In reference to the patent: US20150107498

This process of adding MgO/Mg(OH)2 and/or Ca(NO3)2 to HFO was widely practiced art. Don't understand prior knowledge can be patented.... As matter of an example - I did not know this patent was filed or pending till today but I gave lecture on fuel additives solution to mitigating SO3 and other gases at plant using Pentol product.

I have read the text of the patent and find it disturbing prior art can be patented!

3 Answers 3


US20150107498 is a publication of a pending patent application and not an issued patent. Accordingly, nothing in this application is "patented" yet.

Also, keep in mind that the claims of an issued patent define what is "patented" and not the specification and drawings. For example, the specification and drawings can (and typically do) discuss things that are well known in the art. On the other hand, the requirement for patent claims to be allowed by the patent examiner is that the claims define an invention that is new and non-obvious in view of the prior art.


It was granted as US10124288B2 on 2018-11-13. The claims have many detailed steps including temperature and pressure ranges. Unusually, the granted claim 1 seems broader than the claim 1 of the published application.

During examination the examiner looked at eight previous U.S. patents that dated from 1971 to 2005.


Do you have a published article (journal, online) which discusses this method in depth? Patents can be re-examined if prior art was not included in the original patent examination.

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