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Small-scale GTL plants. Invention analysis


Small-scale GTL plants are complex technical structures in which technological operations are sequentially carried out to convert raw organic feedstock, first into synthesis gas, and then into various hydrocarbons. Presently, such plants are manufactured by several companies, mainly for use in remote areas of oil production for the beneficial utilization of associated gas. In a previous comment dated 28/10/2022, we reviewed the current technology status of small-scale GTL (the capacities of small-scale GTL range between 0.1–10 MMscfd, including mini- and micro-GTL).
This article provides a statistical analysis of patent documents to some extent related to the production of syngas by small-scale GTL over the past 20 years from 2002 to 2021.

Statistical analysis includes:

Inventions: 929 (including 325 patents)
Offices: 23
Countries: 17
Applicants: 241
Individual IPC subgroups: 433
Total IPC subgroups assigned: 4094

The peak of patenting activity by the number of granted patents fell on 2011-2013, then there was a significant decline, even if we take into account that the last two statistical years cannot be unambiguously representative due to the long time needed for publishing, searching and processing of inventions. At the same time, the relationship of patent applications to the total number of patent documents was quite high back in 2018 and 2019, however, already in 2019, the number of start applications that were not incorporated in previously formed patent families fell sharply, which additionally indicates a decline in patenting activity.

Small-scale GTL, syngas production. Relationship of number of applications to total number of documents by year

In total, during the period under consideration, patent documents were registered in 23 patent offices. Among them, the undisputed leader was the American USPTO with a share of 37.5% and more than 120 patents. However, in the past five years, the share of the Chinese patent office CNIPA has significantly increased in terms of the number of registered patent applications. Besides, additional popularity was gained by EPO, INPI (BR), and EAPO patent offices.

Small-scale GTL, syngas production. Breakdown of inventions by patent offices. Patents, 2002-2021 (left); Applications, 2017-2021 (right)

A completely different distribution of activity can be seen when considering the countries involved in patenting. Here, the share of US residents by the number of granted patents was about 80%, and in terms of the number of registered patent applications over the past five years – more than 55%. Residents of the United Kingdom also demonstrated steady patenting activity with the shares of over 10%. As for the other countries, the shares were much smaller.

Small-scale GTL, syngas production. Countries participating in patenting process. Number of patents obtained by resident applicants in 2002-2021. Patents, 2002-2021 (left); Applications, 2017-2021 (right)

The largest number of patents for the period under consideration was granted to Velocys Inc. (US). Battelle Memorial Institute (US) and CompactGTL (GB) also made it to the top three most active patent holders, but far behind the leader.

Small-scale GTL, syngas production. Top applicants. Patents, 2002-2021

In the past five years, American Greyrock Energy Inc. and Greyrock Technology LLC. have become the leaders by the number of registered patent applications. The ten most active applicants also included BP PLC (GB), Shell Internationale Research Maatschappij B.V. (NL), Velocys Inc. (US), Sasol Technology (Pty) Ltd (ZA), BD Energy Systems LLC (US), Fluor Technologies Corporation (US), Rosneft (RU), and Shell Oil Company (US).

Below are the calculated data of Market involvement ratio (bubble size) for the ten most active Applicants, defined as volume ratio multiplied by ownership ratio, where Volume ratio – share of applicant documents in total number of documents, and Ownership ratio – applicant's participation share in total number of documents.

Small-scale GTL, syngas production. Top 10 applicants by intellectual property market involvement. Patents, 2002-2021(left); Applications, 2017-2021 (right), %

Among the three main types of technical solutions in inventions, the Applicants most often chose methods and devices, while compositions were much less common. In patent documents related to small-scale GTL, the Gas to liquid (GTL) process chain was mentioned in almost 80% of cases. The share of references to CTL (Coal to liquid) and BTL (Biomass to Liquid) in total accounted for about 17% of inventions.

The following IPC subgroups were assigned to about 35-40% of inventions:

B01J 19/00 Chemical, physical, or physico-chemical processes in general;
B01J 19/24 Stationary reactors without moving elements inside;
B01J 8/02 Apparatus for such processes with stationary particles, e.g. in fixed beds;
B01J 37/02 Impregnation, coating or precipitation;
C10G 2/00 Production of liquid hydrocarbon mixtures of undefined composition from oxides of carbon;
C01B 3/38 Silicon; Compounds thereof /Layered base-exchange silicates, e.g. clays, micas or alkali metal silicates of kenyaite or magadiite type

In the majority of cases, the technical solutions proposed in the inventions were aimed at solving the problems of Low efficiency of main processes, High OPEX / Repair and replacement, and High CAPEX / Equipment.

Small-scale GTL, syngas production. Breakdown of documents by mentioned problems. Patents, 2002-2021 (left); Applications, 2017-2021 (right)


AOP-Administrative and organisational problems, HCD-High CAPEX / Development, HCE-High CAPEX / Equipment, HCG-High costs in general, HOM-High OPEX / Maintenance, HORR-High OPEX / Repair and replacement, LECR-Low efficiency due to catalyst replacement, LEEL-Low efficiency due to energy losses, LEFQ-Low efficiency due to feed quality, LEMP-Low efficiency of main processes, LESP-Low efficiency of secondary processes, SES-Saving ecosystems, UP-Unclear problem, WEGC-Water, energy or gas consumption

Among the patent documents considered in this review, the largest patent family contains 50 inventions and is represented by the core document AU2014346844B2 (core document is a base document for which a complete description of the invention is available in generally-accessible patent databases):

Chemical reactor with manifold for management of a flow of gaseous reaction medium thereto / P: AU2014346844B2/ IPC: B01J12/00, B01J4/00, B01J8/02, B01J8/06, B01J8/18, B01J19/00, B01J19/24, C01B3/38 / Finnerty Caine M, Dewald Paul / Watt Fuel Cell Corp / Appl. date: 05/11/2014; Publ. date: 12/10/2017. Technologies: FTG, GTL / Technology elements: MFT, SGM / Problems: HORR, LEMP / Invention types: D / Rating: 14 / Claims: 10

The patent family having core document US8124177B2 contains 29 inventions:

Tailored and uniform coatings in microchannel apparatus / P: US8124177B2/ IPC: B05D7/22 / Tonkovich Anna Lee, Yang Barry L, Mazanec Terry, Daly Francis P, Fitzgerald Sean P, Arora Ravi, Qiu Dongming, Yang Bin, Perry Steven T, Jarosch Kai, Neagle Paul W, Hesse David John, Taha Rachid, Long Richard, Marco Jeff, Yuschak Thomas D, Ramler Jeffrey J, Marchiando Mike / Velocys / Appl. date: 23/03/2005; Publ. date: 28/02/2012. Technologies: FTG, GTL / Technology elements: MFT, SGM / Problems: HORR, LEMP / Invention types: D / Rating: 18 / Claims: 20

Below is a list of patents having the highest rating, calculated according to the Advanced Energy Technologies methodology:

Small-scale GTL, syngas production. Prominent patent documents by rating, 2002-2021:

Multiphase mixing process using microchannel process technology / P: US7816411B2/ IPC: B01F3/04, B01F3/06 / Tonkovich Anna Lee, Silva Laura J, Hesse David John, Marchiando Michael Alan, Lamont Micheal Jay, Qiu Dongming, Dritz Terrence Andrew, Pagnotto Kristina M, Stevenson Richard, Perry Steven T, Fanelli Maddalena, Arora Ravi, Yang Bin, Fitzgerald Sean Patrick, Sullivan Timothy J, Jarosch Kai Tod Paul, Yuschak Thomas / Velocys Inc / Appl. date: 23/11/2009; Publ. date: 19/10/2010. Technology categories: GTL / Technology elements: SGM / Problems: LEMP / Technical solution types: C, D, M / Claims: 63 / Rating: 22;

Process for upgrading a carbonaceous material using microchannel process technology / P: US8100996B2/ IPC: B09B3/00, C01B3/34, C10J3/46 / Simmons Wayne W, Litt Robert Dwayne, Tonkovich Anna Lee, Silva Laura J, Ryan Daniel Francis, Stangeland Bruce, Brophy John, McDaniel Jeffrey S / Velocys Inc / Appl. date: 09/04/2009; Publ. date: 24/01/2012. Technology categories: BTL, FTG, GTL / Technology elements: MFT, SGM / Problems: HORR, LEMP / Technical solution types: C, M / Claims: 94 / Rating: 21;

Process and apparatus for converting natural gas to higher molecular weight hydrocarbons using microchannel process technology / P: US7829602B2/ IPC: C07C27/00 / Litt Robert Dwayne, Simmons Wayne W / Velocys Inc / Appl. date: 18/01/2008; Publ. date: 09/11/2010. Technology categories: FTG, GTL / Technology elements: FTC, MFT, SGM / Problems: LEMP, SES, WEGC / Technical solution types: C, M / Claims: 43 / Rating: 21;

Process of conducting reactions or separation in a microchannel with internal fin support for catalyst or sorption medium / P: US7896935B2/ IPC: B01J8/00, B01D53/02, C07C5/00 / Tonkovich Anna Lee, Qiu Dongming, Long Richard Q, Yang Barry L, Yuschak Thomas, Perry Steven T / Velocys Inc / Appl. date: 28/12/2006; Publ. date: 01/03/2011. Technology categories: FTG, GTL / Technology elements: MFT, SGM / Problems: HORR, LEMP / Technical solution types: C, D / Claims: 48 / Rating: 21;

Oxidation process using microchannel technology and novel catalyst useful in same / P: US7226574B2/ IPC: C01B3/02, C01B31/18 / Long Richard Q, Tonkovich Anna Lee, Daymo Eric, Yang Barry L, Wang Yong, Daly Francis P / Velocys Inc / Appl. date: 30/05/2003; Publ. date: 05/06/2007. Technology categories: GTL / Technology elements: SGM / Problems: HORR, LEMP / Technical solution types: C, M / Claims: 76 / Rating: 21.

For more information on the inventions in the field of small-scale GTL and patent research methodology, please visit