CA3090050C - Method and device for the production of a synthetic gasoline - Google Patents

Abstract

The invention relates to a method for the catalytic conversion of feed alcohol to a product mixture, containing water and a hydrocarbon mixture of olefins, n-paraffins, isoparaffins, aromatics and naphthenes, in a reactor, containing a catalyst, wherein the feed alcohol has a water content of less than 20 % by mass, and separation of the product mixture in several stages to obtain a durene-containing heavy aromatic fraction and a stable gasoline fraction.

Description

METHOD AND DEVICE FOR THE PRODUCTION OF A SYNTHETIC GASOLINE
The invention relates to a method and a device for producing a synthetic gasoline, in particular a high-octane gasoline for use as gasoline and made from alcohols.
Methods for producing gasoline from alcohols are known. Thus, the synthesis of high-octane gasoline from methanol was developed in the 1970's via the Mobil Oil Corporation's MTG
process ("methanol to gasoline"), which, among others, is described in US
3,894,102 A. In the first stage, a product is synthesised from a mixture of carbon monoxide and hydrogen over a catalyst mixture consisting of a methanol synthesis catalyst and an acidic dehydration catalyst which mainly contains dimethyl ether (DME). After product cooling and separation, the dimethyl ether thus produced is contacted in the second stage with a crystalline aluminosilicate zeolite catalyst, and a product is formed which mainly consists of liquid aromatic hydrocarbons in the gasoline boiling range (C5 to 400 F).
The conversion of methanol into a hydrocarbon product can be carried out in fixed bed reactors (see, e.g., US 3,998,899 A, US 3,931,349 A and US 4,035,430 A) and in reactors with catalyst fluid beds (see, e.g., US 4,071,573 A and US 4,138,440 A). In the MTG process, the methanol is dehydrated, usually an y alumina catalyst is used, and an equilibrium mixture of methanol, dimethyl ether, and water is formed. This mixture is then converted to a hydrocarbon product in a boiling range from light hydrocarbons to gasoline and water in a ZSM-5 (zeolite) catalyst bed.
The main problem to be solved with regard to the MTG process is the problem of temperature control in the reactor. As a result of the strongly exothermic reaction, approx. 1740 kJ per kilogram of converted methanol are released when methanol is converted to hydrocarbons. In an adiabatic reactor, this would lead to a temperature rise of approximately 650 C, which would cause extremely rapid catalyst ageing or even destruction thereof. In addition, the adiabatic temperature rise would lead to the formation of undesirable by-products.
A method for avoiding an excessive temperature rise in the catalyst bed is described in US
3,931,349. The strong exothermic reaction from methanol to gasoline hydrocarbons is controlled in a system of parallel catalyst beds. The feed methanol is evaporated and in the Date Recue/Date Received 2020-07-29

2 first stage is converted by contact with an y alumina catalyst into a mixture of dimethyl ether, methanol and water, wherein 15 to 20 % of the total heat of the reaction from methanol to gasoline hydrocarbons are released.
The reaction product of the dehydration of methanol is diluted with the light hydrocarbon gases <C5 from the second reaction stage of the conversion. These gases are separated from the reaction product of the hydrocarbon synthesis after it has cooled, they are compressed and preheated and then mixed with the feed stream of the reactor. The circulating gas cools the catalyst bed during the exothermic reaction of the oxygenates to hydrocarbons on a crystalline ZSM-5. The reaction of the hydrocarbon synthesis is carried out at the lowest possible pressure in order to minimise the undesirable formation of high molecular weight aromatic compounds, such as durene. The space velocity, based on pure methanol, is 1 h-1 and the partial pressure of the methanol is 1 bar. The low partial pressure of the reactant limits the formation of undesirable heavy aromatics.
US 3,998,899 A describes a process for converting Ci to C3 alcohols, preferably methanol, into hydrocarbons in the gasoline boiling range. In a first catalytic stage, ether products are formed from the alcohols and, in a second catalytic stage, zeolite components in the gasoline boiling range are formed on a crystalline ZSM-5 zeolite.
US 4,814,535 A describes a method which makes it possible to keep the degree of conversion constant in a reaction period, despite the gradual deactivation of the catalyst by coke deposits.
For this purpose, the inlet temperature into the reactor for hydrocarbon synthesis is gradually increased by 3 to 9 C, in which case the octane number remains constant.
The methods described above require a very high recycle ratio (circulating gas to feed stream), which makes the process complex due to the necessary cooling, compression, and subsequent heating of the circulating gas.
If the ratio of circulating gas to feed stream is reduced in order to increase the effectiveness of the process, this causes an increase in the temperature difference across the catalyst bed, which is reflected not only in a faster ageing rate of the catalyst, but also in the increase in the water vapour partial pressure (due to the greater proportion of water vapour during reduction Date Recue/Date Received 2020-07-29

3 of the proportion of circulating gas). A high water vapour partial pressure has a negative effect on the life of the catalyst, especially when the reaction temperatures are high.
US 4,404,414 A therefore describes a method of heat dissipation, by means of which the .. desired temperatures in the catalyst bed can be maintained with reduced recycling ratios. The arrangement of the reactors is designed so that the reactors for the oxygenate feed are arranged in parallel, but for the circulating gas they are arranged in series.
The special reactor arrangement means that the total amount of recycled gas can be reduced by half with the same temperature differences across the catalyst beds.
In US 4,788,369 A, the LPG fraction (propane, n-butane and isobutane, and small amounts of light olefins) is separated from the reaction product and returned to the reactor in order to dissipate the heat of reaction. A major advantage of using the LPG fraction as a recycle stream over the otherwise customary recycling of the light hydrocarbon gases is the improvement in the economics of the process. There was a slight increase in the gasoline yield (by approximately 1 %), since the olefins contained in the recycled LPG stream have been converted to gasoline hydrocarbons, but the normal paraffins have not been converted.
In US 4,035,430 A, in order to limit the temperature rise over the catalyst bed of the hydrocarbon synthesis, the feed material (methanol or the product of the DME
synthesis) is diluted with light hydrocarbons <C5 and sometimes also with durene, which has been separated out of the C10, hydrocarbon fraction by crystallisation. The recycling of durene reduced the aromatics content in the product (aromatics except for durene) compared to the process without durene recycling in a lower T range (<430 C), while it increased in a higher temperature range (>430 C). By increasing the aromatics content in the product at higher temperatures (>430 C), the gasoline selectivity could be increased in this way.
WO 2011/061198 Al describes a two-stage method and a corresponding device for the production of hydrocarbons. Starting with synthesis gas, in the first step methanolis generated, which is then converted to gasoline hydrocarbons and water in the second step.
The method is characterised in particular by purification of the water obtained.
Unconverted methanol contained therein is catalytically converted to synthesis gas. Furthermore, recycling of both the synthesis gas thus obtained and of the unconverted synthesis gas is provided.
Date Recue/Date Received 2020-07-29

4 US 4,058,576 A describes a method for more efficient dissipation of the heat released in the conversion of methanol to gasoline by dividing the intermediate product reactions into 3 successive process steps. The reaction stages of the methanol conversion to dimethyl ether (DME), the conversion of the DME into olefins, and the olefin conversion into gasoline hydrocarbons are carried out in separate catalyst beds.
US 4,052,479 A also describes a multi-stage process for converting alcohols into gasoline and olefin hydrocarbons. For this purpose, DME is first isolated in an intermediate step and, with very short contact times, this is preferably converted to olefin hydrocarbons and gasoline. Short contact times are achieved at very high loads with a space velocity in a range from 10 to 2000 h-1 (Liquid Hourly Space Velocity - LHSV), preferably from 50 to 1000 h-1. At the same time, the high load is a disadvantage of the process.
US 4,387,263 A therefore describes a process for the production of gasoline and C2 to C4 olefins from a mixture of methanol and optionally water vapour, in which high olefin yields are achieved even at significantly lower LHSV.
DE 10 2005 048 931 Al also discloses a method for the preparation of C2-C4 olefins from methanol or dimethyl ether. An educt mixture of alcohol, dimethyl ether and water is passed over a catalyst bed in a reactor and is converted to a product mixture which is separated in the first step into a Cs_ olefin-rich mixture, a C5+ hydrocarbon-rich mixture and an aqueous phase.
A high mass fraction of water in the educt mixture of 20 to 91%, measured on the total mass of the alcohol-water mixture, enables a high proportion of lower olefins to be generated.
The object of the invention is to develop a method and a corresponding device for producing synthetic gasoline from oxygenates, in particular from alcohols, in particular with a small proportion of olefins, in which the composition of the gasoline is variable and can be controlled in a targeted manner.
This object is achieved by a method for the production of a synthetic gasoline (in the form of a stable gasoline fraction) comprising the following steps:
Date Recue/Date Received 2020-07-29 a. catalytic conversion of feed alcohol into a product mixture containing water and a hydrocarbon mixture of olefins, n-paraffins, isoparaffins, aromatics, and naphthenes in a reactor containing a catalyst, wherein the feed alcohol has a water content of less than 20 mass%.

5 b. separation of the product mixture obtained in step I) into:
- a liquid hydrocarbon phase, - an aqueous phase containing the unconverted alcohol, and - a gas phase containing Ci to C5 hydrocarbons c. recycling of the gas phase obtained in step II) to step I) d. separation of the liquid hydrocarbon phase obtained in step II) into - a C3 to C4 hydrocarbon fraction and - a gasoline hydrocarbon fraction (= C5+ fraction) containing a durene-containing heavy aromatics fraction e. separation of the gasoline hydrocarbon fraction obtained in step IV) into a durene-containing heavy aromatics fraction and a stable gasoline fraction.
The raw feed alcohol in the method is referred to as the feed alcohol. It is known to the person skilled in the art that alcohol, in particular alcohol of technical quality, can still have a proportion of water.
In one embodiment, the feed alcohol is an alcohol-water mixture.
According to the invention, the feed alcohol has a water content of less than 20 mass%, preferably less than 15 mass%, in particular less than 5 mass%.
Mass% denotes the mass fraction of the total mass, in %.
In one embodiment, the mass fraction of water in the feed alcohol is at least 1 % of the total mass of the feed alcohol.
In one embodiment, the mass fraction of water in the feed alcohol is 1 to <20 %, preferably 1 to <15% of the total mass of the feed alcohol.
Date Recue/Date Received 2020-07-29

6 In one embodiment, the feed alcohol is anhydrous.
The feed alcohol is fed into the circulating gas in liquid or gaseous form.
In one embodiment, the circulating gas is the gas phase recycled to the reactor in step I) in step III).
The circulating gas is heated together with the feed alcohol to the reaction temperature. The mixture obtained is fed into the reactor in gaseous form. This mixture is designated as feed gas.
In one embodiment, the catalytic conversion of feed alcohol in a feed gas into a product mixture containing water and a hydrocarbon mixture of olefins, n-paraffins, isoparaffins, aromatics, and naphthenes takes place in a reactor containing a catalyst, in which case the feed gas contains a feed alcohol having a water content of less than 20 mass% (related to the total mass of the feed alcohol).
In one embodiment, the mole fraction of the alcohol (pure alcohol without water) in the total feed gas at the reactor inlet is between 20 and 90 mol% (related to the total amount of feed gas).
In one embodiment, the feed gas contains inert gas and feed alcohol.
In one embodiment, the feed gas contains feed alcohol and recycled components.
The method according to the invention in step I) advantageously gives a hydrocarbon fraction with a small proportion of olefins. In one embodiment, the mass fraction of the olefins in the hydrocarbon mixture formed is less than 20 %, preferably less than 10 %, particularly preferably less than 5 %, and in particular less than 2 % of the total mass of the hydrocarbon mixture formed.
Date Recue/Date Received 2020-07-29

7 In variant VI, the method contains the following steps:
a) catalytic conversion of alcohol into a product mixture containing water and a hydrocarbon mixture of olefins, n-paraffins, isoparaffins, aromatics, and naphthenes, in a reactor containing a catalyst b) separation of the product mixture obtained in step a) into:
- a liquid hydrocarbon phase, - an aqueous phase containing the unconverted alcohol, and - a gas phase containing Ci to C5 hydrocarbons c) separation of the unconverted alcohol from the aqueous phase obtained in step b) 1.0 d) recycling of the alcohol separated off in step c) as feed material to step a) e) division of the gas phase from step b) into a first and a second part and recycling of the first part of the gas phase obtained in step b) to step a) f) removal of C3 to C5 hydrocarbons from the second part of the gas phase from step e) g) combination of the C3 to C5 hydrocarbons obtained in step f) with the liquid hydrocarbon phase obtained in step b) h) separation of the liquid hydrocarbon phase obtained in step g) into - a C3 to C4 hydrocarbon fraction and - a gasoline hydrocarbon fraction (= C5+ fraction) containing a durene-containing heavy aromatics fraction i) recycling the C3 to C4 fraction separated off in step h) as feed material to step a) j) separation of the gasoline hydrocarbon fraction obtained in step h) into a durene-containing heavy aromatics fraction and a stable gasoline fraction.
According to the invention, in step I) or in step a) of the variant of method VI, the catalytic conversion of feed alcohol into a product mixture containing water and a hydrocarbon mixture of olefins, n-paraffins, isoparaffins, aromatics, and naphthenes takes place in one reactor, preferably an isothermal reactor.
For the purposes of the invention, the term "alcohol" includes organic compounds R-OH which .. contain at least one OH group (hydroxy group) which is bonded to an alkyl residue (R). For the purposes of the invention, "alcohol" is understood to mean both a single alcohol and also a Date Recue/Date Received 2020-07-29

8 mixture of several alcohols. In the following, the feed alcohol or the mixture of several alcohols is called "feed alcohol" for better understanding.
Water may be contained in the feed alcohol.
The catalytic conversion takes place in several reaction steps. Produced from the alcohol is an ether, from which olefins are subsequently produced. In subsequent reactions, various hydrocarbons are formed, consisting of olefins, n-paraffins, isoparaffins, aromatics, and naphthenes. If the conversion is not complete, intermediate products of the reaction, such as ethers and lower olefins (ethylene, propylene, butylene), are also present in the product in addition to the feed alcohol.
For the purposes of the invention, ethers are organic compounds which contain an ether group R-O-R ¨ an oxygen atom (0) which is substituted by alkyl residue (R). Ethers are formed from alcohols, preferably on an acidic catalyst, by dehydrating them (elimination of water).
Depending on the feed alcohol, different ethers are formed as intermediate products. Dimethyl ether is produced from methanol, diethyl ether is produced from ethanol, and dipropyl ether is produced from propanol.
The alcohol is expediently and preferably selected from compounds containing at least one OH group which is bonded to an alkyl residue having 1 to 3 carbon atoms. The alkyl residue can be either branched or unbranched.
The alcohol is preferably selected from the following: methanol, ethanol, isopropyl alcohol (2-propanol), and n-propanol (1-propanol), with the alcohol particularly preferably being methanol.
The feed alcohol can first be synthesised according to the prior art.
Advantageously, the water contained in the reaction product (e.g., in the raw methanol) does not have to be separated off in the method according to the invention before it is fed into the reactor, but can be fed into the process together with the alcohol. Thus, a distillation stage can advantageously be omitted.
As a rule, the feed alcohol is an alcohol-water mixture with a water content of less than 20 %
of the total mass of the feed alcohol. In one embodiment, the feed alcohol contains 1 to 20 mass% of water (based on the total mass of the alcohol-water mixture). In one embodiment, Date Recue/Date Received 2020-07-29

9 the feed alcohol contains less than 20 mass% of water (related to the total mass of the alcohol-water mixture), preferably less than 15 mass%, and particularly preferably less than 10 mass%.
In step a) of variant V1, it is advantageously possible to generate a hydrocarbon mixture with a mass fraction of olefins of less than 20% of the total mass of the hydrocarbon mixture formed.
The presence of a higher proportion of water (in the form of water vapour) in the reactor would, on the one hand, promote the formation of lower olefins and, on the other hand, would reduce the formation of heavy hydrocarbons.
Furthermore, the presence of water also leads to a certain shortening of the service life of the catalyst by deactivation (partly irreversible) of the active acid centres.
The control of the water content of the feed gas into the reactor is therefore not insignificant, and a low water content in the feed alcohol of less than 20 % is advantageous both for the product formed as well as in economic terms.
The proportion of olefins in the end product is therefore advantageously lower. A gasoline with a low olefin content is characterised by a very high storage stability. In particular, the octane number of the gasoline remains constant over a long time.
In one embodiment, the alcohol is produced from renewable raw materials, which can be used to produce sustainable, CO2-neutral gasoline.
For the catalytic conversion, the alcohol, for example methanol, is fed into a reaction zone in a reactor containing a catalyst and is completely or incompletely converted there.
In one embodiment, the feeding takes place at a pressure between 5 and 15 bar.
In the embodiment for producing a low-aromatics gasoline, the inlet temperatures into the reactor are between 300 and 350 C.
Date Recue/Date Received 2020-07-29 In one embodiment for producing a gasoline high in aromatic compounds, the inlet temperatures into the reactor are between 350 and 460 C.
The catalyst usually contains zeolites as the catalytically active component.
In one 5 embodiment, the catalyst contains ZSM-5 zeolites. In one embodiment, a ZSM-5 catalyst with an SiO2 to A1203 ratio of the zeolite of at least 30:1, preferably higher, is used.
The reaction of methanol to hydrocarbons on a zeolite-containing catalyst is highly exothermic.
The reaction temperature has a very large influence on the reaction rate and thus the

10 composition of the reaction product and the selectivity of the process.
If the temperatures rise too much due to the exothermic reaction, this can lead to a rapid deactivation of the active centres of the catalyst, which has a negative effect on the reaction time between the regenerations and the service life of the catalyst.
A prerequisite for targeted control of the process (with regard to the reaction product composition and selectivity of the main product) and economic process management (service life of the catalyst, frequency of regeneration, catalyst load) is mastery of the exothermic nature of the reaction through internal cooling of the catalyst bed.
After filling the reactor with fresh catalyst or after a catalyst regeneration, all of the feed alcohol impinges on the first catalyst layer and reacts at the beginning of the method, which results in a sharp rise in temperature in this region and a weakening of the active centres due to their partial deactivation. The rise in temperature in the subsequent catalyst regions gradually decreases, since less and less of the feed alcohol remains and therefore the amount converted gradually decreases.
The next time alcohol is fed in, the temperature in the first catalyst region no longer rises so much, since the activity of this catalyst region has been weakened due to the high temperatures that have already occurred. The temperature front therefore moves further into the next, even more active, catalyst layer.
An efficient removal of the heat of reaction is essential.
Date Recue/Date Received 2020-07-29

11 In one embodiment of the method for producing a low-aromatics product, the temperature difference in the catalyst bed in the region of the temperature front is a maximum of 40 K at the beginning of a reaction period to a maximum of 20 K at the end of a reaction period.
In one embodiment for the production of a low-aromatics product, the temperature in the catalyst bed is between 300 and 370 C, depending on the degree of deactivation of the catalyst.
In the embodiment of a process for producing a product high in aromatic compounds, the temperature difference in the catalyst bed in the region of the temperature front is a maximum of 70 K at the beginning of a reaction period up to a maximum of 30 K at the end of a reaction period.
In one embodiment for producing a product high in aromatic compounds, the temperature in the catalyst bed is between 350 and 490 C, depending on the degree of deactivation of the catalyst.
The heat of reaction is removed from the reaction region of the reactor by heat exchange.
In one embodiment, the reactor contains internal fittings in the form of plates, tubes, and other elements for heat exchange, in which case the catalyst is located in the elements and the cooling medium is located around the elements or vice versa. The flow of the reaction gas can take place in the axial direction (from top to bottom or from bottom to top) or in the radial direction (from an inner central tube to the outside) to avoid excessive pressure losses.
The heat transfer medium is located in the heat exchange elements or also outside these elements. Heat transfer media which may be used include all suitable media which evaporate or condense in the temperature range of reaction and regeneration or which maintain the physical state and dissipate the heat of reaction by convection.
The heat transfer medium for dissipating the heat of reaction goes through a constant cycle. It absorbs the heat from the reaction zone, flows outward (outside the catalyst bed), transfers the heat to a second heat transfer medium, preferably boiling water, either in the interior of the Date Recue/Date Received 2020-07-29

12 reactor or outside the reactor in a separate heat exchanger, and then returns to the reaction zone for heat absorption.
The cooling of the heat transfer medium takes place outside the reactor in a heat exchanger, in which preferably saturated steam is generated at a pressure of at least 20 bar, particularly preferably of at least 40 bar.
The heat transfer medium can also be conducted to the reaction zone in several zones, each with a different temperature. This means that the temperature of the heat transfer medium can be set lower in the region of high reaction temperature than in regions with a lower reaction temperature. The number of heat transfer zones with different temperatures is only limited by the economy of the reactor.
A reactor in which the heat of reaction is removed according to the heat pipe concept can also be used as the reactor. In this concept, the heat transfer medium is located in the interior of heat exchange elements, where it evaporates by absorbing the heat from the reaction system and condenses again by releasing heat to a second heat transfer medium (preferably boiling water), which is preferably located in the upper part of the reactor outside the catalyst bed and cools the heat exchange elements. Condensation and evaporation in the interior of the heat exchange elements take place in a closed system. The boiling water evaporates when the heat is absorbed by the heat transfer medium. The resulting saturated steam preferably has a pressure of at least 20 bar, particularly preferably at least 40 bar. In this type of reactor, the reaction gas can either flow axially (from top to bottom or from bottom to top) through the catalyst bed or in the radial direction to avoid excessive pressure losses (from an inner central tube to the outside).
In one embodiment, the reactor (R) is an isothermal tubular reactor.
According to the invention, in step I) or a) in Vi, the alcohol, for example the methanol, is converted into a product mixture containing water and a hydrocarbon mixture containing olefins, n-paraffins, isoparaffins, aromatics, and naphthenes.
Date Recue/Date Received 2020-07-29

13 The mass fraction of the olefins in the hydrocarbon mixture formed is advantageously less than 20 %, preferably less than 10 %, particularly preferably less than 5%, and in particular less than 2 % of the total mass of the hydrocarbon mixture formed.
In one embodiment, the reaction mixture is subsequently cooled to 45 C, preferably to 35 C, in heat exchangers, air coolers, and cooling water coolers. In one embodiment, cooling takes place using a further coolant down to 5 C.
During cooling, water, alcohol, and the condensable hydrocarbons condense. In the next step, this product mixture is separated into three fractions.
According to the invention, in step II) or b) in V1, the product mixture obtained in step I) or a) in V1 is separated into:
- a liquid hydrocarbon phase, - an aqueous phase containing the unconverted alcohol, and - a gas phase containing C1 to C5 hydrocarbons.
In one embodiment, the product mixture is separated in a three-phase separator (S).
The aqueous phase from step II) or b) in V1 contains the alcohols which have not been converted during the reaction, for example methanol.
After the separation in step II) or b) in V1, unconverted intermediate products may be contained both in the gas phase (e.g., dimethyl ether, diethyl ether, ethylene) and in the liquid hydrocarbon phase (e.g., dimethyl ether, diethyl ether, dipropyl ether, propylene, butylene).
In one embodiment, the unconverted alcohol is separated from the aqueous phase. In variant V1, this is step c).
In one embodiment, the aqueous phase obtained in step II) or b) in V1 is separated in a separation device into water, and unconverted alcohol and the unconverted alcohol is recycled to step I) or a) in V1 .
Date Recue/Date Received 2020-07-29

14 In one embodiment, the separation takes place in a separation device K3. In one embodiment, the separation device K3 is a column.
In one embodiment, the separation takes place at 2-3 bar. The separation device K3 is equipped with a top product cooler and a bottom heater. In one embodiment, the top temperature is 70 to 90 C, preferably 80 to 85 C, and the bottom temperature is 110 to 150 C, preferably 120 to 130 C.
In one embodiment, the separated alcohol is returned to the reactor as feed material. In variant V1, this is step d).
In one embodiment, it is liquid and, together with the feed alcohol, it is fed into the gas circuit on the pressure side of the compressor and, together with the circulating gas (i.e., with the gas phase obtained in step II) or b) in V1), is heated in heat exchangers by cooling the hot reaction product in counterflow and is evaporated. After final heating to the reaction temperature, the mixture enters the reactor in gaseous form.
Since the feed alcohol is preferably methanol, this circuit is also called the methanol circuit.
According to the invention, the gas phase obtained in step II) or b) in V1 is returned to step I) or a) in V1.
In one embodiment, the gas phase from step II) or b) in variant V1 contains light gaseous hydrocarbons which do not condense on cooling of the reaction product. These are both inert components that no longer react in the reaction zone of the reactor (e.g., methane, ethane, CO2, nitrogen) and also intermediate reaction products (e.g., dimethyl ether, ethylene) which, when used again in the reactor, react further and are converted to the desired gasoline hydrocarbons.
In one embodiment, a small proportion of the gas phase from step II) is discharged from the gas circuit in order to avoid the accumulation of inert components in the gas circuit.
A predetermined target pressure of the feed gas should expediently be maintained at the reactor inlet. The pressure setting at the inlet into the reactor can advantageously be regulated Date Recue/Date Received 2020-07-29 by regulating the discharge of gas from the gas circuit when the pressure rises at the reactor inlet.
The main part of the recirculating gas is returned to the reactor.

In one embodiment, the gas phase obtained in step II) or b) in variant V1 is divided, and the first part (= main part) is returned to the reactor R. The division takes place by opening of a valve in the gas line from the three-phase separator to the separation device K4, which opens in the event of excess pressure at the reactor inlet. The other, second part of the gas phase 10 flows to the compressor, which compresses the gas and conveys it to the reactor. In variant V1, this is step e). In one embodiment, the separation device K4 is a column.
With the aid of a compressor the main part of the gas phase (first part) is conveyed back as a circulating gas to the reactor inlet (to step I) or a) in V1), where it causes a dilution of the feed

15 material. By means of the compressor, the pressure losses in the gas circuit are compensated for, and the amount of circulating gas can be set (according to the target volume flow).
The other part of the gas phase (second part) is removed from the device by regulating the pressure at the inlet of the reactor.
The second part of the gas phase is separated in a further step. In variant V1, this is step f).
In one embodiment, the division of the gas phase is not carried out and, therefore, no circulating gas flow (i.e., part of the gas phase from step II) or b) in V1) is returned to the reactor. The entire gas phase is discharged from the device after separation in the three-phase separator. In this embodiment, the desired temperatures in the reactor can be maintained solely by cooling the catalyst bed inside the reactor, so there is no need to dilute the starting materials with circulating gas.
In one embodiment, the second part of the gas phase is separated in a separation device K4, for example in a separation gas column. The gas phase is separated at a pressure of 10 to 20 bar, preferably at 15-16 bar. It is necessary to compress the gas to this pressure before it Date Recue/Date Received 2020-07-29

16 enters the separation device. The separation gas column is equipped with a top product cooler.
The top temperature is -30 to -10 C, preferably -20 C to -25 C.
This separates off the C3 to C5 hydrocarbons.
In a subsequent step, these C3 to C5 hydrocarbons that are separated off are combined with the liquid hydrocarbon phase obtained in step II) or b) in V1. In variant V1, this is step g).
In one embodiment, a part of the gas phase obtained in step II) orb) in V1 is separated off in a separation device in a C3 to C5 hydrocarbon fraction, and this fraction is combined with the liquid hydrocarbon phase obtained in step II).
In one embodiment, this hydrocarbon phase is then separated in step IV) into a C3 to C4 fraction and a gasoline hydrocarbon fraction including a durene-containing heavy aromatics fraction.
Depending on the reaction conditions, the liquid hydrocarbon phase obtained in step II) or b) in variant V1 contains more or fewer C3 and C4 hydrocarbons. If the methanol conversion is incomplete, the intermediate product dimethyl ether (DME) is also a constituent of the reaction product. Part of the DME is contained in the liquid hydrocarbon phase.
Primarily C5+
compounds are contained in the liquid hydrocarbon phase.
C3 and C4 hydrocarbons may be the paraffins propane, butane, and isobutane.
Under certain reaction conditions in which the feed material is not fully converted, olefinic intermediate products such as propylene, butylene, and isobutylene can also emerge from the reactor and can be contained in the liquid hydrocarbon phase.
In one embodiment, the liquid hydrocarbon phase obtained in step II) or b) in variant V1 is fed together with the C3 to C5 fraction into a separation device Kl.
In step IV) or h) in V1, the C3 to C5+ hydrocarbons are separated into - a C3 and C4 hydrocarbon fraction and - a gasoline hydrocarbon fraction (= C5+ fraction) containing a durene-containing heavy aromatics fraction.
Date Recue/Date Received 2020-07-29

17 In the context of the invention, a heavy aromatics fraction means a fraction containing aromatic hydrocarbons having a higher molecular weight. These are aromatic hydrocarbon compounds containing 9 to 11 carbon atoms. The benzene ring can be methylated several times.
In one embodiment, the C3 to C4 fraction is separated off from the liquid hydrocarbon phase as a top product in a separation device Kl, which can be a column. The separation in the column takes place at a pressure of 10 to 20 bar, preferably 13 to 17 bar. The column is equipped with a top product cooler and a bottom heater. The top temperature is 10 to 90 C, preferably 20-70 C, and the bottom temperature 150 to 250 C, preferably 180-225 C. The parameters strongly depend on the composition of the mixture to be separated.
In one embodiment, the top product consists of the paraffins propane, butane and isobutane.
At least part of this C3 to C4 fraction of such a composition can be withdrawn as a saleable "liquefied petroleum gas (LPG)" product.
In one embodiment, the C3 to C4 fraction contains olefins, and/or dimethyl ether, and/or saturated C3 to C4 hydrocarbons.
In one embodiment, at least a portion of the C3 to C4 hydrocarbon fraction separated off in step .. IV) is recycled in the circuit to the inlet of the reactor as feed material to step I) or a) in variant V1.
According to the invention, the gasoline hydrocarbon fraction (C5+ fraction) separated off in the separation device contains a stable gasoline fraction and a durene-containing heavy aromatics fraction containing durene, iso-durene, and other multiply-methylated aromatics.
Durene (1,2,4,5-tetramethylbenzene) and iso-durene (1,2,3,5-tetramethylbenzene) are heavy methylated aromatics that have the property of solidifying in the temperature range in which gasoline is used (ambient temperature before the fuel enters the engine). The solidification temperature of durene is 79.2 C, and that of iso-durene is -20 C. For this reason, these tetramethylbenzenes should not be contained in gasoline.
Date Recue/Date Received 2020-07-29

18 In the process according to the invention, they are separated from the liquid portion of the hydrocarbon product, for example by distillation.
The gasoline hydrocarbon fraction from step IV) or h) in variant V1, containing C5+
hydrocarbons, is further separated into a durene-containing heavy aromatics fraction and a stabilised gasoline fraction in step V) or j) in V1.
In one embodiment, the durene-containing heavy aromatics fraction contains durene, iso-durene, and multiply methylated aromatics.
In one embodiment, the gasoline hydrocarbon fraction is separated in a separation device K2.
The separation device K2 can be a column which is equipped with a top product cooler and a bottom heater.
In one embodiment, the separation takes place at a pressure of 1 to 3 bar, preferably 1.2 to 2.5 bar, at a top temperature of 50 to 90 C, preferably 60-75 C, and a bottom temperature in the range from 200 to 260 C, preferably 230-240 C.
In this case, a stable gasoline fraction and a durene-containing heavy aromatics fraction are obtained. The stable gasoline fraction is the desired gasoline product with a high octane number of >90 RON, preferably >1= 95 RON.
In one embodiment, durene is crystallised out of the durene-containing heavy aromatics fraction.
In one embodiment, the heavy aromatics fraction is placed in a crystalliser KR1, in which the durene which crystallises out at about 79-80 C is separated off by crystallisation.
In one embodiment, the crystallised durene is dissolved in alcohol and/or in gasoline hydrocarbons and, together with the alcohols used and recycled, is recycled to the reactor.
In one embodiment, it is not pure durene, but rather the bottom product of the separation device K2 (heavy durene-containing aromatics fraction) which is completely or partly returned to the Date Recue/Date Received 2020-07-29

19 reactor without the durene being separated off. In this case, no crystalliser KR1 and no dissolving device V1 for releasing the durene are required.
In one embodiment, the gasoline hydrocarbon fraction from step IV) or h) in variant V1 is further separated in the separation device K2. If K2 is a column, for example, iso-pentane at a pressure of 1.1 to 3 bar, preferably 1.2 to 2.5 bar, is separated off in the top of the column at 30-50 C, the boiling fraction of the C6-C7 paraffin hydrocarbons is separated off in a side outlet at 50-100 C, and the stable gasoline fraction is separated off in a further side outlet.
Isopentane and the stable gasoline fraction are then mixed. The mixture corresponds to the .. desired stable gasoline product. The durene-containing heavy aromatics fraction is obtained in the bottom at a bottom temperature of 220 to 250 C, preferably 230-240 C.
In one embodiment, the fraction of the C6 - C7 hydrocarbons, or a part thereof, is recycled to the reactor to step I) or a) in V1.
The method according to the invention is advantageously characterised in that the linking of several material circuits to/from the reactor during the synthesis of hydrocarbons enables the setting of variable reaction conditions in wide ranges.
A special feature of the method is the high flexibility of the product composition by variation of the process parameters. The method is intended to make it possible to respond to special requirements for the gasoline composition. In this way, a gasoline or a gasoline blend of a composition can be produced in accordance with economic and ecological/political requirements. In particular, the method makes it possible to produce a gasoline with low emissions during combustion with reduced CO2 emissions and reduced particle formation potential. If required, a gasoline blend with a high octane number can be produced which is characterised by a high proportion of high-octane isoparaffinic and/or aromatic components.
For high-performance engines, gasolines with a very high octane number (RON 98 and higher) are necessary. Very high octane numbers can no longer be achieved solely through a high isoparaffin content in gasoline. In addition to the isoparaffins, a certain proportion of high-octane aromatics in the gasoline is necessary for this. Aromatics can reach octane numbers of up to approx. RON 120 to 150 (e.g., toluene - RON 124; p-xylene - RON 146).
Date Recue/Date Received 2020-07-29 Due to the higher aromatics content, premium gasoline cannot achieve the ecologically advantageous high H:C ratio, but has very good combustion properties due to the high octane number, which reduces fuel consumption. Despite the higher carbon content, this gasoline can also contribute to the reduction of CO2 emissions by producing it in a PtL
process ("power to 5 liquid") and, if possible, from raw materials made from a "renewable"
(biomass for CO2 generation) or "regenerative" (water for hydrogen production) source or from industrial waste gases (CO2 or CO2 and H2).
The method according to the invention and the device according to the invention can 3.0 advantageously not only be integrated into the PtL process chain, but can also be combined with conventional processes for the production of synthesis gas from a fossil source (e.g., from natural gas) and subsequent methanol synthesis from the synthesis gas.
In the method according to the invention, stabilised crude methanol can be used 15 advantageously as the feed material without the need for further processing of the crude methanol by costly separation off of the water contained therein as well as other alcohols and oxygenates.
The gasolines produced according to the invention can be used not only directly in the engine,

20 but also as blended gasolines in refineries for admixture into the gasoline pool. As blended gasolines, they serve, on the one hand, to increase the octane number and, on the other hand, to reduce the CO2 footprint of the refinery gasoline.
When a gasoline with a high isoparaffin content and low aromatics content is used as blended gasoline, the carbon content in the mixed finished gasoline is reduced, and the CO2 content in the exhaust gas and the particle formation potential during combustion is reduced in this manner.
The method according to the invention can advantageously be used to produce gasolines with a variable composition by adapting process parameters.
In the method according to the invention, process parameters such as catalyst load, temperature, degree of conversion, and recycling of certain intermediate products can Date Recue/Date Received 2020-07-29

21 advantageously be set in a targeted manner in such a way that a gasoline with a high isoparaffin content/low aromatics content or with a high aromatics content is obtained.
Two variants for the extreme cases "high isoparaffin content and low aromatics content of gasoline" and "high aromatics content of gasoline" are described below.
For the purposes of the invention, a gasoline with a high isoparaffin content and low aromatics content (low-aromatics) contains 50-65 mass% of isoparaffins and 20-35 mass%
of aromatics.
A gasoline with a high aromatic content (high in aromatic compounds) contains 35 - 70 mass%
of aromatics and 25 - 45 mass% of isoparaffins.
In one embodiment, a gasoline with a high isoparaffin content and low aromatics content (low-aromatics) contains 50-60 mass% of isoparaffins and 25-35 mass% of aromatics.
A gasoline with a high aromatics content (high in aromatic compounds) contains 40 - 60 mass% of aromatics and 25 - 45 mass% of isoparaffins.
Mass% means the mass fraction of the total mass, in %.
Using the process according to the invention, however, it is also possible to produce gasolines with compositions that cover ranges between the two extreme cases.
Process parameters that can be set individually are, for example, catalyst load, contact time with the catalyst, reaction temperature, flow rate, total pressure in the reactor, and the partial pressures of the individual components.
The catalyst load is specified via the parameter of space velocity (LHSV -Liquid Hourly Space Velocity). This results from the quotient of the liquid volume flow of the feed alcohol and the catalyst volume.
In the method according to the invention, the LHSV is defined as the amount of liquid alcohol (at room temperature and normal pressure), based on 1 m3 of catalyst, in m ....3alcohdh n13cat.
The catalyst load indicates the amount of pure feed alcohol (without water) per hour and catalyst volume.
Date Recue/Date Received 2020-07-29

22 According to the reaction mechanism of the MTH reaction described above, DME
and olefins are formed when methanol is converted. These first reaction steps take place relatively slowly, while the subsequent steps of reacting the olefins with the methanol to form further olefins or CH2 fragments and the subsequent reactions are very fast reactions.
Generation of gasoline with high isoparaffin/low aromatics content (low-aromatics and isoparaffin-rich gasoline) The decisive factor for the formation of a high proportion of isoparaffins in the product mixture is initially the incomplete conversion of the starting materials, for example methanol. The following explanation is shown with the example of using methanol.
A high loading of the catalyst with methanol leads to an incomplete reaction or only to a partial conversion of the methanol fed into the reactor. Unconverted methanol and intermediate products such as dimethyl ether and olefins emerge from the reactor. As the load increases, the aromatics content in the product drops. Recycling the olefin-containing C3-C4 fraction promotes the formation of isoparaffins during the reaction.
In one embodiment, the alcohol load (for example methanol load) of the catalyst for producing an isoparaffin-rich gasoline is between 2 and 5 m3meoH/h m3cat., preferably between 2.5 and 4 M3Me01-1/11 M3cat. (based on the total volume of catalyst contained in the reactor).
The high loading of the catalyst with methanol causes an increase in the proportion of olefin hydrocarbons in the reaction product.
The contact time of the feed materials in the catalyst bed also influences the product composition. In the method according to the invention, the contact time in the catalyst bed in the flow direction of the reaction gas can advantageously be adapted to the requirements of the described sub-steps of the MTH reaction.
In one embodiment, the catalyst load and contact time are set by changing the flow cross-section by means of design measures, for example by changing the diameter of the catalyst tubes. An increase in the flow cross-section in the catalyst bed causes an increase in the Date Recue/Date Received 2020-07-29

23 contact time and a reduction in the catalyst load. The opposite effect is brought about by narrowing the flow cross-section.
In one embodiment, the catalyst is partially diluted with inert material to produce an isoparaffin-rich gasoline. The catalyst volume is influenced in a targeted manner by the addition of inert material. By diluting the catalyst with inactive material, the catalyst volume in the affected reactor section is reduced, but the flow conditions remain the same (provided that the inert material has the same particle shape as the catalyst and the gap volume corresponds to that of the catalyst bed without inert material). The contact time is reduced, and the load of the catalyst is increased. In one embodiment, when zeolites are used as catalysts, aluminium oxide materials (ceramics) are used as the inert material.
The slow reactions of dehydration with the formation of dimethyl ether and water and the formation of olefins or CH2 fragments from the oxygenates methanol and DME
take place in the entry region of the methanol into the catalyst bed.
In order to produce gasoline with a high isoparaffin content, loads and contact times are set in the first section of the catalyst bed in the flow direction, which ensure the incomplete conversion of the methanol to DME.
In the following section of the catalyst bed in the flow direction, very short contact times and very high catalyst loads are required in order to ensure that the MTH reaction is terminated when the olefin is formed.
It is only in the last, lower section of the catalyst bed that longer contact times and lower catalyst loads have to be set so that the desired gasoline hydrocarbons with a low aromatics content are formed.
It is advantageous if the load in this area is so high that the intermediate products cannot react further to the end products and components which have not yet been converted -e.g., methanol, DME and olefins - are present in the reaction product.
Date Recue/Date Received 2020-07-29

24 In one embodiment, the C3 to C4 fraction separated off in step IV) or h) in variant VI is recycled to the reactor inlet as starting material to step I) or a) in variant Vi. This stimulates the formation of isoparaffins. At the entry into the catalyst bed, the olefin hydrocarbons or the resulting CH2 fragments can react with the alcohol, for example methanol, and thus lead to an acceleration of the MTH (methanol to hydrocarbons) reaction. In the further course of the reaction, the CH2 fragments methylate the other hydrocarbons formed - such as n-paraffins, naphthenes, and aromatics. Since the formation of aromatics is inhibited under the reaction conditions described above, isoparaffins are mainly formed by the addition of methyl groups to the n-paraffins formed.
In one embodiment, in order to increase the degree of branching of the isoparaffins in the last section of the catalyst bed, for example in the lower third, a zeolite catalyst of the type ZSM-5 is used which is modified with an active component for activating isomerisation reactions, such as, for example, a metallic component, e.g. nickel.
The product composition can advantageously be adjusted by varying the degree of conversion of the oxygenates, for example the methanol.
As already described above, the degree of conversion of, for example, methanol is adjusted by the reaction temperature and the load of the catalyst. A high load (large amount of methanol per catalyst volume >3 h-1) of the catalyst with feed methanol and at low reaction temperatures (300-350 C) can ensure that not all of the methanol fed in is converted on the catalyst, and also that the gasoline hydrocarbons produced in the reaction only partially react further to the end product of the aromatics.
In addition to the unconverted methanol, the intermediate product dimethyl ether, which is formed by dehydration of the methanol, further reacts only incompletely to hydrocarbons under these conditions.
In one embodiment, the degree of conversion of the methanol to produce a petrol rich in isoparaffin is between 70 and 90 %, preferably between 70 and 80 %.
Date Recue/Date Received 2020-07-29 A further process parameter for setting the product composition is the methanol partial pressure.
The methanol partial pressure describes the proportion of methanol in the total feed material 5 into the reactor. It is defined as the molar fraction of methanol in the feed gas multiplied by the total pressure at the inlet into the reactor. The methanol partial pressure reflects the degree of dilution of the methanol with inert components and influences the degree of conversion of the methanol. Low methanol partial pressures indicate a high dilution of the educt, the degree of methanol conversion increases with the degree of dilution of the educt.
By the circulation of certain components (for example: circulating gas - Ci to C4 hydrocarbons and DME) or recycling of the C3/C4 liquid gas components, a certain volume flow through the catalyst bed is set, which, depending on the inflow cross-section of the catalyst bed and the parameters pressure and temperature, sets a specific flow rate of the reaction gas in the reactor.
A high flow rate of the reaction mixture through the catalyst bed is required for good heat transfer from the reaction zone to the heat transfer medium. Flow rates that are too low result in a low heat transfer coefficient on the gas side. Flow rates that are too high cause high pressure losses across the catalyst bed, in particular if the flow path through the catalyst bed is several metres long.
A medium range of the flow rate, which provides both good heat transfer and low pressure losses, should therefore be used.
In one embodiment, the flow rate of the reaction mixture is 0.8 to 3.0 m/s, preferably 1.5 to 2.5 m/s.
In one embodiment for producing an isoparaffin-rich gasoline, the mole fraction of alcohol, for example methanol, in the total amount of feed gas at the reactor inlet is 25 to 50 mol%, preferably 25 to 40 mol%, in which case the feed gas comprises the feed gas and the recycled components.
Date Recue/Date Received 2020-07-29 In one embodiment, "recycled components" are understood to be the hydrocarbon fractions which are referred to in the individual method steps as "recycled to step 1)".
The recycled components include at least the gas phase (circulating gas) obtained in step II).
In one embodiment, the recycled components additionally contain a C3 to C4 fraction separated off in step IV).
In a further embodiment, the recycled components additionally contain alcohol which has been separated off from the aqueous phase obtained in step II).
In a further embodiment, the recycled components preferably also contain a C3 to C4 fraction separated in step IV).
These embodiments can be combined with one another as desired.
To produce a gasoline with a high aromatics content, the recycled components preferably also contain a C6-C7 hydrocarbon fraction separated off in step IV).
In order to produce an isoparaffin-rich gasoline, the recycled components preferably also contain part of the heavy durene-containing aromatics fraction obtained in step V).
In order to produce a gasoline with a low aromatics content and a high isoparaffin content, the reaction temperature in the catalyst bed must be as low as possible, but must be above the initiation temperature of the reaction.
A high increase in the reaction temperature due to the exothermic nature of the reaction must be avoided. In particular in the entry region of the methanol into the catalyst bed, high temperature increases must be avoided, which can be achieved by dilution of the catalyst with inert material.
In one embodiment for producing an isoparaffin-rich gasoline, the catalyst is partially diluted with inert material.
Date Recue/Date Received 2020-07-29 In one embodiment, the first catalyst region, on which the greatest amount of the feed alcohol impinges at the beginning of the reaction phase (about 1/5 to 1/6 of the bed), is diluted with inert material with a mass fraction of 5 to 30 %, particularly preferably 10 to 25 % (based on the total mass of catalyst and inert material) in order to avoid high temperature rises.
In one embodiment, aluminium oxide materials (ceramics) are used as the inert material.
In one embodiment, the reaction temperatures for producing a low-aromatics and isoparaffin-rich gasoline are between 300 and 370 C, preferably between 300 and 350 C.
In one embodiment, the total pressure in the reactor for producing a low-aromatics and isoparaffin-rich gasoline is <15 bar, preferably <11 bar, particularly preferably <10 bar.
In one embodiment, durene is crystallised out of the durene-containing heavy aromatics fraction.
In one embodiment, the heavy aromatics fraction is placed in a crystalliser KR1, in which the durene which crystallises out at about 79-80 C is separated off by crystallisation.
In one embodiment, the durene which has crystallised out is dissolved in the feed alcohol or in the recycled alcohol from the separation device K3 and/or in gasoline hydrocarbons, for example the stable gasoline fraction from step V), in order to produce a low-aromatics and isoparaffin-rich gasoline. The durene solution is then recycled to step I) or a) in variant V1 into the reactor in a circuit.
In one embodiment, in order to produce a isoparaffin-rich gasoline, part of the heavy durene-containing aromatics fraction obtained in step V) is returned to step I).
In this way, the aromatisation activity of the catalyst can be influenced. By recycling of durene to the reactor, the formation of the other aromatics can be reduced, with the result that this method can be used to produce a low-aromatics gasoline. Additional positive effects include Date Recue/Date Received 2020-07-29 increasing the intermediate product regeneration time or reducing the frequency of necessary catalyst regenerations and reducing the ageing of the catalyst and increasing its service life.
In one embodiment, hydrogen is additionally fed into the methanol circuit and/or into the reactor in order to produce a gasoline product with a high isoparaffin content and a low aromatics content.
The hydrogen serves to saturate the olefinic and aromatic components which are low in hydrogen, to convert these components to n-paraffins and isoparaffins and naphthenes, and to avoid or reduce the formation of coke on the catalyst surface. Reduced coke formation increases the intermediate product regeneration time and the service life of the catalyst.
The addition of hydrogen enables the isoparaffin content in the reaction product to be increased. Increasing the isoparaffin content/reducing the aromatics content increases the H/C
ratio of the product such that, beginning at a certain ratio of the isoparaffins to the aromatics in the product, the stoichiometrically required amount of hydrogen is greater than that present in the feed alcohol.
Starting with methanol as the preferred feed material, the maximum isoparaffin content of the gasoline of 75 mass% (mass percentage = mass fraction of the total mass, in %) with an aromatics content in the gasoline of approximately 11 mass% can be achieved by the addition of hydrogen. The amount of hydrogen required is approximately 1 to 5 mass%, preferably 1 to 2 mass%, based on the alcohol to be converted, for example methanol.
The minimum feed pressure of the hydrogen must be above the system pressure in the gas circuit.
In one embodiment, the hydrogen is fed in at a pressure of 8 to 15 bar, preferably 9 to 12 bar, particularly preferably 10 bar.
In one embodiment, in order to reduce the formation of aromatics and/or to produce an isoparaffin-rich gasoline, in particular at the beginning of a reaction cycle, part of the durene-containing heavy aromatics fraction, for example from step j) in variant V1 without separation off of the durene, is recycled to the reactor to step I) or a) in V1. This method promotes the Date Recue/Date Received 2020-07-29 build-up of a carbon pool on the active catalyst surface, so that its activity is weakened and fewer aromatics are formed. The ageing of the catalyst will be reduced and its service life increased.
Production of gasolines with a high aromatics content (high-aromatics) The process parameters have to be adjusted accordingly in order to produce gasolines with a high aromatics content.
It is important to convert the starting materials as completely as possible at the beginning of the reaction.
If the catalyst has a low load of methanol/DME, the starting material can be completely converted. Intermediate products such as dimethyl ether and olefins are converted into secondary products such as paraffins and aromatics.
The separation off of unconverted oxygenates, such as methanol, from the water is also important for the production of high-aromatics gasolines.
Particularly when changing between the reaction and regeneration phases, it is necessary to separate the unconverted methanol from the reaction water.
It is necessary to carry out the catalyst regeneration periodically because the catalyst, preferably consisting of zeolites, loses activity in the course of the reaction phase due to coke deposits on the surface of the active centres, which can be compensated for by the gradual increase in the temperature in the reactor (which increases the reaction rate). In this way, the degree of conversion of the feed material can be kept constant to a certain degree.
Above a certain degree of deactivation, however, the conversion rate drops, and the activity of the catalyst can only be restored by burning the coke off from the catalyst surface (=
regeneration). For this reason, the phases of the reaction and the regeneration alternate periodically during the entire period of catalyst use.
Date Recue/Date Received 2020-07-29 In one embodiment, the duration of the reaction phase is 3 to 5 weeks, and the duration of the regeneration phase is 3 to 10 days, preferably 1 week.
In the starting phase of the reaction regime or when changing from the reaction regime to the 5 regeneration regime, the conversion of the feed alcohol is incomplete and, in one embodiment, the unconverted alcohol is separated from the water using the separation device K3 and is returned to the reactor in the circuit. On the one hand, a high product selectivity is achieved and, on the other hand, the water is purified to a residual alcohol content.
10 The preferred formation of aromatics from the intermediate products is promoted by a high level of catalyst activity. The reaction temperature is crucial for high activity. High reaction temperatures must be set in order to produce a high-aromatics gasoline.
In one embodiment, the reaction temperature for producing a gasoline with a high aromatics 15 content is between 350 and 490 C.
The reaction temperatures are limited towards the top of the range in order to avoid irreversible deactivation of the catalyst.
20 A high reaction temperature can be achieved by setting a high inlet temperature of the feed gas into the reactor and a correspondingly higher temperature of the heat transfer medium at the inlet into the reactor and by dispensing with or using limited inert material for dilution of the catalyst.

25 In one embodiment, the catalyst is mixed with 5-30 % inert material, preferably 10-25 %, only in the inlet region of the alcohol (about 20 to 100 mm catalyst bed height).
This leads to the avoidance of catalyst deactivation due to excessive temperatures, since the amount of alcohol converted is greatest in this range.
30 The return of the liquid gas (mainly C3-C4 paraffin hydrocarbons) to the reactor in step i) has, in this reaction mode, the purpose of additionally diluting the educt in order to avoid excessively high reaction temperatures and the resulting rapid catalyst deactivation.
Date Recue/Date Received 2020-07-29 As already described above, in one embodiment, a C6-C7 hydrocarbon fraction containing C6-C7 paraffins is additionally separated from the gasoline hydrocarbon fraction and returned to the reactor to step I) or a) in V1. In one embodiment, the separation takes place via a side outlet of separation device K2.
The C6-C7 paraffin hydrocarbons contained therein can be partially converted to aromatics under the reaction conditions described below.
In one embodiment, the degree of conversion of the alcohol to produce a gasoline with a high aromatic content is between 95 and 100 %, preferably between 98 and 100 %. The degree of conversion of the oxygenate, for example the feed alcohol at the reactor inlet, is adjusted using the reaction temperature. An almost complete degree of conversion of the oxygenate is set by a high reactor temperature. With a high degree of conversion and low catalyst load, the intermediate products react to a large extent up to the aromatic hydrocarbons.
In one embodiment, the loading of the catalyst with the feed alcohol (for example feed methanol) in order to produce a high-aromatics gasoline is low: preferably, the LHSV = 0.2 to 2.0 m3meoH/h m3õt., particularly preferably, the LHSV = 0.5 to 1.5 m3meoH/h m'cat. (based on the total volume of catalyst contained in the reactor).
In one embodiment for producing a high-aromatics gasoline, the mole fraction of the alcohol, for example methanol, of the feed gas at the reactor inlet is 40 to 90 mol%, preferably 50 to 90 mol%, wherein the feed gas comprises the feed alcohol and recycled components.
The dilution of the alcohol with inert gas is correspondingly low, which worsens the heat transfer from the reaction region to the heat transfer medium. This leads to higher reaction temperatures which promote the formation of aromatics.
In one embodiment, the feed alcohol is not diluted in the reactor, i.e., it is not mixed with hydrocarbon gases. This means that no circulating gas is returned to the reactor; the gas circuit in the method is omitted. In this embodiment, the gas phase at the separator outlet serves as heating gas after the C3-05 hydrocarbons have been separated off.
Date Recue/Date Received 2020-07-29 If the oxygenates (e.g., the feed methanol and the intermediate product DME
that is formed) are completely converted and the said conditions (low catalyst load, high reaction temperature) are set, the reaction product will contain no or only a few olefin hydrocarbons.
Device:
The invention also relates to a device for the synthesis of a synthetic gasoline (Fig. 2a block flow diagram - Device for the production of gasoline from feed alcohol with recycling of circulating gas), comprising the following components:
I. a reactor (R) for the catalytic conversion of alcohols into a product mixture that contains a hydrocarbon mixture and water, II. a three-phase separator (S) for separating the product mixture obtained in the reactor (R) into a liquid hydrocarbon phase, an aqueous phase that contains unconverted alcohol, and a gas phase, III. a first separation device (K1) which is suitable for separating a liquid hydrocarbon phase that contains hydrocarbons having 3 to 11 carbon atoms into a C3-C4 fraction and a C5+ fraction, IV. a second separation device (K2), which is suitable for separating a hydrocarbon phase containing hydrocarbons with 5 to 11 carbon atoms into a durene-containing heavy aromatics fraction and a stable gasoline fraction, V. a connecting line (VL1) from the reactor R to the three-phase separator S for transporting the reaction product that contains Ci-Cii hydrocarbons, water and alcohol, VI. a connecting line (VL3) from the three-phase separator (S) to the first separation device (K1), which is suitable for transporting a liquid hydrocarbon phase that contains hydrocarbons with 3 to 11 carbon atoms, VII. a connecting line (VL5) from the first separation device (K1) to the second separation device (K2), which is suitable for transporting a C5+ hydrocarbon fraction, VIII. a return line (RL1) from the three-phase separator (S) to the reactor (R) for recycling the gas phase separated off in the three-phase separator (S).
Date Recue/Date Received 2020-07-29 In one variant (Figs. la, 2b), the device comprises the following components:
a. a reactor (R) for the catalytic conversion of alcohols into a product mixture that contains a hydrocarbon mixture and water, b. a three-phase separator (S) for separating the product mixture obtained in the reactor (R) into a liquid hydrocarbon phase, an aqueous phase that contains unconverted alcohol, and a gas phase, c. a first separation device (K1) which is suitable for separating a liquid hydrocarbon phase that contains hydrocarbons having 3 to 11 carbon atoms into a C3-C4 fraction and a C5+ fraction, d. a second separation device (K2) which is suitable for separating a hydrocarbon fraction that contains hydrocarbons having 5 to 11 carbon atoms into a durene-containing heavy aromatics fraction and a stable gasoline fraction, e. a third separation device (K3) which is suitable for separating an aqueous phase that contains alcohol into water and alcohol, in which case the alcohols preferably contain 1 to 3 carbon atoms, f. a fourth separation device (K4) which is suitable for separating a gas phase that contains Ci-05 hydrocarbons into a Ci-C2 hydrocarbon fraction and a C3-05 hydrocarbon fraction, g. a first connecting line (VL1) from the reactor R to the three-phase separator S for transporting the reaction product that contains Ci-Cii hydrocarbons, water, and alcohol, h. a second connecting line (VL2) from the three-phase separator (S) to the third separation device (K3), which is suitable for transporting an aqueous phase that contains alcohol, i. a third connecting line (VL3) from the three-phase separator (S) to the first separation device (K1), which is suitable for transporting a liquid hydrocarbon phase that contains hydrocarbons having 3 to 11 carbon atoms, j. a fourth connecting line (VL4) from the fourth separation device (K4) to the first separation device (K1), which is suitable for transporting C3-05 hydrocarbons, k. a fifth connecting line (VL5) from the first separation device (K1) to the second separation device (K2), which is suitable for transporting a liquid hydrocarbon phase that contains hydrocarbons having 5 to 11 carbon atoms, Date Recue/Date Received 2020-07-29 I. a sixth connecting line (VL6) from the three-phase separator (S) to the fourth separation device (K4), which is suitable for transporting a hydrocarbon gas that contains hydrocarbons having 1 to 5 carbon atoms, m. a first return line (RL1) from the three-phase separator (S) to the reactor (R) for recycling part of the gas phase separated in the three-phase separator (S), n. a second return line (RL2) from the third separation device (K3) to the reactor (R) for recycling the unconverted alcohol, o. a third return line (RL3) from the first separation device (K1) to the reactor (R) for recycling the C3-C4 hydrocarbon fraction.
The embodiment is shown by way of example in Fig. 2b (1a), which shows a block flow diagram of a device for the production of gasoline from feed alcohol, with recycling of circulating gas, the C3 C4 fraction and the unconverted alcohol:
In one embodiment, the components reactor R, three-phase separator S, first separation device K1, and second separation device K2 are connected in series.
In one embodiment, at least the separation devices K1 and K2 are distillation columns. In a further embodiment, all separation devices K1 to K4 are distillation columns.
The reactor R is connected via the reaction product in the connecting line VL1 to the separator S, the separator S is connected via the liquid hydrocarbon phase in the connecting line VL3 to the first separation device K1, for example, a gasoline stabilisation column, and the separation device K1 is connected via the liquid fraction C3-C4 (top product of the separation device K1) in a return line RL3 to the reactor R and is directly connected via its bottom product via a connecting line VL5 to the second separation device K2, for example a gasoline separation column.
In one embodiment, the device contains a return line (RL3) from the first separation device (K1) to the reactor (R) for recycling the C3-C4 hydrocarbon fraction.
Date Recue/Date Received 2020-07-29 In one embodiment, the separator S is directly connected via the aqueous phase in the connecting line VL2 to a third separation device K3, for example to a methanol column, the top product (alcohol) of which is connected to the reactor R in the return line RL2.
5 In one embodiment, the three-phase separator S is connected via the Ci-05 hydrocarbon gas in the connecting line VL6 to a separation device K4, for example to a separation gas column.
According to the invention, the three-phase S is connected via the liquid hydrocarbon phase from the separator S in the connecting line VL3 to the separation device Kl.
The separation device K4 is directly connected to the separation device K1 via the C3 to C5 hydrocarbon fraction in the connecting line VL4.
In one embodiment (Figs. 2c, 1 b, 1c), the device additionally contains a crystalliser KR1, which is suitable for crystallising out durene from a durene-containing fraction or heavy aromatics fraction.
In one embodiment, the separation device K2 is connected directly to the crystalliser KR1 via a connecting line VL7.
In one embodiment (Figs. 2c, 1 b, 1c), the device additionally contains a dissolving device V1 for dissolving the durene separated off in the crystalliser KR1 and a fourth return line RL4 from the crystalliser KR1 with the dissolving device Vito the reactor R, which is suitable for transporting dissolved durene. The crystalliser KR1 is connected to the reactor R in a return line RL4 via the durene dissolved in the dissolving device Vi.
In one embodiment (Figs. 2e, le), the second separation device K2, for example a gasoline separation column, is equipped with a side outlet for separating off the C6-C7 paraffin hydrocarbon fraction from the bottom product from the separation device K1 .
In this embodiment, the second separation device K2 is connected to the reactor R via the C6-C7 paraffin hydrocarbon fraction in a return line RL6.
Date Recue/Date Received 2020-07-29 In one embodiment (Figs. 2c, 2d, lc, 1d), in particular when a gasoline product is produced with a high isoparaffin content and a low aromatics content, the device is optionally equipped with an additional external hydrogen source and supply of hydrogen in a line Ll to the reactor R. The additional supply of hydrogen serves to saturate the low-hydrogen olefinic and aromatic components with hydrogen and to convert them to n-paraffins and isoparaffins and naphthenes and to reduce the coke formation on the catalyst surface. Reduced coke formation increases the intermediate product regeneration time and the service life of the catalyst.
In one embodiment (Figs. 2d, 1d) in order to reduce the formation of aromatics, in particular at the beginning of a reaction cycle, part of the methylated aromatics fraction of the separation device K2, for example a gasoline separation column, can be returned to the reactor without the durene having been separated off beforehand. The second separation device K2 is connected to the reactor R in a return line RL5 via its bottom product, the heavy methylated aromatics fraction (or a part thereof). This method promotes the build-up of a carbon pool on the active catalyst surface, whereby its activity is weakened and fewer aromatics C6 to Cg are formed. The ageing of the catalyst will be reduced and its service life increased.
In order to implement the invention, it is also expedient to combine the above-described embodiments and features of the claims.
Exemplary embodiments The invention will be explained in greater detail in the following with reference to some exemplary embodiments and accompanying drawings. The embodiments are intended to describe the invention without limiting it.
Figures la to le show block flow diagrams of the method according to the invention for producing isoparaffin-rich gasoline (Figs. la, lb, lc and 1d) and high-aromatics gasoline (Figs.
la and le) from alcohol, for example from methanol.
Fig. la: Device for the production of gasoline of variable composition Date Recue/Date Received 2020-07-29 Fig. lb: Device with durene recycling for the production of isoparaffin-rich gasoline without the addition of hydrogen Fig. lc: Device with durene recycling for the production of isoparaffin-rich gasoline with the addition of hydrogen Fig. 1d: Device with recycling of aromatics for the production of isoparaffin-rich gasoline and with the addition of hydrogen Fig. le: Device with recycling of the C6-C7 paraffin hydrocarbons for the production of high-aromatics gasoline Furthermore, Figures 2a to 2e show simplified block flow diagrams of the device.
Figures 2b, 2c and 2d show methods of producing isoparaffin-rich gasoline, and Figures 2a and 2e show methods of producing high-aromatics gasoline from alcohol, for example from methanol.
Fig. 2a - block flow diagram of the device for the production of gasoline from feed alcohol Recycling of circulating gas Fig. 2b - block flow diagram of the device for the production of gasoline from feed alcohol with recycling of circulating gas, the C3-C4 fraction and the unconverted alcohol Fig. 2c - block flow diagram of the device for the production of gasoline from feed alcohol with recycling of circulating gas, the C3-C4 fraction, the unconverted alcohol, and dissolved durene and, optionally, the addition of hydrogen Fig. 2d - block flow diagram of the device for the production of gasoline from feed alcohol with recycling of circulating gas, the C3-C4 fraction, the unconverted alcohol, and aromatics and, optionally, the addition of hydrogen Fig. 2e - block flow diagram of the device for the production of gasoline from feed alcohol with recycling of circulating gas, the unconverted alcohol and C6 - C7 paraffins Exemplary embodiment 1:
Figs. lc, lb/2c show a block flow diagram of the method according to the invention for the production of high-octane isoparaffin-rich gasoline from feed alcohol (in this exemplary embodiment = methanol) with durene recycling.
Date Recue/Date Received 2020-07-29 The separation devices K1 to K4 are columns in this case.
For the production of a high-octane gasoline, methanol feed (100% Me0H) is mixed with the recycled (RL2) unconverted methanol (from the separation device K3), in the synthesis reactor R, and is fed into the gas circuit in liquid form. At the same time, the olefin-containing liquid gas fraction having a composition of 2-4 mass% of ethylene, 15-25 mass% of propylene, 30-50 mass% of butylene, 5-15 mass% of butane, 2-4 mass% of pentene, 2-6 mass% of i-pentane, 5-15 mass% of DME, and 2-7 mass% of methanol from the separation device K1 in RL3 and the durene dissolved in the methanol (about 3 - 5 mass%, based on the amount of methanol entering the reactor) from the crystalliser KR1 and the dissolving device V1 in RL4 fed into the gas circuit (only at the beginning of each reaction phase).
The said liquids methanol, C3-C4 fraction, and the durene dissolved in the methanol are evaporated in countercurrent to the hot reaction product in a heat exchanger.
Then the total stream - consisting of recirculating gas and the gaseous streams of methanol, the C3-C4 fraction and the durene - is heated in an furnace up to the required reactor inlet temperature of 340 C . The furnace is heated with heating gas, which is a constituent of the reaction product and was previously separated off in a distillation column K4 as the top product.
The gaseous mixture enters the reactor R. With the aid of a compressor which conveys the circulating gas to the reactor, the mass flow of the circulating gas can be adjusted in such a way that a molar fraction of the methanol in the feed gas in the reactor is 40 to 45 mol%.
In the gasoline synthesis reactor R there is an exothermic reaction of the conversion of the methanol and certain components in the feed gas - such as DME and olefins -into hydrocarbons, which are mainly in the boiling range of gasoline. Of the methanol, 95 % is converted under the set conditions. The heat released is dissipated in the reactor by an internal heat exchanger, which contains a suitable heat transfer medium. The heat transfer medium is cooled in a separate heat exchanger. Steam at a pressure of 30 bar is generated from condensate and used in the separation devices K1, K2 and K3, which serve to separate the product, as the heating medium for the bottom heaters. The condensate from the bottom heaters of the separators flows back to the cooler of the heat carrier of the reactor.
Date Recue/Date Received 2020-07-29 The mixture of feed materials is fed into the reactor at a pressure of 7 barg.
The conversion of the methanol takes place in an isothermal tubular reactor R with a catalyst bed consisting of a ZSM-5 catalyst, which was diluted with 10-25 % inert material in the inlet region for the feed materials. The other catalyst regions are diluted with inert material to different degrees of dilution.
The method steps according to the invention are explained below using exemplary embodiments.
a. The 340 C hot reaction product from the gasoline synthesis reactor R is cooled in countercurrent to the 50 C cold feed product in heat exchangers to 75 C , then the reaction product is further cooled in a cooler, which can be a water cooler and a cold water cooler or a combination of air cooler and water cooler and cold water cooler, to 5 C and is fed to the three-phase separator S in the connecting line VL1, whereby the water, the unconverted methanol and the condensable hydrocarbons condense out.
b. The separator S separates the cooled reaction product into 3 phases - an aqueous phase, a liquid hydrocarbon phase, and a gaseous hydrocarbon phase.
c. The aqueous phase from the separator S is led in the connecting line VL2 to the third column K3 and separated into methanol and water. The top product of column K3 is the methanol which has not been converted in the reactor R and has a residual water content which is partly returned as reflux to the top of the column. The column K3 separates the methanol-water at a top pressure of 1.2 barg, a top temperature of 85 C, and a bottom temperature of 130 C.
d. The amount of methanol not converted in the reactor R is removed from the column K3 as the top product (water content: approximately 7 mass%), then flows in the return line RL2 to the gas circuit and is mixed with the feed alcohol (100 %
methanol) before both are added to the gas cycle.
The bottom product of the separation device K3 is the water purified from the methanol.
The degree of purification depends on the separation performance of the separation device K3. The methanol content in the purified water is <5 ppm.
e. Part of the gas phase is returned to the reactor R with the aid of a compressor in the circuit in the return line RL1 (first part of the gas phase). The compressor conveys the Date Recue/Date Received 2020-07-29 gas to the reactor R with an outlet pressure in the range of 9 to 11 barg and compensates for the pressure losses in the gas circuit.
f. A partial flow of the gas phase from the separator (second part of the gas phase) is discharged from the gas circuit and conveyed to the fourth separation device, a 5 separation gas column K4, with the aid of a further compressor in the connecting line VL6.
The pressure in column K4 is preferably approximately 15 bar. The separation gas column K4 has no bottom heater. The hydrocarbon gas emerging from the top of the column (mainly Ci-C2 hydrocarbon and small amounts of C3-C4 hydrocarbon) is cooled, 10 preferably down to -20 C. A conventional cooling medium from a chiller is used for cooling in the top product cooler.
The gaseous product (C1-C2 hydrocarbons) emerging from the top product separator is used as the heating gas in the furnace for preheating the feed material of the reactor R.
15 The liquid product from the top product separator of the separation device K4 partly flows back as reflux to the separation device K4, and the other part is removed as a liquid product and mixed with the bottom product obtained from the separation device K4.
g. The mixture consists of C3-05 hydrocarbons and is added in the connecting line VL4 to 20 the separation device K1, a stabilising column. The main feed material of the stabilising column K1 is the liquid hydrocarbon phase of the reaction product which flows in the connecting line VL3 from the separator S to the column K1. The pressure in the separator S corresponds to the reactor inlet pressure minus the pressure losses in the reactor and in the heat exchangers for cooling the reaction product. It is approximately 25 2.2 barg.
h. The liquid phase from the separator S is heated to 120 C and fed into the stabilising column K1.
The column K1 serves to stabilise the liquid hydrocarbons, which means that the low-boiling components C3-C4 and partly C5 are separated off at the top of the column. The 30 aim of the separation in the column K1 is to set the vapour pressure of the gasoline according to the specification.
The column K1 separates the liquid hydrocarbons into a liquid gas fraction (mainly C3-C4 and DME) and a C5+ fraction at a pressure of 15-16 barg. The temperature of the Date Recue/Date Received 2020-07-29 bottom heater is approximately 220 C. The C5+ hydrocarbons from the bottom of the column are fed via the connecting line VL5 into the separation device K2, a gasoline separation column.
i. The top product cooler of the stabilisation column K1 cools the top product (liquefied gas fraction - mainly C3-C4 and DME) to approximately 20 C. The liquid top product obtained is fed into the gas circuit with the aid of the return line RL3, and part is removed as product.
j. The gasoline separation column K2 has a top pressure of 0.2 barg and a top temperature of 70 C. The temperature of the top heater is approximately 240 C. In the separation device K2, stable gasoline is obtained as the top product and a heavy hydrocarbon fraction with a high durene content (approximately 90 mass%) and other alkyl aromatics with carbon numbers of 10 and 11 is obtained as the bottom product.
Durene (1,2,4,5-tetramethylbenzene) is an alkyl aromatic with a low solidification temperature of approximately 79 C and can be separated from the other aromatic compounds by crystallisation. For this purpose, the bottom product of the separation device K2 is fed in the connecting line VL7 to a crystalliser KR1.
In the crystalliser KR1, the durene is separated from the other components by cooling of the bottom product to a temperature of <79 C, preferably 60 C. The solid durene is separated in the crystallisation unit KR1 and part of the durene is then dissolved in methanol in the dissolving device V1. The methanol-durene mixture in the return line RL4 is then fed into the gas circuit as a liquid solution.
The gasoline product has the following composition:
Date Recue/Date Received 2020-07-29 Table 1: Composition of the gasoline mass% vol%
n-paraffins 1.5 1.8 Isoparaffins 61.6 64.2 Olefins 7.8 9.0 Naphthenes 3.3 3.2 Aromatics 25.2 21.3 Oxygenates 0.6 0.5 100.0 100.0 The vapour pressure of the gasoline is 45 kPa.
Exemplary embodiment 2 - Production of a high-aromatics gasoline:
Fig. 2a shows a block flow diagram of the method according to the invention for producing gasoline with circulating gas. If suitable parameters are set, this method can be used to produce a high-aromatics high-octane gasoline from methanol, as the following example shows.
The device contains the following main equipment: a reactor R with cooling of the reaction zone for the synthesis of hydrocarbons from methanol, a separator S for separating the cooled reaction product into liquid hydrocarbons, water with methanol and a gas phase, a separation device K1 for separating the liquid gas components from the liquid hydrocarbons and a separation device K2 for separating the liquid hydrocarbons from the bottom of the separation device K1 into a stable gasoline fraction and a fraction of heavy methylated aromatics.
In the device, part of the gas phase (main part) is returned from the separator S in the return line RL1 to the reactor.
Furthermore, the device contains a compressor for maintaining the gas circuit to/from the reactor as well as tanks and heat exchangers, inter alia.
Date Recue/Date Received 2020-07-29 In the exemplary embodiment 2, feed alcohol in the form of 100 mass% of methanol is fed in.
A zeolite-containing catalyst of the ZSM-5 type is used in the gasoline synthesis reactor.
The conditions at the entry into the reactor are 375 C and 6 barg. The LHSV
of the methanol is 1.0 h-1. The mole fraction of the methanol in the feed gas into the reactor is 55.1 mol%. The degree of conversion of the methanol in the reactor is 100.0 %.
Table 2 shows the material balance of the entire device.
Table 2: Material balance of the device Inlet Outlet mass% mass% mass%
Methanol 100.0 Heating gas 7.5 17.2 Liquid gas 3.5 8.0 Gasoline 29.6 67.6 Heavy gasoline 3.2 7.2 Total 43.8 100.0 Water 56.2 Total 100.0 Total 100.0 The gasoline selectivity (based on the mass of the hydrocarbons produced) is 67.6 %.
Date Recue/Date Received 2020-07-29 Table 3 shows the composition of the gasoline produced.
Table 3: Composition of the gasoline mass% vol%
n-paraffins 5.5 6.4 Isoparaffins 42.5 48.0 Olefins 2.4 2.7 Naphthenes 8.4 8.1 Aromatics 41.2 34.8 Oxygenates 0 0 100.0 100.0 The octane number of the gasoline is RON = 100.
Date Recue/Date Received 2020-07-29 Reference signs or list of abbreviations R Reactor for the catalytic conversion of alcohols S Three-phase separator 5 K1 First separation device, e.g., gasoline stabilisation column K2 Second separation device, e.g., gasoline separation column K3 Third separation device, e.g., methanol column K4 Separation gas separation device, separation gas column KR1 Crystalliser 10 V1 Dissolving device for dissolving durene VL1 Connection line from the reactor R to the three-phase separator S
for transporting the reaction product containing C1-C11 hydrocarbons, water and alcohol, VL2 Connection line from the three-phase separator S to the separation device K3 for transporting the aqueous phase containing alcohol 15 VL3 Connection line from the three-phase separator S to the separation device K1 for transporting the liquid C3-C11 hydrocarbons VL4 Connection line from the separation device K4 to the separation device K1 for transporting the liquid C3-05 hydrocarbons VL5 Connection line from the separation device K1 to the separation device K2 for 20 transporting the liquid C5-C11 hydrocarbons VL6 Connection line from the three-phase separator S to the separation device K4 for transporting the hydrocarbon gases VL7 Connection line from the separation device K2 to the crystalliser KR1 for the transport of the heavy aromatic fraction 25 .. RL1 Return line from the three-phase separator S to the reactor R for recycling the hydrocarbon gas RL2 Return line from the separation device K3 to the reactor R for recycling the unconverted alcohol RL3 Return line from the separation device K1 to the reactor R for recycling the C3-C4 30 hydrocarbons RL4 Return line from the dissolving device for dissolving durene 1/1 to the reactor R for recycling the durene Date Recue/Date Received 2020-07-29 RL5 Return line from the separation device K2 to the reactor R for recycling the heavy aromatics fraction RL6 Return line from the separation device K2 to the reactor R for recycling the C6-C7 paraffin hydrocarbons Date Recue/Date Received 2020-07-29

Claims (9)

Claims

1. A method for production of a synthetic gasoline with high isoparaffin content in the range of 50-65 mass% and with low aromatics content in the range of 20-35 mass%, comprising the following steps:
l) catalytic conversion of feed alcohol in a feed gas into a product mixture containing water and a hydrocarbon mixture of olefins, n-paraffins, isoparaffins, aromatics, and naphthenes within an isothermal tubular reactor reactor containing a catalyst, wherein the reaction temperature in the isothermal tubular reactor is between and 370 C, wherein the feed alcohol has a water content of less than 20 mass%;
II) separation of the product mixture obtained in step I) into:
- a liquid hydrocarbon phase, - an aqueous phase containing the unconverted alcohol, and - a gas phase containing Ci to C5 hydrocarbons;
III) recycling of the gas phase obtained in step II) to step I);
IV) separation of the liquid hydrocarbon phase obtained in step II) into - an olefin-containing C3 tO C4 hydrocarbon fraction, and - a gasoline C5+ hydrocarbon fraction containing a durene-containing heavy aromatics fraction; and V) separation of the gasoline hydrocarbon fraction obtained in step IV) into a durene-containing heavy aromatics fraction and a stable gasoline fraction, wherein in step l), the alcohol load of the catalyst is 2 to 5 m ¨3alcohol/hm3cat, and Date Recue/Date Received 2022-12-30 wherein for production of gasoline with high isoparaffin content the catalyst is partially diluted with 5-30 mass% inert material in the alcohol entry region, based in the total mass of catalyst and inert material, and wherein the olefin-containing C3 to C4 fraction separated off in step IV) is recycled to step I) as feed material, wherein the mole fraction of the alcohol at the reactor inlet is 25 to 50 mol%, based on the total amount of feed gas, wherein the feed gas comprises the feed alcohol and recycled components.

2. The method according to claim 1, wherein the aqueous phase obtained in step II) is separated into water and alcohol, and the alcohol is recycled to step I).

3. The method according to claim 1 or 2, wherein a C3 tO Cy hydrocarbon fraction is separated from part of the gas phase obtained in step II) and is combined with the liquid hydrocarbon phase obtained in step II).

4. The method according to any one of claims 1 to 3, wherein, in order to produce an iso-paraffin-rich gasoline, part of the heavy durene-containing aromatics fraction obtained in step V) is recycled to step I), or that the durene is crystallised out from the durene-containing heavy aromatics fraction obtained in step V), and part of the crystallised durene is dissolved in alcohol and/or gasoline hydrocarbons and recycled to step I).

5. The method according to any one of claims 1 to 4, wherein, in order to produce an iso-paraffin-rich gasoline, hydrogen is additionally fed into the reactor in step I).

6. A device for the synthesis of synthetic gasoline with high isoparaffin content in the range of 50-65 mass% and with low aromatics content in the range of 20-35 mass%õ
comprising the following components:
l. an isothermal tubular reactor (R), containing a catalyst, for the catalytic conversion of alcohols into a product mixture containing a hydrocarbon mixture and water, wherein in the alcohol entry region the catalyst is partially diluted with 5-mass% inert material, based in the total mass of catalyst and inert material, Date Recue/Date Received 2022-12-30 II. a three-phase separator (S) for separating the product mixture obtained in the reactor (R) into a liquid hydrocarbon phase, an aqueous phase containing unconverted alcohol, and a gas phase, III. a first separation device (K1) which is suitable for separating a liquid hydrocarbon phase that contains hydrocarbons having 3 to 1 1 carbon atoms into a C3 to C4 fraction, and a C5+ fraction, IV. a second separation device (K2), which is suitable for separating a hydrocarbon phase that contains hydrocarbons with 5 to 1 1 carbon atoms into a durene-containing heavy aromatics fraction, and a stable gasoline fraction, V. a connecting line (VL1) from the isothermal tubular reactor R to the three-phase separator S for transporting the reaction product, which contains Ci to Cli hydrocarbons, water, and alcohol, VI. a connecting line (VL3) from the three-phase separator (S) to the first separation device (K1), which is suitable for transporting a liquid hydrocarbon phase that contains hydrocarbons with 3 to 1 1 carbon atoms, VII. a connecting line (VL5) from the first separation device (K1) to the second separation device (K2), which is suitable for transporting a C5+ hydrocarbon fraction, VIII. a return line (RL1) from the three-phase separator (S) to the isothermal tubular reactor (R) for returning the gas phase separated off in the three-phase separator (S), and IX. a return line (RL3) from the first separation device (K1) to the isothermal tubular reactor (R) for returning the C3-C4_ hydrocarbon fraction, wherein the components I. to IV are connected in series, and wherein the device contains a fourth separation device (K4) which is suitable for sep-arating a gas phase containing C1 to C5 hydrocarbons into a Ci to C2 hydro-carbon fraction and a C3 tO C5 hydrocarbon fraction, and Date Recue/Date Received 2022-12-30 a connecting line (VL6) is arranged from the three-phase separator (S) to the fourth separating device (K4), which is suitable for transporting a hydrocar-bon gas that contains hydrocarbons having 1 to 5 carbon atoms, and a connecting line (VL4) is arranged from the fourth separating device (K4) to the first separating device (K1), which is suitable for transporting C3 tO C5 hydrocarbons.

7. The device according to claim 6, wherein the device additionally contains a crystalliser (KR1) for crystallising out durene from the durene-containing heavy aromatics fraction, a connecting line (VL7) from the second separation device (K2) to the crystalliser (KR1) for transporting a heavy aromatics fraction, a dissolving device (V1) for dissolving part of the durene separated off in the crystalliser, and a return line (RL4) from the dissolving device V1 to the isothermal tubular reactor R for recycling the dissolved durene.

8. The device according to claim 6 or 7, wherein the device additionally contains a return line (RL5) from the second separation device (K2) to the isothermal tubular reactor (R) for returning part of the durene-containing heavy aromatics fraction.

9. The device according to any one of claims 6 to 8, wherein the device contains a third separation device (K3) which is suitable for separating an aqueous phase containing alcohol into water and alcohol, and that a connecting line (VL2) from the three-phase separator (S) to the third separation device (K3) is arranged which is suitable for transporting an aqueous phase, which contains alcohol, and that a return line (RL2) from the third separation device (K3) to the isothermal tubular reactor (R) is arranged for recycling of the unconverted alcohol.
Date Recue/Date Received 2022-12-30