Aenert news. Invention analysis
In our earlier article "2023 Global Gas Flaring Tracker Report: 139 billion m3 gas flared during 2022" (18.05.2023) we have revised the trends in the amount of associated petroleum gas flared globally in 2022, compared to previous years. Also, we have previously analyzed different aspects of small-scale GTL technologies (09.11.2022, 03.11.2022, and 28.10.2022) that can be employed in converting associated petroleum gas into liquid hydrocarbon products. Now we will take a look at new advancements in the field of associated petroleum gas utilization disclosed in respective patent documents. For this purpose we have collected more than 8000 inventions published over the past 20 years and analyzed them using the Advanced Energy Technologies methodology. The patents and patent applications under revision were published in 52 patent offices around the world by 1915 applicants from 39 countries.

Associated petroleum gas. Cumulative number of patents and applications*, relationship of number of applications to total number of documents by year


*Areas representing patents and applications are overlapping

In the pool of documents revised for this article, the peak values in the number of published applications were achieved in 2011-2018, with a slight decline afterwards. As for granted patents, the most productive years were 2013-2020. Recently, the number of start documents that didn’t belong to any previously formed patent family was varying greatly, reaching a peak of 72% in 2021.

A peak in the number of new applicants appearing in the collection of documents related to the subject under consideration was seen in 2012, after which there was a steady decline in the values. The number of new IPC subgroups in the documents was on a rise until it achieved its largest value in 2016. The number of new patent offices vas varying throughout the period under consideration, with a noticeable decline in recent years. This may indicate a gradual decrease in the interest of the authors in this field of technology, although technological diversity can be evaluated as high in the collection of inventions.

The largest number of patents were granted during the twenty-year period in the USPTO (US) patent office – more than 28% of the entire pool of patents. It was followed by Rospatent (RU) and CNIPA (CN) with around 16% and 11%, respectively. USPTO (US) (around 27%), CNIPA (CN) (around 16%), and WIPO (13%) were leading by the number of recent patent applications registered in the 5-year period. IP Australia (AU), CIPO (CA), EPO, and JPO (JP) should also be mentioned as the patent offices that granted more than 5% of patents each on the subject of interest in the collection under revision.

Associated petroleum gas. Breakdown of inventions by patent offices. Patents, 20 years (left); Applications, 5 years (right)



The United States also holds the first position by being the country of residence for the largest number of applicants participating in the patenting process, having more than 47% of all cases in patents granted during the 20-year period, and more than 51% in the case of 5-year applications. In the case of patents, it was followed by Russia (almost 15%), and the United Kingdom (almost 9%), while in applications – by China (more than 11%), and Saudi Arabia (more than 5%).

Following is a list representing top 10 applicants with the highest Market involvement ratio for patents published in the 20-year period (Market involvement ratio = volume ratio multiplied by ownership ratio, where Volume ratio - share of applicant documents in total number of documents, Ownership ratio - applicant's participation share in total number of documents):

Associated petroleum gas. Top applicants by Market involvement ratio. Patents

In the pool of patents describing the technologies of associated petroleum gas utilization, Velocys Inc (US) had a strong lead by the number of documents among all applicants – 282 patents. It was followed by ExxonMobil Upstream Research Company (US) - 195, CompactGTL (GB) - 120, and ExxonMobil Research and Engineering Company (US) – 119 documents. In terms of recently published patent applications, the leaders were ExxonMobil Upstream Research Company (US) - 90, General Electric (US) - 88, and Saudi Arabian Oil Company (SA) - 57 documents.

Associated petroleum gas. Top applicants by Market involvement ratio. Applications
 

The most commonly-encountered problems in the collection of patents and patent applications related to associated petroleum gas utilization were High OPEX / Equipment and consumables, Environmental and social impact, and High CAPEX / Equipment and consumables. Generally, technical solutions disclosed in the patent documents under revision were represented in the form of methods. A considerable number of documents also disclosed devices, while compositions were encountered much less often in the documents. The most popular IPC subgroups assigned to the patent documents were: C10G2/00 (Production of liquid hydrocarbon mixtures of undefined composition from oxides of carbon); B01J19/00 (Chemical, physical or physico-chemical processes in general; Their relevant apparatus); C01B3/38 (using catalysts); C10L3/10 (Working-up natural gas or synthetic natural gas); and B01J19/24 (Stationary reactors without moving elements inside).

The largest patent family of the entire collection made for the present analysis includes 212 patent documents and is represented by core document US20160351931A1 (Core document is a base document for which a complete description of the invention is available in generally-accessible patent databases):

INTEGRATED ELECTRICAL POWER AND CHEMICAL PRODUCTION USING FUEL CELLS / A: US20160351931A1 / IPC: H01M8/0612, H01M8/04089, H01M8/0662, H01M8/04746, F02C6/18, C01B3/48, C07C1/04, C10G2/00, C07C29/152, H01M8/14, H01M8/04791 / Berlowitz Paul J, Barckholtz Timothy A, Hershkowitz Frank / ExxonMobil Research and Engineering Company / Appl. date: 15.08.2016; Publ. date: 01.12.2016 / United States Patent and Trademark Office / Core document: US20160351931A1 / Technology categories: EP, LF / Technology elements: GTL, GTP / Problems: ESI, LEPP / Technical solution types: D, M / Claims: 22 / Rating: 16

It is followed by patent families having 82 and 45 patent documents and represented by core documents US8784535B2 and US20170058708A1, respectively:

Pressure-temperature swing adsorption process for the separation of heavy hydrocarbons from natural gas streams / P: US8784535B2 / IPC: B01D53/047 / Ravikovitch Peter I, Johnson Robert A, Deckman Harry W, Anderson Thomas N / ExxonMobil Research and Engineering Company, Ravikovitch Peter I, Johnson Robert A, Deckman Harry W, Anderson Thomas N / Appl. date: 27.02.2012; Publ. date: 22.07.2014 / United States Patent and Trademark Office / Core document: US8784535B2 / Technology categories: LF / Technology elements: P / Problems: HCG, LEGT / Technical solution types: M / Claims: 35 / Rating: 19

MODIFIED GOSWAMI CYCLE BASED CONVERSION OF GAS PROCESSING PLANT WASTE HEAT INTO POWER AND COOLING / A: US20170058708A1 / IPC: F01K21/00, F25B43/00, F28D21/00, F01K25/06, F25B9/00, F25J3/06, F01K7/16, F01K13/00, F25B11/02, F28D15/00 / Noureldin Mahmoud Bahy Mahmoud, Kamel Akram Hamed Mohamed / Saudi Arabian Oil Company / Appl. date: 22.12.2015; Publ. date: 02.03.2017 / United States Patent and Trademark Office / Core document: US20170058708A1 / Technology categories: O / Technology elements: P / Problems: ESI, LEGT / Technical solution types: D, M / Claims: 34 / Rating: 15

The following abbreviations are used in the documents hereinbefore and hereinafter: D - Device; M - Method; C - Composition; EP - Energy production; LF - Liquid fuel; O - Other; ESI - Environmental and social impact; HCEC - High CAPEX / Equipment and consumables; HCG - High costs in general; HCPP - High cost of production processes; HOEC - High OPEX / Equipment and consumables; LEG - Low efficiency in general; LEGT - Low efficiency / Gas treatment; LELQ - Low efficiency / Location and quality of gas; LEPP - Low efficiency / Production process; GTL - Gas to liquid; GTP - Gas to power; P - Preparation.

Associated petroleum gas. Breakdown of documents by family size. Patents and applications



Following are several examples of patent documents having the highest rating calculated using the Advanced Energy Technologies methodology, from the pool of documents related to associated petroleum gas utilization:

Associated petroleum gas. Prominent patent documents by rating:

Fischer-tropsch synthesis using microchannel technology and novel catalyst and microchannel reactor / P: AU2004315214B2 / IPC: C10G2/00 / Tonkovich Anna Lee, Kibby Charles, et al. / Velocys Inc / Appl. date: 15.12.2004; Publ. date: 18.08.2005 / IP Australia / Core document: US7084180B2 / Technology categories: LF / Technology elements: GTL, P / Problems: ESI, HCPP, HOEC, LEG, LELQ / Technical solution types: C, M / Claims: 21 / Rating: 24

Fischer-Tropsch synthesis using microchannel technology and novel catalyst and microchannel reactor / P: US8188153B2 / IPC: C07C27/00, B01J8/00 / WangYong, Tonkovich Anna Lee, et al. / Velocys Inc / Appl. date: 05.03.2010; Publ. date: 29.05.2012 / United States Patent and Trademark Office / Core document: US7084180B2 / Technology categories: LF / Technology elements: GTL, P / Problems: ESI, HCPP, HOEC, LEG, LELQ / Technical solution types: C, M / Claims: 38 / Rating: 23

Fischer-Tropsch synthesis using microchannel technology and novel catalyst and microchannel reactor / P: US9453165B2 / IPC: B01J19/00, B01J23/75, B01J23/755, B01J23/83, B01J23/889, B01J23/89, B01J23/94, B01J35/00, B01J35/04, B01J35/10, B01J37/02, B01J37/03, B01J38/48, C10G2/00, C10G21/00, C10G45/58, C10G47/00, C10L1/08, C10M105/04 / Wang Yong, Tonkovich Anna Lee, et al. / Velocys Inc / Appl. date: 30.04.2015; Publ. date: 27.09.2016 / United States Patent and Trademark Office / Core document: US20130217793A1 / Technology categories: LF / Technology elements: GTL / Problems: HCEC, HOEC, LELQ / Technical solution types: C, D, M / Claims: 140 / Rating: 23

Fischer-tropsch synthesis using microchannel technology and novel catalyst and microchannel reactor / P: US7084180B2 / IPC: C07C27/00 / Wang Yong, Tonkovich Anna Lee, et al. / Velocys Inc / Appl. date: 28.01.2004; Publ. date: 01.08.2006 / United States Patent and Trademark Office / Core document: US7084180B2 / Technology categories: LF / Technology elements: GTL, P / Problems: ESI, HCPP, HOEC, LEG, LELQ / Technical solution types: C, M / Claims: 84 / Rating: 23

Fischer-tropsch synthesis using microchannel technology and novel catalyst and microchannel reactor / P: AU2010202533B2 / IPC: C10G2/00 / Tonkovich Anna Lee, Kibby Charles, et al. / Velocys Inc / Appl. date: 17.06.2010; Publ. date: 28.02.2013 / IP Australia / Core document: US7084180B2 / Technology categories: LF / Technology elements: GTL, P / Problems: ESI, HCPP, HOEC, LEG, LELQ / Technical solution types: C, M / Claims: 20 / Rating: 23

Increasing efficiency in an LNG production system by pre-cooling a natural gas feed stream / P: AU2016292348B9 / IPC: F25J1/00, F25J1/02, F25J3/02 / Pierre Fritz, Gupte Parag A, Huntington Richard A, Denton Robert D / ExxonMobil Upstream Research Co / Appl. date: 14.06.2016; Publ. date: 05.09.2019 / IP Australia / Core document: US20170016668A1 / Technology categories: O / Technology elements: P / Problems: ESI, HCG, LEGT / Technical solution types: D, M / Claims: 22 / Rating: 23

Integration Of Molten Carbonate Fuel Cells In Methanol Synthesis / P: US9343764B2 / IPC: H01M8/04, C01B3/16, C01B3/34, C01B3/50, C04B7/36, C07C1/04, C07C29/151, C10G2/00, C10K3/04, C21B15/00, C25B3/02, F02C3/22, H01M8/06, H01M8/14 / Berlowitz Paul J, Barckholtz Timothy Andrew, Lee Anita S, Hershkowitz Frank / Berlowitz Paul J, Barckholtz Timothy Andrew, Lee Anita S, Hershkowitz Frank, Exxonmobil Res & Eng Co / Appl. date: 13.03.2014; Publ. date: 17.05.2016 / United States Patent and Trademark Office / Core document: US20160351931A1 / Technology categories: EP, LF / Technology elements: GTL, GTP / Problems: ESI, LEPP / Technical solution types: D, M / Claims: 24 / Rating: 23

In the collection of patents and patent applications related to associated petroleum gas utilization, the majority of documents disclose technical solutions related to production of liquid fuel from gas, which generally comprise technical solutions based on Fischer-Tropsch synthesis, and particularly, microchannel GTL technologies. It is followed by treatment of produced gas, for instance desulphurization and carbon dioxide removal, reformation, etc; and by gas-to-power technologies for producing electric energy by combusting the gas in specialized engines or for use as a fuel for turbines. Below we revise several examples of inventions that concern these groups of technical solutions.

- US9890041B2 - synthesis gas production from associated petroleum gas involves splitting the feedstock in a first stream and a second by-pass stream, adding steam to the first stream and preheating for first pre-reforming, combining the pre-reformed gas with the bypassed stream for second pre-reforming, and reforming the resulting gas into synthesis gas;

- US10260005B2 - wastewater treatment costs are reduced by a method of converting associated petroleum gas and other feedstocks to liquid fuel using a two-phase process, comprising converting the feedstock to syngas, reducing oxygen content by a redox catalyst, and converting the syngas to hydrocarbons and a water fraction that can be recycled back to syngas generation or to oil recovery process without removing carboxylic acids;

- US10010858B2 - a process for treating associated gas for LNG production or pipeline transportation comprises adding steam and hydrogen, producing a reformed gas in an adiabatic steam reformer, cooling the reformed gas by a heat exchanger, separating the gas to recover process condensate and a de-watered gas mixture, removing CO₂, H₂, and CO, and drying the resulting methane. The process avoids undesirable processing steps and doesn’t require the use of ballasting agents;

- US10537849B2 - CO₂ is removed from gas by a method comprising separating the crude gas to natural gas stream and CO₂ stream, mixing the CO₂ stream with make-up methane or air, raising the temperature of the mixture to an oxidation reactor inlet value, catalytically oxidizing the methane from the mixture, and passing the resulting gas through the heat exchanger to heat the CO₂ stream. The invention is aimed at improving gas utilization efficiency, reducing the amount of gas flared or vented, etc.;

- US11643991B2 - Operating life of an engine for power generation is improved by a piston having a sidewall with grooves having uneven variations that alternate in opposite directions and have irregular amplitude peaks around the piston's circumference at ambient temperature, and which are specifically designed to counteract thermally induced distortions that occur during piston operation.

Gas to liquid

Patent US9890041B2 by Haldor Topsoe A/S (DK) discloses a process for conversion of gaseous feedstock, such as associated petroleum gas, to synthesis gas. The process comprises splitting the feedstock into a first stream (at least 30% of the hydrocarbon feedstock) and a second by-pass stream. High pressure steam from a downstream condensate stripper is added to the first stream for adiabatic catalytic pre-reforming (steam-to-carbon ratio – 0.60-1.30) and the mixture is preheated to 380-480°C. The bypassed stream combined with the pre-reformed gas for further pre-adiabatic catalytic reforming (steam-to-carbon ratio – 0.30-0.80). The resulting pre-reformed gas is reformed by using SMR, HER, ATR, CPO, POx, or their combination into synthesis gas. Sulphur compounds are removed from the feedstock before splitting and prior to the pre-reforming stages. The catalyst used in the pre-reforming stages is a solid nickel with a steam reforming catalyst suitable for operation below 650°C. The produced synthesis gas can be used to produce liquid fuel, for instance, by Fischer-Tropsch synthesis process, and tail gas or off-gas from such process can be used in the main process.

The authors propose the invention to be used with associated petroleum gas, where other solutions may be less effective due to its location.

The patent belongs to a family comprising 18 patent documents published in WO, CA, AU, KR, MX, EA, CL, US, BR, SA, and UA between 2015 and 2023.



Image from: US9890041B2

1 - natural gas; 2 - hydrogen stream; 3 - desulfurized hydrocarbon feedstock; 4 - bypass stream; 5 - major hydrocarbon feedstock stream; 6 - steam; 7 - pre-reformed gas; 8 - combined stream; 9 - pre-reformed gas; 10 - heater; 20 - hydrodesulfurization unit; 30 - heat exchanger; 40 - first pre-reforming unit; 50 - second pre-reforming unit.

Patent US10260005B2 published by Greyrock Energy Inc. (US) discloses a method for converting associated gas or other gases to liquid fuel and a catalyst for such process. The method comprises converting the feedstock into syngas with great oxygen content, a portion of the oxygen is reduced using a redox catalyst, resulting in syngas of desirable content. The redox catalyst is a copper lanthanide material with more than two weight percent of copper and less than one weight percent of a lanthanide, which is coated on a high surface area support (alumina, silica, carbon, or their mixtures). Using a catalyst, the syngas is converted to hydrocarbons and a water fraction preferably comprising less than 25 ppm of carboxylic acids (methanoic acid, ethanoic acid, propanoic acid, etc.). The conversion catalyst comprises a substrate with a surface having a 6.0-8.0 pH (preferably alumina). The water fraction is recycled back to syngas generation without removing carboxylic acids, or used in oil recovery process. The hydrocarbons produced from the syngas comprise less than 25 percent wax. The claims of the document provide alternative versions of implementing the invention and additional details.

The authors of the invention mention that the proposed method reduces costly waste-water disposal problem.

The patent is a part of a family consisting of 23 patent documents published in 2018-2023 in the CA, US, WO, AU, EP, MA, EA, and AU patent offices.



Image from: US10260005B2

Preparation

Patent US10010858B2 published by Johnson Matthey Plc (GB) discloses a process for treating natural gas, associated gas or other gaseous feedstocks to make it more suitable for LNG production or pipeline transportation. The process involves a system comprising a saturator for adding steam and hydrogen; an adiabatic steam reformer containing a catalyst comprising 0.1-10% by weight of Pt, Pd, Ir, Rh, or Ru to produce a reformed gas comprising methane, steam, carbon dioxide, carbon monoxide and hydrogen; heat exchanger connected to the reformer to cool the reformed gas mixture to below the dew point; separator to recover process condensate and provide a de-watered gas mixture. The system further comprises an acid gas recovery unit (a membrane, a physical wash solvent system, or an amine wash system) to generate a methane stream by removing carbon dioxide, hydrogen, and carbon monoxide; and a drying unit with a solid or liquid desiccant compound for drying the methane. The system can further comprise a liquefaction unit, a purification unit for removing mercury, a desulphuriser vessel, a fired heater, heat exchangers, mixing unit, or may be integrated into an offshore natural gas processing facility, etc.

With reference to the prior-art solutions, the authors mention such drawbacks as the need to use ballasting agents, or the need in additional treatment steps, such as separation and methanation, making the process more complex.

The patent belongs to a family comprising 17 patent documents published in 2010-2018 in WO, AU, CN, KR, EP, US, JP, BR, and MY.



Image from: US10010858B2

200 - gas feed stream; 202 - first purification vessel; 204 - mercury absorbent; 206 - gas stream; 208 - fired heater; 210,216,217,220,228,232,234,240,252,258,260 - lines; 212 - desulphuriser vessel; 214 - desulphurisation absorbent; 218 - saturator; 222 - reformer vessel; 224 - steam reforming catalyst; 226 - heat exchanger; 230 - first separator; 236 - heat exchanger; 238 - second separator; 242 - condensate stripper ; 244 - water feed stream; 246 - boiler feed water; 248 - water/steam stream; 250 - hot water stream; 254 - pump; 256 - acid gas recovery unit; 262 - drier vessel; 264 - heat exchangers ; 266 - liquefied natural gas stream.

Patent US10537849B2 by Johnson Matthey Davy Technologies Limited (GB) discloses a method of removing CO₂ from crude natural gas for further use instead of flaring or venting. The method comprises separating the crude gas to produce a natural gas stream with lower CO₂ content, and a CO₂ stream, where carbon dioxide is the major component. Mixing CO₂ stream with make-up methane or make-up air and raising the temperature of the mixture by a heat exchanger to an oxidation reactor inlet temperature (T1). Passing the heated mixture to the catalytic oxidation reactor to oxidize the methane. The resulting gas stream is removed at outlet temperature T2 higher than the T1. It is passed through the heat exchanger to heat the CO₂ stream. T1 and T2 are measured and adjusted by the amount of make-up methane and/or air. The claims of the invention propose several membrane-based options for the separation process including one, two, and three-membrane processes, optionally comprising a compression stage. The process of the invention further describes optional two or more sub-reactors and heat exchangers, iridium or platinum-based catalysts, and preferred operational parameters.

With reference to the prior-art solutions, the authors mention such drawbacks as low efficiency of gas utilization, excessive amount of gas flared or vented, and various cost-related aspects.

The patent is a part of a patent family comprising 22 documents published between 2016 and 2022 in CA, WO, TW, GB, AR, AU, CN, EP, EA, US, PH, BR, MX, and ZA.



Image from: US10537849B2

21 - feeding line; 22,25 - fans; 23 - mixing line; 24 - mixing line; 26 - heat exchanger; 27 - inlet line; 28 - oxidation reactor; 29 - outlet line; 30 - gas removal line; 31 - controller; 32,33 - detectors.

Gas to power

Patent US11643991B2 published on 09.05.2023 by AI Alpine US Bidco LLC (US) discloses a distortion compensation system for a groove of a piston of a reciprocating engine. The system comprises the piston having a top surface and a sidewall with a groove to accommodate a piston ring. The first groove has a surface with uneven variations (curved protrusions, curved recesses, or their combination) that alternate in opposite directions and have irregular amplitude peaks around the piston's circumference at ambient temperature. They can have undulations and vary unevenly both axially and circumferentially. These surface variations are specifically designed to counteract thermally induced distortions that occur during piston operation within a combustion chamber. The system may have a controller that controls a tool to create the surface variations in the piston's groove. The controller uses a map of temperature distribution and distortions in the piston at elevated temperatures to arrange the surface variations, aiming to decrease and oppose the distortions that occur at these higher temperatures relative to the ambient temperature. The claims of the invention also disclose the method of identifying temperature distortions in the piston at an elevated temperature. According to the authors, associated petroleum gas can be used as a fuel for an engine comprising the system of the invention.

The authors are aimed at improving the operating life of the engine.

The invention belongs to a patent family comprising 8 documents published between 2017 and 2023 in US, WO, and EP.



Image from: US11643991B2

10 - engine; 12 - combustion chamber; 16 - pressurized oxidant; 18 - fuel; 20 - piston; 25 - piston assembly; 26 - cylinder; 28 - inner annular wall; 30 - cylindrical cavity; 34 - axial direction; 36 - radial direction; 38 - circumferential direction; 40 - top portion; 42 - top groove; 44 - top ring; 50 - additional annular grooves; 52 - additional rings; 54 - crankshaft; 56 - connecting rod; 58 - pin; 59 - pinhole; 60 - fuel injector; 62 - valve; 64 - exhaust valve; 78 - pin axis; 80 - thrust axis; 82 - major thrust side; 84 - minor thrust side; 86 - first pin side.

During the analysis of inventions for this article, it was revealed that main trends in the industry are related to conversion of associated petroleum gas into liquid fuel, including Fischer-Tropsch-based processes, methanol or dimethyl ether production, and other options. Technologies of gas injection for secondary or tertiary oil production were described in a surprisingly small number of documents. Also, few inventions disclosed advancements in gas flaring procedures, which is natural, considering modern trends in sustainable production.

More detailed information about inventions in the field of associated petroleum gas utilization, and patent research methodology can be found on aenert.com, and in Associated Petroleum Gas. Preparation, Injection, Conversion. Patent Database. October 2021.

By the Editorial Board