T 0194/17 03-12-2020

1. Applicable provisions of the EPC

1.1 The patent is based on an International application which was filed under the PCT on 12 July 2005 and was still pending at the time of entry into force of the revised EPC (EPC 2000) on 13 December 2007.

1.2 According to Articles 1(1) and 6, first sentence of the Decision of the Administrative Council of 28 June 2001 on the transitional provisions under Article 7 of the Act revising the EPC of 29 November 2000 (Special edition No. 4, OJ EPO 2007, 217), Articles 54(2), 56, 87, 100, 111 and 113 EPC 1973 as well as Articles 52, 54(3) and 153 EPC (2000) apply. With respect to potentially colliding European applications pursuant to Article 54(3) EPC, however, the provisions of Article 54(4) EPC 1973 continue to apply. By analogy, with respect to potentially colliding Euro-PCT applications pursuant to Article 54(3) EPC, the provisions of Article 158(2) EPC 1973 and Rule 106 EPC 1973 continue to apply. Since Rules 57a and 67 EPC 1973 are linked respectively to Articles 100 and 111 EPC 1973, they are to be applied in the present case (by analogy with J 10/07, OJ EPO 2008, 567).

2. Applicable Rules of Procedure of the Boards of Appeal

2.1 The revised version of the Rules of Procedure of the Boards of Appeal (RPBA 2020) came into force on 1 January 2020 (Articles 24 and 25(1) RPBA 2020).

2.2 Subject to the transitional provisions (Article 25 RPBA 2020), the revised version also applies to appeals pending on the date of the entry into force.

2.3 In the present case the statement of grounds of appeal was filed before 1 January 2020. Thus, Article 12(4) to (6) RPBA 2020 does not apply, and instead Article 12(4) RPBA 2007 applies to the grounds of appeal (Article 25(2) RPBA 2020).

2.4 Since the summons to the oral proceedings has been notified before 1 January 2020, Article 13 RPBA 2007 is to be applied for questions regarding any amendment to the respondent's appeal case in response to the summons.

3. Main request - Article 100(b) EPC 1973

3.1 The appellant submitted that the patent does not sufficiently disclose how feature p) of apparatus claim 8 as well as the preferred embodiments of the invention defined in claims 6, 11 and 12 can be put into practice.

3.2 The Board shares the respondent's view that these objections are not persuasive:

3.2.1 With respect to feature p) of claim 8, the Board agrees with the appellant insofar as the wording of this feature is not limited to the normal mode of operation of the apparatus. In the context of this claim for an apparatus, feature p) must be construed as a functional feature specifying that the conduit of features g) and h) must be suitable for feeding the first compressor with cooled air having a temperature near the boiling temperature of the liquid stream which is removed from the distillation column system (feature m)). Thus, feature p) may be construed in a broad manner when assessing novelty or inventive step.

However, when seeking to put into practice the apparatus of claim 8, the skilled person would read feature p) in the context of the patent as a whole and they would immediately understand that feature p) relates to the normal mode of operation of the apparatus for producing pressurized gaseous products. The Board shares the respondent's view that the skilled person would know, without exceeding their normal skill and knowledge, how to implement feature p). This is confirmed by the teaching of E1 (column 3, lines 58 to 65 and process step c) in claims 1, 10, 18, 24, 28, 37).

3.2.2 With respect to claim 6, paragraph 22 of the patent makes clear that, in the absence of any turboexpanders, the addition of cryogenic liquid 30 shall provide essentially all the refrigeration required by the process.

3.2.3 With respect to claims 11 and 12, it is clear in the light of the patent as a whole that the term "said fluid feed stream" refers to the liquid feed stream which is fed to the distillation column system when the two cold compressors are in operation.

3.3 Therefore, the ground of opposition under Article 100(b) EPC 1973 does not prejudice the maintenance of the patent as granted.

4. Main request, Claim 1 - Novelty

4.1 The appellant contends that the subject-matter of claim 1 lacks novelty in light of E1.

4.2 It is in dispute among the parties whether E1 discloses feature c) of claim 1. Whilst it follows from column 5, lines 7 to 10 of E1 that, in contrast with the embodiment shown in figure 1, the single cold compressor 7 may be replaced by two cold compressors connected in series, it cannot be directly and unambiguously derived from E1 that the first compressor's outlet gas would then be cooled in the main heat exchanger 4, before being introduced into the second compressor.

Thus, the Board agrees with the respondent that feature (c) of claim 1 requiring cooling at least a portion of the first pressurized gas stream in said exchanger to form a first cooled pressurized gas stream, is not disclosed by E1.

5. Main request - Claim 1, Inventive step

5.1 The appellant argued that the above distinguishing feature does not involve an inventive step.

5.2 The Board is not persuaded that the technical problem to be solved can be seen as that set out in the decision under appeal (see point 2.4.5) of how to improve fluid feed, since this formulation ignores the actual effect of the distinguishing feature, which is to allow for a more isothermal compression and thus a more energy-efficient compression. In view of this, the objective technical problem is considered to be one of how to improve the method of E1 in terms of energy efficiency.

5.3 It is accepted common general knowledge in the art that intercooling between compression stages is standard practice in order to improve efficiency.

Faced with the above problem, the question is then whether the skilled person would need to exercise an inventive step in order to decide to carry out this intercooling in the main heat exchanger. As set out by the appellant, two heat exchangers are potentially available in the installation of figure 1 of E1 which could be used as cold sources for intercooling:

- the main heat exchanger (MHE) 4 in which the liquid oxygen product from pump 6 is evaporated. The MHE ranges from about ambient temperature at the warm end to slightly above minus 180°C at the cold end (see Figure 2);

- the subcooler 5 for supercooling in counterflow at temperatures below the cold end of the MHE.

5.4 The temperature T2 at the outlet of the cold compressor 7 in figure 1 can also be read in figure 2 as being slightly below minus 100°C. This temperature is the starting temperature for intercooling in the case of two serial cold compressors. The flow compressed in the first cold compressor ("first pressurised gas flow" as defined by the European patent) must be cooled from just under minus 100°C to the inlet temperature T1 (just under minus 120°C in Figure 2). By contrast the subcooler 5 operates at temperatures lower than the cold end of the MHE.

E1 also indicates at column 5, lines 10 to 12 of E1 that "the sum of the compression heat is about equal to the excess of cold produced by the vaporization of oxygen". This is a direct indication that the compression heat should be dissipated in the MHE rather than in some alternate cooling device such as a conventional intercompression water cooler as suggested by the respondent in their reply to the grounds. A water cooler would in any case be unsuitable for such temperatures.

5.5 The Board also considers that if the authors of E1 had intended the two compressors of the variant suggested at column 5, lines 7 to 13 be simply connected to the two available turbines (for example by replacing the brake 10 by a compressor as suggested by the respondent), then this would have been stated.

5.6 In conclusion, the Board is of the opinion that it would not only be (i) obvious for the skilled person to carry out intercooling, but also (ii) to carry out this intercooling in the main heat exchanger 4 of E1.

5.7 Therefore, the subject-matter of claim 1 as granted lacks an inventive step.

6. Auxiliary requests - Admission into the appeal proceedings

6.1 The auxiliary requests essentially correspond to those filed with the response to the grounds of appeal.

6.2 In its provisional opinion, the Board explicitly drew the respondent's attention to the appellant's submission that the auxiliary requests failed to meet the requirements of Rule 57a EPC 1973 since they were not accompanied by any reasons as to why they overcome a ground of opposition (see paragraph 14.2).

6.3 However, despite this indication and the Board's provisional opinion indicating a probable negative outcome for the respondent as regards inventive step (see paragraph 13.5), at no stage in the written appeal proceedings were any supporting arguments presented setting out why the auxiliary requests overcome a ground of opposition or their technical relevance. Such requests - which are not self-explanatory - are considered by the Board as being submitted only on the date of their substantiation, i.e. during the oral proceedings.

6.4 According to the established case-law of the boards of appeal, such late filed requests will only be admitted if they are prima facie (clearly) allowable (Articles 13(1) and 13(3) RPBA 2007).

6.5 In this case, the amendments introduced in the auxiliary requests do not clearly overcome the objection of lack of inventive step in light of E1. In fact, in the oral proceedings, the respondent acknowledged that the amendments of the first auxiliary request did not change the assessment of inventive step when starting from E1. Also the respondent's submissions relating to sufficiency of disclosure (see paragraph XII (a) above) would tend to indicate that it is well known to add a cryogenic liquid from a reservoir to provide refrigeration in the absence of turbo expansion.| |

6.6 Thus, since the amended sets of claims of all the auxiliary requests were not prima facie (clearly) allowable, the Board decided not to admit them into the proceedings.

7. In the absence of any allowable claim request, the patent must be revoked.

8. The non admittance of the auxiliary requests into the proceedings results in the respondent's request for remittal being deprived of content. The request is thus refused.

9. Substantial procedural violations and reimbursement of the appeal fee

9.1 In the decision under appeal (point 2.4.6 of the reasons), the opposition division held that the subject-matter of claim 1 involved an inventive step when starting from E1 as closest prior art, because it was not obvious for the skilled person to modify E1 by performing an intermediate cooling step in the heat exchanger. The opposition division based its decision on the argument that, "although it may be required to cool the air stream after the first compressor in order to remove the heat of compression, such a cooling step can be performed using any kind of refrigeration e. g. from the product streams or from an external source". The appellant submits that this crucial argument was neither discussed at the oral proceedings, nor mentioned in the written proceedings. However, it appears that this argument was at least implicitly submitted in the respondent's response to the notice of opposition. Indeed, on page 4, paragraph 2 of its response, the respondent argued that, when starting from E1, the skilled person would contemplate placing a water cooled refrigerant between the two stages to allow isothermal compression and thereby improve efficiency. This argument of the respondent was also mentioned in the annex to the summons to oral proceedings. In conclusion, the Board is of the view that the appellant had sufficient opportunity to present counter-arguments, as required by Article 113(1) EPC 1973, and that no procedural violation occurred in this respect.

9.2 In the notice of opposition (point 5), the appellant raised objections of insufficiency of disclosure against claims 6, 11 and 12 as granted. However, the written decision is silent as to why the opposition division did not find these objections convincing. Hence, the decision is not sufficiently reasoned in this respect which constitutes a substantial procedural violation (Article 113(1) EPC 1973).

9.3 The Board notes that a substantial procedural violation of this order could in principle be sufficient reason for setting aside the contested decision, remitting the case to the opposition division (Article 111(1) EPC 1973 and Article 11 RPBA) and reimbursing the appeal fee (Rule 67 EPC 1973). However, in the oral proceedings, the appellant requested that the case not be remitted to the opposition division and that it be decided by the Board itself.

9.4 In view of the principle of procedural economy, the length of the opposition (appeal) proceedings to date, the already advanced age of the patent and the fact that the violation concerns dependent claims, the Board acceded to the appellant's request.

9.5 Pursuant to Rule 103(1)(a) EPC, in order for a refund of the appeal fee to be ordered, three requirements must be met: (1) the appeal is allowed, (2) a substantial procedural violation occurred (3) which renders the reimbursement equitable.

9.6 According to the established case law of the boards of appeal, in order to render the reimbursement of the appeal fee equitable, a causal link must exist between the alleged procedural violation and the filing of the appeal (see the Case Law of the Boards of Appeal of the EPO, 9th edition, July 2019, V.A.9.7.1, in particular T 272/08 and T 840/07).

9.7 In the present case, the appellant's objections under Article 100(b) EPC regarding claims 6, 11 and 12 were one issue among many others. Moreover, the appellant requested the Board to examine these objections itself rather than remit the case. The Board subsequently found that these particular objections did not prejudice the maintenance of the patent (see paragraphs 3.2.2 and 3.2.3 above). Therefore, there is no link between either the filing of the appeal or its success and the substantial procedural violation, which would justify a reimbursement.

9.8 Consequently, the request for reimbursement of the appeal fee is refused.