Process and apparatus for regenerating catalysts from the methanol to olefin process

Abstract

A process for regenerating a catalyst from an MTO process is disclosed. The process includes providing an oxygen stream and a preheated carbon dioxide recirculation stream, and mixing the oxygen stream and the preheated carbon dioxide recirculation stream to provide a carbon dioxide-rich oxidation stream. The carbon dioxide-rich oxidation stream is moved to a regenerator unit to provide a carbon dioxide-rich flue gas stream. The carbon dioxide-rich flue gas stream is filtered to remove catalyst fines to produce a filtered flue gas stream. The carbon dioxide recirculation stream is taken in from the filtered flue gas stream.

Description

[Technical Field]

[0001] (Priority statement) This application claims priority to U.S. Provisional Patent Application No. 63 / 495,542, filed April 11, 2023, which is incorporated herein by reference in its entirety.

[0002] (Field of invention) This technical field relates to processes and apparatus for regenerating catalysts from fluid catalytic processes. In particular, this field relates to processes for regenerating catalysts from fluid catalytic processes using carbon dioxide recirculation flow. [Background technology]

[0003] Carbon dioxide is a so-called greenhouse gas, and its concentration in the atmosphere is desired by many. Carbon dioxide can be converted to oxygenated substances such as methanol or dimethyl ether. Molecular sieves, such as microporous crystalline zeolites and non-zeolite catalysts, particularly silicoaluminophosphate (SAPO), are known to promote the conversion of oxygenated substances into hydrocarbon mixtures, especially hydrocarbon mixtures consisting mostly of light olefins. A highly efficient methanol-to-olefin (MTO) process can convert oxygenated substances into light olefins, which have typically been considered for plastic production. The light olefins produced from the MTO process are highly concentrated in ethylene and propylene.

[0004] Alternative processes are also used in the production of light olefins. In one approach, hydrocarbon oxygenates, more specifically methanol or dimethyl ether, are used as alternative feedstocks for producing light olefin products. Once the oxygenates are formed, this process involves catalytically converting the oxygenates, such as methanol, into the desired light olefin product in a methanol-to-olefin (MTO) process. In the MTO process, carbonaceous material, i.e., coke, is deposited on the catalyst as the catalyst moves through the reaction zone. The carbonaceous material is removed from the catalyst by oxidative regeneration in one or more regeneration zones, and the moving bed of catalyst particles removed from the reaction zone is contacted with an oxygen-containing gas stream at a temperature and oxygen concentration sufficient to allow a desired amount of carbonaceous material to be removed from the catalyst by combustion. In some cases, it is advantageous to regenerate the catalyst only partially, for example, to remove 30-80% by weight of the carbonaceous material. During this regeneration, incomplete combustion of coke occurs, producing a mixture of water, carbon dioxide, and carbon monoxide. The ratio of net carbon dioxide to carbon monoxide produced during regeneration can range from 1.0 to 10.0. This results in a carbon monoxide concentration in the flue gas ranging from 0 mol% to 8 mol%.

[0005] Oligomerization of light olefins is a process that can carry out the conversion of C2-C6 olefins to more desirable products. More specifically, C2-C6 olefins can be converted into liquid fuels, including products in the range of naphtha, jet fuel, and diesel.

[0006] Jet fuel is one of the few petroleum fuels and cannot be easily replaced by electric motor systems because refueling aircraft, which electric motors cannot supply, requires high energy output. In certain regions, substantial incentives are currently available for green jet fuel.

[0007] Conventional catalyst regenerators typically include a container having a coke catalyst inlet, a regenerated catalyst outlet, and a combustion gas distributor for supplying air or other oxygen-containing gas to the catalyst bed present in the container. A cyclone separator removes the catalyst that has been entrained into the flue gas before the flue gas leaves the regenerator.

[0008] Flue gas formed by burning coke in a regenerator is treated to remove particulate matter and convert it to carbon monoxide (CO), and then the flue gas is usually released into the atmosphere. Furthermore, incomplete combustion into carbon monoxide can result from insufficient fluidization or aeration of the coke catalyst in the regenerator, or from insufficient distribution of the coke catalyst within the regenerator. Generally, flue gas exiting a regenerator contains carbon monoxide, carbon dioxide, nitrogen, and water, along with small amounts of other chemical species. Flue gas treatment methods are effective, but they have high capital and operating costs.

[0009] Furthermore, the flue gas can be optionally treated to remove catalyst fine particles and other particulate matter. The treated flue gas can then be discharged into the atmosphere.

[0010] Due to environmental concerns regarding greenhouse gas emissions, separating greenhouse gases before releasing flue gas into the atmosphere is becoming increasingly important. Carbon dioxide is the most important and longest-living greenhouse gas in the Earth's atmosphere. Carbon dioxide capture from flue gas remains expensive in terms of both capital expenditure and operational costs. In fluid catalytic processes, air is used to regenerate spent catalysts. As a result of this operation, carbon dioxide in the flue gas has a lower concentration, in contrast to the concentration of undesirable components from a carbon dioxide capture standpoint, resulting in high capital expenditures due to the large volume of flue gas, as well as significant operational costs as high solvent circulation rates and solvent regeneration loads. Separately, flue gas requires extensive flue gas treatment before carbon capture to meet stringent specifications to avoid high solvent decomposition rates. This results in high capital expenditures and operational costs, involving various longer impurity removal operations.

[0011] Decades of research and recent changes in government regulations have made it extremely necessary to find ways to reduce the carbon intensity of products such as petrochemicals, biofuels, or synthetic fuels (efuels) from MTO units. In MTO units, carbon dioxide can typically be captured from the MTO regenerator flue gas using a solvent process, which requires significant additional equipment and energy to regenerate the solvent.

[0012] Therefore, there is a need for processes and equipment that improve energy efficiency and energy recovery while reducing carbon dioxide emissions and, optionally, the capital expenditures and operating costs of the carbon dioxide capture section as a flue gas treatment section. [Overview of the project]

[0013] This disclosure provides a process and apparatus for regenerating a catalyst from an MTO process. Generally, air is used in a regenerator to burn coke derived from the spent catalyst. The atmosphere contains a large amount of nitrogen, which results in a low partial pressure of carbon dioxide. This process discloses supplying a carbon dioxide-rich oxidation flow to the regenerator instead of air. The flue gas from the regenerator by this process has an economically desirable amount of carbon dioxide from the standpoint of carbon dioxide capture compared to the undesirable components resulting from the use of air in the regenerator. [Brief explanation of the drawing]

[0014] Various embodiments are described below with reference to the following drawings, where similar numbers indicate similar elements. [Figure 1] This is a schematic diagram of a process and apparatus for regenerating a catalyst from an MTO unit according to an exemplary embodiment of the present disclosure. [Figure 2] This is a schematic diagram of a process and apparatus for regenerating a catalyst from an MTO unit according to another exemplary embodiment of the present disclosure. [Figure 3] This is a schematic diagram of a process and apparatus for regenerating a catalyst from an MTO unit according to yet another exemplary embodiment of the present disclosure. [Figure 4] Schematic diagram of a process and apparatus for regenerating a catalyst from an MTO unit according to yet another exemplary embodiment of the present disclosure. [Figure 5] Schematic diagram of a process and apparatus for regenerating a catalyst from an MTO unit according to yet another exemplary embodiment of the present disclosure. [Figure 6] Schematic diagram of a process and apparatus for regenerating a catalyst from an MTO unit according to yet another exemplary embodiment of the present disclosure. [Figure 7] Schematic diagram of a process and apparatus for regenerating a catalyst from an MTO unit according to yet another exemplary embodiment of the present disclosure. [Figure 8] Schematic diagram of a process and apparatus for regenerating a catalyst from an MTO unit according to yet another exemplary embodiment of the present disclosure. [Figure 9] Schematic diagram of a process and apparatus for regenerating a catalyst from an MTO unit according to yet another exemplary embodiment of the present disclosure. [Figure 10] Schematic diagram of a process and apparatus for regenerating a catalyst from an MTO unit according to yet another exemplary embodiment of the present disclosure. [Figure 11] Schematic diagram of a process and apparatus for regenerating a catalyst from an MTO unit according to yet another exemplary embodiment of the present disclosure. [Figure 12] Schematic diagram of a process and apparatus for regenerating a catalyst from an MTO unit according to yet another exemplary embodiment of the present disclosure.

DETAILED DESCRIPTION OF THE INVENTION

[0015] Definitions The term "communicate" means that the flow of material between the listed components is functionally possible.

[0016] The term "downstream communication" means that in downstream communication, at least a portion of the material flowing to the subject component can flow functionally from the object component.

[0017] The term "upstream connection" means that in an upstream connection, at least a portion of the material flowing from the target component can functionally flow to the component from which it is connected.

[0018] The terms "direct connection" or "direct" mean that the flow from the upstream components enters the downstream components without passing through fractionation or transformation units and undergoing compositional changes due to physical fractionation or chemical transformation.

[0019] The term “column” refers to a distillation column (singular or plural) for separating one or more different volatile components. Unless otherwise specified, each column includes a condenser at the top to condense and reflux a portion of the top flow returning to the top of the column, and a reboiler at the bottom to vaporize a portion of the bottom flow and return it to the bottom of the column. The feed into the column may be preheated. The top pressure is the pressure of the top vapor at the column's vapor outlet. The bottom temperature is the liquid bottom outlet temperature. The top line and bottom line refer to the net lines from column to column downstream of any reflux or reboil. A stripper column may omit the reboiler at the bottom of the column and instead provide the heating requirements and separation propulsion from a fluidized inert medium such as vapor. A stripper column typically feeds the feed into a top tray and removes the main product from the bottom.

[0020] As used herein, the term “separator” means a vessel having an inlet and at least a top vapor outlet and a bottom liquid outlet, and which may also have an aqueous outlet from the boot. A flash drum is a type of separator that can be downstream-communicated with a separator that can operate at higher pressures.

[0021] As used herein, the term “component-rich flow” means that a rich flow exiting a container has a higher concentration of components than the feed into the container.

[0022] As used herein, the term “rich” means more than 50%, preferably more than 75%, and more preferably more than 90%.

[0023] Detailed explanation To date, MTO catalyst regeneration has been carried out primarily using air containing nitrogen and oxygen. Because this process uses air, it requires large blowers and introduces nitrogen into the flue gas, which is undesirable for carbon dioxide capture. To capture carbon dioxide from this process, an adsorbent containing a solvent is required, which then necessitates additional equipment and utilities for regeneration.

[0024] In addition to optionally utilizing off-gases and oxygenated materials from olefin-jet complexes (OTJs) to heat or generate synthesis gas, MTO catalyst regeneration using a mixture of carbon dioxide and oxygen would be useful in combination with an electrolytic cell, carbon capture unit, and MeOH synthesis unit, combined with a potential high-pressure boiler (to save on compression costs). The greater the degree of process and utility integration in the OTJ complex, the more reductions in capital and operating costs, as well as carbon intensity, are expected. Furthermore, using carbon dioxide instead of air to transport oxygen allows for a reduction in the size of the flue gas treatment section, as less gas volume is required for carbon dioxide, which has a larger molecular weight than nitrogen, the largest component of air.

[0025] This disclosure discloses the integration of oxygen combustion between methanol synthesis and the MTO process, which offers numerous advantages in the overall carbon dioxide-jet fuel complex. In this disclosure, the by-product oxygen generated during water electrolysis for hydrogen production is sent directly to the MTO regenerator, eliminating the need for a replenishment air blower and significantly reducing the size of the flue gas recirculation compressor, both of which provide a significant reduction in electrical utility in the MTO regenerator section. Furthermore, by using oxygen instead of air to burn the MTO catalyst coke, the flue gas is concentrated with carbon dioxide instead of nitrogen. When the flue gas is diluted with carbon dioxide, it is difficult to efficiently capture the carbon, the flow usually burns, and the carbon is released into the atmosphere. Therefore, by using flue gas concentrated with carbon dioxide instead of nitrogen, it becomes possible to efficiently recover the carbon dioxide in the flue gas and recirculate it to the methanol synthesis unit, thereby avoiding net carbon dioxide emissions.

[0026] A process for regenerating a catalyst from a fluid catalyst process is disclosed. The fluid catalyst process may be any fluid catalyst process that regenerates a catalyst, including an MTO process. Flue gas from the regenerator of the fluid catalyst process is used to produce superheated steam and saturated steam.

[0027] Heat can be recovered from the flue gas at different points depending on the process requirements. To maximize heat recovery from the flue gas flow, various levels of superheated, high-pressure steam and saturated steam can be generated. In the case of a partial combustion regenerator, the CO combustor may be located upstream of the steam generator.

[0028] When air is used as a combustion gas, a large amount of inert matter, particularly nitrogen in the regenerator flue gas, further lowers the partial pressure of carbon dioxide. Nitrogen occupies unnecessary volume, resulting in large equipment sizes for the regenerator and downstream flue gas treatment equipment. Due to the low partial pressure of carbon dioxide, the cost of carbon dioxide capture is relatively high, which may be the reason for the resistance of refiners to implementing carbon dioxide capture technology. When the captured carbon dioxide stream is supplied to a methanol plant, any nitrogen or other inert matter remaining in the captured carbon dioxide stream accumulates in the system. This requires purging and can be detrimental to the overall process efficiency. The disclosed process replaces air with a carbon dioxide-rich oxidizing stream containing carbon dioxide and up to 35 mol% oxygen. The carbon dioxide-rich oxidizing stream containing carbon dioxide and oxygen significantly increases the partial pressure of carbon dioxide in the flue gas, allowing for lower capital and operational costs for carbon dioxide capture.

[0029] Flue gas from the regenerator in the MTO process may contain unconverted carbon monoxide. The unconverted carbon monoxide in the flue gas can be burned to carbon dioxide in a CO combustor that generates high-pressure steam. The flue gas is removed from the regenerator and fed into the CO combustor in the heat recovery section, where a combustion air stream is added to burn the flue gas, releasing heat which is then recovered. The use of air in the CO combustor can also result in the accumulation of nitrogen gas in the flue gas stream obtained from the CO combustor. This nitrogen from the CO combustor can be eliminated by replacing the air supplied to the CO combustor, dry air purge points, and other purges such as the fluffing air in the regenerator with a portion of the oxygen-rich carbon dioxide oxidation stream and a recirculated carbon dioxide stream.

[0030] The regenerator unit may be a partial combustion unit or a complete combustion unit. In a partial combustion regenerator unit, the flue gas typically contains up to 10%, more specifically 2% to 5%, of carbon monoxide, which is used as the primary fuel source in a downstream CO combustor where the flue gas is burned to release heat, and this heat is recovered. By operating the regenerator in partial combustion mode to maximize the carbon monoxide yield, the unit limits the amount of heat released within the regenerator compared to complete combustion of coke into carbon dioxide. This results in a decrease in the regenerator temperature.

[0031] Figure 1 shows a process and apparatus 101 for regenerating a catalyst from an MTO reactor 100, according to an exemplary embodiment.

[0032] One aspect of the present disclosure includes a process for regenerating a catalyst from a fluid catalyst process. The method includes supplying an oxygen stream to line 104 from an oxygen source 90. Typically, the oxygen stream is supplied from an air separation unit (ASU). However, the applicant has found that the oxygen stream may be taken from an electrolytic cell 92, which may be the oxygen source 90. Thus, the oxygen stream in line 104 may be supplied from the electrolytic cell 92. In one embodiment, the oxygen source 90 for providing the oxygen stream 104 can be selected from an air separation unit (ASU) or an electrolytic cell 92. In an exemplary embodiment, the oxygen source 90 is an electrolytic cell 92.

[0033] Examples of electrolytic cells 92 include, but are not limited to, polymer electrolyte membrane / proton exchange membranes (PEM / PEMEC), alkaline electrolysis cells (AEC), anion exchange membranes (AEM), and solid oxide electrolysis cells (SOE / SOEC). Various types of electrolytic cells may be used as electrolytic cells 92. According to this disclosure, utilities generated in the MTO process may be used in the electrolytic section of electrolytic cell 92. Specifically, the superheated vapor flow of line 126 may be used in electrolytic cell 90. In PEM, AEC, AEM, and SOEC electrolytic cells, electricity generated in the power recovery section of the MTO regenerator 120 (not shown) may be used. In addition, in SOEC electrolytic cells, heat in the form of vapor may be used in the SOEC to reduce the need for utilities that are generated and delivered to the process and apparatus 101. In SOEC electrolytic cells, 25% to 30% of the total energy requirement may be supplied by heat. In exemplary embodiments, heat from the MTO regenerator flue gas may be supplied to the SOEC electrolytic cell. Apart from incorporating heat generated from the MTO regenerator flue gas, other heat sources are also envisioned for integration. Furthermore, apart from using electricity to decompose water, electricity generated in process units such as those disclosed earlier may also be used for compression for electrolytic cells such as AEC, AEM, and PEM electrolytic cells 92. If the electrolytic cell 92 is installed in the MTO regenerator flue gas section, electricity generated in the expander turbine may be used. In exemplary embodiments, the electrolytic cell 92 may use thermal energy or steam generated in the MTO regenerator 120.

[0034] Referring to Figure 1, the oxygen source 90 is the electrolytic cell 92. The electrolytic cell 90 may be selected from one or more electrolytic cells, including but not limited to polymer electrolyte membrane / proton exchange membrane (PEM / PEMEC), alkaline electrolytic cell (AEC), anion exchange membrane (AEM), and solid oxide electrolytic cell (SOE / SOEC), as previously mentioned. The water flow in line 96 is supplied to the electrolytic cell 92. The water flow in line 96 may include water recirculated from the MTO reactor section 100. Heat is also supplied to the electrolytic cell 92 from any suitable heat source, such as steam in line 126. In an exemplary embodiment, the heat to the electrolytic cell 92 is supplied from any suitable process unit of the MTO unit. However, the heat to the electrolytic cell 92 can be supplied from any other heat source. Various utilities produced in the MTO unit can be used in the electrolytic cell 92. The hydrogen produced in the electrolytic cell 92 can be taken out in line 98 and supplied to the methanol synthesis unit 80. The oxygen stream is taken from the electrolytic cell 92 via line 104 and transferred to the mixer 196.

[0035] The oxygen stream from line 104 and the carbon dioxide recirculation stream from line 186 are moved to a mixing unit or mixer 196 to provide a carbon dioxide-rich oxidation stream in line 197. The carbon dioxide-rich oxidation stream in line 197 is moved to a regenerator unit 120. The spent catalyst stream from the MTO reactor 100 in line 102 is also moved to the regenerator unit 120. In one embodiment, the carbon dioxide-rich oxidation stream in line 197 contains an oxygen concentration of 30 mol% or less.

[0036] Methanol can be produced from methanol synthesis unit 80 by hydrogenating carbon dioxide and, optionally, carbon monoxide, on a methanol synthesis catalyst. Suitable methanol synthesis catalysts may be zinc oxide and copper on an alumina support. Synthesis conditions include temperatures of 200°C to 300°C and pressures of 3500 kPa (g) (500 psig) to 10000 kPa (g) (1500 psig). Reaction equilibrium typically requires methanol separation and recycling of unreacted reagents back into the synthesis reaction. A methanol stream is supplied to line 82.

[0037] The methanol stream of line 82 is filled into the MTO reactor 100 and contacts the MTO catalyst under MTO reaction conditions to convert methanol to olefins and water. The methanol stream of line 82 may contain methanol, dimethyl ether, ethanol, or a combination thereof. The MTO reactor 100 can fluidize the catalyst under high-speed flow conditions. The MTO catalyst may be a silicoaluminophosphate (SAPO) catalyst. SAPO catalysts and their formulations are generally taught in U.S. Patents 4,499,327(A), 10,358,394, and 10,384,986. The MTO reaction conditions involve contact with the SAPO catalyst at a pressure of 140 kPa(g)(20 psig) to 400 kPa(g)(60 psig). The MTO reaction temperature should be 325°C to 510°C. The weight hourly space velocity (WHSV) in an MTO reactor is measured between 1 and 15 hours. -1 This is within the specified range. The MTO catalyst is separated from the olefin product stream after the MTO reaction.

[0038] In the MTO process, catalyst particles are repeatedly circulated between the MTO reactor 100 and the MTO regenerator unit 120. During regeneration, coke deposited on the catalyst particles during the reaction in the reaction zone is removed at high temperatures by oxidation in the regenerator unit 120. Removal of the coke deposits restores the activity of the catalyst particles to a point where they can be reused in the MTO reactor 100. This disclosure concerns the handling of the flue gas flow in line 122 from the regenerator. The regenerated catalyst is discharged from the regenerator unit 120 in line 103 and recirculated to the MTO reactor 100.

[0039] The production logistics for light olefins, including ethylene, propylene, and other olefins, along with water and oxygenated materials, are discharged from the MTO unit to product line 105. Line 105 transports the MTO products to the MTO product unit 210. The MTO product unit 210 may include a light olefin recovery process for separating the light olefins for further value extraction. The MTO product unit 210 may also include an olefin decomposition process for breaking down larger olefins into light olefins, or, in an olefin-fuel unit, for oligomerizing lighter olefins to fuel-range olefins. The oligomerization unit may include a hydrogenation section for hydrogenating the fuel-range olefins into saturated fuel. The products are discharged from the MTO product unit 210 in product line 212. Furthermore, off-gases and / or undesirable liquid by-products from the fractionation column of the MTO product unit 210 are discharged in line 214, while heavy oxygenates produced from the MTO reactor 100 are discharged from the MTO product unit 210 in line 216. Some or all of the off-gases and heavy oxygenates may be supplied from the MTO product unit 210 to the partial oxidation unit 220.

[0040] In the partial oxidation unit 220, oxygen is added to line 218 in amounts less than stoichiometric to achieve only partial oxidation of hydrocarbons and oxygenated materials to carbon monoxide. From the partial oxidation unit 220, a carbon monoxide-rich partial oxidation flow is supplied to line 222. The destination of the partial oxidation flow in line 222 may be the methanol synthesis unit 80 for methanol synthesis. In contrast to complete combustion, only partial oxidation occurs in the partial oxidation unit 220, so little water is formed and the generation of contaminants is likely to be minimal. Therefore, the carbon monoxide-rich partial oxidation flow in line 222 can be supplied to the decontaminated synthesis flow in line 241. However, the composition of the partial oxidation flow in line 222 determines the injection location. For example, if the contaminant concentration in the partial oxidation flow of line 222 is high, the injection location of the partial oxidation flow may be in line 132 upstream of the decontamination reactor. Furthermore, if trace amounts of contaminants are present in the partial oxidation flow that need to be removed, the injection location may be in line 182 upstream of the contaminant removal unit 190. The injection location is also affected by the pressure of the partial oxidation flow in line 222 and the flow pressure at the injection location.

[0041] Maximizing the carbon monoxide concentration and minimizing the amount of oxygen in the partial oxidation stream of line 222 is beneficial for the overall economics of the process. This reduces the amount of hydrogen required by the methanol synthesis unit 80 to produce the same amount of methanol, generating more vapor and reducing overall utility consumption. The reactions in the methanol synthesis unit 80 and their heats of reaction (ΔH) may be as follows:

[0042]

number

[0043] The carbon dioxide-rich flue gas flow from line 122 is taken out of the MTO regenerator 120. The carbon dioxide-rich flue gas flow from line 122 is hot, and heat can be recovered from the carbon dioxide-rich flue gas flow from line 122 before further processing. The complete or partial combustion MTO regenerator 120 may operate at temperatures in the range of 625°C to 740°C or 640°C to 700°C.

[0044] The carbon dioxide-rich flue gas flow in line 122 is moved to the heat recovery section 125 to transfer heat from the carbon dioxide-rich flue gas flow in line 122 to the boiler feedwater flow in line 127, forming the partially cooled carbon dioxide-rich flue gas flow in line 132 and the steam flow in line 126. The heat recovery section 125 may include HRSG 129. Thus, the carbon dioxide-rich flue gas flow in line 122 is moved to the superheated steam section of HRSG 129 to transfer heat to the saturated steam flow, producing the superheated steam flow in line 126 and the partially cooled carbon dioxide-rich flue gas flow. The partially cooled carbon dioxide-rich flue gas flow then exchanges heat with the boiler feedwater flow in line 127 to cool the partially cooled carbon dioxide-rich flue gas flow in the saturated steam section, producing the saturated steam flow and the cooled carbon dioxide-rich flue gas flow in line 132. The blowdown flow in line 133 is also taken out of the saturated steam section. A portion of the saturated steam flow may be superheated in the superheated steam section, while the remaining saturated steam flow in line 136 can be sent to other parts of the process and apparatus for use as needed. The partially cooled carbon dioxide-rich flue gas flow in line 132 is taken out of the saturated steam section of HRSG 129 and moved to the decontamination reactor 140. The outlet temperature of the flue gas flow from HRSG 129 may be in the range of 150°C to 290°C.

[0045] The partially cooled carbon dioxide-rich flue gas flow of line 132 can be filtered in filter 150 for particle removal. Filter 150 may include a bag filter or an electrostatic precipitator. In one embodiment of the process, filter 150 is a bag filter. The bag filter 150 may operate at atmospheric pressure. In an alternative embodiment, filter 150 may be a high-pressure filter designed to operate at approximately the same pressure as the regenerator unit 120. An advantage of the high-pressure filter is the potential to reduce the power required by the downstream compressor. The filtered material from filter section 150 may include catalyst fines that can be removed in filter section 150. The filtered material can be removed from the process in line 155. The filtered flue gas flow of line 152 is moved to water removal section 111 to separate carbon dioxide from the filtered flue gas flow.

[0046] In one embodiment, the operating pressure of the regenerator 120 may be 70 kPa(g)(10 psig) to 350 kPa(g)(50 psig), depending on the processing purpose of the MTO reactor 100. The operating pressure of the filter 150 may be 70 kPa(g)(10 psig) to 350 kPa(g)(50 psig) or 10 kPa(g)(1.5 psig) to atmospheric pressure, depending on the design constraints of the filter type. This pressure difference potentially represents a considerable amount of energy. In another embodiment, the carbon dioxide-rich flue gas flow of line 122 may be moved to a third-stage separator (not shown), which separates the catalyst fines into a catalyst-rich underflow flow and a decatalyzed overflow flow. The decatalyzed overflow flow is moved to an expander to recover hydraulic energy. The expanded decatalyzed overflow flow may be moved to a heat recovery section 125. The expander may be mechanically connected to a generator to generate electricity, or it may be mechanically connected to a compressor to reduce power consumption by the compressor.

[0047] The filtered flue gas flow in line 152 still has a fairly high temperature. Thermal energy can still be recovered from the filtered flue gas flow in line 152. Optionally, the filtered flue gas flow in line 152 may be cooled in a first cooler 160 and then moved to a first knockout drum (KOD) 163. Alternatively, the filtered flue gas flow in line 152 may be moved directly to the first KOD 163 without further cooling. The first cooler 160 may use cooling water and / or chilled water as a cooling medium. Alternatively, the first cooler 160 may be an air cooler. In one aspect of this disclosure, the first cooler 160 may be optional, and the filtered flue gas flow in line 152 may be moved directly to the first KOD 163.

[0048] In the first KOD 163, water is separated from the cooled and filtered flue gas flow of line 162 to provide a carbon dioxide flow, which is taken out from the top of the KOD in line 164. The water is taken out as flow 165 from the bottom of the first KOD 163. This process recirculates a portion of the carbon dioxide flow in line 164 to the regenerator unit 120. Thus, a portion of the carbon dioxide flow in line 164 can be taken in and mixed with the oxygen flow in line 104 to provide a carbon dioxide-rich oxidation flow in line 197 for the MTO regenerator unit 120. In one embodiment, the carbon dioxide flow is separated into a carbon dioxide flow for recirculation in line 166 and a carbon dioxide flow for methanol synthesis in line 168.

[0049] The carbon dioxide flow for recirculation in line 166 may be moved to a carbon dioxide recirculation compressor 170 to provide a compressed carbon dioxide recirculation flow in line 172. The compressed carbon dioxide recirculation flow in line 172 at the outlet of the carbon dioxide recirculation compressor 170 is hot. The compressed carbon dioxide recirculation flow in line 172 may have a temperature of 220°C (428°F) to 260°C (471°F). The compressed carbon dioxide recirculation flow in line 172 can be moved to a steam generator 175 to provide a partially cooled carbon dioxide recirculation flow in line 176 and a steam flow in line 177 from the water flow in line 174. In an exemplary embodiment, the generator 175 is a low-pressure steam generator 175 that provides a low-pressure steam flow in line 177. The partially cooled carbon dioxide recirculation flow in line 176 is cooled in a second cooler 178 to provide a cooled carbon dioxide recirculation flow in line 179, which is moved to a second KOD 184. The second cooler 178 may be an air cooler. Alternatively, the second cooler 178 may use cooling water and / or chilled water as a cooling medium.

[0050] Cooling and condensation of the cooled and filtered flue gas flow in line 152 using the first cooler 160 may result in aqueous phase formation. This may cause carbon dioxide formation due to the reaction of carbon dioxide with water. Carbon dioxide formation may cause carbonic acid corrosion in downstream equipment. Therefore, the metallurgy of the first cooler 160 and the first KOD 163 is suitably selected to withstand any carbonic acid corrosion. According to one embodiment of the present disclosure, a heater 167 may be located upstream of the carbon dioxide recirculation compressor 170. According to one embodiment, the heater 167 may be used to raise the temperature of the carbon dioxide flow for recirculation of line 166, providing a heated carbon dioxide flow for recirculation of line 169 which is then moved to the carbon dioxide recirculation compressor 170. According to an exemplary embodiment, the carbon dioxide flow for recirculation of line 166 is moved to the heater 167 to raise the temperature of the carbon dioxide flow by 5°C (9°F) to 50°C (90°F) above the dew point of the carbon dioxide flow to avoid carbonic acid corrosion in any of the downstream equipment. The heated carbon dioxide flow for recirculation in line 169 is moved to the carbon dioxide recirculation compressor 170 to provide the compressed carbon dioxide recirculation flow for line 172, and then moved to the low-pressure steam generator 175 and the second cooler 178 as described above. The heater 167 is advantageously located downstream of the first KOD 163 to allow for greater water condensation and separation of water in the KOD.

[0051] In the second KOD 184, water is separated from the cooled carbon dioxide recirculation flow in line 179 to provide a dry carbon dioxide recirculation flow, which is taken out from the top of the KOD to line 186. Water is taken out from the bottom of the second KOD 184 as flow 187. The dry carbon dioxide recirculation flow in line 186 is mixed with the oxygen flow in line 104 in mixer 196 and then moved to the MTO regenerator 120. In some embodiments, a deoxygenation operation may be included in the water separation section 111 or the decontamination reactor 140 to meet the specifications regarding the use of carbon dioxide.

[0052] The carbon dioxide stream for methanol synthesis in line 168 may also require preparation for use in methanol synthesis. The methanol synthesis carbon dioxide stream should be compressed to the methanol synthesis pressure. However, the methanol synthesis carbon dioxide stream in line 168 may require processing in a pressure swing adsorption (PSA) unit or a thermal swing adsorption (TSA) unit for the removal of trace contaminants such as oxygen and optionally water. Other particulate matter may be removed in a contaminant removal unit 190. The methanol synthesis carbon dioxide stream in line 168 may be compressed in a methanol carbon dioxide compressor 180 to an intermediate pressure suitable for contaminant removal. The compressed synthesis carbon dioxide stream in line 182 may be fed to a contaminant removal unit 190 for contaminant removal. The contaminant-decontaminated carbon dioxide stream in line 192 exits the contaminant removal unit 190. The storage carbon dioxide stream in line 194 may be taken from the contaminant-decontaminated carbon dioxide stream in line 192 for storage. The contaminant-free synthesis flow can then be taken up to line 241 for methanol synthesis, possibly after supplementing the partial oxidation flow in line 222.

[0053] In an exemplary embodiment, the contaminant removal unit 190 is a pressure swing adsorption (PSA) unit. The compressed synthetic carbon dioxide stream of line 182 is moved to the pressure swing adsorption (PSA) unit 190 to remove contaminants from the compressed synthetic carbon dioxide stream of line 182 or to reduce their concentration to a lower level. The contaminants are adsorbed by the adsorbent present in the PSA unit 190, but carbon dioxide is not adsorbed by the adsorbent and passes through the floor. The PSA adsorbent may be selected from silica gel, NaY zeolite, and 13X zeolite. The PSA unit 190 may include a single or multilayer bed of adsorbents of different compositions. Light molecules such as carbon dioxide can leave the PSA unit 190 at high pressure in the contaminant-removed stream of line 192. The adsorbed heavy molecules are then desorbed from the PSA unit 190 at low pressure and recovered.

[0054] In an exemplary embodiment, the contaminant removal unit 190 is a temperature swing adsorption (TSA) unit. The compressed synthetic carbon dioxide stream of line 182 is moved to the TSA unit 190 to remove contaminants from the compressed synthetic carbon dioxide stream of line 182 or to reduce their concentration to a lower level. The contaminants are adsorbed by the adsorbent present in the TSA unit 190, but carbon dioxide is not adsorbed by the adsorbent and passes through the floor. The adsorbent can be selected from APG-III, molecular organic structures, NaY zeolite, and 13X zeolite. The TSA unit 190 may contain a single or multilayer bed of adsorbents of different compositions. Light molecules such as carbon dioxide can leave the TSA unit 190 at low temperatures within the contaminant-removed stream of line 192. The adsorbed heavy molecules are then desorbed from the TSA unit 190 and recovered at higher temperatures, such as above 288°C (550°F).

[0055] Prior to methanol synthesis, the contaminant-free stream from line 241 may be further compressed to the synthesis pressure in the synthesis compressor 200. To supply methanol to the MTO reactor 100, the synthesis carbon dioxide stream is supplied to the methanol synthesis unit 80 via line 202.

[0056] According to exemplary embodiments of the present disclosure, the methanol synthesis unit 80 includes a reverse water-gas shift section and a methanol conversion section. A portion of the synthesized carbon dioxide stream from line 202 and the hydrogen stream from line 98 are transferred to the reverse water-gas shift section. The combined feed stream is transferred to a booster compressor, which can compress the combined feed stream to a specific pressure required by the reverse water-gas shift section. In exemplary embodiments, the reverse water-gas shift reactor may operate at pressures of 800 kPa(a)(116 psia) to 1,200 kPa(a)(175 psia) and 900 kPa(a)(131 psia) to 1,100 kPa(a)(160 psia). The combined feed stream may be heated before being transferred to the reverse water-gas shift reactor. According to exemplary embodiments, the reverse water-gas shift reactor may operate at temperatures ranging from 350°C (662°F) to 600°C (1112°F), preferably from 400°C (752°F) to 500°C (932°F).

[0057] Suitable reverse water-gas shift catalysts may include zinc oxide and copper on an alumina support. The reaction equilibrium typically requires cooling and separation of the reactor products and recirculation of unreacted reagents into the reverse water-gas shift reaction to obtain sufficient conversion.

[0058] The product of the reverse water-gas shift reactor is synthesis gas, which is a mixture of carbon monoxide, carbon dioxide, hydrogen, and water. The synthesis gas may optionally be moved to a methanol conversion section along with another part of the hydrogen.

[0059] Methanol conversion may involve the hydrogenation of carbon monoxide to methanol. The methanol conversion catalyst may be zinc oxide and copper on an alumina support. Reactor conditions for the methanol conversion reactor include temperatures of 150°C (302°F) to 300°C (572°F) and pressures of 5 MPa(a) (727 psia) to 10 MPa(a) (1454 psia), which can provide selectivity exceeding 99%. The methanol conversion reaction is exothermic, and lower reaction temperatures are preferred. In one embodiment, the methanol conversion unit may comprise two reactors connected in series with an intercooler. In further alternative embodiments, one or more of the reactors may be water-cooled or gas-cooled reactors.

[0060] In exemplary alternative embodiments, the methanol synthesis unit 80 may use a direct carbon dioxide hydrogenation reactor instead of using both a reverse water-gas shift reactor and a methanol conversion reactor. In the carbon dioxide hydrogenation reactor, carbon dioxide is mixed with hydrogen, heated, and packed into the reactor, which is then brought into contact with a bed of methanol conversion catalyst to produce methanol. The reactor effluent may be flushed to recirculate the gaseous reactants, while the liquid effluent is fractionated to provide an overhead methanol product stream and a bottom stream of water. The conditions and catalysts for direct carbon dioxide hydrogenation may be the same as those for carbon monoxide hydrogenation.

[0061] Referring now to Figure 2, another exemplary embodiment of the process and apparatus 101' for regenerating a catalyst from the MTO reactor 100 is shown. Many of the elements in Figure 2 have the same configuration and the same reference numerals as in Figure 1. Elements in Figure 2 that correspond to elements in Figure 1 but have a different configuration have the same reference numerals as in Figure 1, but are denoted with a prime symbol (').

[0062] In the embodiment shown in Figure 2, the oxidation unit 220' operates in a complete combustion mode, completely converting hydrocarbons into carbon dioxide and water. The oxidation unit 220' may also be a combustion heater providing various heating functions within the complex. In one embodiment, a portion of the carbon dioxide recirculation flow from line 186 may be moved to the oxidation unit 220' to dilute the oxygen flow that is moved to the oxidation unit 220'. As shown in Figure 2, a portion of the dry carbon dioxide recirculation flow may be taken in as a first partial flow from line 183 and moved to the oxidation unit 220' to dilute the oxygen flow from line 218. The first portion of the carbon dioxide recirculation flow from line 183 may be combined with the oxygen flow from line 218 to provide a combined combustion gas flow to line 219. A second portion of the carbon dioxide recirculation flow from line 185 is moved to the mixer 196. The combined combustion gas flow from line 219 is moved to the oxidation unit 220'. The first portion of the carbon dioxide recirculation flow in line 183 provides sufficient oxygen dilution so that the combined combustion gas flow from line 219 to the oxidation unit 220' can contain 15 mol% to 35 mol% oxygen. In another embodiment, the first portion of the carbon dioxide recirculation flow in line 183 and the oxygen flow from line 218 may be directed separately to the oxidation unit 220'. The oxidation unit flue gas flow in line 222' is supplied to the carbon dioxide-rich flue gas flow in line 132, providing a mixed flow to line 137. The mixed flow in line 137' is directed to the filter 150. The remainder of the embodiment in Figure 2 operates in the same manner as in Figure 1.

[0063] Referring here to Figure 3, another exemplary embodiment of the process and apparatus for regenerating the catalyst from the MTO reactor 100 is discussed with reference to process and apparatus 101''. In the exemplary embodiment shown in Figure 3, the process and apparatus 101'' includes an additional heat recovery exchanger 191. Many of the elements in Figure 3 have the same configuration and the same reference numerals as in Figure 1. Elements in Figure 3 that correspond to elements in Figure 1 but have a different configuration have the same reference numerals as in Figure 1, but are denoted with a double prime symbol ('').

[0064] In the embodiment shown in Figure 3, the filtered flue gas flow in line 152'' is heat-exchanged with the carbon dioxide recirculation flow in line 186'' in heat exchanger 191 to provide a preheated carbon dioxide recirculation flow in line 193 and a partially cooled and filtered flue gas flow in line 153. In the exemplary embodiment, heat exchanger 191 is a gas-gas type heat exchanger. The remainder of the embodiment in Figure 3 operates in the same manner as in Figure 1.

[0065] Referring here to Figure 4, another exemplary embodiment of the process and apparatus for regenerating the catalyst from the MTO reactor 100 is discussed with reference to process and apparatus 101''. Many of the elements in Figure 4 have the same configuration and the same reference numerals as in Figure 2. Elements in Figure 4 that correspond to the elements in Figure 2 but have a different configuration have the same reference numerals as in Figure 2, but are denoted with the triple-prime symbol (''').

[0066] The embodiment in Figure 4 is the same as in Figure 2, but utilizes the heat exchanger 191 described in Figure 3. The rest of the embodiment in Figure 4 operates in the same way as in Figure 2.

[0067] Referring here to Figure 5, another exemplary embodiment of the process and apparatus 101# for regenerating a catalyst from the MTO reactor 100 is shown. Many of the elements in Figure 5 have the same configuration and the same reference numbers as in Figure 1. Elements in Figure 5 that correspond to elements in Figure 1 but have a different configuration have the same reference numbers as in Figure 1, but are denoted with a hashtag symbol (#).

[0068] In the exemplary embodiment shown in Figure 5, the MTO regenerator 120# operates under partial combustion conditions, the oxidation unit 220# operates in partial oxidation mode, and the CO combustor is located on the flue gas line 122# from the regenerator 120#. Thus, the heat recovery section 125# uses the CO combustor 124 and HRSG 129#.

[0069] When the MTO regenerator 120# is operating under partial combustion conditions, a portion of the carbon dioxide-rich oxidizing flow from line 197 is moved to the CO combustor 124 in line 199 to provide an oxidizing flow for the CO combustor 124. The carbon dioxide-rich oxidizing flow from line 197 is separated into a first portion in line 198 and a second portion in line 199. The first portion of the carbon dioxide-rich oxidizing flow from line 198 is moved to the MTO regenerator 120, and the second portion of the carbon dioxide-rich oxidizing flow from line 199 is moved to the CO combustor 124 in the heat recovery section 125#.

[0070] The carbon dioxide-rich oxidizing flow from line 198 is transferred to MTO regenerator 120#, which operates under partial combustion conditions. From MTO regenerator 120, the carbon dioxide-rich flue gas flow from line 122# is taken out. The carbon dioxide-rich flue gas flow from line 122# may have a carbon monoxide concentration of 0 mol% to 8 mol%. Under partial combustion operation, the carbon dioxide-rich flue gas flow from line 122#, along with the fuel gas flow 121 and a second portion of the carbon dioxide-rich oxidizing flow from line 199, is sent to the CO combustor 124 of heat recovery section 125#, where the carbon monoxide present in the carbon dioxide-rich flue gas flow of line 122 is oxidized to carbon dioxide. The fully combusted flow from line 128 is then sent from the CO combustor to the HRSG unit 129# of heat recovery section 125#. In exemplary embodiments, the flue gas outlet temperature of the MTO regenerator for a partially or completely combusted MTO regenerator may be in the range of 625°C (1157°F) to 740°C (1360°F) or 640°C (1184°F) to 700°C (1290°F). The flue gas temperature exiting the CO combustor may be in the range of 890°C (1630°F) to 1040°C (1900°F).

[0071] The CO combustor 124 can generate a carbon dioxide-rich flue gas flow in line 128, which has low residual oxygen and is therefore advantageous as a feed for methanol synthesis. The CO combustor 124 can also burn various additional waste flows from the complex. In alternative embodiments, some or all of the off-gases and / or undesirable liquid by-products from line 214, as well as some or all of the heavy oxygenated products from line 216, may be moved to the CO combustor 124 to replace or increase the fuel gas flow in line 121. In yet another alternative embodiment, waste gases such as hydrogen, carbon monoxide, and dimethyl ether, as well as waste liquid products such as fusel oil, produced in the methanol synthesis unit 80, may be similarly sent to the CO combustor 124.

[0072] In one embodiment, the CO combustor 124 may operate at a pressure between atmospheric pressure and 35 kPa(g)(5 psig), which depends on the back pressure to the filter 150. In an alternative embodiment, the CO combustor 124 may operate at a pressure of 70 kPa(g)(10 psig) to 350 kPa(g)(50 psig) based on the operating pressure of the regenerator 120. It would be advantageous to operate the CO combustor 124 at a higher pressure to reduce the power required by the downstream carbon dioxide recirculation compressor 170 and methanol-carbon dioxide compressor 180.

[0073] The carbon dioxide-rich flue gas flow in line 128 is moved to the superheated steam section of HRSG129# to transfer heat to the saturated steam flow, producing the superheated steam flow and a partially cooled carbon dioxide-rich flue gas flow in line 126. The partially cooled carbon dioxide-rich flue gas flow then exchanges heat with the boiler feedwater flow in line 127 to cool the partially cooled carbon dioxide-rich flue gas flow in the saturated steam section, producing the saturated steam flow and a cooled carbon dioxide-rich flue gas flow in line 132#. The blowdown flow in line 133 is also taken out of the saturated steam section. A portion of the saturated steam flow may be superheated in the superheated steam section, while the remaining saturated steam flow in line 136 can be sent to other parts of the process and equipment for use as needed. The partially cooled carbon dioxide-rich flue gas flow in line 132# is taken out of the saturated steam section of HRSG129# and moved to filter 150. The rest of the process is the same as described in Figure 1.

[0074] Process and apparatus 101 for regenerating catalyst from MTO reactor * Another exemplary embodiment is shown in Figure 6. In the exemplary embodiment shown in Figure 6, the regenerator 120 operates in partial combustion mode and the oxidation unit 220 operates in partial oxidation mode. As shown in Figure 6, the CO combustor 124 is located downstream of the water removal section 111. Many of the elements in Figure 6 have the same configuration and the same reference numerals as in Figure 1. Elements in Figure 6 that correspond to elements in Figure 1 but have a different configuration have the same reference numerals as in Figure 1, but are marked with an asterisk ( * ) is attached.

[0075] In the embodiment shown in Figure 6, the CO combustor 124 is located downstream of the first KOD 163, with its overhead line 164 and carbon dioxide recirculation line 166 * It is arranged in communication with the downstream unit and replaces the heater 167.

[0076] When the MTO regenerator 120 is operating under partial combustion, a portion of the carbon dioxide-rich oxidation stream in line 197 is diverted to the CO combustor in line 199 to prevent nitrogen accumulation in the flue gas stream. The carbon dioxide-rich oxidation stream in line 197 is split into a first portion in line 198 and a second portion in line 199. The first portion of the carbon dioxide-rich oxidation stream in line 198 is diverted to the MTO regenerator 120, and the second portion of the carbon dioxide-rich oxidation stream in line 199 is diverted to the CO combustor 124 downstream of the first KOD163 in the water separation section 111. * The carbon dioxide-rich oxidation stream in line 198 is diverted to the MTO regenerator 120 operating under partial combustion conditions. From the MTO regenerator 120, a carbon dioxide-rich flue gas stream in line 122 is withdrawn. The carbon dioxide-rich flue gas stream in line 122 is enriched with carbon monoxide. The recycled carbon dioxide-rich flue gas stream in line 166 is combined with the fuel gas stream in line 121 and the second portion of the carbon dioxide-rich oxidation stream in line 199 and sent to the CO combustor 124 to oxidize the carbon monoxide present in the recycled carbon dioxide-rich flue gas stream in line 166 to carbon dioxide. The complete combustion stream in line 228 from the CO combustor 124 may appear in line 228. The flue gas temperature exiting the CO combustor 124 in line 228 may range from 890°C to 1040°C. * to the CO combustor 124 downstream of the first KOD163 in the water separation section 111.

[0077] The carbon dioxide-rich oxidation stream in line 198 is diverted to the MTO regenerator 120 operating under partial combustion conditions. From the MTO regenerator 120, a carbon dioxide-rich flue gas stream in line 122 is withdrawn. The carbon dioxide-rich flue gas stream in line 122 is enriched with carbon monoxide. The recycled carbon dioxide-rich flue gas stream in line 166 is combined with the fuel gas stream in line 121 and the second portion of the carbon dioxide-rich oxidation stream in line 199 and sent to the CO combustor 124 to oxidize the carbon monoxide present in the recycled carbon dioxide-rich flue gas stream in line 166 to carbon dioxide. * The recycled carbon dioxide-rich flue gas stream in line 166 is combined with the fuel gas stream in line 121 and the second portion of the carbon dioxide-rich oxidation stream in line 199 and sent to the CO combustor 124 to oxidize the carbon monoxide present in the recycled carbon dioxide-rich flue gas stream in line 166 to carbon dioxide. * The recycled carbon dioxide-rich flue gas stream in line 166 is combined with the fuel gas stream in line 121 and the second portion of the carbon dioxide-rich oxidation stream in line 199 and sent to the CO combustor 124 to oxidize the carbon monoxide present in the recycled carbon dioxide-rich flue gas stream in line 166 to carbon dioxide. * The recycled carbon dioxide-rich flue gas stream in line 166 is combined with the fuel gas stream in line 121 and the second portion of the carbon dioxide-rich oxidation stream in line 199 and sent to the CO combustor 124 to oxidize the carbon monoxide present in the recycled carbon dioxide-rich flue gas stream in line 166 to carbon dioxide. * The recycled carbon dioxide-rich flue gas stream in line 166 is combined with the fuel gas stream in line 121 and the second portion of the carbon dioxide-rich oxidation stream in line 199 and sent to the CO combustor 124 to oxidize the carbon monoxide present in the recycled carbon dioxide-rich flue gas stream in line 166 to carbon dioxide. * The complete combustion stream in line 228 from the CO combustor 124 may appear in line 228. * The flue gas temperature exiting the CO combustor 124 in line 228 may range from 890°C to 1040°C.

[0078] The carbon dioxide-rich flue gas flow in line 228 is moved to the superheated steam section of the second HRSG 229 to transfer heat to the partial steam flow, which can produce the superheated steam flow and the partially cooled carbon dioxide-rich flue gas flow in line 226. The partially cooled carbon dioxide-rich flue gas flow is then heat-exchanged with the boiler feedwater flow in line 227 to cool the partially cooled carbon dioxide-rich flue gas flow in the saturated steam section, which produces the saturated steam flow and the cooled recirculated carbon dioxide-rich flue gas flow in line 232. The condensed flow in line 233 is taken out of the saturated steam section. A portion of the saturated steam flow may be superheated in the superheated steam section, while the remaining saturated steam flow in line 236 is used in the process and apparatus 101 as needed. * It can be sent to other parts. The partially cooled carbon dioxide-rich flue gas flow of line 232 may be taken out of the saturated steam section of the second HRSG 229, compressed in the carbon dioxide recirculation compressor 170, and then used to generate additional steam in the steam generator 175. The rest of the process is the same as described in Figure 1.

[0079] Maximizing the carbon monoxide concentration and minimizing the amount of oxygen in the carbon dioxide-rich flue gas flow of line 122 is beneficial for the overall economics of the process. This reduces the amount of hydrogen required by the methanol synthesis unit 80 to produce the same amount of methanol, generating more steam and reducing overall utility consumption.

[0080] Further exemplary embodiments of the process and apparatus 101^ for regenerating a catalyst from the MTO reactor 100 are shown in Figure 7. In the exemplary embodiment shown in Figure 7, the regenerator 120 operates in partial combustion mode, and the oxidation unit 220^ operates in full oxidation mode. Many of the elements in Figure 7 have the same configuration and reference numerals as those in Figure 5. Elements in Figure 7 that correspond to elements in Figure 5 but have a different configuration have the same reference numerals as in Figure 5, but are denoted with a carat symbol (^).

[0081] As shown in Figure 7, the CO combustor 124 is located in the heat recovery section 125#, while the oxidation unit 220# operates in full oxidation mode. The oxidation unit 220# may also be a combustion heater providing various heating functions within the complex. As shown in Figure 7, a portion of the carbon dioxide recirculation flow may be taken in as a first partial flow in line 183 and moved to the oxidation unit 220#. In one exemplary embodiment, the first portion of the carbon dioxide recirculation flow in line 183 may be combined with the oxygen flow in line 218 to provide a combined combustion gas flow in line 219. A second portion of the carbon dioxide recirculation flow in line 185 is moved to the mixer 196. The combined combustion gas flow in line 219 is moved to the oxidation unit 220#. The first portion of the carbon dioxide recirculation flow in line 183 provides sufficient dilution of oxygen so that the combined combustion gas flow in line 219 to the oxidation unit 220# can contain 15 mol% to 35 mol% oxygen. In an alternative embodiment, the first portion of the carbon dioxide recirculation flow in line 183 and the oxygen flow in line 218 may be directed separately to the oxidation unit 220#.

[0082] In the embodiment of Figure 7, the oxidizing flow in line 222 is mixed with the cooled carbon dioxide-rich flue gas flow in line 132 to provide the mixed flow in line 137. The mixed flow in line 137 is moved to filter 150. The remainder of the embodiment of Figure 7 is the same as in Figure 5.

[0083] Figure 8 shows additional exemplary embodiments of the process and apparatus 101+ for regenerating the catalyst from the MTO reactor 100. In the exemplary embodiment shown in Figure 8, the regenerator 120 operates in partial combustion mode, and the oxidation unit 220+ operates in full oxidation mode. Many of the elements in Figure 8 have the same configuration and reference numerals as those in Figure 6. Elements in Figure 8 that correspond to elements in Figure 6 but have a different configuration have the same reference numerals as in Figure 6, but are denoted with a cross symbol (+).

[0084] As shown in Figure 8, the CO combustor 124+ is located downstream of the water removal section, while the oxidation unit 220+ is operated in full oxidation mode and may be a combustion heater. As shown in Figure 8, a portion of the carbon dioxide recirculation flow may be taken in as a first partial flow in line 183 and moved to the oxidation unit 220+. The first portion of the carbon dioxide recirculation flow in line 183 may be combined with the oxygen flow in line 218 to provide a combined combustion gas flow in line 219. The second portion of the carbon dioxide recirculation flow in line 185 is moved to the mixer 196. The combined combustion gas flow in line 219 is moved to the oxidation unit 220+. The first portion of the carbon dioxide recirculation flow in line 183 provides sufficient dilution of oxygen so that the combined combustion gas flow in line 219 to the oxidation unit 220+ can contain 15 mol% to 35 mol% oxygen. In another embodiment, the first portion of the carbon dioxide recirculation flow in line 183 and the oxygen flow in line 218 may be directed separately to the oxidation unit 220+.

[0085] In the embodiment of Figure 8, the oxidizing flow in line 222+ is mixed with the cooled carbon dioxide-rich flue gas flow in line 132 to provide a mixed flow in line 137+, which is then transferred to filter 150. Other locations may be suitable for introducing the oxidizing flow into line 222+. The remainder of the embodiment of Figure 8 is the same as in Figure 6.

[0086] Further exemplary embodiments of the process and apparatus 101! for regenerating a catalyst from the MTO reactor 100 are shown in Figure 9. Many of the elements in Figure 9 have the same configuration and the same reference numerals as in Figure 5. Elements in Figure 9 that correspond to the elements in Figure 5 but have a different configuration have the same reference numerals as in Figure 5, but are denoted with an exclamation mark (!).

[0087] In the exemplary embodiment shown in Figure 9, the regenerator 120 operates in partial combustion mode, and the oxidation unit 220 operates in partial oxidation mode. As shown in Figure 9, the CO combustor 124 is employed in the heat recovery section 125, but the filtered flue gas flow of line 152 is heat-exchanged with the carbon dioxide recirculation flow of line 186 in the heat exchanger 191 to provide a preheated carbon dioxide recirculation flow of line 193 and a partially cooled and filtered flue gas flow of line 153. In the exemplary embodiment, the heat exchanger 191 is a gas-gas type heat exchanger. The remainder of the embodiment in Figure 9 operates in the same manner as in Figure 5.

[0088] Further exemplary embodiments of the process and apparatus 101@ for regenerating a catalyst from the MTO reactor 100 are shown in Figure 10. Many of the elements in Figure 10 have the same configuration and reference numerals as those in Figure 6. Elements in Figure 10 that correspond to elements in Figure 6 but have a different configuration have the same reference numerals as in Figure 6, but are denoted with an at sign (@).

[0089] In the exemplary embodiment shown in Figure 10, the regenerator 120 operates in partial combustion mode, and the oxidation unit 220 operates in partial oxidation mode. As shown in Figure 10, the CO combustor 124@ is employed downstream of the water removal, but the filtered flue gas flow in line 152@ is heat-exchanged with the carbon dioxide recirculation flow in line 186@ in the heat exchanger 191 to provide a preheated carbon dioxide recirculation flow in line 193 and a partially cooled and filtered flue gas flow in line 153. The remainder of the embodiment in Figure 10 operates in the same manner as in Figure 6.

[0090] Further exemplary embodiments of the process and apparatus 101 for regenerating a catalyst from the MTO reactor 100 are shown in Figure 11. Many of the elements in Figure 11 have the same configuration and reference numerals as those in Figure 9. Elements in Figure 11 that correspond to the elements in Figure 9 but have a different configuration have the same reference numerals as in Figure 9, but are denoted by a dollar sign ($).

[0091] In the exemplary embodiment shown in Figure 11, the regenerator 120 operates in partial combustion mode, and the oxidation unit 220 operates in full oxidation mode. As shown in Figure 11, the CO combustor 124 is used in the heat recovery section 125, and the filtered flue gas flow of line 152 is heat-exchanged with the carbon dioxide recirculation flow of line 186 in the heat exchanger 191 to provide a preheated carbon dioxide recirculation flow of line 193 and a partially cooled and filtered flue gas flow of line 153, while the oxidation unit 220 operates in full oxidation mode. The oxidation unit 220 may be a combustion heater that provides various heater roles in the complex. As shown in Figure 11, a portion of the carbon dioxide recirculation flow of line 186 may be taken in as a first partial flow of line 183 and moved to the oxidation unit 220. The first portion of the carbon dioxide recirculation flow of line 183 may be combined with the oxygen flow of line 218 to provide a combined combustion gas flow of line 219. The second portion of the carbon dioxide recirculation flow in line 185 is moved to the mixer 196 in line 193 after heat exchange in the heat exchanger 191. The combustion gas flow in line 219 is moved to the oxidation unit 220. The first portion of the carbon dioxide recirculation flow in line 183 provides sufficient oxygen dilution so that the combined combustion gas flow from line 219 to the oxidation unit 220 can contain 15 mol% to 35 mol% oxygen. In another embodiment, the first portion of the carbon dioxide recirculation flow in line 183 and the oxygen flow in line 218 may be moved separately to the oxidation unit 220. In the embodiment of Figure 11, the oxidation flow in line 222 is mixed with the cooled carbon dioxide-rich flue gas flow in line 132 to provide the mixed flow in line 137, which is moved to the filter 150. The remainder of the embodiment of Figure 11 is the same as in Figure 9.

[0092] Further exemplary embodiments of the process and apparatus 101% for regenerating a catalyst from the MTO reactor 100 are shown in Figure 12. Many of the elements in Figure 12 have the same configuration and reference numerals as those in Figure 10. Elements in Figure 12 that correspond to the elements in Figure 10 but have a different configuration have the same reference numerals as those in Figure 12, but are denoted with a percent sign (%).

[0093] In the exemplary embodiment shown in Figure 12, the regenerator 120 operates in partial combustion mode, and the oxidation unit 220 operates in full oxidation mode. As shown in Figure 12, the CO combustor 124@ is employed downstream of the water removal, but the filtered flue gas flow in line 152@ is heat-exchanged with the carbon dioxide recirculation flow in line 186@ in the heat exchanger 191 to provide a preheated carbon dioxide recirculation flow in line 193 and a partially cooled and filtered flue gas flow in line 153. The oxidation unit 220 operates in full oxidation mode. The remainder of the embodiment in Figure 12 operates in the same manner as in Figure 10.

[0094] To maintain the same volumetric flow rate as in the basic case, the temperature inside the regenerator unit 120 may decrease as a result of introducing more mass of inert gas into the MTO regenerator 120 due to the increased molecular weight of carbon dioxide compared to air, which is mostly nitrogen. To keep the regenerator temperature constant, the following means may be used: a) installing an electric heating coil inside the regenerator and using electricity generated in the process or from any source; b) installing an electric heater to further heat the preheated carbon dioxide recirculation flow of line 194 and using electricity generated in the process or from any source; c) directly burning fuel gas and / or natural gas inside the regenerator; d) continuously burning a direct combustion air heater; e) burning torch oil and / or slurry oil inside the MTO regenerator 120; or f) reducing the duty cycle of the catalytic cooler in the MTO regenerator 120. Using electricity to heat the coils inside the regenerator unit is a more sustainable and environmentally friendly means. This process includes using electricity generated from the MTO process disclosed above as a heat source for the heating coil in the regenerator unit 120. Alternatively, heat and / or electricity from any suitable renewable energy source or fuel gas flow may also be used in the regenerator unit 120.

[0095] Any of the lines, conduits, units, devices, containers, surrounding environments, zones, or similar entities described above may comprise one or more monitoring components, including sensors, measuring devices, data acquisition devices, or data transmission devices. Signals, process, or state measurements, and data from the monitoring components can be used to monitor conditions within, around, and on process equipment. Signals, measurements, and / or data generated or recorded by the monitoring components may be collected, processed, and / or transmitted via one or more networks or connections, which may be private or public, general or specific, direct or indirect, wired or wireless, encrypted or unencrypted, and / or a combination thereof. This specification is not intended to limit it in this respect. Furthermore, the figures may include one or more exemplary sensors placed on one or more conduits. Nevertheless, sensors may be present on each flow so that corresponding parameters can be controlled accordingly.

[0096] Signals, measurements, and / or data generated or recorded by monitoring components may be transmitted to one or more computing devices or systems. A computing device or system may include at least one processor and memory for storing computer-readable instructions that, when executed by at least one processor, cause one or more computing devices to perform a process that may include one or more steps. For example, one or more computing devices may be configured to receive data from one or more monitoring components relating to at least one part of equipment associated with a process. One or more computing devices or systems may be configured to analyze the data. Based on the analysis of the data, one or more computing devices or systems may be configured to determine one or more recommended adjustments to one or more parameters of one or more processes described herein. One or more computing devices or systems may be configured to transmit encrypted or unencrypted data containing one or more recommended adjustments to one or more parameters of one or more processes described herein. [Examples]

[0097] We simulated the disclosed process of an MTO unit processing 2,000 metric tons of methanol per day and determined the carbon dioxide flow rates to the unit shown in the table.

[0098] [Table 1]

[0099] The net carbon dioxide flow represents the incremental carbon dioxide produced in the regenerator from combustion coke and in the CO boiler from combustion CO2, which can be used to fill the methanol synthesis of CO. This incremental carbon dioxide is not available in conventional CO boilers and when air is used as the regeneration gas. Conventionally, carbon dioxide is diluted with nitrogen and is difficult to recover economically. The incremental carbon dioxide can be used to produce an additional 8810 lb / hour of methanol.

[0100] Specific Embodiments The following will be explained in conjunction with specific embodiments, but it should be understood that this explanation is intended to illustrate the scope of the preceding explanation and the attached claims, and is not intended to limit them.

[0101] A first embodiment of the present disclosure is a process for regenerating a catalyst from an MTO process, comprising: providing an oxygen stream and a carbon dioxide recirculation stream; mixing the oxygen stream and the carbon dioxide recirculation stream to provide a carbon dioxide-rich oxidation stream; moving the carbon dioxide-rich oxidation stream to a regenerator unit to provide a carbon dioxide-rich flue gas stream; filtering the carbon dioxide-rich flue gas stream to remove catalyst particles and produce a filtered flue gas stream; and separating the filtered flue gas stream to provide a carbon dioxide recirculation stream and a carbon dioxide stream for methanol synthesis. An embodiment of the present disclosure is one or all of the first embodiments of this paragraph from the preceding embodiments of this paragraph, further comprising: preheating the carbon dioxide recirculation stream by heat exchange with the filtered flue gas stream to provide a preheated carbon dioxide recirculation stream; and mixing the preheated carbon dioxide recirculation stream with an oxygen stream to provide a carbon dioxide-rich oxidation stream. One embodiment of the present disclosure is one or all of the first embodiments of this paragraph from the preceding embodiments of this paragraph, further comprising: partially removing water from a filtered flue gas stream to produce a partially dehydrated flue gas stream; separating the partially dehydrated flue gas stream to provide a carbon dioxide recirculation stream and a carbon dioxide stream for methanol synthesis; and transferring the carbon dioxide stream for methanol synthesis to a methanol synthesis unit. One embodiment of the present disclosure is one or all of the first embodiments of this paragraph from the preceding embodiments of this paragraph, further comprising: transferring the carbon dioxide stream for methanol synthesis to a contaminant removal unit; in the contaminant removal unit, removing oxygen and optionally water from the carbon dioxide stream for methanol synthesis to produce a treated carbon dioxide stream; and transferring the treated carbon dioxide stream to a methanol synthesis unit to produce a methanol stream. One embodiment of the present disclosure is one or all of the first embodiments of this paragraph from the preceding embodiments of this paragraph, wherein the methanol synthesis unit includes a reverse water-gas shift section and a methanol converter section.One embodiment of the present disclosure is any or all of the first embodiments of this paragraph, from the preceding embodiments of this paragraph, wherein the methanol synthesis unit includes a direct carbon dioxide hydrogenation section. One embodiment of the present disclosure is any or all of the first embodiments of this paragraph, from the preceding embodiments of this paragraph, wherein the methanol synthesis unit includes a dry methane reforming section. One embodiment of the present disclosure is any or all of the first embodiments of this paragraph, from the preceding embodiments of this paragraph, wherein the carbon dioxide-rich oxidation flow includes an oxygen concentration of 35 mol% or less. One embodiment of the present disclosure is any or all of the first embodiments of this paragraph, from the preceding embodiments of this paragraph, wherein the oxygen flow is supplied from an electrolytic cell or an air separation unit. One embodiment of the present disclosure is any or all of the first embodiments of this paragraph, from the preceding embodiments of this paragraph, further comprising transferring heat from the carbon dioxide-rich flue gas flow to the boiler feedwater flow in a heat recovery section to form a partially cooled carbon dioxide-rich flue gas flow and steam flow. One embodiment of the present disclosure is one or all of the first embodiments of this paragraph from the preceding embodiments of this paragraph, comprising: the heat recovery section being a waste heat recovery boiler (HRSG), which transfers heat from a carbon dioxide-rich flue gas flow to a boiler feedwater flow within the HRSG to form a partially cooled carbon dioxide-rich flue gas flow and steam flow; and filtering the partially cooled carbon dioxide-rich flue gas flow to produce a filtered flue gas flow. One embodiment of the present disclosure is one or all of the first embodiments of this paragraph from the preceding embodiments of this paragraph, further comprising: separating a carbon dioxide-rich oxidized flow into a first part and a second part; moving the first part of the carbon dioxide-rich oxidized flow to a regenerator unit; and moving the second part of the carbon dioxide-rich oxidized flow to a CO combustor in the heat recovery section. One embodiment of the present disclosure is one or all of the first embodiments of this paragraph from the preceding embodiments of this paragraph, wherein the MTO process utilizes a SAPO catalyst.One embodiment of the present disclosure is one or all of the first embodiments of this paragraph from the preceding embodiments of this paragraph, further comprising: moving a carbon dioxide-rich flue gas flow to a third stage separator (TSS) to separate catalyst particles into an underflow flow and provide a carbon dioxide-rich flue gas flow with reduced catalyst particles in the overflow flow; generating electricity from the overflow flow in an expander; and moving the overflow flow to a heat recovery section. One embodiment of the present disclosure is one or all of the first embodiments of this paragraph from the preceding embodiments of this paragraph, further comprising: cooling the filtered flue gas flow to provide a cooled and filtered flue gas flow; separating water from the cooled and filtered flue gas flow to provide a dry flue gas flow; and separating the dry flue gas flow to provide a carbon dioxide recirculation flow and a carbon dioxide flow for methanol synthesis. One embodiment of the present disclosure is one or all of the first embodiments of this paragraph from the preceding embodiments of this paragraph, further comprising: compressing a carbon dioxide recirculation flow to provide a compressed carbon dioxide recirculation flow; optionally, moving the compressed carbon dioxide recirculation flow to a low-pressure steam generator to provide a low-pressure steam flow and a partially cooled carbon dioxide recirculation flow; optionally, cooling the partially cooled carbon dioxide recirculation flow to provide a cooled carbon dioxide recirculation flow; optionally, separating water from the cooled carbon dioxide recirculation flow to provide a dry carbon dioxide recirculation flow; optionally, preheating the dry carbon dioxide recirculation flow by heat exchange with a filtered flue gas flow to provide a preheated dry carbon dioxide recirculation flow; and moving the preheated dry carbon dioxide recirculation flow to a regenerator unit. One embodiment of the present disclosure is one or all of the embodiments prior to this paragraph to the first embodiments of this paragraph, further comprising heating a recirculating carbon dioxide flow to provide a warm carbon dioxide recirculating flow and recirculating the warm carbon dioxide recirculating flow to a regenerator unit. One embodiment of the present disclosure is one or all of the embodiments prior to this paragraph to the first embodiments of this paragraph, wherein the HRSG includes a superheated steam section and a saturated steam section.One embodiment of the present disclosure is one, any, or all of the first embodiments of this paragraph from the preceding embodiments of this paragraph, further comprising: moving a carbon dioxide-rich flue gas flow to the superheated steam section of an HRSG to generate a superheated steam flow and a heat-exchanged carbon dioxide-rich flue gas flow; moving a boiler feedwater flow and a heat-exchanged carbon dioxide-rich flue gas flow to the saturated steam section of an HRSG to form a partially cooled carbon dioxide-rich flue gas flow and a saturated steam flow; introducing at least a portion of the saturated steam flow into the superheated steam section of an HRSG; and superheating the saturated steam flow with the carbon dioxide-rich flue gas flow to generate a superheated steam flow.

[0102] A second embodiment of the present disclosure is a process for regenerating a catalyst from an MTO process, comprising: providing an oxygen stream and a preheated carbon dioxide recirculation stream; mixing the oxygen stream and the preheated carbon dioxide recirculation stream to provide a carbon dioxide-rich oxidation stream; separating the carbon dioxide-rich oxidation stream into a first and a second portion; moving the first portion of the carbon dioxide-rich oxidation stream to a regenerator unit to provide a carbon dioxide-rich flue gas stream; moving the second portion of the carbon dioxide-rich oxidation stream to a heat recovery section to provide a partially cooled carbon dioxide-rich flue gas stream and vapor stream; filtering the partially cooled carbon dioxide-rich flue gas stream to remove catalyst particles and produce a filtered flue gas stream; and taking in a carbon dioxide recirculation stream from the filtered flue gas stream.

[0103] A third embodiment of the present disclosure is a apparatus for regenerating a catalyst, comprising: a heat recovery section including a superheated steam section and a saturated steam section; a superheated steam section having a flue gas inlet, a flue gas outlet, a saturated steam inlet, and a superheated steam outlet, wherein the flue gas inlet of the superheated steam section is in fluid communication with the outlet of a regenerator unit; a saturated steam section having a flue gas inlet, a flue gas outlet, a boiler feedwater inlet, and a saturated steam outlet, wherein the flue gas inlet of the saturated steam section is in fluid communication with the flue gas outlet of the superheated steam section; and the saturated steam outlet of the saturated steam section is in fluid communication with the saturated steam inlet of the superheated steam section. A device for regenerating a catalyst, comprising: a filter section having a section, a flue gas inlet, a flue gas outlet, and a filter material outlet, wherein the flue gas inlet of the filter section is in fluid communication with the flue gas outlet of the saturated steam section of the heat recovery section; a heat exchanger having a flue gas inlet and a flue gas outlet, wherein the flue gas inlet of the heat exchanger is in fluid communication with the flue gas outlet of the filter section; and a carbon dioxide separation unit in fluid communication with the flue gas outlet of the heat exchanger, wherein the carbon dioxide separation unit is in thermal communication with the flue gas outlet of the filter section via a carbon dioxide recirculation flow within the heat exchanger.

[0104] Without further detail, it is expected that those skilled in the art will be able to utilize the Disclosure to the fullest extent without departing from the spirit and scope of the Disclosure, readily identify its essential characteristics, and make various changes and modifications to adapt it to various uses and conditions. Accordingly, the prior preferred specific embodiments should be interpreted as merely illustrative examples and not in any way limiting the remainder of the Disclosure, but are intended to cover various modifications and equivalent configurations that fall within the scope of the appended claims.

[0105] In the above, all temperatures are given in degrees Celsius, and all parts and percentages are based on weight unless otherwise indicated.

Claims

1. This is a process for regenerating catalysts from the MTO process. To provide an oxygen flow and a carbon dioxide recirculation flow, The oxygen stream and the carbon dioxide recirculation stream are mixed to provide a carbon dioxide-rich oxidation stream. The carbon dioxide-rich oxidation flow is moved to the regenerator unit to provide a carbon dioxide-rich flue gas flow. A process comprising filtering the carbon dioxide-rich flue gas flow to remove catalyst fine particles and generate a filtered flue gas flow.

2. The carbon dioxide recirculation flow is preheated by heat exchange with the filtered flue gas flow to provide the preheated carbon dioxide recirculation flow. The process according to claim 1, further comprising mixing the preheated carbon dioxide recirculation flow with the oxygen flow to provide the carbon dioxide-rich oxidation flow.

3. The water is partially removed from the filtered flue gas flow to produce a partially dehydrated flue gas flow, To separate the partially dehydrated flue gas flow and provide the carbon dioxide recirculation flow and the carbon dioxide flow for methanol synthesis, The process according to claim 1, further comprising transferring the carbon dioxide stream for methanol synthesis to a methanol synthesis unit.

4. Transferring the carbon dioxide stream for methanol synthesis to a contaminant removal unit, In the aforementioned contaminant removal unit, oxygen and optionally water are removed from the carbon dioxide stream for methanol synthesis to produce a treated carbon dioxide stream. The process according to claim 1, further comprising transferring the treated carbon dioxide stream to the methanol synthesis unit to generate a methanol stream.

5. The process according to claim 4, wherein the methanol synthesis unit includes a reverse water-gas shift section and a methanol conversion section.

6. The process according to claim 4, wherein the methanol synthesis unit includes a direct carbon dioxide hydrogenation section.

7. The process according to claim 4, wherein the methanol synthesis unit includes a dry methane reforming section.

8. The process according to claim 1, wherein the carbon dioxide-rich oxidation flow contains an oxygen concentration of 35 mol% or less.

9. The process according to claim 1, wherein the oxygen stream is supplied from an electrolytic cell or an air separation unit.

10. The process according to claim 1, further comprising transferring heat from the carbon dioxide-rich flue gas flow to the boiler feedwater flow in the heat recovery section to form a partially cooled carbon dioxide-rich flue gas flow and steam flow.

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