Discussion
61.I begin with Argent’s argument. This followed the suggestion made in the Application that a biodiesel containing the two identified esters within the stated ranges has technical advantages over other biodiesels. I think that the inventive concept being advanced by Mr Johnson can be more clearly be expressed as the following technical insight: A biodiesel composition comprising 7-10.5% by weight methyl octadecenoate and 39-41% by weight methyl cis-9-octadecanoate has the following advantages over biodiesels of a different composition: (i) a higher cetane number, (ii) a lower cold filter plugging point, (iii) a lower density and (iv) it can be made from sewer grease. 62.Mr Davis argued that these so-called advantages would have been dismissed as nonsense by the skilled person. They could not, therefore, form the basis of the inventive concept. 63.His reasoning began with the following propositions, which he said had been established on the evidence: (1)The identity and proportions of the esters in a biodiesel (the ester profile) are determined by the hydrocarbon profile of the feedstock used to make the biodiesel. (2)The hydrocarbon profile of sewer grease is dependent on its source. (3)The cetane number for a biodiesel can be predicted from its constituents. (4)The cetane number of the two example biodiesels in the Application was entirely predictable. (5)Neither the cetane value nor the cold filter plugging point is determined by the proportion of methyl octadecanoate and methyl heptadecanoate as suggested in the Application. 64.Propositions (1) and (2) were agreed by Mr Baumgartner and Mr Scott. I will treat them as agreed facts, known to the skilled person as Mr Davis submitted. 65.Mr Scott was cross-examined about proposition (3). It was clear from his answer that he did not have the expertise to answer this even if he had been entitled to give expert evidence. He sent samples to an accredited laboratory and the laboratory would send him the cetane result. Neither did Mr Scott have the expertise to comment on proposition (4). 66.Mr Baumgartner said in his witness statement that the cetane number of a biodiesel can be predicted from the proportions of fatty acid esters present. I was invited to treat this, in effect, as expert evidence regarding the predictability of cetane numbers. It was inadmissible as such. There was no support for propositions (3) and (4). 67.Mr Baumgartner was cross-examined on a related topic. He was asked whether he found the cetane and cold filter plugging point values of examples 1 and 2 in the Application (both within claim 1) surprising. He said that he did. In re-examination he was asked to give the reason for his surprise regarding the cetane number. He stated two reasons, which were not quite reasons for his surprise, more possible explanations for the cetane number which had apparently occurred to him at the time. One was that the cetane number was within analytical error and the other was that the wrong sample had been given to the laboratory. This was admissible evidence as to what Mr Baumgartner had thought when he was surprised by the cetane number, but not admissible as expert evidence regarding the accuracy of the cetane number. 68.Proposition (5) is irrelevant to claim 1. Methyl heptadecanoate is an ester required in claim 2 and subsequent claims. 69.Mr Scott was cross-examined about the selection of esters for claims 1 and 2 and the proportions chosen. He said that having received cold filter plugging point and cetane results, these were the esters and proportions which he had decided to use for the claims. 70.The first two agreed propositions lead me to the view that the skilled person reading the Application would believe that in order to make a claim 1 biodiesel from sewer grease it would be necessary to start with a sewer grease having a hydrocarbon profile that matched the ester profile of claim 1. These first two propositions would not result in the skilled person rejecting out of hand the idea that claim 1 biodiesels have the stated advantages over other biodiesels. 71.Propositions (3) to (5) were not established on the evidence. Propositions (3) and (4) were in any event double-edged. Mr Baumgartner’s surprise at the cetane and cold filter plugging point values stated in the Application was consistent with Argent’s case that they were two of the surprising advantages of claim 1 biodiesels. 72.It was my impression that Mr Baumgartner did not believe that they were the correct values for those biodiesels. Mr Davis invited me to assume that those values were indeed wrong and conclude that the skilled person would have known this and would consequently have rejected an inventive concept based on the alleged cetane and cold filter plugging point advantages of the claim 1 products. Although not mentioned, I think that he was asking me to decide the same in respect of density. In the absence of evidence on which I could reach that conclusion Mr Davis submitted that it was common sense. 73.I am neither able nor entitled to treat Mr Davis’ proposed assumption and conclusion as common sense. 74.The argument was put another way. Mr Davis said that paragraphs [0094] and [0095] of the Application were very important to the skilled person’s understanding of the inventive concept. I will set them out: “[0094] A further advantage of the biodiesel composition of the present invention is that it provides a biodiesel that is useable as a fuel and/or as part of a fuel blend, and that is derived from a starting material that would otherwise be a waste material. This is the case irrespective of whether the biodiesel of the present invention has improved physical properties over known biodiesels. For example, if the biodiesel of the present invention was identical or similar in physical properties to known biodiesels, it would still be advantageous given the impurity and low cost of the starting material. [0095] The improved processes as described herein enable the use of impure and poor quality feedstocks to produce high quality biodiesel. To date, it has been otherwise impracticable to use such feedstocks as a source of fats and oils (and greases) for producing fuels such as biodiesel.” 75.Mr Davis submitted that these paragraphs teach that the process described in the Application allows the use of poor quality feedstocks, hitherto impractical as a starting point for making biodiesels. This process is presented as a surprising advantage quite aside from the advantages of the claimed biodiesels. Therefore the inventive concept could and would have been derived from that process. 76.I agree that the skilled person would have understood from those paragraphs that a new process was being suggested. I think that two possible inferences would have initially occurred to the skilled person. The first was that the method for making biodiesel set out in the Application was intended to be of general applicability to all poor quality feedstocks, sewer grease being the prime example. But if that were the case, the skilled person would have expected to see a claim to the method. 77.The skilled person is taken to know some patent law, derived from professional advice, see Virgin Atlantic Airways Ltd v Premium Aircraft Interiors UK Ltd [2009] EWCA Civ 1062; [2010] RPC 8, at [10]-[15]. Indeed, part of Mr Davis’ argument was that the reader of the Application has a sophisticated understanding of key passages of the judgment of the Court of Appeal in Lundbeck (see above). I think a skilled person of that sophistication reading paragraphs [0094] and [0095] would have expected a claim to a general method for processing sewer grease into biodiesel if it was indeed a general method. He might also have thought that there could have been claims to such a method at an earlier stage of the prosecution of the Application, but these had not survived the scrutiny of the EPO examiner. 78.The second possible inference was that paragraphs [0094] and [0095] were teaching the reader that a sewer grease having a hydrocarbon profile corresponding to the ester profile of the claim 1 biodiesel surprisingly may be used as a feedstock. In other words, a fourth advantage of the claim 1 biodiesel composition is that it can be made from sewer grease because sewer grease with an equivalent hydrocarbon profile can be processed. This second inference would have been consistent with the claims and in my view would have been the interpretation of paragraphs [0094] and [0095] that the skilled person would have adopted. 79.Neither line of thought would have led the skilled person towards a belief that the inventive concept was the three-stage process for making biodiesels proposed by Mr Davis. 80.I would add that even if the skilled person were to think about a process of that nature as the inventive concept, it is not clear to me why he would fasten on to the three steps identified in Mr Davis’ skeleton. For example, why not all the steps set out in BDI’s pleaded case on the inventive concept? Or alternatively some other supportable generalisation? 81.Finally, Mr Davis relied on Mr Reichel’s evidence in his witness statement in support of the contention that the three-step process was invented by BDI employees. Mr Reichel did not say that. His evidence was that in the course of the Motherwell project for Argent BDI personnel carried out those three steps, among others. He did not say that a process consisting of the three steps was newly devised by anyone at BDI.