Do two wrongs make a right?


CompactGTL Limited v (1) Velocys PLC (2) Velocys Inc. (3) Battelle Memorial Institute

This case looked at a variety of different issues. It is of interest in particular in relation to the allowability of amendments and corrections of a patent.

Velocys Inc. was the exclusive licensee of European Patents (UK) Nos. 1206508 and 1206509 of Battelle Memorial Institute. The patents related to catalysts for use in the Fischer-Tropsch process (FT process; conversion of hydrocarbons). Velocys brought an infringement action against CompactGTL Limited. CompactGTL denied infringement and contended that the patents were invalid. Velocys applied to amend the patents.

Amendment and Correction

Velocys applied first to amend the patents to correct the term “residence time” (of the feed stream with the catalyst) to “contact time”.

It was common ground that following Moelnlycke Health Care AB v Wake Forest University Health Sciences [2009] EWHC 2204 (Pat) this was only possible under section 76(3) Patents Act 1977 if the references to “residence time” were an obvious mistake of the type correctable under rule 139 European Patent Convention, that is, mistakes where it is immediately evident that nothing else would have been intended than what is offered by the correction. It was also common ground that without amendment the claims were invalid for insufficiency.

The judge indicated that correctability was a question for the court reading the specification through the eyes of the skilled person. He considered that the correction was allowable. He noted that contact time is preferred by practitioners, with residence time being of more interest to academics. He reviewed the references to contact time and residence time in the description and how they would be read by the skilled person. He noted that the examples were consistent with the corrected claim wording only. In addition, the judge commented:

A final small point is that… it is common ground that the specifications do contain a different obvious mistake, namely the erroneous reference to Fig.1 instead to Fig. 2. In my view this would confirm to the skilled reader that the specifications had not been drafted with the utmost care, and thus encourage him to conclude that the references to a residence time of less than 5 seconds were also mistaken.

The judge did not accept CompactGTL’s argument that the skilled person would consult the patent applications as filed to decide whether correction was necesssary. He also did not accept that it was relevant that Velocys had applied to amend at a late stage, which was argued by CompactGTL to imply that the mistake had not been obvious to Velocys.

Thus, the first amendment was allowed.

Velocys also applied to introduce new dependent claims as fallback positions if its defence of validity of the main claims was unsuccessful.

The judge held that a conditional application of this type (“Auxiliary Request” in EPO terminology) was permissible. However, he did not accept that the amendments would be allowable if the main claims were found valid. He noted that section 75(5) Patents Act 1977 requires discretion in UK post-grant amendment to be exercised with regard to the principles applicable under the EPC. He noted that amendments to add new dependent claims to valid main claims would not be permitted in EPO opposition proceedings or limitation proceedings.

Thus, following the conclusion on validity below, the second amendment was refused.

The UKIPO had objected to inclusion of the word “about” for limits of ranges in the new dependent claims. The judge agreed that this was undesirable but found that it did not make the amendments unallowable.


CompactGTL contended that the ‘509 patent was anticipated by a United States patent document, Hunter, relating to catalysts for treating automobile exhaust gases. The judge did not accept that Hunter anticipated the patent. The Hunter catalyst was not suitable for FT synthesis as it would only operate for a short time before overheating. Also, Hunter disclosed platinum group metals in general but did not disclose the particular metals osmium and ruthenium required by the claims.

CompactGTL contended that the ‘508 patent was anticipated by an International patent publication, Schanke, relating to catalysts for FT synthesis. The judge did not accept this. The judge preferred Velocys’s expert witness’s calculation of contact time from Schanke. This was 5.2 seconds, outside the claim range of less than 5 seconds.

Thus, the patents were novel.


CompactGTL contended that both patents were obvious over Schanke.

The judge found that the skilled person would not have started from Schanke:

Given (i) the scepticism with which the skilled person would approach Schanke [because of poor heat transfer properties of its catalyst], (ii) the absence of attention which it had received, (iii) the underwhelming results it reported, (iv) the fact that Schanke had not demonstrated that his solution to the heat transfer problem would work and (iv) the fact that any attempt to make it work would involve a research project, I consider that the skilled person would conclude that Schanke did not represent a worthwhile starting point for development.

However, the judge went on to consider the arguments starting from Schanke in detail. He concluded on the facts that even if the skilled person had started from Schanke the inventions would not have been obvious.


The judge held that the patents were infringed. He held that the catalyst structure of a stack of corrugated and arced sheets used by CompactGTL was a porous structure/porous support as required by the claims, and that a layer of alumina on the sheets was a buffer layer as required by the claims.

Case No. [2014] EWHC 2951 (Pat)

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