Synergy of the Conventional Crude Oil and the FT-GTL Processes for Sustainable Synfuels Production: The Game Changer Approach-Phase One Category

Introduction

The term Petroleum simply refers to “crude oil and natural gas a.k.a. crude oil petroleum and natural gas petroleum” which broadly encompasses Natural Gas, Shale Gas/Tight Gas, Gas Condensate, Crude Oil, Tight Oil/Shale Oil (oil-in-shale), Bitumen (sticky black pools or pitch or tar), Natural Asphalts (sticky black lumps), Oil Shale (shale- bearing-oil), Oil Sand/Tar Sand, and Gas Hydrate. It falls into two broad categories (conventional and unconventional). The conventional crude oil petroleum exists naturally in liquid form while the conventional natural gas petroleum exists naturally in gaseous form. On the other hand, the unconventional crude oil petroleum exists naturally in semi- solid or solid forms such as {Extra-heavy oil, Tight Oil/Shale Oil (oil-in-shale), Bitumen (sticky black pools or pitch or tar), Natural Asphalts (sticky black lumps), Oil Shale (shale- bearing-oil), Oil Sand/Tar Sand} while the unconventional natural gas petroleum exists naturally as [Distillate or Condensate gas or Condensable Vapor, Shale Gas/Tight Gas, Gas Hydrate]. Petroleum in all its form, is composed primarily of hydrocarbons (compounds containing only carbon and hydrogen) ranging from Methane (CH4) to Asphaltene (C80H162) [1], and other minor inorganic elements such as oxygen (O2), nitrogen (N2), carbon dioxide (CO2), sulfur (S), hydrogen sulfide (H2S), carbonyl sulfides (COS), carbon disulfide (CS2), mercaptans (RSH) , mercury (Hg), water vapor (H2O) and trace metals such as tin (Sn), lead (Pb), helium (He), sodium (Na), magnesium (Mg), calcium (Ca), copper(Cu), silver (Ag), gold (Au), boron (B), uranium (U), nickel (Ni), platinum (Pt), iron (Fe), cobalt (Co), chromium (Cr), silicon (Si), arsenic (As), antimony (Sb), molybdenum (Mo) and vanadium (V), etc. [2]. Also, all petroleum reservoirs occurring in any of the physical states (solid, liquid or gas) with few exceptions contain some “natural gas petroleum”, which is commonly measured in cubic feet, and the gas volume written in multiples of 1,000 abbreviated as M [3]. Each natural gas stream, like each crude oil is a unique mixture that is mostly composed of the lower-molecular weight hydrocarbons of the paraffin or alkane series (general molecular formula CnH2n+2 i.e. saturated hydrocarbons such as methane, ethane, propane butanes et cetera), with smaller amounts (usually only trace) of olefin hydrocarbons (i.e. ethene, ethyne, propene, butene et cetera), naphthenic hydrocarbons, and non-hydrocarbon compounds. The simplest member of the series is methane, with chemical formula CH4- one atom of carbon combined with four hydrogen atoms. Usually, the raw petroleum natural gas may come from any one of four types of gas wells: (i) Dry gas wells—these wells typically produce only raw natural gas that contains no hydrocarbon liquids, such gas is called non-associated gas. (ii) Condensate wells—these wells produce raw natural gas along with natural gas liquid, such gas is also called associated gas and often referred to as “wet gas”. (iii) Gas hydrates wells- these wells typically produce only raw natural gas that contains no hydrocarbon liquids, from ice-like structures found on the Ocean floor and in permafrost around the Arctic (i.e. methane clathrates in the ocean floor, abiotic methane in the ocean floor, permafrost hydrates), such gas is called non- associated gas. They are pure methane hydrocarbon in solid state, which is vaporized straight to gaseous methane. (iv) Crude oil wells—raw natural gas that comes from crude oil wells is called associated gas. This gas can exist separate from the crude oil in the underground formation, or dissolved in the crude oil. Historically, mankind started to use crude oil petroleum or crude oil petroleum products since 6000 B. C. It was first use as bitumen asphalt to coat the inside and the outside of the Ark by Noah before the Great Flood in the Tigris- Euphrates valley. Ever since then, there has been continuous and increasing record of the use of crude oil petroleum products till date. The turning point for its consumption in vast quantities began 1857 with the introduction of the first kerosene lamps and the invention of internal combustion engine in 1862. It spread slowly in what has been called the “Kerosene Age” 1859-1900 [4], because, although petroleum products were also largely used for lubricants, the main aim of refining crude oil then was to produce kerosene (C12-C16) for lamp oil (illuminating fuel). Then C11-C1, comprising (gasoline, methane et cetera) was regarded as waste product and was flared off. Kerosene was first distilled from bituminous Coal (Nova Scotia coal) and oil shale experimentally in 1846 [5], by Abraham Gesner, a Canadian geologist resident in Pittsburgh America. Subsequently, in 1851, Samuel Martin Kier began selling lamp oil which he distilled from crude oil, to local miners under the name “carbon oil”. By 1852, the increased supply of petroleum allowed oil refiners to entirely side-step the oil-from-coal, for illuminating oil from petroleum. Commercial production of kerosene started in 1854 and the petroleum-based illuminating oil was widely sold as kerosene.

Due to the dominant use of the Internal Combustion Engine near the beginning of the twentieth century, gasoline became the chief product being derived from crude oil petroleum, leading to what might be called the “gasoline age” 1900-date. The initial gasoline sold, comprised C3- C11 distillate from the crude oil petroleum, which resulted to rapid evaporation/consumption in the internal combustion engine, until 1910 when Dr. Walter O. Snelling an American Chemist and explosive expert with US Bureau of mines, while researching on the properties of petrol (gasoline), separated gaseous fractions from liquid ones, thus discovering the existence of propane, hence LPG (C3 and C4). Thus, the present petrol (gasoline)/naphtha are comprised of (C5-C11).

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Presently the overall products from the petroleum refining are usually grouped into four Categories: light distillates (LPG, Gasoline, and Naphtha); middle distillates (Kerosene, Jet Fuel, and Diesel); heavy distillates and residuum (Heavy Fuel Oil, Lubricating Oils, Wax, and Asphalt), (Figure 1). Hence, the fossil crude oil petroleum is considered the most important energy source, providing fuel for transportation, electricity generation and raw material from which many key substances are made (plastics, pharmaceutical drugs, automobile parts, etc). Until recently, the Fuel Gas (byproduct of crude oil petroleum refining operation) comprising methane (C1) and ethane (C2) are generally not marketable; rather it is either used as fuel for refinery heaters/furnaces or flared [6].

Notably, the present transportation fuels (for automobiles: vehicles/cars/trucks/boats; jets, rockets and airplanes; locomotives/trains, and marine ships) produced from conventional crude oil petroleum refineries are Regular and Premium Gasoline {i.e. Regular Motor Spirit “RMS”– super petrol and Premium Motor Spirit “PMS”}; Kerosene {i.e. Dual Purpose Kerosene “DPK– illuminating kerosene and Aviation Treatment Kerosene “ATK”}, Diesel {i.e. Automotive Gas Oil “AGO” – Light Gas Oil}; Heavy Gas Oil {i.e. Low Pour Fuel Oil “LPFO”) all of which emit greenhouse gases on combustion, that are consider to be responsible for global warming (which refers to the increasing temperature of the atmospheric environment). Hence, the current strong quest for cleaner (alternative/renewable) energy.

Although renewable and clean energy are growing fast, with the exception of biomass that can generate similar products in very low quantity, it is very evident that there is no alternative energy source or combinations that will be enough to replace fossil petroleum (crude oil and natural gas), especially in the transportation sector [7] which currently consumes from 75 to 80% of the crude oil produced or for power generation and petrochemicals that uses gas {methane, ethane, propane and butane (C1 to C4 hydrocarbons)} as the primary source of energy. Evidently, at the onset, petroleum was used in its raw form, but currently it is mostly used in its premium refined forms. Practically therefore, it implies that the only option is to continue the trend of improving the products as well as managing/reusing the associated waste until we can achieve zero emissions. This makes it apparent that the world should transition from the “gasoline/diesel age” to “Synfuels age”. Meanwhile, there is already a (synthetically produced) aviation fuel for reducing emissions, which is produced from  sustainable  biomass resources and has very similar chemical properties to fossil aviation fuel (jet fuel). Studies suggest that up to 80% of CO2 emissions can be reduced by using  the Sustainable Aviation Fuels (SAF) compared to conventional jet fuel [8].

On the other hand, in 1925, Franz Fishcher and Han Tropsch developed a catalyst that converted a mixture of hydrogen and carbon monoxide (H2 + CO, generated from the reformation of purified methane a.k.a. natural gas) called syngas “synthesis gas or synthetic gas” at 1 atm. and 2500C-3000C into liquid hydrocarbons {liquid synthetic fuels such as diesel, gasoline, naphtha, kerosene etc., or chemical liquids such as methanol, ammonia, refinery hydrogen, dimethylether (DME), ethanol and other alcohols etc.}. The technology is popularly known as Fischer-Tropsch (FT) Gas-to-Liquids “FT-GTL” process and it function more-like a natural gas refinery (NGR). Since the 1990s, the technology is applied to convert the {petroleum natural gas, coal seam methane, biogas from biomass and municipal landfill gas, as well as the gaseous products from the gasification of bitumen from oil sands, solid coal, biomass (woods, leaves, saw-dust, etc.), biodegradable material components of municipal solid waste (MSW) and mixed plastic waste (MPW)} to synthetic liquid fuels which are carbon neutral (burns with very low CO2 emissions). The transportation fuels produced from gas-to-liquid (GTL) facilities, comprising of high quality synthetic liquid fuels such as GTL-LPG, GTL-gasoline, GTL- kerosene, GTL-diesel, GTL-fuel oils/lubricants, etc [9, 10] are considered renewable and sustainable clean development mechanism (CDM) for reducing greenhouse gas (GHG) emissions. Other regular by-products are electricity, fertilizer, different chemicals, etc [11].

The synergy of the conventional petroleum refining operation and the FT-GTL unit (a.k.a. natural gas refinery “NGR”) concept, as presented in this article basically implies the addition of specialized treatment units/sections (such as the hydrocarbons steam reforming unit, the FT-GTL unit and the CO2 capture unit) to the present petroleum refining units for the production of only synthetic liquid fuels (gasoline, kerosene, diesel, etc.). Operationally, it retains all the activities performed in the conventional petroleum crude oil refinery, but instead of loading the products into the storage tanks as end products, it is routed to the steam reforming unit to convert it to hydrogen (H2) and carbon monoxide (CO) mixture/combination known as synthesis gas (syngas), which becomes the feedstock for the FT-GTL process unit. Furthermore, the vast sources of methane {natural gas reserves-associated and non-associated, as well as substitute natural gas/synthetic natural gas (SNG) from gas in tight sands and shale’s, coal seams (coal-bed-methane), oil shale, geo-pressured reservoirs, volcanoes, anaerobic bacteria decomposition of vegetable matter under water, wetland, landfills and atmospheric methane, etc.}, [3, 12, 13], can be a corollary processing feedstock raw material for the FT-GTL process unit i.e. additional abundant categories of concurrent FT-GTL process raw material.

The process could be termed Clean petroleum refinery (CPR) a.k.a. Synfuels petroleum refinery (SPR), which leads the world to the fully “Synfuels age” and enable the continued use of fossil energy to help the growing demand in energy thereby achieve the intertwined pressing global challenges goals of economic growth, environmental conservation, and energy security (3E).

Present Petroleum Crude Oil Refining Technique

Crude oil petroleum is a naturally occurring, brownish- green to black liquid found underground or underwater in geologic formations/fields beneath the Earth’s surface or water surface. Although they may appear to be the same, no two petroleum occurring in different reservoirs are exactly alike, for each consists of mixtures of countless different hydrocarbons (including alkanes/paraffin, cycloalkanes/ naphthenes, aromatic, or more complicated chemicals like asphaltenes and sulfur, nitrogen, oxygen, phosphorous as trace elements or impurities), each has different characters and qualities in the basic elements, which define its physical and chemical properties, like color and viscosity [3]. Principally, it can be divided into four groups according to their percentage of hydrocarbons of the three series {paraffinic-(normal-paraffin/alkane series or iso-paraffin/ branched – chain paraffins series); naphthenic- naphthene/ cyclo-paraffin series and aromatic/benzene series), (Figure 2).

1. The paraffin base crude usually possesses low percentage of sulfur.

2. Naphthenic base crudes (Nigerian, Venezuela, etc) are often rich in sulfur.

3. Aromatic base crude are quite scarce with respect to the other types, but are produced in certain areas of Iran, Russia and Mexico. Asphalts are solid to semisolids with high boiling point and high molecular weight. They are made up of cyclic hydrocarbons with substantial amount of sulfur, nitrogen and oxygen contents.

4. Mixed base crude represent about 75% of the total production in the world; among them are the majority of the Middle East crudes.

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Hence, the crude oil petroleum refinery (also referred to as oil refinery) is an industrial complex that involves many different processing units and auxiliary facilities that are used to transform/refine crude oil petroleum of all categories into everyday desirable useful products. The complex process involves both chemical reactions and physical separations.

Refineries fall into three broad categories Topping plant, Asphalt plants and Cracking refinery plants: The simplest is the topping plant, which consists only of a distillation unit and probably a catalytic reformer to provide octane. Yields from this plant would most closely reflect the natural yields from the crude processed. Typically only condensate or light sweet crude would be processed at this type of facility [14].

Asphalt plants are topping refineries that run on heavy crude oil because they are only interested in processing asphalt.

Cracking refinery plants operates with the addition of a fluid catalytic cracking unit (FCCU) or Coker or a hydrocracker. This refinery takes the gas oil portion from the crude distillation unit (a stream heavier than diesel fuel, but lighter than HFO) and breaks it down further into gasoline and distillate components using catalysts, high temperature and / or pressure. Furthermore, it processes residual fuel, the heaviest material from the crude unit and thermally cracks it into lighter product in a Coker or a hydrocracker. Also hydro-cracking is a process used to remove sulfur from finished products. Refineries that have large hydro- cracking capability have the ability to process crude oil with higher sulfur content. Whereas the simplest refineries are usually limited to atmospheric and vacuum distillation, integrated refineries incorporate fractionation, conversion, treatment and blending with lubricant, heavy fuels and asphalt manufacturing; they may also include petrochemical processing.

Basically, there are three steps in the conventional petroleum refining process – Separation, Conversion, and Treatment. The process begins with the distillation, or fractionation, of crude oils into separate hydrocarbon groups. The operation of the crude oil distillation unit (CDU) often referred to as the ‘atmospheric distillation unit’ (because it operates at slightly above atmospheric pressure), is based on the fact that some of the compounds in crude oil are volatile (easily vaporized) due to their low boiling points and others are less volatile and have higher boiling points. The crude oil is desalted and sent through a furnace where it is first heated to about 400oC (750oF) so that all the components are partially vaporized and then passed into the CDU at the bottom. In the fractionating column, more heat is applied and concentrated at the bottom to fully vaporize the hydrocarbons. As the fully vaporized hydrocarbons travel upward in the column to the top below room temperature (20°C or 68°F), they will cool until they condense back into a liquid form. It would be impossible to isolate every molecule and make finished products from each molecule. For convenience, mixtures of hydrocarbon compounds/molecules with similar properties are isolated and condensed to liquids at their various boiling points (i.e. are sorted or separated into various batches/ fractions of different appropriate boiling temperature ranges). Those with high boiling points will not move far up the column, whereas those with low boiling points will move towards the top, before cooling considerably for condensation. These fractions can be differentiated from one another by their different volatility, odor, texture and their relative ease to ignition and burning. The fractions are collected in horizontal trays at different heights on the column. Each of which can then be processed further in the other refinery processing units (through cracking, reforming and other conversion processes) to yield the desired products i.e. redistilled to improve purity and then further treated to obtain different liquid fuels and petrochemicals. Thus, these initial products (separate hydrocarbon groups) are subsequently subjected to various treatments and separation processes, such as solvent extraction to get other new products, while impurities are removed by other various methods such as dehydration, desalting, hydro-treating and sweetening (e.g. sulfur removal), in order to produce further finished products [15]. Cracking is the process whereby the chemical structure of heavier hydrocarbons (long-chain of hydrocarbons or of petroleum fractions) are changed/split, by heating under pressure (thermal cracking) or by heating in the presence of catalyst (catalytic cracking), into two or more lighter (short- chain) hydrocarbon molecules (e.g. C14 H30 → C7H16 + C7 H14). This reaction indicates the decomposition of tetra decane, a constituent of kerosene into heptane and heptene, then to other products, Figure 3.

Reforming is the process whereby the chemical structures of lighter hydrocarbons are changed/re-combined, by heating under pressure (thermal reforming) or by heating in the presence of catalyst (catalytic reforming). Thus, cracking in-tells breaking down large, heavy hydrocarbon molecules, while reforming in-tells reshaping (isomerization process i.e. changing a compound into its isomers e.g. improving gasoline quality from low- grade to premium/best – grade) or rebuilding light hydrocarbon molecules (C1-C4) to form larger/heavier hydrocarbon molecules (C5-C10 and heavier).

Notably, since the composition of the various crude oil petroleum from different parts of the world and different reservoirs varies, refineries are designed to process either the light sweet crude oil petroleum or process heavy crudes; hence the compositions of the fractions thus collected also vary according to the source. The typical gasoline consists of a mixture of paraffins (alkanes), cycloalkanes (naphthenes), and olefins (alkenes), diesel  is composed of about 75% saturated hydrocarbons {primarily paraffins including (normal & iso), and cycloparaffins}, and 25% aromatic hydrocarbons (including naphthalenes and alkylbenzenes) [16, 17, 18]. Figure 4a compares the different product yield for 3 typical types of crude oil petroleum processed in a simple distillation refinery, while Figure 4b shows a sample distillation curve.

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The overall commercial petroleum products yields, from simple refineries Figure 5 and integrated refineries Figure 6 are summarized as follows:

• The very lightest fraction, taken off at the top of the column, which remains as vapor is technically called refinery gases. It contains considerable quantities of gases consisting mainly of hydrogen, methane, ethane, ethene, propane, propene, the butanes, and the butenes. Also it is referred to as petroleum gas due to the dominant C1-C4 (methane, ethane, propane and butane) components in the stream. While the C1 and C2 are usually burnt as ‘fuel gas’ for refinery heaters/furnances or converted to liquefied natural gas ‘LNG’, C3 and C4 are converted to liquefied petroleum gas ‘LPG’ and sold in high pressure gas cylinders or tanks for lighting and heating (cooking gas) purposes in homes and in science laboratories. They are also used for synthesizing large number of compounds e.g. methanol, butadiene etc. and as high-pressure solvent. In addition butane is used in the production of high – grade petrol. Actually there are two butanes, normal butane containing a straight chain of carbon atoms, and iso-butane which has a branched carbon chain. It is this isomer which is used in making special petrol (see section 5.1.4 below). In general, these simple hydrocarbons, especially the alkenes (ethene, propene) and ethyne, constitute most of the essential raw materials for the petrochemical and chemical industries [20].
• The smallest/lowest boiling fraction of the condensed liquid is a complex mixture containing C5-C11 volatile hydrocarbons such as pentane, hexane, heptane, octane and nonane, hydrocarbons which distilled off between

20oC-70oC (or 70oF to 106oF) and 70 oC-160oC (or 160oF to 320oF) are known as gasoline (petrol), and naphtha’s/ benzine (used in the chemical industry), respectively. They are used to run cars and as solvent for grease, paints and stains.

• NOTE: That benzine is another term for the liquid naphtha’s which are used as cleaning fluids. Thus should not be confused with the aromatic hydrocarbon benzene, C6H6.
• The next slightly heavier distilled fraction is kerosene (paraffin oil) which consists of the C12-C15 hydrocarbons boiling between 160oC-250oC (or 320oF to 480oF). It is used in kerosene lamps and stove, and as fuel in jet engines, aero-planes and tractors.
• Condensing heavier again is diesel oil (light oil and heavy oil)/heating oil/fuel oils/gas oil which comprise the C14-C18 hydrocarbons boiling between 250oC-350oC (or 480oF to 660oF). It is used in diesel engines of trains, Lorries, tractors, and for central heating and raw material in the cracking process.

• The next heavier distillate is lubricants/grease/waxes which consist of the hydrocarbon compounds with C26-C40, which boil at 301°C-400°C (or 575°F to 750°F). It is used as lubricant for moving parts of machine and engines and also for making Vaseline or petroleum jelly, grease ointments, cosmetics and creams. The paraffin wax is used for making candles and polish [21, 22].
• The heaviest and largest of the hydrocarbons (40-plus carbon atoms) is residue/bitumen/asphalt drawn off from the base of the fractionating column as soon as they enter the column. This is a complex mixture of non- soluble solids made of polycyclic hydrocarbons [23]. It is used as a roofing material and in road surfacing as a protective coating. If the residue which remains after distillation is a wax-like solid consisting largely of paraffin hydrocarbons the crude is designated as paraffin base. If the residue is a black pitch-like solid the crude is called asphalt base. Often a clear-cut distinction cannot be made and the crude is described as being mixed base oil.

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Present Synfuels Plants Process Technique

Synthetic liquid hydrocarbons fuels a.k.a. Synfuels can be produced from substitute/synthetic natural gas (S.N.G.) otherwise known as syngas (mixture of carbon monoxide and hydrogen) derived from virtually any hydrocarbon feedstock/source e.g. fossil fuels ( such as coal , crude oil, shale oil/ oil shale, tar sands), biocrops/biomass (plants and plant- derived substance waste), or other recyclable material (garbage, human and animal waste), by reaction with steam or oxygen or by reforming of natural gas i.e. methane [38, 39]. In practice, Synfuels are either produced by direct conversion of the source substance into liquid transportation fuels, or indirect conversion, in which the source substance is converted initially into syngas (derived from gasification of solid feedstock’s such as coal or biomass or by reforming of natural gas), which then goes through additional conversion process to become liquid fuels. This definition of synthetic fuel also enables unconventional crude oil (oil sands  and oil shale)  to be considered as synthetic fuel sources, and in addition to liquid fuels, synthesized gaseous fuels (unconventional gas-tight gas, shale gas, coal-bed methane etc.) are also considered to be synthetic fuels. Similarly by extension, clean solid fuels produced by conversion of coal, oil shale or tar sands, and various forms of biomass, can be included [40, 41, 42].

Hence, the traditional/direct methods for the conversion of solid feedstock’s to Synfuels are carbonization and pyrolysis, hydrogenation, and thermal dissolution, which initially yield fuel oils (syncrude), that is further processed to become liquid fuels, Figure 14, such as diesel or gasoline. This investigation will focus on the indirect conversion by reforming of saturated hydrocarbons liquid products of the crude oil petroleum refineries.

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Synergy of the Petroleum Crude Oil Refinery and the FT-Synfuels Production Techniques

The proposed IJN-clean petroleum refinery “CPR” a.k.a. Synfuels petroleum refinery “SPR” (courtesy Azuberths Research Complex, Owerri, Nigeria), basically implies the addition of specialized treatment units/sections to the present petroleum refining units for the production of only synthetic liquid fuels (gasoline, kerosene, diesel, etc.) such as the reforming unit (steam reforming, partial oxidation, auto- thermal reforming), the FT-GTL unit and the CO2 capture unit. By extension, with these additional units the refinery incorporates a thermo-chemical reactor unit much like the solar refinery (which uses the generated CO2 and steam/ H2O plus waste heat) and steam turbine electricity generator, in real-time to convert CO2 to syngas (CO/H2 mixture) and generate grid power respectively.

Operationally, it retains all the activities performed in the conventional petroleum crude oil refinery configuration which is used to break the crude oil to the different present end-products i.e. Regular and Premium gasoline {i.e. Regular motor spirit “RMS “–super petrol and Premium motor spirit “PMS”}; kerosene {i.e. Dual purpose kerosene “DPK– illuminating kerosene and Aviation treatment kerosene “ATK”}, diesel {i.e. Automotive gas oil “AGO” – Light Gas oil}; Heavy Gas oil and lubricating oils {i.e. low Pour fuel oil “LPFO”), etc. Then instead of loading the products into the storage tanks as end products, it is routed to the reforming unit to convert it to hydrogen (H2) and carbon monoxide (CO) mixture/combination known as synthesis gas (syngas). Subsequently, the H2 and CO combination can be selectively routed to any of the three categories of the FT-GTL units based on market demand. Inside the FT-GTL units, it is first routed to the reactor/catalyst reactor which converts the H2 and CO to long chain hydrocarbons. Finally the long chain hydrocarbons are routed to the cracker/distiller which yields the different GTL end products i.e. synthetic liquid fuels such as GTL-LPG, GTL-gasoline, GTL-kerosene, GTL- diesel, GTL-fuel oils/lubricants, etc. stored in the final end products storage tanks. Technically, the general reaction formula for steam reforming of saturated hydrocarbon components {CnHm + nH2O → nCO + (m/2+n) H2}, can be applied to convert the entire end products stream from the conventional petroleum refinery (comprising C1 to C70+) to carbon monoxide and hydrogen (CO + H2) mixture, for subsequent production of Synfuels, Figure 21.

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(a) (b) Figure 21: Reaction formula for the steam reforming of saturated hydrocarbon components of the present petroleum crude oil refinery end products. Notably, the end products from the existing petroleum crude oil refineries fall into two categories: the internal combustion engine transportation fuels products “C5 to C20 fractions” comprising gasoline (petrol), kerosene (paraffin oil) and diesel fuels and the non-transportation fuel products (e.g. liquefied natural gas “LNG” (C1/C2), liquefied petroleum gas “LPG”, liquid naphtha’s, lubricants, waxes, base oils, etc.).

Logistically, the IJN-clean petroleum refinery (CPR) concept could be targeted at reforming only the internal combustion engine transportation fuels products, figure 21b. This is based on the assumption, that the direct uses of the non- transportation fuel products are carbon neutral, for instance C1/C2 could be used as fuel or liquefied natural gas (LNG), C3 /C4 is the liquefied petroleum gas (LPG). Liquid naphtha’s (benzine) is used in different commercial chemical industries (Olefin plant feedstock). C20+ constitutes waxes and synthetic lubricants, e.g. drilling fluids waxes, lubricating oils, polishes, bitumen for surfacing roads and roofing, plus other high value specialty products. Figures 22, 23 and 24 are the alternate configurations of the proposed IJN-clean petroleum refinery “CPR” a.k.a. Synfuels petroleum refinery “SPR” originating from the author which can utilize any of the syngas conversion technique to convert the present petroleum crude oil refined products into ultra-clean, non-toxic, biodegradable, lower- carbon liquid transportation fuels that can take the place of petroleum gasoline, aviation fuel, diesel, marine fuel oil etc., without any engine modifications and using existing distribution infrastructure.

Precisely:

• In Figure 22, the present petroleum crude oil refineries products are routed to the auto-thermal reforming unit were it is converted into syngas. The syngas is then channeled into the FT-GTL reactors to generate the various end products as well as waste heat, super heated steam and carbon dioxide. The combined CO2 (from reforming unit and the FT-reactors), steam and waste heat (from the FT-reactors) is routed into a thermo-chemical reactor (similar to the solar thermal fuel production chemical reactor), which generates O2 and syngas (H2/CO). While the resulting (H2/CO) is channeled into the FT-GTL reactor the oxygen is routed into the auto-thermal reforming unit to supplement the oxygen produced in the air separation unit (ASU).
• On the alternative, in Figure 23, fractions of the syngas generated in the auto-thermal reforming unit is channeled into four GTL possible options (GTM- MTG Process, STG + Process, FT- GTL process and the ethanol/ higher alcohol production processes) that convert it to useful end products to accommodate all the market demands.
• Figure 24 is a mega IJN-clean petroleum refinery plant configuration that incorporates both the steam reforming and the auto-thermal reforming units. In this case all the oxygen required for the auto-thermal reformation is generated from the thermo-chemical reactor. Thus it eliminates the cost of the air separation system. All the other operations are very similar to the figure 22 configuration. In both cases fraction of the super heated steam produced in the FT-GTL reactors is used to run steam turbine(s) for power generation.

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Conclusion and Recommendation

Apart from the common/major petroleum products such as LPG, Gasoline, Naphtha, Paraffin Wax, Kerosene, Diesel (Gasoil), Fuel Oil, Lubricating oil, Bitumen/Asphalt, etc, most of which are used for transportation and producing electricity, there are lots of incredible second level petroleum products being derived after several refining processes, such as plastics, clothes, beauty products, bicycle tires, fishing lures, perfumes, food preservatives, dentures, lipstick, vitamin capsules, petroleum jelly, medicines, furniture, appliances, solar panels, PVC pipes, bulletproof vests, consumer electronics, wind turbines, automobile parts and so on.

Every existing petroleum crude oil refineries can be upgraded to the IJN-Clean Petroleum Refinery (CPR) a.k.a. Synfuels Petroleum Refinery (SPR). While new refineries can be built to route the products from the distillation unit directly into the reformer thereby eliminate the cost of installing other integrated refining units. Ultimately, this will reduce the retail price of the Synfuels.

The overall products from the crude oil petroleum refining operation can be reformed to syngas “synthesis gas or synthetic gas” via steam reforming or dry reforming or bi-reforming and subsequently converted to Synfuel “Synthetic liquid fuels” using the FT-GTL Fischer-Tropsch (FT) Technology a.k.a. FT-GTL synthesis process.

Since the FT-GTL unit operation is capital intensive, there are two possible scenarios or routes to the conversion of conventional crude oil refinery products to Synfuels. (a) Target only the conversion of the fractions needed for transportation/combustion operations, which constitutes about 30% - 50% of the straight-cut primary distillation products (optimization). (b) Reform all the primary distillation products.

The synergy of petroleum crude oil refining and FT- syngas process techniques will prolong the expected life span of the fossil energy sources as well as reduce the cost of transportation fuels due to additional surplus production from using the waste byproducts, CO2, steam/H2O and waste heat in the adjoined chemical reactor operating much like the e-fuels or solar fuels production facilities. Furthermore fraction of the CO2 and steam/H2O generated in the FT process unit can be used for dry reforming or bi-reforming of a fraction of the conventional crude oil refinery products into syngas (CO + H2 mixture).

The sole production of Synfuels energy carriers, i.e., to power internal combustion engines in the form of gasoline (or petrol), diesel, fuel oil for electricity and transportation fuels from existing petroleum crude oil refineries could be an efficient means of meeting some of the main Sustainable Development Goals (SDGs) set by the United Nations General Assembly in 2015 for the year 2030 in particular Affordable and Clean Energy.

Apparently, the endless products derivable from functional groups reactions, carbon black, olefins, aromatics and aliphatic petrochemicals, polymerization processes establishes the fact that the fossil petroleum (crude oil and natural gas) is virtually everything to mankind development. Meaning that we are not going to transition out of oil and natural gas, rather we will transition away from emissions i.e. producing these products in a way that has lower and lower emissions.

The extra investment for the petroleum crude oil refinery upgrade to Synfuels refinery will not only enhance products quality, but will also, at least double the production quantity thereby drastically reducing the retail costs to the consumers of all the varieties of the end products. Furthermore, all the FT-GTL synthetic liquid fuels products out performs there petroleum crude oil products equivalents.

My recommendation is that, for the purpose of saving mankind from the overall growing climate change danger, the editorial board should seek for collaboration between all the stakeholders, including the publisher and author, with governments across the globe to embark on the refinery synergy concept. This entails mandating all the existing petroleum crude oil refineries operators to upgrade to the clean petroleum technology. It will be by far cheaper than producing “Blue hydrogen”, “Green hydrogen”, “Grey hydrogen”, “Brown hydrogen”, “Blue and green ammonia” and other related or possible alternatives because more than 70% of the infrastructures are already in place in the existing petroleum crude oil refineries worldwide.