WO2015070332A1

WO2015070332A1 - Conversion of synthesis gas into liquid hydrocarbons via fischer tropsch synthesis

Info

Publication number: WO2015070332A1
Application number: PCT/CA2014/000823
Authority: WO
Inventors: Franciscus Johanna Arnoldus Martens
Original assignee: Nexen Energy Ulc
Priority date: 2013-11-13
Filing date: 2014-11-13
Publication date: 2015-05-21
Also published as: CA2938299A1; CA2911660A1; CA2911660C

Abstract

A process for converting at least one synthesis gas, having a molar H₂ to CO ratio between about 0.25 and 1, into at least one hydrocarbon, via Fischer-Tropsch synthesis by contacting the at least one synthesis gas with at least one catalyst, forming at least one hydrocarbon, wherein said at least one catalyst has Water Gas Shift and Fischer-Tropsch synthesis activity.

Description

CONVERSION OF SYNTHESIS GAS INTO LIQUID HYDROCARBONS VIA

FISCHER TROPSCH SYNTHESIS

FIELD

[0001] The present disclosure relates to improvements in the Fischer-Tropsch ("FT") synthesis and/or process for converting synthesis gas into liquid hydrocarbons suitable for use as liquid fuel or as chemical feedstock.

BACKGROUND

[0002] FT-synthesis is a collection of catalyzed chemical reactions that converts a mixture of carbon monoxide (CO) and hydrogen (H₂) into hydrocarbons and water. A variety of catalysts have been used, but the commercially viable catalysts are comprised of the transition metals: cobalt, iron, and ruthenium. In addition to the transition metal, the catalysts typically contain a number of promoters, including alkali metal oxides and copper. The products of FT-synthesis include alkanes (hydrocarbons with a C-C single straight bond) and alkenes (also called olefins (hydrocarbons having at least one unsaturated C=C double bond)), which are both suitable for diesel fuel. Other FT-synthesis products include alcohol or other oxygenated hydrocarbons at times, which may be beneficial in some circumstances.

[0003] FT-synthesis has been undergoing development since the 1910's. Examples include the following: 1) BASF, German Patent DRP 293,787 (1913); 2) A. Mittasch and C. Schneider, US Patent 1,201,850 (1916); 3) Fischer and Tropsch, German Patent 484337 (1925); and 4) Kinetics of the Fischer-Tropsch Synthesis on Iron Catalysts (1964), Anderson, R.B. et al. Bulletin 614, Bureau of Mines, United States Department of the Interior.

[0004] Current market development and new application is directed toward FT- synthesis using a Cobalt-based catalyst for high FT activity and maximizing the production of long chained alkanes. Companies involved in Cobalt-based FT-synthesis include Shell (SMDS Bintulu, Pearl GTL Qatar) and Sasol (Oryx Qatar), as well as Velocys, BP-Davy, and Axens. When syngas feed is rich in H₂ and at preferred temperature, the Cobalt-based FT- synthesis reaction forms mainly alkanes and water according to the overall reaction: n CO + (2n+l) H₂ -» C_nH_2n+2 + n H₂0

[0005] The product is mainly paraffinic oil (saturated hydrocarbons). Consequently the overall molar H₂ to CO consumption ratio is about (2n+l)/n ~ 2. The typical Cobalt-based FT reaction temperature is 220 - 230 degrees Celsius.

[0006] Natural gas ("NG") is the most desirable feedstock from the standpoint of the 1) chemical H₂ demand, 2) the minimal cleaning steps required, and 3) the economics for stranded NG resources.

[0007] Liquid and solid based feedstocks have the drawback of shortage of H₂ in the reaction scheme, as well as process steps required to remove a larger range of impurities being present at larger quantities (e.g. sulfur containing compounds, ammonia, hydrogen cyanide, metal carbonyls, metals as gas or trapped in compounds/ashes).

[0008] Cobalt-based catalysts' Water Gas Shift ("WGS") activity is too low to compensate, for shortage of H₂.

[0009] Iron-based catalysts have both FT and WGS activity. The FT reaction produces

H₂0 (steam) (same as for the Cobalt-based catalyst), and at shortage of H₂, the WGS reaction responds as follows:

CO + H₂0 (steam) - C0₂ + H₂

[0010] The typical FT reaction temperature currently practiced is 220-240°C (low- temperature-FT) or 330-360°C (high-temperature-FT).

[001 1] With low H₂ present and at preferred temperatures, the combined FT and WGS reactions form mainly alkenes and C0₂ according to the overall reaction:

2n CO + n H₂ -» C_nH_2n+ n C0₂

[0012] The product is mainly olefinic oil (having at least one unsaturated C=C double bond). Consequently the overall molar ¾ to CO consumption ratio is about n/2n = ½ . By practice we found that the overall consumption ratio is closer to 0.55 than 0.50 [0013] The following is an example of a current process configuration used in the field:

[0014] A refinery, producing a heavy residual feedstock (vacuum residue, visbroken residue, or de-asphalter residue), being in need of 1 10,000 Sm /hr pure ¾ to satisfy the Hydro- cracker H₂ demand, and having the application of partial oxidation ("POX") of the residual feedstock, requires the subsequent raw synthesis gas cleanup step at a rate of 19,300 kmol/hr followed by hydrogen extraction via a pressure swing absorber ("PSA"), with the PSA-offgas used as a fuel gas and/or as feed to a combined cycle unit producing electricity and superheated steam. The POX synthesis gas has a molar ¾ to CO ratio of 0.9, and the PSA-offgas has a molar H₂ to CO ratio of 0.35.

[0015] The high value product is pure H₂, while the high CO containing PSA-offgas is only getting the heating equivalent value of Natural Gas, which in many regions now is a fraction of that of liquid fuels.

[0016] The economics for conversion of the CO-containing gas to liquid hydrocarbons is very attractive, even with increased consumption of Natural Gas to compensate for the alternative use of the CO-containing gas.

[0017] Two currently practised schemes are now discussed below. Both schemes apply a Cobalt-based catalyst. This requires an increase of the POX synthesis gas molar H₂ to CO ratio from 0.9 to about 1.8.

[0018] In the first scheme the desired ratio is achieved by mixing the H₂-lean POX synthesis gas with enough H₂-rich steam methane reformer ("SMR") synthesis gas having a molar H₂ to CO ratio of about six (6). This requires the integration of two (2) world scale SMRs. In addition, the hydro-cracker H₂ demand is to be satisfied via one additional world scale SMR + WGS + PSA combination. The FT hydrocarbon liquid production is between 21,000 and 29,000 bbl/day, depending on the design efficiency of the process (e.g. multiple reactors in series and/or FT-offgas recycle), and in the less efficient case, an even larger amount of FT-offgas is routed to the fuelgas pool. Although straightforward, the complexity added to the refinery is challenging. [0019] In the second scheme, the desired ratio is achieved by applying WGS to one portion of the POX synthesis gas, removing the C0₂ by acid gas absorption, and mixing this synthesis gas portion with the other portion of the POX synthesis gas. The FT hydrocarbon liquid production is between 10,000 and 12,000 bbl/day, depending on the design efficiency of the process (e.g. multiple reactors in series and/or FT-offgas recycle).

[0020] Unavoidably, the hydro-cracker H₂ demand needs to be satisfied, requiring the addition of one world scale SMR + WGS + PSA combination.

[0021] The FT reactions are exothermic, releasing some 15% of the chemical energy content of the synthesis gas, which typically is transferred via indirect heat exchange to raise saturated steam. The steam pressure controls the FT synthesis temperature. For a Cobalt-based FT catalyst, the synthesis is controlled below 230 degrees Celsius to prevent excessive CH₄ production. As a consequence, the co-production of saturated steam is at a pressure of 1.7 to 2.0 MPa only, which is of low value to the refinery.

[0022] There is a need to reduce complexity in existing FT process technologies.

[0023] There is also a need to generate steam at a more useful (higher) pressure. SUMMARY

[0024] In one aspect, there is provided a process for converting ¾-lean syngas into one or more hydrocarbons, comprising: supplying a H₂-lean syngas, including H₂ and CO in a molar ratio of less than 1.0, and adscititious H₂0 to the reaction zone such that a reaction mixture becomes disposed in sufficient proximity to a catalyst material within the reaction zone, the catalyst material having both water gas shift activity and Fischer-Tropsch synthetic activity, such that the conversion is effected.

[0025] In some implementations, for example, the H₂0 of the adscititious H₂0 is adscititious relative to any H₂0 that is produced during the conversion of the H -lean syngas [0026] In some implementations, for example, the effected conversion includes at least

Fischer-Tropsch synthesis.

[0027] In some implementations, for example, the H₂0 of the adscititious H₂0 is adscititious relative to any H₂0 that is produced during the Fischer-Tropsch synthesis.

[0028] In some implementations, for example, the reaction mixture is generated by admixing of the H₂-lean syngas and the adscititious H₂0.

[0029] In some implementations, for example, the supplying of the adscititious H₂0 to the reaction zone is effected independently of the supplying of the H₂-lean syngas to the reaction zone.

[0030] In some implementations, for example, the H₂0 of the adscititious H₂0 is in the form of steam.

[0031] In some implementations, for example, the molar H₂/CO ratio is between 0.25 and 1.0, such as, for example, between 0.25 and 0.6, and such as, for example, between 0.25 and 0.5.

[0032] In some implementations, for example, the ratio of moles of H₂ to moles of CO within the supplied ¾-lean syngas is less than 0.55, the ratio of moles of H₂0 of the supplied adscititious H₂0 to moles of CO of the supplied H₂-lean syngas is defined in accordance with the following formula:

H₂0/CO_feed = A x (0.55 - H₂/CO_feed) or, equivalently:

the ratio of moles of H₂0 of the supplied adscititious H₂0 to moles of CO of the supplied H₂- lean syngas =

A x (0.55 - (the ratio of moles of H₂ of the H₂-lean syngas to moles of CO of the H₂-lean syngas); wherein A is between 1.0 and 1.3 [0033] In some implementations, for example, prior to the supplying of the H₂-lean syngas to the reaction zone, any treatment of the H₂-lean syngas feedstock is such that no H₂ enrichment of the H₂-lean syngas is effected prior to the reaction zone.

[0034] In some implementations, for example, the catalyst material includes a Fe-based catalyst material.

[0035] In some implementations, for example, the catalyst material is activated.

[0036] In some implementations, for example, the catalyst material includes at least one promoter.

[0037] In some implementations, for example, the at least one promoter includes one or more metal oxides, and wherein the metal oxide is an oxide of any one of manganese, potassium, chromium, and copper.

[0038] In some implementations, for example, the reaction zone is disposed at a pressure of between 0.2 to 7 MPa, such as, for example, between 1.5 to 6 MPa, and such as, for example, between 1.5 to 3 MPa.

[0039] In some implementations, for example, the reaction zone is disposed at a temperature of between 240 degrees Celsius and 320 degrees Celsius, such as, for example, between 260 degrees Celsius and 300 degrees Celsius, and such as, for example, between 270 degrees Celsius and 290 degrees Celsius.

[0040] In some implementations, for example, at least one of the one or more hydrocarbons that are produced by the conversion is liquid at standard temperature and pressure conditions.

[0041] In some implementations, for example, the H₂-lean syngas is derived from any one of bitumen, heavy oil, shale oil, heavy hydrocarbon residues from a heavy oil or bitumen upgrading process, natural gas, coal, biomass, organic waste.

[0042] In some implementations, for example, the heavy hydrocarbon residue includes a residual product from any one of atmospheric distillation, vacuum distillation, deasphalting, coking, visbreaking, thermal cracking, fluid catalytic cracking, resid fluid catalytic cracking, or any combination thereof.

[0043] In another aspect, there is provided a process for upgrading a hydrocarbon feed comprising: converting the hydrocarbon feed to a first syngas; separating the first syngas into at least a H₂-rich stream and a H₂-lean syngas, wherein the H₂- lean syngas includes H₂ and CO in a molar ratio of less than 1.0; and supplying the ¾-lean syngas and adscititious H₂0 to the reaction zone such that a reaction mixture becomes disposed in sufficient proximity to a catalyst material within the reaction zone, the catalyst material having both water gas shift activity and Fischer-Tropsch synthetic activity, such that conversion of the H₂-lean syngas to one or more hydrocarbons is effected.

[0044] Relative to the H₂-lean syngas, the H₂-rich stream includes a higher concentration of H₂

[0045] In some implementations, for example, the H₂0 of the adscititious H₂0 is adscititious relative to any H₂0 that is produced during the conversion of the H₂-lean syngas.

[0046] In some implementations, for example, the effected conversion includes at least

Fischer-Tropsch synthesis.

[0047] In some implementations, for example, the H₂0 of the adscititious H₂0 is adscititious relative to any H₂0 that is produced during the Fischer-Tropsch synthesis.

[0048] In some implementations, for example, the reaction mixture is generated by admixing of the H₂-lean syngas and the adscititious H₂0.

[0049] In some implementations, for example, the supplying of the adscititious H₂0 to the reaction zone is effected independently of the supplying of the H₂-lean syngas to the reaction zone. [0050] In some implementations, for example, the H₂0 of the adscititious H₂0 is in the form of steam.

[0051] In some implementations, for example, the ratio of moles of H₂ to moles of CO within the H₂-lean syngas is between 0.25 and 1.0, such as, for example, between 0.25 and 0.6, and such as, for example, between 0.25 and 0.5.

[0052] In some implementations, for example, the ratio of moles of H₂ to moles of CO within the supplied H₂-lean syngas is less than 0.55, the ratio of moles of H₂0 of the supplied adscititious ¾0 to moles of CO of the supplied ¾-lean syngas is defined in accordance with the following formula:

H₂0/CO_feed = A x (0.55 - H₂/CO_feed) or, equivalently:

A x (0.55 - (the ratio of moles of H₂ of the H₂-lean syngas to moles of CO of the H₂-lean syngas); wherein A is between 1.0 and 1.3

[0053] In some implementations, for example, prior to the supplying of the H₂-lean syngas to the reaction zone, any treatment of the H₂-lean syngas feedstock is such that no H₂ enrichment of the H₂-lean syngas is effected prior to the reaction zone.

[0054] In some implementations, for example, the catalyst material includes a Fe-based catalyst material.

[0055] In some implementations, for example, the catalyst material is activated.

In some implementations, for example, the catalyst material includes at least [0057] In some implementations, for example, the at least one promoter includes one or more metal oxides, and wherein the metal oxide is an oxide of any one of manganese, potassium, chromium, and copper.

[0058] In some implementations, for example, the reaction zone is disposed at a pressure of between 0.2 to 7 MPa, such as, for example, between 1.5 to 6 MPa, and such as, for example, between 1.5 to 3 MPa.

[0059] In some implementations, for example, the reaction zone is disposed at a temperature of between 240 degrees Celsius and 320 degrees Celsius, such as, for example, between 260 degrees Celsius and 300 degrees Celsius, and such as, for example, between 270 degrees Celsius and 290 degrees Celsius.

[0060] In some implementations, for example, at least one of the one or more hydrocarbons that are produced by the conversion is liquid at standard temperature and pressure conditions.

[0061] In some implementations, for example, the heavy hydrocarbon residue includes a residual product from any one of atmospheric distillation, vacuum distillation, deasphalting, coking, visbreaking, thermal cracking, fluid catalytic cracking, resid fluid catalytic cracking, or any combination thereof.

[0062] In some implementations, for example, the converting of hydrocarbon feed to a first syngas is effected by any one of gasification, partial oxidation, auto-thermal reforming, steam reforming, or any combination thereof

[0063] In some implementations, for example, the process further comprises effecting hydrocracking with the H₂-rich stream separated from the first syngas.

[0064] In another aspect, there is provided a process for upgrading a hydrocarbon residue and producing bitumen (an oil based semi solid substance) via steam-assisted gravity drainage ("SAGD") using steam that is generated by at least the heat produced by the upgrading, comprising: converting the heavy hydrocarbon residue to a syngas product; converting the syngas product via at least Fischer-Tropsch synthesis, wherein the conversion is effected within a reaction zone disposed at a temperature of greater than 260 degrees Celsius; transferring heat, from the converting, to a steam generator; with the transferred heat, effecting generation of steam by the steam generator; and supplying steam to a hydrocarbon reservoir via a SAGD injection well to effect mobilization of bitumen within the hydrocarbon reservoir.

[0065] In some implementations, for example, the transferred heat is transferred from the reaction zone.

[0066] In some implementations, for example, the transferred heat is transferred from

Fischer-Tropsch products generated by the converting.

[0067] In some implementations, for example, the temperature within the reaction zone is between 260 degrees Celsius and 300 degrees Celsius, such as, for example, between 270 degrees Celsius and 290 degrees Celsius.

[0068] In some implementations, for example, the reaction zone is disposed at a pressure of between 0.2MPa to 7 MPa, such as, for example, between 1.5 MPa to 6 MPa, and such as, for example, 1.5 MPa to 3 MPa.

[0069] In some implementations, for example, the conversion is effected by a catalyst material.

[0070] In some implementations, for example, the catalyst material is activated.

[0071] In some implementations, for example, the catalyst material includes a Fe-based catalyst material.

[0072] In some implementations, for example, the catalyst material includes at least one promoter. [0073] In some implementations, for example, the at least one promoter includes one or more metal oxides, and wherein the metal oxide is an oxide of any one of manganese, potassium, chromium, and copper.

[0074] In some implementations, for example, at least one of the one or more hydrocarbons that are produced by the conversion by at least Fischer- Tropsch synthesis are liquid at standard temperature and pressure conditions.

[0075] In some implementations, for example, the converting of the heavy hydrocarbon residue includes: converting the heavy hydrocarbon to a first syngas; and separating the first syngas into at least a H₂-rich stream and a H₂-lean syngas, wherein the H₂- lean syngas defines the syngas product such that the conversion, by at least Fischer-Tropsch synthesis, is of the H₂-lean syngas.

[0076] In some implementations, for example, the process further comprises effecting hydrocracking with the H₂-rich stream separated from the first syngas.

[0077] In some implementations, for example, the H₂-lean syngas includes H₂ and CO in a molar ratio of less than 1.0, and prior to the conversion, by at least Fischer-Tropsch synthesis, the process further comprises: supplying the H₂-lean syngas and adscititious H₂0 to the reaction zone such that a reaction mixture becomes disposed in sufficient proximity to a catalyst material within the reaction zone, the catalyst material having both water gas shift activity and Fischer-Tropsch synthetic activity, such that the conversion, by at least Fischer- Tropsch synthesis, is effected.

[0078] In some implementations, for example, the H₂0 of the adscititious H₂0 is adscititious relative to any H₂0 that is produced during the conversion of the H₂-lean syngas.

[0079] In some implementations, for example, the H₂0 of the adscititious H₂0 is adscititious relative to any H₂0 that is produced during the Fischer-Tropsch synthesis. [0080] In some implementations, for example, the reaction mixture is generated by admixing of the H₂-lean syngas and the adscititious H₂0.

[0081] In some implementations, for example, the supplying of the adscititious H₂0 to the reaction zone is effected independently of the supplying of the H₂-lean syngas to the reaction zone.

[0082] In some implementations, for example, the H₂0 of the adscititious H₂0 is in the form of steam.

[0083] In some implementations, for example, the ratio of moles of H₂ to moles of CO within the supplied H₂-lean syngas is between 0.25 and 1.0, such as, for example, between 0.25 and 0.6, and such as, for example, between 0.25 and 0.5.

[0084] In some implementations, for example, when the ratio of moles of H₂ to moles of CO within the supplied H₂-lean syngas is less than 0.55, the ratio of moles of H₂0 of the supplied adscititious H₂0 to moles of CO of the supplied H₂-lean syngas is defined in accordance with the following formula:

H₂0/CO_feed = A x (0.55 - H₂/CO_fted) or, equivalently:

A x (0.55 - (the ratio of moles of H₂ of the H₂-lean syngas to moles of CO of the H₂-lean syngas); wherein A is between 1 and 1.3.

[0085] In some implementations, for example, prior to the supplying of the H₂-lean syngas to the reaction zone, any treatment of the H₂-lean syngas feedstock is such that no H₂ enrichment of the H₂-lean syngas is effected prior to the reaction zone.

[0086] In some implementations, for example, the heavy hydrocarbon residue includes a residual product from any one of atmospheric distillation, vacuum distillation, deasphalting, coking, visbreaking, thermal cracking, fluid catalytic cracking, resid fluid catalytic cracking, or any combination thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

[0087] In the drawings, embodiments of the invention are illustrated by way of example. It is to be expressly understood that the description and drawings are only for the purpose of illustration and as an aid to understanding, and are not intended as a definition of the limits of the invention.

[0088] Embodiments will now be described, by way of example only, with reference to the attached figures, wherein:

[0089] Figure 1 is a flow diagram illustrating the processing of a synthesis gas via a

Fischer-Tropsch synthesis;

[0090] Figure 2 is a flow diagram illustrating the processing of a synthesis gas, produced by a heavy oil or bitumen upgrading process, via a Fischer-Tropsch synthesis; and

[0091] Figure 3 is a flow diagram illustrating the processing of a synthesis gas via a

Fischer-Tropsch synthesis, and using heat produced within the process for generating steam for use in a steam-assisted gravity drainage process.

DETAILED DESCRIPTION

[0092] Referring now to Figure 1 , there is provided a configuration used in processing synthesis gas, according to one embodiment.

[0093] Synthesis gas (or "syngas") 10 is fed into a guard bed 20, to remove any catalyst poisons (such as H₂S, COS, NH₃, HCN) from the synthesis gas 10, prior to introduction into a Fisher-Tropsch ("FT") reactor 30 which includes an Iron-based catalyst 31. The FT process is effected within the FT reactor 30. The effluent from FT reactor 30 consists of two streams, a first stream being a wax product stream 40, and a second stream 50 that is cooled via a cooler 60 and further separated via a separator 70, into three streams, an aqueous product stream 41, an oil product stream 42 and a tail-gas stream 39. The tail-gas stream 39 is recovered via olefin oligomerization 80, resulting in an oil product stream 46 and a fuel gas stream that optionally is separated 81 into a hydrogen gas stream 44, which is sent to an upgrader, an LPG product stream 43 for sales, and a residual fuel gas stream 45.

[0094] Table 1 below provides the data when implementing the FT process using the system configuration of Figure 1 when the feed 10 is derived from partial oxidation ("POX") synthesis gas. Table 2 below provides data when implementing the FT process using the system configuration of Figure 1 when the feed 10 is derived from a H₂-lean syngas resulting from separating a POX synthesis gas into at least a H₂-rich stream and a H₂-lean syngas, such as, for example, by way of a separation effected by pressure swing absorption. Relative to the H₂-lean syngas, the H₂-rich stream includes a higher concentration of H₂.

TABLE 1 POX synthesis gas (syngas) processed according Figure 1.

TABLE 2 PSA-offgas (syngas) processed according Figure 1.

Table 3 below summarizes the two cases.

TABLE 3

[0095] Referring now to Figure 2, there is depicted a process for FT synthesis from a synthesis gas in a typical heavy oil or bitumen-processing scenario, according to another embodiment.

Step 1

[0096] A hydrocarbon stream 100 is generated from

(a) a residual (reject) product from i) atmospheric distillation, ii) vacuum distillation, iii) de- asphalting, iv) visbreaking, v) coking, or

(b) from concentrated biomass, such as via i) torrefaction or ii) liquefaction (hydrothermal, pyrolysis).

Step 2

[0097] A raw synthesis gas 120 is generated by partial oxidation (gasification) 1 10 of the hydrocarbon stream 100 obtained in step 1.

[0098] The molar H₂ to CO ratio of said synthesis gas 120 is optionally tuned by proper selection of

(a) the gasification temperature and/or

(b) moderator addition (e.g. water, steam or C0₂), and/or

(c) co-firing of a lighter hydrocarbon such as i) natural gas, ii) refinery gas, iii) FT-offgas,

(d) off-spec or surplus of liquids such as FT-liquids, methanol etc. Step 3

[0099] The raw synthesis gas 120 is cleaned and modified in any possible sequence and way, such as:

(a) washing or scrubbing with water (not shown)

i) to remove solids, and/or

ii) to remove gaseous component (NH₃, HCN, COS, H₂S), optionally in

chilled water, and/or

iii) to remove water vapor, optionally with chilled water

(b) catalyst enhanced conversion COS and HCN hydrolysis 130, such as over an alumina bed, a ZnO bed or other oxide containing catalyst, prior to acid gas removal

(c) acid gas removal 140 (H₂S, C0₂, COS, NH₃, HCN, iron carbonyl, nickel carbonyl) using i) amine liquid (such as MEA, DEA, MDEA or DIPA process);

ii) alcoholic liquid (such as methanol with Rectisol process); or

iii) glycol liquid (such as dimethyl ethers of polyethylene glycol with

Selexol process)

(d) absorption on guard-bed 150 (active carbon, zinc-oxide, zinc-copper) or sacrificial-bed 160 (catalyst, spent Iron-based FT catalyst)

(e) modified by adding C0₂ and/or steam at suitable temperature over suitable catalyst to modify the H₂ to CO ratio of the synthesis gas (not shown).

(f) modified by extracting H₂ 170, such as via

i) a PSA process, and/or

ii) via a membrane, having the advantage that the CO rich gas remains

at pressure (so no FT feedgas compressor required),

and with minimum depressurization of the H₂ pure gas (not shown).

Step 4 [00100] The cleaned and modified synthesis gas, of any one of the processes in Step 3, is compressed or letdown to a suitable pressure and heated or cooled 180 as required for FT- synthesis.

(a) Advantageously with Step 3f, the compression of PSA tailgas results in a temperature increase, reducing the need for external heating.

(b) Advantageously with Step 3d, the removal of catalyst poison over a sacrificial catalyst, such as an Iron-based FT catalyst, results in a desirable temperature increase.

Step 5

[00101] Optionally, if desired, the clean and conditioned synthesis gas of Step 4 may be treated for H₂ to CO ratio by any of the following:

(a) addition of H₂ 190, such as from excess of H₂ available (not needed by hydro-cracker 200), and/or

(b) addition of a H₂-rich gas such as from

i) a steam methane reformer ("SMR") with or without a downstream WGS

Converter,

being dry (majority of the water condensed) or being wet (not shown); ii) an auto thermal reformer (not shown);

iii) a partial oxidation process (115) using a light feedstock

(such as natural gas, refinery gas, methanol, naphtha), requiring

relatively few and easy cleaning steps;

(c) addition of steam (adscititious H₂0) 210, such as by admixing with the synthesis gas of Step 4, intended for increasing the H₂ content of the synthesis gas (where the synthesis is a H₂- lean synthesis gas, wherein the H₂-lean synthetis gas includes H₂ and CO in a molar ratio of less 1.0, such as between 0.25 and 1.0, such as between 0.25 and 0.6, such as between 0.25 and 0.5) via the in-situ watergas shift ("WGS") occurring at the FT-catalyst; and/or (d) no additional modification of the synthesis gas.

Step 6

[00102] The synthesis gas of Step 4 or 5 is processed in a FT reactor 220 over a FT- synthesis active catalyst that is also a WGS active catalyst.

In this embodiment, the FT reactor 220 is selected from:

(a) one single reactor, or multiple reactors in parallel having the inlets and outlets connected to a common inlet- and outlet-header respectively; recycling of part of the product gas stream from the reactor(s) to the feed synthesis gas stream to the reactor(s) is optional; if recycle of product gas is applied, then, optionally, the recycle stream is treated, and there is further included, optionally: i) removing some FT liquid product 230 and/or condensable water 240 by

subsequent cooling, discharging and reheating, and/or

ii) removing FT gases 250 that reduce the conversion rate and/or reaction

selectivity, such as H₂0 and/or C0₂; or

(b) two or more reactors in series, with optional intermediate removal of some FT liquid product and/or condensable water by subsequent cooling, discharging and reheating, and/or with optional removing FT gases that reduce the conversion rate and/or reaction selectivity, such as H₂0 and/or C0₂.

Each reactor may be constructed from multiple reactors in parallel having the inlets and outlets connected to common inlet- and outlet-headers respectively.

[00103] FT-synthesis is an exothermal process, with FT hydrocarbon product distribution being very sensitive to the process temperature. The higher the temperature the more undesirable gases are produced (e.g. CH₄) at higher temperatures. The FT reaction temperature may be controlled by indirect exchange of the heat of reaction with water at boiling conditions, whereby the steam or water pressure is the regulating factor. For the FT catalyst in a fixed bed configuration, the heat can be exchanged via a shell and tube heat exchanger with the catalyst at the tube side and the boiling water at the shell side. The reverse configuration can also be practiced. For the FT catalyst in a slurry the three phase (catalyst, hydrocarbon, gas) bubble column reactor is cooled via a submerged heat exchanger, such as cooling coils having boiling water as a coolant on coil side. In some embodiments, for example, the temperature within the reaction zone of the FT reactor is between 240 degrees Celsius and 320 degrees Celsius (such as, for example, between 260 degrees Celsius and 300 degrees Celsius, such as, for example, between 270 degrees Celsius and 290 degrees Celsius). By providing such reaction zone temperature, boiling water may be produced at a pressure, such as 4.2 MPa which is suitable for application to steam-assisted gravity drainage ("SAGD"), without significantly increasing light gas production.

[00104] In some embodiments, for example, the reactor zone of the FT reactor is disposed at a pressure of between 0.2 and 7 MPa, such as between 1.5 and 6MPa, such as between 1.5 and 3MPa.

[00105] It has been found that the FT synthesis activation energy increases when lowering the H₂ to CO ratio of the synthesis gas. Thus, for given temperature, the FT conversion rate reduces when lowering the H₂ to CO ratio of the synthesis gas. For the application of synthesis gas with low H₂ to CO ratio the increase of the FT-reaction temperature from the typical 220-240 degrees Celsius to 270-290 degrees Celsius range or above is advantageous, as it increases the conversion rate.

[00106] In comparison to the Cobalt-based catalysts, the Iron-based catalyst advantageously supports the higher FT-reactor temperature without producing relatively undesirable high quantities of CH₄, versus the Cobalt-based catalyst. For the higher FT-reactor temperature application, one or more promoters, such as one or more oxides of the elements manganese and/or potassium and/or chromium and/or copper are contained in the Iron-based catalyst formulation to improve stability and performance.

[00107] The Iron-based catalyst supports the WGS reaction, while the Cobalt based catalyst does not. [00108] For the Iron-based catalyst, and for a synthesis gas having, at the FT reactor inlet, a molar H₂ to CO ratio below the overall consumption ratio of 0.55, the total CO consumption rate per reactor pass is high, as the CO consumption occurs from both the FT- synthesis and the WGS reaction. Effective utilization of the CO and H₂ can be achieved in one reactor pass without the need for FT-offgas recycling.

[00109] A further benefit of the described process is, that by employing a low H₂ to CO ratio synthesis gas, the water partial pressure in the FT reactor remains low, which sustains long catalytic service. Namely, oxidation of the Iron-based catalyst by water is a much more important deactivation mechanism than the deactivation mechanism by C0₂.

[001 10] Another benefit of the described process is that in employing a more CO rich synthesis gas, the H₂ availability is lower which suppressing termination of the hydrocarbon chain growth (resulting in more heavy waxes) and suppressing methane formation.

Step 7

[001 1 1] Treatment or refining of the FT-products.

(a) Light olefin recovery 225.

With the Iron-based catalyst and at the higher FT-reactor temperature, some more light alkenes (olefins) are produced. In principle this reduces the yield of the liquid hydrocarbons (C₅-C₂₂).

The light products can largely be recovered by the polymerization of the light (C₂-C₅) olefins over an appropriate catalyst that is known in the art.

In some embodiments, for example, the conversion is over an acidic catalyst.

In some embodiments, for example, by processing the reagents over a solid phosphoric acid catalyst (for example, UOP CatPoly process), a high-octane olefinic motor gasoline and some distillate may be yielded. In some embodiments, for example, processing the reagents over an acidic MFI-type zeolite catalyst (for example, PetroSA Conversion of Olefins to Distillate process), yielding some olefinic naphtha and distillate.

In all cases the products can be used as is, separated in appropriate fractions, and/or further refined (e.g. by hydro-processing).

(b) Suitable use of FT-offgas 250 as a fuelgas

The remainder of the FT-offgas is made suitable as a fuelgas for firing in boilers 256 by: i) condensing of the majority of the water vapor and removal of the water, ii) condensing and removal of the hydrocarbon (e.g. paraffins, that

may solidify and block feed lines upon further cool down,

iii) optional scrubbing of the offgas to remove C0₂ 255 (acid gas removal such as via amine or Selexol), with the objective to increase the fuelgas heating value and/or for C0₂ production and/or purification (e.g. for carbon capture).

(c) Distillation 260 of FT liquid hydrocarbons

Naphtha is a desirable product, as it is in high demand as a diluent in the bitumen mining. The boiling range is between 30 and 200 degrees Celsius, with carbon number between five (5) and twelve (12). By distillation this fraction is removed, and the remainder is used as a chemical feedstock or treated in a hydro-cracker.

(d) Hydro-cracking or Thermal-cracking

The bottom product of the distiller is fed to the hydro-cracker 200, which is to produce lighter products by i) breaking alkane (paraffinic) chains, and/or ii) to saturate the C=C double bond of the alkenes (olefins) and/or to break-down oxygenates.

Alternatively the bottom product can be co-processed with the de-asphalted oil in a thermal cracker.

(e) The hydrocarbon products, oxygenates and water-soluble oxygenates can be processed in various other ways as described in the art (e.g. De Klerk, A. Fischer-Tropsch refining; Wiley- VCH: Weinheim, 201 1 ; ISBN 978-3-527-32605-1).

[001 12] In some embodiments, for example, heat, at between 260 degrees Celsius and 300 degrees Celsius (such as, for example, between 270 degrees Celsius and 290 degrees Celsius), is transferred from the process to effect steam generation at 4.2 MPa. In this respect, and referring to Figure 3, there is provided a process upgrading a hydrocarbon residue and producing bitumen via steam-assisted gravity drainage ("SAGD") using steam that is generated by at least the heat produced by the upgrading. The process includes:

(a) converting the heavy hydrocarbon residue 500 (such as, for example, resulting from processing of bitumen or heavy oil) to a syngas product 502, such as, for example, in a gasifier 504;

(b) converting the syngas product 502 to one or more hydrocarbons 508 via at least Fischer- Tropsch synthesis within a reactor 506, wherein the conversion is effected within a reaction zone disposed at a temperature of greater than 260 degrees Celsius;

(c) transferring heat, from the converting, to a steam generator 510;

(d) with the transferred heat, effecting generation of steam 512 by the steam generator from water 51 1 ; and

(e) supplying steam to a hydrocarbon reservoir via an injection well 514 (of a SAGD well pair including the injection well 514 and the production well 516) to effect mobilization of bitumen within the hydrocarbon reservoir. [001 13] In the above description, for purposes of explanation, numerous details are set forth in order to provide a thorough understanding of the present disclosure. However, it will be apparent to one skilled in the art that these specific details are not required in order to practice the present disclosure. Although certain dimensions and materials are described for implementing the disclosed example embodiments, other suitable dimensions and/or materials may be used within the scope of this disclosure. All such modifications and variations, including all suitable current and future changes in technology, are believed to be within the sphere and scope of the present disclosure. All references mentioned are hereby incorporated by reference in their entirety.

Claims

1. A process for converting H₂-lean syngas into one or more hydrocarbons, comprising: supplying a H₂-lean syngas, including H₂ and CO in a molar ratio of less than 1.0, and adscititious H₂0 to the reaction zone such that a reaction mixture becomes disposed in sufficient proximity to a catalyst material within the reaction zone, the catalyst material having both water gas shift activity and Fischer-Tropsch synthetic activity, such that the conversion is effected.

2. The process as claimed in claim 1 ; wherein the H₂0 of the adscititious H₂0 is adscititious relative to any H₂0 that is produced during the conversion of the H₂-lean syngas

3. The process as claimed in claim 1 ; wherein the effected conversion includes at least Fischer-Tropsch synthesis

4. The process as claimed in claim 3 ; wherein the H₂0 of the adscititious H₂0 is adscititious relative to any H₂0 that is produced during the Fischer-Tropsch synthesis

5. The process as claimed in any one of claims 1 to 4; wherein the reaction mixture is generated by admixing of the H₂-lean syngas and the adscititious H₂0.

6. The process as claimed in any one of claims 1 to 5; wherein supplying of the adscititious H₂0 to the reaction zone is effected independently of the supplying of the H₂-lean syngas to the reaction zone.

7. The process as claimed in any one of claims 1 to 6; wherein the H₂0 of the adscititious H₂0 is in the form of steam.

8. The process as claimed in any one of claims 1 to 7; wherein the ratio of moles of H₂ to moles of CO within the supplied H₂-lean syngas is between 0.25 and 1.0.

9. The process as claimed in any one of claims 1 to 7; wherein the ratio of moles of H₂ to moles of CO within the supplied H₂-lean syngas is between 0.25 and 0.6.

10. The process as claimed in any one of claims 1 to 7; wherein the ratio of moles of H₂ to moles of CO within the supplied H₂-lean syngas is between 0.25 and 0.5.

1 1. The process as claimed in any one of claims 1 to 10; wherein when the ratio of moles of ¾ to moles of CO within the supplied H₂-lean syngas is less than 0.55, the ratio of moles of H₂0 of the supplied adscititious ¾0 to moles of CO of the supplied H₂-lean syngas is defined in accordance with the following formula: the ratio of moles of ¾0 of the supplied adscititious H₂0 to moles of CO of the supplied H₂- lean syngas =

12. The process as claimed in any one of claims 1 to 11 ; wherein, prior to the supplying of the ¾-lean syngas to the reaction zone, any treatment of the H₂-lean syngas feedstock is such that no H₂ enrichment of the H₂-lean syngas is effected prior to the reaction zone.

13. The process as claimed in any one of claims 1 to 12; wherein the catalyst material includes a Fe-based catalyst material.

14. The process as claimed in claim 13; wherein the catalyst material includes at least one promoter.

15. The process as claimed in claim 13; wherein the at least one promoter includes one or more metal oxides, and wherein the metal oxide is an oxide of any one of manganese, potassium, chromium, and copper.

16. The process as claimed in any one of claims 1 to 15; wherein the reaction zone is disposed at a pressure of between 0.2 to 7 MPa.

17. The process as claimed in any one of claims 1 to 15; wherein the reaction zone is disposed at a pressure of between 1.5 to 6 MPa.

18. The process as claimed in any one of claims 1 to 15; wherein the reaction zone is disposed at a pressure of between 1.5 to 3 MPa.

19. The process as claimed in any one of claims 1 to 18; wherein the reaction zone is disposed at a temperature of between 240 degrees Celsius and 320 degrees Celsius.

20. The process as claimed in any one of claims 1 to 18; wherein the reaction zone is disposed at a temperature of between 260 degrees Celsius and 300 degrees Celsius.

21. The process as claimed in any one of claims 1 to 18; wherein the reaction zone is disposed at a temperature of between 270 degrees Celsius and 290 degrees Celsius.

22. The process as claimed in any one of claims 1 to 21 ; wherein at least one of the one or more hydrocarbons that are produced by the conversion is liquid at standard temperature and pressure conditions.

23. The process as claimed in any one of claims 1 to 22; wherein the H₂-lean syngas is derived from any one of bitumen, heavy oil, shale oil, heavy hydrocarbon residues from a heavy oil or bitumen upgrading process, natural gas, coal, biomass, organic waste.

24. The process as claimed in claim 23; wherein the heavy hydrocarbon residue includes a residual product from any one of atmospheric distillation, vacuum distillation, deasphalting, coking, visbreaking, thermal cracking, fluid catalytic cracking, resid fluid catalytic cracking, or any combination thereof.

25. A process for upgrading a hydrocarbon feed comprising: converting the hydrocarbon feed to a first syngas; separating the first syngas into at least a H₂-rich stream and a H₂-lean syngas, wherein the H₂- lean syngas includes H₂ and CO in a molar ratio of less than 1.0, and supplying the H₂-lean syngas and adscititious H₂0 to the reaction zone such that a reaction mixture becomes disposed in sufficient proximity to a catalyst material within the reaction zone, the catalyst material having both water gas shift activity and Fischer-Tropsch synthetic activity, such that conversion of the H₂-lean syngas to one or more hydrocarbons is effected.

26. The process as claimed in claim 25; wherein the H₂0 of the adscititious H₂0 is adscititious relative to any H₂0 that is produced during the conversion of the H₂-lean syngas.

27. The process as claimed in claim 25; wherein the effected conversion includes at least Fischer-Tropsch synthesis

28. The process as claimed in claim 27; wherein the H₂0 of the adscititious H₂0 is adscititious relative to any H₂0 that is produced during the Fischer-Tropsch synthesis.

29. The process as claimed in any one of claims 25 to 28; wherein the reaction mixture is generated by admixing of the H₂-lean syngas and the adscititious H₂0.

30. The process as claimed in any one of claims 25 to 29;

Wherein supplying of the adscititious H₂0 to the reaction zone is effected independently of the supplying of the H₂-lean syngas to the reaction zone.

31. The process as claimed in any one of claims 25 to 30; wherein the H₂0 of the adscititious H₂0 is in the form of steam.

32. The process as claimed in any one of claims 25 to 31 ; wherein the ratio of moles of H₂ to moles of CO within the supplied H₂-lean syngas is between 0.25 and 1.0.

33. The process as claimed in any one of claims 25 to 31 ; wherein the ratio of moles of H₂ to moles of CO within the supplied H₂-lean syngas is between 0.25 and 0.6.

34. The process as claimed in any one of claims 25 to 31 ; wherein the ratio of moles of H₂ to moles of CO within the supplied H₂-lean syngas is between 0.25 and 0.5.

35. The process as claimed in any one of claims 25 to 34; wherein when the ratio of moles of ¾ to moles of CO within the supplied H₂-lean syngas is less than 0.55, the ratio of moles of ¾0 of the supplied adscititious H₂0 to moles of CO of the supplied H₂-lean syngas is defined in accordance with the following formula: the ratio of moles of H₂0 of the supplied adscititious H₂0 to moles of CO of the supplied H₂- lean syngas =

A x (0.55 - (the ratio of moles of ¾ of the H₂-lean syngas to moles of CO of the H₂-lean syngas); wherein A is between 1.0 and 1.3.

36. The process as claimed in any one of claims 25 to 35; wherein, prior to the supplying of the H₂-lean syngas to the reaction zone, any treatment of the H₂-lean syngas feedstock is such that no ¾ enrichment of the H₂-lean syngas is effected prior to the reaction zone.

37. The process as claimed in any one of claims 25 to 36; wherein the catalyst material includes a Fe-based catalyst material.

38. The process as claimed in claim 37; wherein the catalyst material includes at least one promoter.

39. The process as claimed in claim 37; wherein the at least one promoter includes one or more metal oxides, and wherein the metal oxide is an oxide of any one of manganese, potassium, chromium, and copper.

40. The process as claimed in any one of claims 25 to 39; wherein the reaction zone is disposed at a pressure of between 0.2 to 7 MPa.

41. The process as claimed in any one of claims 25 to 39; wherein the reaction zone is disposed at a pressure of between 1.5 to 6 MPa.

42. The process as claimed in any one of claims 25 to 39; wherein the reaction zone is disposed at a pressure of between 1.5 to 3 MPa.

43. The process as claimed in any one of claims 25 to 42; wherein the reaction zone is disposed at a temperature of between 240 degrees Celsius and 320 degrees Celsius.

44. The process as claimed in any one of claims 25 to 42; wherein the reaction zone is disposed at a temperature of between 260 degrees Celsius and 300 degrees Celsius.

45. The process as claimed in any one of claims25 to 42; wherein the reaction zone is disposed at a temperature of between 270 degrees Celsius and 290 degrees Celsius.

46. The process as claimed in any one of claims 25 to 45; wherein at least one of the one or more hydrocarbons that are produced by the conversion is liquid at standard temperature and pressure conditions.

47. The process as claimed in any one of claim 25 to 46; wherein the heavy hydrocarbon residue includes a residual product from any one of atmospheric distillation, vacuum distillation, deasphalting, coking, visbreaking, thermal cracking, fluid catalytic cracking, resid fluid catalytic cracking, or any combination thereof.

48. The process as claimed in any one of claims 25 to 47; wherein the converting of hydrocarbon feed to a first syngas is effected by any one of gasification, partial oxidation, auto-thermal reforming, steam reforming, or any combination thereof

49. The process as claimed in any one of claims 25 to 48; further comprising: effecting hydrocracking with the H₂-rich fraction.

50. A process for upgrading a hydrocarbon residue and producing bitumen (oil based semi solid substance) via steam-assisted gravity drainage ("SAGD") using steam that is generated by at least the heat produced by the upgrading, comprising: converting the heavy hydrocarbon residue to a syngas product; converting the syngas product via at least Fischer-Tropsch synthesis, wherein the conversion is effected within a reaction zone disposed at a temperature of greater than 260 degrees Celsius; transferring heat, from the converting, to a steam generator; with at least the transferred heat, effecting generation of steam by the steam generator; and supplying steam to a hydrocarbon reservoir via a SAGD injection well to effect mobilization of bitumen within the hydrocarbon reservoir.

51. The process as claimed in claim 50; wherein the transferred heat is transferred from the reaction zone.

52. The process as claimed in claim 50 or 51 ; wherein the transferred heat is transferred from Fischer-Tropsch products generated by the converting.

53. The process as claimed in any one of claims 50 to 52; wherein the temperature within the reaction zone is between 260 degrees Celsius and 320 degrees Celsius.

54. The process as claimed in any one of claims 50 to 52; wherein the temperature within the reaction zone is between 270 degrees Celsius and 290 degrees Celsius.

55. The process as claimed in any one of claims 50 to 54; wherein the reaction zone is disposed at a pressure of between 0.2MPa to 7 MPa.

56. The process as claimed in any one of claims 50 to 54; wherein the reaction zone is disposed at a pressure of between 1.5 MPa to 6 MPa.

57. The process as claimed in any one of claims 50 to 54; wherein the reaction zone is disposed at a pressure of between 1.5 MPa to 3 MPa.

58. The process as claimed in any one of claims 50 to 57; wherein the conversion is effected by a catalyst material.

59. The process as claimed in claim 58; wherein the catalyst material include a Fe-based catalyst material.

60. The process as claimed in claim 58 or 59; wherein the catalyst material includes at least one promoter.

61. The process as claimed in claim 60; wherein the at least one promoter includes one or more metal oxides, and wherein the metal oxide is an oxide of any one of manganese, potassium, chromium, and copper.

62. The process as claimed in any one of claims 50 to 61 ; wherein at least one of the one or more hydrocarbons that are produced by the conversion by at least Fischer-Tropsch synthesis are liquid at standard temperature and pressure conditions.

63. The process as claimed in any one of claims 50 to 62; wherein the converting of the heavy hydrocarbon residue includes: converting the heavy hydrocarbon to a first syngas; and separating the first syngas into at least a H₂-rich stream and a ¾-lean syngas, wherein the H₂-lean syngas defines the syngas productsuch that the conversion, by at least Fischer-Tropsch synthesis, is of the the H₂-lean syngas.

64. The process as claimed in claim 63, further comprising: effecting hydrocracking with the H2-rich stream.

65. The process as claimed in claim 63 or 64; wherein the H₂-lean syngas includes H₂ and CO in a molar ratio of less than 1.0; and wherein, prior to the conversion, by at least Fischer-Tropsch synthesis, the process further comprises: supplying the H₂-lean syngas and adscititious H₂0 to the reaction zone such that a reaction mixture becomes disposed in sufficient proximity to a catalyst material within the reaction zone, the catalyst material having both water gas shift activity and Fischer-Tropsch synthetic activity, such that the conversion, by at least Fischer-Tropsch synthesis, is effected.

66. The process as claimed in claim 65; wherein the H₂0 of the adscititious H₂0 is adscititious relative to any H₂0 that is produced during the conversion of the H₂-lean syngas

67. The process as claimed in claim 65 or 66; wherein the H₂0 of the adscititious H₂0 is adscititious relative to any H₂0 that is produced during the Fischer-Tropsch synthesis.

68. The process as claimed in any one of claims 65 to 67; wherein the reaction mixture is generated by admixing of the H₂-lean syngas and the adscititious H₂0.

69. The process as claimed in any one of claims 65 to 68; wherein the supplying of the adscititious H₂0 to the reaction zone is effected independently of the supplying of the H₂-lean syngas to the reaction zone.

70. The process as claimed in any one of claims 65 to 69; wherein the H₂0 of the adscititious H₂0 is in the form of steam.

71. The process as claimed in any one of claims 65 to 70; wherein the ratio of moles of H₂ to moles of CO within the supplied H₂-lean syngas is between 0.25 and 1.0.

72. The process as claimed in any one of claims 65 to 70; wherein the ratio of moles of H₂ to moles of CO within the supplied H₂-lean syngas is between 0.25 and 0.6.

73. The process as claimed in any one of claims 65 to 70; wherein the ratio of moles of H₂ to moles of CO within the supplied H₂-lean syngas is between 0.25 and 0.5.

74. The process as claimed in any one of claims 65 to 73; wherein, when the ratio of moles of H₂ to moles of CO within the supplied H₂-lean syngas is less than 0.55, the ratio of moles of H₂0 of the supplied adscititious H₂0 to moles of CO of the supplied H₂-lean syngas is defined in accordance with the following formula: the ratio of moles of H₂0 of the supplied adscititious H₂0 to moles of CO of the supplied H₂- lean syngas = A x (0.55 - (the ratio of moles of H₂ of the H₂-lean syngas to moles of CO of the H₂-lean syngas); wherein A is between 1 and 1.3.

75. The process as claimed in any one of claims 65 to 74; wherein, prior to the supplying of the ¾-lean syngas to the reaction zone, any treatment of the H₂-lean syngas feedstock is such that no H₂ enrichment of the ¾-lean syngas is effected prior to the reaction zone.

76. The process as claimed in any one of claims 65 to 75; wherein the heavy hydrocarbon residue includes a residual product from any one of atmospheric distillation, vacuum distillation, deasphalting, coking, visbreaking, thermal cracking, fluid catalytic cracking, resid fluid catalytic cracking, or any combination thereof.