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Title:
PROCESS AND PLANT FOR IMPROVING GASOLINE OCTANE RATING
Document Type and Number:
WIPO Patent Application WO/2023/001695
Kind Code:
A1
Abstract:
Process and plant for producing a gasoline product from a methanol feed stream, the process comprising the steps of: conducting a portion of the methanol feed stream to a methanol-to-gasoline reactor for producing a raw gasoline stream comprising C2-compounds, C3-C4 compounds, and C5+ hydrocarbons; separating from the raw gasoline stream: a stream comprising the C2-compounds, a stream comprising the C3-C4 compounds, and a gasoline stream comprising the C5+ hydrocarbons i.e. stabilized gasoline; upgrading the stabilized gasoline, suitably by conducting it to a hydroisomerization (HDI) step and/or hydrocracking (HOC) step; optionally conducting a methanol feed stream, suitably another portion of said methanol feed stream, to a water removal step for producing a dehydrated methanol stream; and blending a methanol stream together with a separate stream comprising one or more oxygenates other than methanol, with at least a portion of the upgraded gasoline stream for producing said gasoline product, and wherein said methanol stream is: a portion of said methanol feed stream, or a dehydrated methanol stream produced from conducting the methanol stream, suitably a portion thereof, to a water removal step.

Inventors:
HIDALGO VIVAS ANGELICA (DK)
NGUYEN THOA THI MINH (DK)
VANNBY RICKARD (DK)
JØRGENSEN MATHIAS (DK)
Application Number:
PCT/EP2022/069776
Publication Date:
January 26, 2023
Filing Date:
July 14, 2022
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
TOPSOE AS (DK)
International Classes:
C10G3/00; C01B3/32; C01B3/38; C07C51/12; C10G45/58; C10G47/18; C10G65/12; C10G69/02; C10L1/06; C10L1/182; C10L1/222
Domestic Patent References:
WO2016116612A12016-07-28
WO2011060116A22011-05-19
WO2011060116A22011-05-19
WO2016116612A12016-07-28
WO2019228797A12019-12-05
WO2019020513A12019-01-31
Foreign References:
CN102732332A2012-10-17
US20080216391A12008-09-11
US9964256B22018-05-08
US20190040331A12019-02-07
US4564643A1986-01-14
US20080216391A12008-09-11
CN102732332A2012-10-17
US4788369A1988-11-29
US4481305A1984-11-06
US4520216A1985-05-28
EP20216617A2020-12-22
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Claims:
CLAIMS

1. Process for producing a gasoline product from a methanol feed stream, the process comprising the steps of: i) conducting at least a portion of the methanol feed stream to a methanol-to-gasoline reactor under the presence of a catalyst active for converting the methanol feed stream into a raw gasoline stream comprising C2-compounds, C3-C4 compounds, and C5+ hydrocarbons; ii) separating from the raw gasoline stream: ii-1) a stream comprising the C2-compounds, ii-2) a stream comprising the C3-C4 compounds, and ii-3) a gasoline stream comprising the C5+ hydrocarbons; iii) upgrading the gasoline stream comprising the C5+ hydrocarbons, suitably by con- ducting it to a hydroisomerization (HDI) and/or hydrocracking (HDC) step, thereby pro ducing an upgraded gasoline stream; iv) blending a methanol stream together with a separate stream comprising one or more oxygenates other than methanol, with at least a portion of the upgraded gasoline stream for producing said gasoline product, and wherein said methanol stream is: - a portion of said methanol feed stream, or

- a dehydrated methanol stream produced from conducting the methanol stream, suitably a portion of said methanol feed stream, to a water removal step. 2. Process according to claim 1, wherein the methanol stream in step iv) represents 10 wt% or less, e.g. 1-5 wt% of the methanol feed stream.

3. Process according to any of claims 1-2, wherein the methanol stream, suitably the dehydrated methanol stream, and the one or more oxygenates other than methanol, are combined into a multi-oxygenate-blend prior to blending with the at least a portion of the upgraded gasoline stream.

4. Process according to any of claims 1-3, wherein the blending of the one or more ox ygenates is conducted during the process for producing the gasoline product, i.e. in- situ. 5. Process according to any of claims 1-4, wherein the separate stream comprising one or more oxygenates other than methanol is externally sourced. 6. Process according to any of claims 3-5, wherein a metal-free octane booster, such as a N-methyl aniline compound, is provided for forming the multi-oxygenated blend, and wherein the metal-free octane booster is not an oxygenate.

7. Process according to any of claims 1-6, wherein the separate stream comprising one or more oxygenates other than methanol is a stream comprising higher alcohols and/or higher ethers, suitably comprising only higher alcohols, such as ethanol and/or isobuta nol.

8. Process according to any of claims 3-7, wherein the proportion of the methanol stream, suitably the dehydrated methanol stream, to the one or more oxygenates other than methanol in the multi-oxygenate-blend is 35 wt% or lower, such as dehydrated methanol/oxygenates other than methanol of 35/65 wt% or 20/80 wt%.

9. Process according to any of claims 7-8, wherein the one or more oxygenates other than methanol is: ethanol and/or iso-butanol.

10. Process according to claim 9, wherein the multi-oxygenate-blend is: 2.7/2.7 vol.% methanol/iso-butanol, or 2.7/4.2/2.6 vol.% methanol/ethanol/iso-butanol. 11. Process according to any of claims 1-10, wherein prior to the upgrading step, the gasoline stream comprising the C5+ hydrocarbons in step ii-3), i.e. stabilized gasoline stream, is conducted to a fractionation column for separating light gasoline as over head stream, fuel oil as bottom stream, and intermediate stream as the gasoline stream comprising the C5+ hydrocarbons in step ii-3 being conducted to said upgrad- ing step.

12. Process according to any of claims 1-11, further comprising: prior to step i), produc ing said methanol feed stream by methanol synthesis of a methanol synthesis gas, and wherein the methanol synthesis gas is generated by: a) steam reforming of a hydrocarbon feed such as natural gas, and/or b) at least partly by electrolysis of water and/or steam.

13. Process according to claim 12, wherein: a) the steam reforming step is conducted in an electrically heated reformer (e-re- former), suitably powered by electricity derived from renewable resources such as wind, hydropower and/or solar energy; b) the methanol synthesis gas is generated by: b-1) combining air separation, autothermal reforming or partial oxidation, and electrolysis of water and/or steam; or b-2) combining the use of water electrolysis in an alkaline or PEM electrolysis unit, or steam in a solid oxide electrolysis cell (SOEC) unit, thereby generating a hydro gen stream, together with the use of a CC>2-rich stream in a SOEC unit for generating a stream comprising carbon monoxide and carbon dioxide, then combining the hydrogen stream and the stream comprising carbon monoxide and carbon dioxide for generating said methanol synthesis gas.

14. Plant for carrying out the process according to any of claims 1-13.

Description:
Title: Process and plant for improving gasoline octane rating

The present invention relates to a process and plant for converting a methanol feed stream into a gasoline product. Embodiments of the invention include converting the methanol feed into raw gasoline, subsequently producing a stabilized gasoline by re moving C2-compounds and C3-C4 compounds from the raw gasoline, subsequently upgrading the stabilized gasoline, suitably by a hydroisomerization (HDI) and/or a hy drocracking step (HDC), conducting a methanol stream, suitably a portion of said meth anol feed stream, to an optional water removal step for producing a dehydrated metha nol stream, and blending the methanol stream, suitably the dehydrated methanol stream together with a separate stream comprising oxygenates other than methanol, with at least a portion of the upgraded gasoline stream for producing said gasoline product. Embodiments of the invention further include combining the dehydrated meth anol and the oxygenates other than methanol into a multi-oxygenate blend prior to blending with the at least a portion of the upgraded gasoline stream. The proportion of the dehydrated methanol to the oxygenates other than methanol in the multi-oxygenate blend is suitably 35 wt% or lower. The octane rating of the gasoline product is thereby improved by incorporating into the upgraded gasoline stream methanol already availa ble in the process/plant produced by upstream methanol synthesis, so that the octane rating improvement is conducted in-situ i.e. during the operation of the process. The methanol feed stream is produced upstream by methanol synthesis of a methanol syn thesis gas.

Applicant’s TIGAS™ technology - Topsoe Improved Gasoline Synthesis, provides for the option of producing gasoline from methanol (MTG), but also producing gasoline from a synthesis gas (STG).

In the latter, the synthesis of methanol, dimethyl ether (DME) and gasoline are inte grated by passing synthesis gas (gas mixture of H2, CO and CO2) to an oxygenate (methanol/DME) reactor and then converting the oxygenate(s) into gasoline in gasoline reactors.

The former (MTG) is also a known technology for gasoline synthesis from oxygenates such as methanol. It involves a process/plant comprising a MTG section (methanol-to- gasoline section) and a downstream distillation section. The MTG section may also be referred as MTG loop and comprises: a MTG reactor; a product separator for withdraw ing a bottom water stream, an overhead recycle stream from which an optional fuel gas stream may be derived, as well as a raw gasoline stream comprising C2 compounds, C3-C4 paraffins (LPG) and C5+ hydrocarbons (gasoline boiling components); and a re cycle compressor for recycling the overhead recycle stream by combining it with the oxygenate feed stream, e.g. methanol feed stream. The overhead recycle stream (or simply, recycle stream) acts as diluent, thereby reducing the exothermicity of the oxy genate conversion. In the downstream distillation section, C2 compounds are removed in a de-ethanizer, such as de-ethanizer column, and then a C3-C4 fraction (C3-C4 compounds) is removed as LPG as the overhead stream in a LPG-splitting column (LPG splitter), while stabilized gasoline is withdrawn as the bottoms product. The stabi lized gasoline or the heavier components of the stabilized gasoline may optionally be further upgraded and thereby refined, e.g. by conducting hydroisomerization (HDI) and/or hydrocracking (HDC) thus producing an upgraded gasoline product.

US 2019040331 discloses a method for preparing a fuel composition a the distribution point, i.e. , at fuel terminals, which comprises a base fuel such as a Blendstock for Oxy genate Blending “BOB”, an oxygenate and an octane-boosting additive described therein as N-methyl aniline, which method comprises: blending an additised oxygenate with a base fuel, wherein the additised oxygenate comprises an oxygenate and an oc tane-boosting additive. The oxygenate can be e.g. methanol or preferably ethanol.

US 4564643 discloses a particular process and catalyst for producing, from a synthesis gas, a mixed alcohol comprising methanol and higher alcohols than methanol. These mixed alcohols are used as an alcohol component to be added to gasoline. The metha nol content in the mixture is at least 45 wt%.

Methanol is readily available in MTG or STG plant or process and a small amount could be blended to the gasoline as an octane booster, however, it also has a signifi cant negative effect by increasing vapor pressure. US 2008/0216391 discloses a pProcesses and reactor system for the conversion of ox ygenated hydrocarbons to hydrocarbons, ketones and alcohols useful as liquid fuels, such as gasoline, jet fuel or diesel fuel, and industrial chemicals.

WO 2011/060116 discloses a process for producing renewable gasoline and fuel com positions produced therefrom. The renewable gasoline is produced from a methanol feed stream.

Applicant’s WO 2016116612 A1 discloses a process for converting methanol to hydro carbons suitable for use as gasoline or blend-stock.

CN 102732332 A discloses a preparation method of a methanol/butanol mixed vehicle fuel, by adding 10-20 wt% of methanol, 40-60 wt% of butanol and 0.5-3 wt% of additive into a mixing tank at normal temperature, mixing for 10-20 minutes, adding 17-50 wt% of petrochemical 93# gasoline into the mixed solution in the mixing tank, and standing for 4-6 hours for use. Hence, the gasoline content is low, i.e. less than 50 wt% while the methanol and butanol content is high, i.e. methanol/butanol higher than 50 wt%, and thus inherently the vehicle fuel is prepared at the distribution point, i.e. at a fuel ter minal.

It would therefore be desirable to be able to in-situ, i.e. during operation of the pro cess/plant, increase the octane rating of gasoline being produced in the process/plant.

It would also be desirable to produce a gasoline product complying with standards ac cording to EU EN228 and/or USA ASTM D4814.

It would also be desirable to boosting the gasoline, in-situ, without impairing gasoline throughput.

Accordingly, in a first aspect, the invention is a process for producing a gasoline prod uct from a methanol feed stream, the process comprising the steps of: i) conducting a portion of the methanol feed stream to a methanol-to-gasoline reactor under the presence of a catalyst active for converting the methanol feed stream into a raw gasoline stream comprising C2-compounds, C3-C4 compounds such as C3-C4 paraffins, and C5+ hydrocarbons; ii) separating from the raw gasoline stream: ii-1) a stream comprising the C2-compounds, ii-2) a stream comprising the C3-C4 compounds, and ii-3) a gasoline stream comprising the C5+ hydrocarbons, i.e. as stabilized gas oline; iii) upgrading the gasoline stream comprising the C5+ hydrocarbons, suitably by con ducting it to a hydroisomerization (HDI) and/or hydrocracking (HDC) step, optionally af ter being conducted to a fractionation step e.g. in a distillation column, thereby produc ing an upgraded gasoline stream; iv) blending a methanol stream together with a separate stream comprising one or more oxygenates other than methanol, with at least a portion of the upgraded gasoline stream for producing said gasoline product, and wherein said methanol stream is:

- a portion of said methanol feed stream i.e. the methanol feed stream of step i), or

- a dehydrated methanol stream produced from conducting the methanol stream, suitably a portion of said methanol feed stream, to a water removal step, suitably a fractionation step e.g. fractionation column.

As used herein, in step i) the methanol to gasoline reactor is suitably for producing gas oline from methanol (MTG), or for producing gasoline from a synthesis gas (STG).

As used herein, the term “comprising” includes “comprising only” i.e. “consisting of”.

As used herein, the term “suitably” means “optionally”, i.e. an optional embodiment.

The term “present invention” and “present application” are used interchangeably.

Methanol is available upstream for gasoline production and a small amount is blended with the gasoline being produced as an octane booster i.e. to increase the octane num ber of the gasoline; however, adding methanol has also a significant negative impact by increasing vapor pressure (e.g. > 3 psi). The increase in vapor pressure caused by methanol addition is by the present invention at least partly off-set by oxygenate(s) other than methanol.

In an embodiment, the methanol stream in step iv) represents 10 wt% or less, e.g. 1-5 wt% of the methanol feed stream. Thereby, gasoline yields and throughput are not im paired by diverting such small amount of the methanol available (methanol feed stream) for octane boosting of the gasoline being produced. It would be understood that wt% is calculated with respect to the methanol feed stream prior to step i), i.e. prior to any splitting of the methanol feed stream into a portion being conducted to the meth- anol-to-gasoline reactor (step i), or into a portion used in the blending step (step iv).

As used herein, the octane number is the Research Octane Number, RON, measured according to ASTM D2699; or Motor Octane Number, MON, measured according to ASTM D2700; or Anti Knock Index (AKI) measured as the average of RON and MOM i.e. (RON+MOM)/2.

As used herein, dehydrated methanol stream means a methanol stream containing 99.8 wt% methanol.

As used herein, the gasoline stream comprising the C5+ hydrocarbons in step ii-3 is also referred to as stabilized gasoline or stabilized gasoline stream.

The vapor pressure of the gasoline being produced, more specifically the upgraded gasoline, needs to be reduced before blending with methanol so that the vapor pres sure of the blend fulfils volatility specifications. However, the reduction in vapor pres sure of the gasoline can result in RON/MON/AKI loss; therefore, the net octane boost could be much diminished. By the present invention, the increase in vapor pressure is not as pronounced as when blending the upgraded gasoline with only methanol.

The present invention thus integrates the use of methanol as a booster in a pro cess/plant where methanol is readily available from upstream methanol synthesis, as it will also become apparent from one or more or the below embodiments, while at the same time off-setting some of the disadvantages in its use e.g., increase in vapor pres sure and need for phase stabilizers. Thereby, there is a reduction of overall cost of octane booster(s) whilst also fulfilling mandates for use of oxygenates in gasoline in ac cordance with EU EN228 and/or USA ASTM D4814.

The invention enables using some methanol for reducing the need for other oxygen ates by using a small portion of the methanol readily available in the plant.

The methanol feed stream to the methanol-to-gasoline reactor, as also explained far ther below, is suitably free of other oxygenates such as higher alcohols. If the methanol feed stream contains water, in accordance with step iv) it is dried by a water removal step, suitably in a fractionation step e.g. in a distillation column before being directed to blending with oxygenate(s) other than methanol and the upgraded gasoline stream.

In an embodiment, the methanol stream, suitably the dehydrated methanol stream, and the one or more oxygenates other than methanol, are combined into a multi-oxygenate blend prior to blending with the at least a portion of the upgraded gasoline stream.

While e.g. the dehydrated methanol stream, as well as the separate stream of oxygen ates other than methanol, and upgraded gasoline may be blended at a common mixing point, it is also advantageous to mix the methanol with the one or more oxygenates other than methanol first, i.e. prior to blending with the upgraded gasoline stream. Thereby a multi-oxygenate blend is produced which may be tailored at will during oper ation of the process/plant for further blending with the upgraded gasoline. The blending of oxygenates is conducted during the process for producing the gasoline, i.e. in-situ, thus as part of the process, and not at a distribution point such as a fuel terminal. The octane rating in the gasoline product is thereby easier to control and produce according to required specifications, in particular according to the standards EU EN228 and/or USA ASTM D4814.

Accordingly, in an embodiment, the blending of the one or more oxygenates (the oxy genates) is conducted during the process for producing the gasoline product, i.e. in- situ.

It would be understood, that as used herein, the term “multi-oxygenate blend” means a mixture of methanol, e.g. dehydrated methanol available in the process/plant, and one or more oxygenates other than methanol. The multi-oxygenate blend does not com prise gasoline e.g. upgraded gasoline. It would also be understood, that the “gasoline product” refers to a product blend of gasoline (here the upgraded gasoline) with oxy genates.

In an embodiment, the separate stream comprising one or more oxygenates other than methanol is externally sourced. The term “externally sourced” means outside the bat tery limits of the process/plant according to the present application. The methanol used in the process, instead, is internally sourced. Suitably also, separate (individual) streams of the one or more oxygenates other than methanol may be provided. For in stance, a stream comprising or comprising only one oxygenate other than methanol, may be combined with another stream comprising or comprising only yet an additional oxygenate other than methanol, and then combined with e.g. the dehydrated methanol stream for thereby forming the multi-oxygenated blend. Suitably, a metal-free octane booster such as a N-methyl aniline compound is provided. A suitably octane booster is for instance the Dorf Ketal proprietary octane booster PX-3495™. For instance, by fur ther addition of 10000 wt ppm (1 wt %) or less, such as 5000 wt ppm of this booster (PX-3495™) increases AKI by >1.0. This booster is not an oxygenate.

Accordingly, in an embodiment, a metal-free octane booster, such as a N-methyl ani line compound, is further provided, i.e. further added, for forming the multi-oxygenated blend, and the metal-free octane booster is not an oxygenate. Suitably, the metal-free octane booster is 1 wt% or less, such as 0.5 wt%.

In an embodiment, the separate stream comprising one or more oxygenates other than methanol is a stream comprising higher alcohols and/or higher ethers, suitably com prising only higher alcohols, such as ethanol and/or isobutanol.

As used herein, the term “higher alcohol” means an alcohol other than methanol and having no more than five carbons.

As used herein, the term “higher ethers” means ethers with five or more C-atoms. The blend of methanol with a higher alcohol e.g. isobutanol, achieves a similar modest octane boost as when using only methanol. The advantage is that methanol is readily available in the process and thus the total cost of the octane boost is decreased. Again, the increase in vapor pressure is not as pronounced as in a blend adding only metha- nol.

In an embodiment, the proportion of the methanol stream, suitably the dehydrated methanol to the one or more oxygenates other than methanol in the multi-oxygenate- blend is 35 wt% or lower, such as dehydrated methanol/oxygenates other than metha- nol (ratio of methanol to oxygenates-other-than-methanol) of 35/65 wt% or 20/80 wt%.

This enables the provision of a multi-oxygenate blend in accordance with at least EU specifications, which only allow the use of methanol concentrations up to 3 vol.% in blend with gasoline (corresponding to up to 3.14 wt%). See below Table 1. Another as- sociated benefit is reducing the need to import, i.e. by externally sourcing, higher amounts of C2+ oxygenates to fulfill specifications regarding minimum amount of oxy genates in the gasoline.

TABLE 1

In an embodiment, the one or more oxygenates other than methanol is: ethanol and/or iso-butanol. Other higher alcohol(s) such as isopropanol or tertbutanol may also be used. For instance, in an embodiment, tertbutanol (t-BuOH) instead of, or in addition to, iso-butanol is utilized. In an embodiment, the one or more oxygenates other than methanol is an ether as defined above, i.e. ethers with five or more C-atoms, such as methyl tertbutyl ether (MTBE).

For instance, in a particular embodiment, the multi-oxygenate-blend is 2.7/2.7 vol.% methanol/isobutanol.

So far, only EU specifications allow the use of methanol concentrations up to 3 vol.% as additive for gasoline, i.e. in blend with gasoline. Methanol as booster had not been considered for the U.S. plants because ASTM D4814 specifications limit the content of methanol to 0.3 vol.% in blend with gasoline. Now, the particular multi-oxygenate blend of 2.7 vol.% methanol / 2.7 vol.% isobutanol, as recited above, would be allowed by not only EU but also US in accordance with specifications EU EN228 and USA D4814 and additionally an EPA (Environmental Protection Agency) substantially similar ruling that has established that in the US, methanol and butanol can be used in equal volumes such that the maximum oxygen (O-content) content in blend with gasoline (product blend of gasoline with oxygenates) is not higher than 2.7 wt% and the total amount of oxygenates not higher than 5.5 vol%.

Table 1 above is for EU specifications, with max O-content of 3.7 wt%. In the same EU specs, there is another class of gasoline for which max O-content is 2.7 wt%. So, the content of the other oxygenate(s) depends on: a) properties of the base gasoline, b) class in the specifications, c) which are the other oxygenates.

In another particular embodiment, the multi-oxygenate blend is 2.7/4.2/2.6 vol.% meth anol/ethanol/isobutanol. A blend of 2.7/4.2/2.6 vol% methanol/ethanol/isobutanol re sults in an oxygenate and oxygen content combination that would be allowed in the EU. In particular, it is possible to obtain a somewhat greater octane boost effect with a multi-oxygenate blend of 2.7/4.2/2.6 vol% methanol/ethanol/isobutanol compared to e.g. using only about 10 vol% ethanol: the total oxygen content of 2.7 methanol + 4.2 ethanol +2.6 isobutthanol is 3.7 wt%, and, if there was only ethanol, about 10 vol%; more specifically 10.4 vol.% ethanol gives same 3.7 wt% oxygen content. The in crease in vapor pressure that would result from adding only methanol (>3 psi) is at least partly off-set by the ethanol and isobutanol in the multi-oxygenates blend (<2 psi, i.e. vapor pressure range of less than 2 psi). The process of the invention enables in-situ tailoring the composition of the gasoline product in compliance with any of the above specifications. This is much more simple, flexible, straightforward, inexpedient and inexpensive approach, than attempting to achieve the same compliance with specifications at the distribution point i.e. at a fuel terminal. The invention enables also to use the available methanol in the plant for cli ents which will include in their scope the blending of oxygenates.

The invention surprisingly enables boosting the gasoline, in-situ, without impairing gas- oline throughput. In fact, by diverting a small portion of the methanol feed stream for blending with the upgraded gasoline, the gasoline throughput (gasoline yield from methanol) is even slightly increased. The conversion of methanol to gasoline also gen erates water, whereas the diverted dehydrated methanol for blending is mixed directly with the upgraded gasoline product and thereby fully accounted therein.

The raw gasoline stream comprises C2- compounds, such as methane, ethane, eth- ene, and the process thus comprises in step ii-1) using a de-ethanizer (de-ethanizer column e.g. fractionation column) for generating the stream comprising the C2- com pounds

Suitably, prior to the upgrading step (step iii), the gasoline stream comprising the C5+ hydrocarbons in step ii-3, i.e. stabilized gasoline stream, is conducted to a fractionation column for separating light gasoline as overhead stream, fuel oil as bottom stream and an intermediate stream as the gasoline stream comprising the C5+ hydrocarbons in step ii-3 being conducted to said upgrading step, suitably to a HDI and/or HDC step.

The material catalytically active in hydroisomerization (HDI) typically comprises an ac tive metal (either elemental noble metals such as platinum and/or palladium or sulfided base metals such as nickel, cobalt, tungsten and/or molybdenum), an acidic support (typically a molecular sieve showing high shape selectivity, and having a topology such as MFI, MEL, MOR, FER, MRE, MWW, AEL, TON and MTT) and a refractory support (such as alumina, silica or titania, or combinations thereof). HDI conditions involve a temperature in the interval 250-400°C, a pressure in the interval 20-150 bar, and a liq uid hourly space velocity (LHSV) in the interval 0.5-8. The material catalytically active in hydrocracking (HDC) typically comprises an active metal (either elemental noble metals such as platinum and/or palladium or sulfided base metals such as nickel, cobalt, tungsten and/or molybdenum), an acidic support (typically a molecular sieve having a topology such as IZA, FAU, MFI, MEL, MOR,

FER, MRE, MWW, AEL, TON and MTT) and a refractory support (such as alumina, sil ica or titania, or combinations thereof). HDC conditions involve a temperature in the in terval 250-400°C, a pressure in the interval 20-150 bar, and a liquid hourly space ve locity (LHSV) in the interval 0.5-8.

In an embodiment, step ii-2) is conducted in LPG-splitting column (LPG splitter). The C3- C4 fraction is thereby separated as LPG as the overhead stream in the LPG-splitting col umn (LPG splitter), while stabilized gasoline is withdrawn as the bottoms product. As used herein, the term “C3-C4 compounds” is also referred to as “LPG”. The term “LPG” means liquid/liquified petroleum gas, which is a gas mixture mainly comprising propane and butane, i.e. C3-C4; LPG may also comprise i-C4 and a minor portion of olefins. The MTG process for producing gasoline is well-known, as for instance disclosed in US 4788369, US 4481305 or US 4520216. During the production of gasoline by the well- known MTG process, the LPG fraction typically constitutes between 15 and 20 wt% of the gasoline product slate. LPG has normally a low value and in the MTG process the value is even lower, because it is very far from specifications, for instance also by the presence of up to about 10 wt% olefins. The gasoline product (C5+ hydrocarbons) is a complex hydrocarbon mixture, comprising e.g. C5-C10 hydrocarbons.

In an embodiment, the catalyst in the methanol-to-gasoline reactor is a zeolitic catalyst having an MFI framework such as ZSM-5, for instance ZSM-5 in its hydrogen form (HZSM-5); and wherein the temperature in the methanol-to-gasoline reactor reactor is

280-400°C, the pressure is in the range 15-25 bar abs; and optionally the WHSV is 1-6 , such as 1-2, for instance 1.5 or 1.6. Suitably also, the methanol-to-gasoline reactor has arranged along its length a fixed bed or a plurality of successive fixed beds com prising the catalyst. As used herein, the term “MFI structure” means a structure as assigned and main tained by the International Zeolite Association Structure Commission in the Atlas of Ze olite Framework Types, which is at http:// www.iza-structure.org/databases/ or for in- stance also as defined in “Atlas of Zeolite Framework Types”, by Ch. Baerlocher, L.B. McCuskerand D.H. Olson, Sixth Revised Edition 2007.

In an embodiment, the process further comprises: prior to step i), producing said meth anol feed stream by methanol synthesis of a methanol synthesis gas, and wherein the methanol synthesis gas is generated by: by steam reforming of a hydrocarbon feed such as natural gas, and/or at least partly by electrolysis of water and/or steam. Thereby, methanol is readily available in the process/plant, as methanol feed in the MTG reactor or a minor portion such as 10wt% or less, as methanol stream in the blending step iv).

The methanol and resulting gasoline product may then be blue or green-stamped.

Blue or green stamped gasoline means a gasoline product utilizing blue or green meth anol, respectively. These are much more environmentally friendly gasoline products than when produced from typical fossil feed derived methanol.

For the purposes of the present patent application, “blue methanol” means methanol originating from a fossil fuel source, but with recovery of CO2 and other greenhouse gases in the process. The CO2 is for instance sequestrated. The fossil fuel source, e.g. natural gas, is converted into methanol synthesis gas which is then converted to meth anol, here ‘blue methanol’. “Green methanol” means methanol originating from a re newable fuel source, such as from solar, wind and hydropower, for producing electricity used in electrolysis of water (steam) for generation of hydrogen and thereby methanol synthesis gas which is then converted to methanol, here ‘green methanol. “Black meth- anol” means methanol originating from a petroleum/coal source.

Where the steam reforming is conducted by the use of electricity from renewable sources, such as by electrically heated steam reforming (e-SMR), for producing the methanol synthesis gas; and/or where electrolysis is used for producing the methanol synthesis gas, the resulting methanol may also be categorized as e-methanol e.g. eMethanol™.

Accordingly, in an embodiment, in a) the steam reforming step is conducted in an elec trically heated reformer (e-reformer), i.e. the steam reforming unit is an e-reformer. The term “e-reformer” is also referred to as “e-SMR” (electrically heated steam methane re former). The e-reformer is suitably powered by electricity derived from renewable re sources such as wind, hydropower and/or solar energy. For a description of e-SMR which is a recent technology, reference is given to in particular applicant’s WO 2019/228797 A1.

In another embodiment, the methanol feed stream is produced from methanol synthe sis gas which is generated at least partly by electrolysis of water and/or steam. Hence, according to this embodiment, in b) the methanol synthesis gas is generated by: b-1) combining air separation, autothermal reforming or partial oxidation, and electroly sis of water and/or steam, as disclosed in Applicant’s WO 2019/020513 A1.

The methanol synthesis gas, which as is well-known in the art, is a mixture comprising mainly hydrogen and carbon monoxide tailored for methanol synthesis, may also be generated by: b-2) combining the use of water electrolysis in an alkaline or PEM electrolysis unit, or steam in a solid oxide electrolysis cell (SOEC) unit, thereby generating a hydrogen stream, together with the use, i.e. the provision, of a CC>2-rich stream in a SOEC unit for generating a stream comprising carbon monoxide and carbon dioxide, then combin ing the hydrogen stream and the stream comprising carbon monoxide and carbon diox ide for generating said methanol synthesis gas, as e.g. disclosed in Applicant’s co pending European patent application No. 20216617.9.

Thereby, an even more sustainable front-end solution i.e. prior to step i) is provided. Accordingly, an even more sustainable approach for the production of raw gasoline, and thereby also the gasoline product downstream, is achieved. The methanol feed stream can be produced from many primary resources (including biomass and waste), particularly in times of low wind and solar electricity costs. It would thus be understood, that as used herein, the term “process” means a process comprising steps i)-iv) related to the production of the gasoline product including addi tion of an oxygenate other than methanol, and the process may also encompass the prior (front-end) production of the methanol feed from a methanol synthesis generated by said steam reforming and/or at least partly by electrolysis of water and/or steam, as recited above.

It would also be understood that the term “process/plant” means process and/or plant.

In a second aspect, the invention encompasses also a plant, i.e. process plant, for car rying out the process according to any of the above embodiments.

Any of the embodiments and associated benefits according to the first aspect of the in vention, may be used in connection with the second aspect of the invention.

The sole accompanying figure shows a process and/or plant layout for producing a gasoline product in accordance with an embodiment of the present invention.

With reference the figure, a process/plant 10 is shown for producing a gasoline product from a methanol feed stream according to an embodiment of the present invention.

A methanol feed stream 1 is split into separate methanol feed streams 3, 5, here de noted as methanol feed stream 3 and methanol split stream 5, The methanol feed stream 3 is conducted to a methanol-to-gasoline loop section 20 comprising a metha- nol-to-gasoline reactor (not shown), thereby producing a raw gasoline stream 11 com prising C2-compounds, C3-C4 compounds, and C5+ hydrocarbons. The methanol split stream 5 is conducted to a water removal step in fractionation column 30, thereby gen erating a water stream 7 and a dehydrated methanol stream 9. The raw gasoline stream 11 is conducted to a separation (stabilizer) section 40 comprising a de ethanizer 40’ and LPG-splitter 40”, suitably as fractionation columns. From the de ethanizer 40’ an off-gas stream 13 comprising the C2-compounds is separated, while in the LPG-splitter 40” a stream comprising the C3-C4 compounds, e.g. LPG stream 15 is separated. A gasoline stream 17 comprising the C5+ hydrocarbons (stabilized gasoline) is also separated and conducted to upgrading section 50 comprising HDI and/or HDC (not shown), for thereby producing upgraded gasoline stream 19.

The dehydrated methanol stream 9 is conducted to a mixing point, suitably in a mixing unit 60, and combined with other oxygenates externally sourced via stream 21. The de hydrated methanol stream 9, and the one or more oxygenates other than methanol in stream 21, are combined into a multi-oxygenate-blend 23 prior to blending with the up graded gasoline stream 19, suitably in mixing unit 70. The mixing point 60 may be omit ted, so that oxygenates externally sourced via 21 are combined directly with the dehy drated methanol stream 9 and the upgraded gasoline stream 19 in mixing unit 70. A gasoline product 25, i.e. product blend of gasoline with oxygenates, of higher octane rating than the upgraded gasoline is thereby withdrawn and transported to distribution points, i.e. fuel terminals. The increase in the octane rating of gasoline being produced in the process/plant is thus conducted in-situ, i.e. during operation of the process/plant 10.

EXAMPLES

Methanol/Ethanol/lsobutanol blends

Blends of gasoline with methanol/ethanol/isobutanol mixtures were studied in connec tion with a process/plant according the accompanying figure described above.

Methanol is one the options considered to boost octane that fulfills European specifica tions, as up to 3 vol% methanol and up to 3.7 wt% oxygen is allowed In U.S. plants; an EPA substantially similar ruling has established that methanol and butanol can be used in equal volumes such that the maximum oxygen content of the product blend of gaso line with oxygenates is not higher than 2.7 wt% and the total amount of oxygenates is not higher 5.5 vol%.

Example 1

The base gasoline is oxygenate-free and it is the base gasoline in the examples, thus in this application corresponding to upgraded gasoline. Vapor pressure (VP) and octane numbers for this and below examples are shown in Table .

Example 2

Sample name: Base gasoline_2.7M (with 2.7 vol.% methanol).

Blend of the base gasoline (Example 1) and 2.7 vol% methanol. The octane rating im provement by 2.7 vol% methanol is relatively modest (+1 AKI number); however, meth anol is readily available in a TIGAS plant (a methanol to gasoline plant). One of the possible disadvantages is the significant increase in VP (>3 psi).

Example 3

Sample name: Base gasoline_2.7M_2.7B (with 2.7 vol% methanol, 2.7 vol.% isobuta nol).

The blend of the base gasoline with methanol and a higher alcohol (here isobutanol), achieves a similar modest octane boost. As before, one of the advantages now is that methanol is available in readily available in the TIGAS process and that the increase is VP is not as pronounced as in the blend with only methanol. The oxygenates and oxy gen content in the blend with 2.7 methanol/2.7 isobutanol would be allowed by both EU EN228 and USA D4814. This is the only blend in Table that at present would be al lowed in USA, provided that the rest of the specifications are fulfilled.

Example 4

Sample name: Base gasoline_2.7M_4.4E_2.7B (with 2.7/4.2/2.6 vol% methanol/etha nol/isobutanol).

The blends of 2.7/4.2/2.6 vol% methanol/ethanol/isobutanol result in an oxygenates and oxygen content combination that would only be allowed in the EU. It is possible to obtain a somewhat greater octane boost effect with a multi-oxygenate blend of 2.7/4.2/2.6 vol% methanol/ethanol/isobutanol compared to 10.4 vol% ethanol

Example 5 Sample name: Base gasoline_2.7M_4.4E_2.7B_booster (as in Example 4 and a metal- free booster).

Further addition of 5000 wt ppm of the Dorf Ketal proprietary octane booster PX- 3495™ increase AKI by >1.0. On the other hand, the increase in VP caused by metha nol addition alone (>3 psi) is, to some extent, off-set by the ethanol and isobutanol in the multi-oxygenates blend (<2 psi).

Table 2, Vapor pressure {VP); Octane number: RON, MON, AKI.

Sample Name Method Base gasoBase gasoBase gaso- Base gaso- Base gaso- line line 2.7M line_2.7M_ line_2.7M_ line_2.7B_ 2.7B 4.4E 2.7B 5000PX3495 methanol methanol methanol, methanol, and isobutaethanol and ethanol, isonol isobutanol butanol and booster

Oxygenates, D 6729 0.0 2.6 5.2 9.5 9.5 vol%

Oxygen , wt% 0 1.40 1.98 3.60 3.58

Vapor PresD 5191 55.6 77.8 73.7 68.8 68.1 sure, kPa Vapor PresD 5191 8.1 11.3 10.7 10.0 9.9 sure, psi RON (Research D 2699 93.4 93.9 94.1 95.6 96.2 Octane No.) MON (Motor D 2700 82.3 83.7 83.9 84.4 85.2 Octane No.)

AKI (Antiknock 87.9 88.8 89.0 90.0 90.7 Index)

Change rela tive to the ref erence 2

VP change, D5191 22.2 18.1 13.2 12.5 kPa

VP change, psi D5191 3.2 2.6 1.9 1.8 RON improveD 2699 0.5 0.7 2.2 2.8 ment MON imD 2700 1.4 1.6 2.1 2.9 provement AKI improve1.0 1.2 2.2 2.9 ment

SG 60/60°F of 0.7511 0.7525 0.7451 0.7460 blend (D 4052) Methanol, 2.6 2.62 2.67 2.66 vol% (D 6729) Ethanol, vol% 4.24 4.22 (D 6729) Isobutanol, 2.58 2.60 2.59 vol% (D 6729) SG 60/60°F of 0.7963 0.7963 0.7963 0.7963 MeOH (D 4814Table X4.1)

SG 60/60°F of 0.7939 0.7939 EtOH (D 4814Table X4.1) SG 60/60°F of 0.8058 0.8058 0.8058 iBuOH (D 4814Table X4.1)

O mass frac0.4993 0.4993 0.4993 0.4993 tion MeOH (D 4814 Table X4.1)

O mass frac0.3473 0.3473 tion EtOH (D 4814 Table X4.1)

O mass frac0.2158 0.2158 0.2158 tion iBuOH(D 4814 Table X4.1)

Calculated O 1.40 1.98 3.60 3.58 content, wt%

SG 60/60°F of blend (D 4052)