetric ratio of hydrocarbon:carbon dioxide:water in the reactant gas stream flowing into the reaction zone; (b) the temperature in the reaction zone; (c) Gas hourly space velocity of the reactant gas streams flowing into the reaction zone At least one of the following is different from setting (iii.x-1) The method of any one of embodiments 71 to 75, wherein x is an integer and x>6.

[0147] The present invention is further illustrated by the following examples and reference examples. EXAMPLES

[0148] Reference Example 1: Measurement of BET specific surface area and Langmuir specific surface area The BET and Langmuir specific surface areas were determined by nitrogen physical sorption at 77 K according to the method disclosed in DIN 66131.

[0149] Reference Example 2: Measurement of crystallinity by XRD Powder X-ray diffraction (PXRD) data were collected using a laboratory diffractometer (D8 Discover, Bruker AXS GmbH, Karlsruhe). A molybdenum X-ray tube was used to prepare the instrument. A bent germanium Johansen-type primary monochromator was used to monochromatize the characteristic K-alpha radiation. Data were collected in Bragg-Brentano reflection geometry. A LYNXEYE area detector was utilized to collect the scattered X-ray signal.

[0150] The powders were milled using an IKA tube mill and a MT40.100 disposable grinding chamber. The powders were placed in a sample holder and flattened using a glass plate.

[0151] Data analysis was performed using DIFFRAC.EVA V4 and DIFFRAC.TOPAS V4 software (Bruker AXS GmbH). Crystallinity was estimated using DIFFRAC.EVA. Default values ​​were used as input for the algorithm (DIFFRAC.EVA User Manual, 2014, Bruker AXS GmbH, Karlsruhe).

[0152] All other parameters were determined using DIFFRAC.TOPAS. Hexagonal LaCoAl 11 O 19 The entire diffraction pattern was simulated using the crystal structures of rhombohedral LaAlO3, cubic CoAl2O4, hexagonal La(OH)3, cubic Co-doped LaAlO3 and corundum. During the simulation, 29 parameters were refined to fit the simulated diffraction to the measured data. The results are shown in Table 1 below.

[0153] [Table 1]

[0154] [Table 2]

[0155] Crystallite size values ​​are reported as Lvol-FWHM in DIFFRAC.TOPAS. To ensure reliable crystallite size values, the diffractometer geometry was entered into the software to allow calculation of the instrument resolution based on a fundamental parameter approach (DIFFRAC.TOPAS User Manual, 2014, Bruker AXS GmbH, Karlsruhe). Scale factors were recalculated by DIFFRAC.TOPAS to mass percent values ​​and recorded.

[0156] Example 1: Preparation of mixed oxide containing cobalt and oxygen The mixed oxides tested as catalysts in a process for producing synthesis gas were prepared according to the following synthesis procedure: 6 kg of aqueous AlOOH solution (Disperal®, Sasol, containing 78% by weight of Al2O3), 1.95 kg of Co(NO3)2·6H2O (Merck, with a purity of 97%) and 4.8 kg of La(NO3)3·6H2O (Fluka, with a purity of 99%) were mixed homogeneously in a kneader and 850 ml of water was added. The mixture was extruded into 4 mm cylinders. These strands were dried in a muffle furnace at 105 ° C for 16 hours. The dried strands were then calcined in a muffle furnace in the following sequence: a) at 490 ° C for 15 minutes, b) at 520 ° C for 120 minutes. The calcined strands were then broken into particles with a diameter of 0.5-1.0 millimeters and finally calcined in air at 1100 ° C for 30 hours.

[0157] The resulting mixed oxide contained 36% by weight of aluminum, 5.8% by weight of cobalt and 23% by weight of lanthanum, calculated as the respective elements. The BET specific surface area of ​​the final catalyst was 11 m, measured according to Reference Example 1. 2 / g.

[0158] Example 2: Catalysis Testing The catalytic tests were carried out in a test rig containing a single reactor. This rig allows test conditions in a wide temperature and pressure range up to 1100°C (at 1.000 bar) and 20 bar (up to 950°C). Carbon dioxide, methane, hydrogen, nitrogen and argon are provided as gas feed for the reactant gas stream and are controlled online by a mass flow controller (MFC). Water is added to the gas feed stream as steam by an evaporator connected to a water reservoir, whereby the input to the evaporator is performed by a high performance liquid chromatography (HPLC) pump controlled by a flow meter. Analysis of the composition of the product stream was performed by on-line gas chromatography using Ar as an internal standard. The gas chromatography analysis allowed the quantification of hydrogen, carbon monoxide, carbon dioxide, methane and C2-components. The duration of the gas chromatography method was about 24 minutes.

[0159] For the catalytic tests, 15 ml of catalyst was used as a flake (particle size 0.5-1.0 μm). The sample was placed in the thermostatic region of the reactor using a ceramic device. The back pressure was measured before the start of the experiment.

[0160] Based on the quantification of the product streams, the methane conversion and carbon dioxide conversion were calculated according to equations [1] and [2]. CH4-conversion ratio: x(CH4)=1-(CH4-out / CH4-in)[1] CO2-conversion rate:x(CO2)=1-(CO2-out / CO2-in)[2]

[0161] Gas hourly space velocity (GHSV) is defined according to equation [3]: GHSV = total gas stream flow rate [L / h] / catalyst fraction volume [L][3]

[0162] Comparative Example 2.1: Catalytic testing of the catalyst of Example 1 in a typical process The reaction parameters commonly used in processes for converting methane to synthesis gas are listed in Table 3. The process starts with a reaction stage where only methane and water are used in the gas feed stream, followed by a lengthy stage where the methane and steam are partially replaced by carbon dioxide. The pressure was 20 bar (abs).

[0163] [Table 3]

[0164] The obtained activities for the preparation of synthesis gas according to the invention are set out in FIG.

[0165] Example 2.2: Catalytic testing of the catalyst of Example 1 in a process according to the invention The reaction parameters used to obtain improved activity according to the process of the present invention are set out in Table 4. In this case, the process starts initially with a reactant gas stream containing methane, carbon dioxide and water. The pressure was 20 bar (abs).

[0166] [Table 4]

[0167] The activity obtained for the preparation of synthesis gas according to the invention is shown in Figure 2. As can be seen from Figure 2, the activity of the catalyst used in the inventive process according to Example 2.2 is twice as high as in Comparative Example 2.1, in particular by using the operating conditions described in Table 4. It can be seen in detail from Figure 2 that the CO2-conversion does not fall below 50% and the CH4-conversion does not fall below 45%. In comparison, it can be seen in Figure 1 that for the process according to the prior art the CO2-conversion does not reach 45% and the CH4-conversion does not reach 50%. This is all the more surprising since the same conditions, such as the change in temperature, gas hourly space velocity and composition of the gas feed, were applied in both the inventive and comparative examples, whereby the contents of steam, methane and carbon dioxide in the gas feed changed over time.

Claims

1. A continuous process for reforming one or more hydrocarbons into synthesis gas containing hydrogen and carbon monoxide, wherein the starting stage of said process comprises: (i) providing a reactor comprising a reaction zone containing a catalyst comprising a mixed oxide containing cobalt and oxygen; (ii) continuously passing an inert gas stream containing one or more inert gases through said reaction zone according to (i); (iii) continuously flowing a reactant gas stream into said reaction zone obtained from (ii), wherein 95 to 100% by volume of said reactant gas stream flowing into said reaction zone consists of one or more hydrocarbons, carbon dioxide, and water; subjecting said reactant gas stream to reforming conditions in said reaction zone; and removing a product stream containing hydrogen and carbon monoxide from said reaction zone.

2. The process according to claim 1, wherein the catalyst is in the form of a shaped article, preferably plate-shaped pellets.

3. The process according to claim 1 or 2, wherein said mixed oxide further comprises one or more of lanthanum and aluminum, preferably lanthanum and aluminum.

4. The process according to claim 1 or 2, wherein said mixed oxide further comprises aluminum, and in said mixed oxide, the weight ratio of cobalt to aluminum, calculated as elements, is preferably at least 0.1:1, more preferably in the range of 0.13:1 to 0.3:1, more preferably in the range of 0.15:1 to 0.25:1, even more preferably in the range of 0.17:1 to 0.22:

1.

5. Before flowing said reactant gas stream into the reactor according to (iii), the reaction zone obtained from (ii) contains 0 to 0.1% by volume, preferably 0 to 0.01% by volume, more preferably 0 to 0.001% by volume of oxygen (O ２ ).

6. A reactant stream containing one or more of hydrocarbons and water, preferably hydrocarbons and water, and containing 0 to 0.1% by volume, more preferably 0 to 0.01% by volume, even more preferably 0 to 0.001% by volume of carbon dioxide is not fed into the reaction zone according to (i) before (iii), the method according to claim 1 or 2.

7. A stream consisting of one or more of hydrocarbons and water, preferably hydrocarbons and water, in an amount of 95 to 100% by volume, preferably 98 to 100% by volume, more preferably 99 to 100% by volume is not fed into the reaction zone according to (i) before (iii), the method according to claim 1 or 2.

8. The reaction zone obtained from (ii) and before (iii) contains 0 to 0.1% by volume, preferably 0 to 0.01% by volume, more preferably 0 to 0.001% by volume of one or more of carbon dioxide and oxygen (O ２ ), preferably carbon dioxide and oxygen (O ２ ), the method according to claim 1 or 2.

9. The hydrocarbon is one or more of methane, ethane, propane and butane, preferably methane, the method according to claim 1 or 2.

10. In the reactant gas stream fed into the reaction zone obtained from (ii), the volume ratio of the hydrocarbon to the carbon dioxide is in the range of 0.75:1 to 1.25:1, preferably in the range of 0.8:1 to 1.2:1, more preferably in the range of 0.9:1 to 1.1:1, even more preferably in the range of 0.95:1 to 1.05:1, the method according to claim 1 or 2.

11. In the reactant gas stream fed into the reaction zone obtained from (ii), the volume ratio of the hydrocarbon to the water is in the range of 1.7:1 to 2.9:1, preferably in the range of 1.8:1 to 2.8:1, more preferably in the range of 1.85:1 to 2.75:1, the method according to claim 1 or 2.

12. Before passing through the reaction zone obtained from (ii), 1 to 50% by volume, preferably 10 to 50% by volume, more preferably 30 to 50% by volume, more preferably 35 to 45% by volume, still more preferably 37 to 40.5% by volume of the reactant gas stream consists of the hydrocarbon, the method according to claim 1 or 2.

13. Before passing through the reaction zone obtained from (ii), 1 to 50% by volume, preferably 10 to 50% by volume, more preferably 30 to 50% by volume, more preferably 35 to 45% by volume, still more preferably 37 to 40.5% by volume of the reactant gas stream consists of carbon dioxide (CO ２ )), the method according to claim 1 or 2.

14. Before passing through the reaction zone obtained from (ii), 1 to 50% by volume, preferably 5 to 35% by volume, more preferably 10 to 25% by volume, more preferably 12 to 23% by volume, still more preferably 14 to 21% by volume of the reactant gas stream consists of water (H ２ O), the method according to claim 1 or 2.

15. During (iii), the reforming conditions in the reaction zone include a setting (iii.1) and a setting (iii.2) achieved immediately after the setting (iii.1), and the setting (iii.1) is different from the setting (iii.2) in at least one of (a) the volume ratio of hydrocarbon:carbon dioxide:water in the reactant gas stream flowing into the reaction zone, (b) the temperature in the reaction zone; (c) the gas hourly space velocity of the reactant gas stream flowing into the reaction zone of claim 1 or 2.

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