Aenert news. Invention analysis
Earlier, in a set of articles related to Liquid Organic Hydrogen Carriers (LOHC) technology we delved into such aspects of the technology as heterocyclic LOHC compounds (29.09.2023, 08.09.2023), hydrogenation and dehydrogenation (17.10.2023, 30.10.2023), LOHC catalysts in general and noble metal catalysts specifically (20.11.2023, 22.12.2023), and dealing with ecological problems in LOHC (13.01.2024).

This time we will review how inventors address the issue of low quality of hydrogen produced in the dehydrogenation process within LOHC technology. This is a relevant issue when it comes to the use of hydrogen as a fuel in fuel cells, or in relation to other cases of hydrogen use where the contaminants can lead to such negative consequences as corrosion or degradation of downstream equipment, catalyst contamination, and others.

Below we provide a brief review of recent patents that address the issue of low hydrogen quality. The documents are considered applicable to this group in cases where the authors state that their invention allows producing a higher-quality hydrogen by avoiding formation of impurities or by treating the produced hydrogen. Such effect can be achieved by specific carrier formulation, by improving dehydrogenation process (e.g. by providing a new catalyst or new method), or by implementing a separate treatment process involving either a mechanical or chemical means for cleaning hydrogen.

Following is a chart showing the top applicants by their patenting share in the pool of recent patents that address the challenge of improving the quality of produced hydrogen in LOHC technology.

Applicants’ share in the intellectual property market, %. Patents, 2019-2023

Value: Market involvement ratio*;  Y axis: Ownership ratio; Bubble size: Volume ratio.
*(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)

In the reviewed set of documents, affiliated organizations of Sinopec China Petroleum & Chemical Corporation (CN) (namely, SINOPEC Beijing Research Institute of Chemical Industry (CN) together with Sinopec Petrochemical Research Institute (CN)), and Qingdao Chuangqixinneng Catalysis Technology Co., Ltd (CN) are leading by the number of patents obtained in the past five years.

The largest patent family in this set of documents comprises 31 patent documents and is represented by core document AU2020269473A1 (Core document is a base document for which a complete description of the invention is available in generally-accessible patent databases). It is followed a patent family having 14 patent documents (WO2020224584A1):

Organic hydrogen storage raw material dehydrogenation catalyst, carrier of the catalyst, hydrogen storage alloy, and method for providing high-purity hydrogen / A: AU2020269473A1 / IPC: C22C19/03, C01B3/56, C22C14/00, C22C23/06, C22C30/00 / Lin Wei; Yang Xue; Song Haitao; et al. / Sinopec RIPP Research Institute of Petroleum Processing (CN); Sinopec China Petroleum & Chemical Corporation (CN) / Appl. date: 06.05.2020; Publ. date: 12.11.2020 / IP Australia / Core document: AU2020269473A1 / Technology categories: OAC, OHC / Technology elements: Hdh, Hct / Problems: EC, HCHD, LEHD / Technical solution types: M, C / Claims: 16 / Rating: 13; the most recent documents in this family were published on 15.11.2022 (CN111892016B) and 21.10.2022 (CN111893360B);
有机储氢原料脱氢催化剂以及该催化剂的载体、储氢合金、和提供高纯度氢气的方法 / en: Catalyst for dehydrogenating organic hydrogen storage raw material, carrier for catalyst, hydrogen storage alloy, and method for providing high purity hydrogen / A: WO2020224584A1 / IPC: B01J23/26 / LIN Wei; YANG Xue; SONG Haitao; SUN Min / Sinopec China Petroleum & Chemical Corporation (CN); Sinopec RIPP Research Institute of Petroleum Processing (CN) / Appl. date: 06.05.2020; Publ. date: 12.11.2020 / World Intellectual Property Organization / Core document: WO2020224584A1 / Technology categories: OAC, OHC, OAN / Technology elements: Hdh, Hct / Problems: LEHD / Technical solution types: M, C / Claims: 14 / Rating: 10; the most recent documents in this family were published on 21.10.2022 (CN111892018B) and 15.07.2022 (CN111895266B).

The following abbreviations are used in the documents above: C - Composition; M - Method; OAC - Arene/Aromatic compound; OHC - Heterocyclic; OAN - Amine; Hct - Catalyst; Hdh - Dehydrogenation; EC - Ecological problems; LEHD - Low efficiency of hydrogenation or dehydrogenation; HCHD - High cost of hydrogenation or dehydrogenation.

In addition to the problem of low hydrogen quality, the most popular problems in this set of patents are Low efficiency of hydrogenation or dehydrogenation, Ecological problems, and High cost of hydrogenation or dehydrogenation.

In the majority of cases, the inventions were represented in the form of methods and compositions, while devices here were proposed in a much lesser number of documents.

To make a deeper analysis, we have further reviewed the patents that provide improved hydrogen quality for LOHC technologies involving toluene (or its hydrogenated version, methylcyclohexane) as the carrier material. In such inventions toluene can be proposed as LOHC material alone, in combination with other materials, or as one of the options proposed by the authors.

Below are top IPC indices that were assigned to these inventions:

According to the International Patent Classification, the IPC indices above have the following definitions: C01B3/00 - Hydrogen; Gaseous mixtures containing hydrogen; Separation of hydrogen from mixtures containing it; Purification of hydrogen; C22C30/00 - Alloys containing less than 50% by weight of each constituent; B01J23/42 - Platinum; C01B3/56 - by contacting with solids; Regeneration of used solids; C22C1/02 - by melting; C22F1/02 - in inert or controlled atmosphere or vacuum; C22F1/18 - High-melting or refractory metals or alloys based thereon; B01J23/46 - Ruthenium, rhodium, osmium or iridium; C01B3/50 - Separation of hydrogen or hydrogen containing gases from gaseous mixtures, e.g. purification; C22C19/03 - based on nickel.

Patents in this collection were issued only by two patent offices. Almost all of them were issued by CNIPA (CN) (about 89%) and a small share – by JPO (JP) (about 11%).

Further, we have made an in-depth review of patents in this collection to determine, which other specific problems they are aimed to resolve. In addition to hydrogen quality, the most noticeable problems here are Costs (11 patents), Safety hazards (10 patents), and Dehydrogenation efficiency (8 patents).

By the Editorial Board