T 0777/07 (Methanol synthesis/MITSUBISHI) 25-02-2011

Main request

1. Admissibility of the main request

1.1 The admissibility of this request has not been questioned by the respondent. The fresh claims can be regarded as a reaction to the questioning of the allowability of the amended claims then on file under Article 123(2) EPC by the respondent and the board (first communication, points 3 and 6). Moreover, the amendments restrict the ambit of the claims as granted.

1.2 Pursuant to Article 13(1) of the RPBA, the board thus admitted this request despite its late filing.

2. Allowability of the amendments (Article 123(2) EPC)

2.1 Claim 1 according to the instant request differs from claim 1 as filed (and as granted) inter alia in that the former additionally comprises the negative expression "without being subjected to CO2 absorption in the carbon dioxide tower (92) in the carbon dioxide recovery apparatus (90)", relating to the processing of the synthesis gas.

2.2 In order for the amendments to be allowable under Article 123(2) EPC, the subject-matter of the amended claim 1, i.e. the combination of features recited in claim 1 including the negative feature, must be directly and unambiguously derivable from the content of the application as filed as a whole, i.e. the description, the claims and/or the drawings.

2.3 In this respect, it remained undisputed

i) that there was no literal basis in the application as filed for the negative wording introduced into claim 1, and

ii) that Figure 1 of the application as filed did not show a carbon dioxide absorbing tower arranged in the flow path of the synthesis gas from the reformer reaction tube (31) to the reactor (53) for the synthesis of methanol.

2.4 First of all, it must be noted that providing a unit for recovering carbon dioxide from a synthesis gas product stream, i.e. downstream of a reformer, is not something unusual in the technical field concerned. In this respect, reference can be made e.g. to document D1, paragraph bridging the two columns and Fig.1, and to document D2, paragraph bridging pages 46 and 47; page 47, right-hand column, first full paragraph and Figure 1 (see unit labelled "CO2 REMOVAL").

2.5 Figure 1 of the application as filed, "schematically illustrating one example of a plant for manufacturing methanol according to the present invention" (page 4, lines 26 to 28; emphasis added), shows a complex arrangement of machinery and piping. Having regard to Figure 1, the board observes that present claim 1 is not restricted to the method schematically illustrated in said figure, since the latter shows many features (e.g. unit operations such as heat exchanges) which are not referred to in claim 1. On the other hand, the schematic Figure 1 and its textual description actually do not show or refer to a unit for recovering carbon dioxide by absorption from the synthesis gas, known as such (see point 2.4 above). However, Figure 1 and its textual description do not exclude the provision of such a unit, if necessary or desired, and it cannot be deduced therefrom that the absence of the specific features excluded from claim 1 was mandatory in a process as schematically illustrated by Figure 1.

2.6 Hence, the fact that Figure 1, illustrating a specific plant, does not show a unit for the recovery of CO2 from the synthesis gas does not amount to a general, direct and unambiguous teaching to do without such a unit in the context of any conceivable method for the production of synthesis gas with all the (positive) features recited in claim 1 in combination.

2.7 In the board's view, the entire text of the application as filed does not contain any express or implicit indication of a general desirability or necessity to do without a CO2 recovery step by means of an absorption tower arranged in the synthesis gas flow path.

2.7.1 This is equally true for the passages describing in more detail the process and plant illustrated by Figure 1 (page 5, line 18, to page 22, line 36) as well as for the more general passages of the description that were cited by the appellant.

2.7.2 At the oral proceedings, the appellant pointed out in particular the passages on page 20, lines 15 to 19, and on page 23, lines 6 to 30.

2.7.3 However, the first quoted passage is too general to imply the presence or absence of a particular process step besides the ones mentioned in claim 1 as filed.

2.7.4 In the second quoted passage, it is stated that "As described above, according to the present invention, it is possible to provide a method of manufacturing a synthesis gas having an H2/(CO+CO2) molar ratio which is suited for the synthesis of methanol at the reformer..." (emphasis added by the board).

i) However, it has to be noted in this respect that the method of claim 1, according to one alternative, expressly comprises feeding the carbon dioxide recovered from the combustion exhaust gas only at a point downstream of the reformer (see the expression "... to the upstream side and/or the downstream side ..."). In the board's view, in this latter process alternative, the molar ratio of the synthesis gas components leaving the reformer ("at the reformer") is subsequently changed by the addition of the recycled CO2.

ii) Furthermore, it has to be considered that in the field of methanol synthesis from synthesis gas it is not uncommon to add CO2 recovered from flue gas to the synthesis gas produced in a steam reforming process, in order to establish the proper molar ratio of the components for the subsequent synthesis of methanol (see D2, page 50, last paragraph, to page 51, second paragraph).

2.7.5 Bearing this in mind, the sentence in the description quoted under point 2.7.4 does not even constitute an implicit disclosure, which could be qualified as direct and unambiguous, of the subset of those methods (intermediate generalisation) showing all the (positively worded) features recited in claim 1 in combination and, at the same time, meeting the condition imposed by the added negative expression. This finding applies in particular to the alternative subset constituted by those methods according to which recycled CO2 is fed to the downstream side of the reformer.

2.8 Since the subset of methods which is the subject-matter of instant claim 1 constitutes subject-matter extending beyond the content of the application as filed, the amendment in question does not meet the requirements of Article 123(2) EPC.

2.9 For the sake of completeness the board additionally notes the following. The claimed subset of methods is defined inter alia by a negative expression, which can be regarded as a disclaimer since it excludes those methods which comprise a step for subjecting the synthesis gas produced to a CO2 absorption step.

2.9.1 Figure 1 and its description illustrate a specific process which does not comprise such a step and can - at least for the sake of argument - be considered to disclose the exclusion or absence of such a step in the specific context of the process illustrated by Figure 1. However, in the absence of a corresponding more general teaching in the description, Figure 1 and its description do not constitute a direct and unambiguous disclosure of said disclaimer (or exclusion) in connection with the much broader set of processes defined by the combination of positive features according to claim 1.

2.9.2 Considering that said disclaimer, which is undisclosed in the broader context of the subject-matter claimed, was not incorporated in order to restore novelty, it is not allowable under Article 123(2) EPC pursuant to decision G 0001/03 (OJ 2004, 413), Order, point 2.1, first indent (see e.g. decision T 0440/04 of 26 November 2008, point 5 of the reasons).

2.10 Consequently, the main request of the appellant is not allowable.

First auxiliary request

3. Admissibility of the first auxiliary request

3.1 Compared to claim 1 of the main request, the instant claim 1 was further amended by replacing certain terms and expressions comprised in its pre-characterising part and also by incorporating additional features into the latter.

3.2 According to the appellant, these amendments were made "to define more clearly that the processes of generating the combustion exhaust gas and the hot synthesis gas and the function of the carbon dioxide absorption tower to be used to absorb carbon dioxide from the combustion exhaust gas but not the synthesis gas". The appellant thus argued that a lack of clarity was overcome by the amendments in question.

3.3 According to Rule 80 EPC, the claims of a European patent "may be amended, provided that the amendments are occasioned by a ground for opposition under Article 100" EPC. However, a possible lack of clarity as invoked by the appellant does not constitute a ground for opposition according to Article 100 EPC.

3.4 Moreover, neither the board nor the respondent had previously called into question the meaning of the pre-characterising part of claim 1. For the board, even without the amendments in question, the wording of claim 1 (as granted and as according to the main request) clearly means that two different gas streams are discharged from the "reformer" (30), i.e. on the one hand the "synthesis gas" and on the other hand the "combustion exhaust gas". The latter gas stream implicitly stems from the combustion of fuel, heats the reformer and is then subjected to carbon dioxide recovery in apparatus (90).

3.5 As a corollary to the above, the amendments allegedly aimed at improving the clarity of the claims appear prima facie to be objectionable under Rule 80 EPC.

3.6 Since this further issue is raised by the amendments in question, the late filed first auxiliary request was not admitted pursuant to Article 13(1) RPBA.

Second auxiliary request

4. Admissibility of the second auxiliary request

4.1 Compared to claim 1 according to the main request, said negative expression has been generalised by replacing the definite article "the" relating to the absorbing tower (90) and the recovery apparatus (90) by the indefinite article "a". Moreover, the reference numerals "(92)" and "(90)" as previously appearing in the negative expression included in claim 1 (according to the main request) were deleted.

4.2 The amended claims according to the instant request can be regarded as an attempt also to overcome the further objection raised in the board's first communication (point 4.1) concerning the lack of clarity of the negative expression comprised in claim 1 then on file. Moreover, since the exclusion is broadened, the ambit of the claim is more restricted compared to claim 1 according to the main request.

4.3 Pursuant to Article 13(1) of the RPBA, the board thus admitted this request despite its late filing.

5. Allowability of the amendment (Article 123(2) EPC)

5.1 Claim 1 according to the second auxiliary request only differs from claim 1 according to the main request in that the wording of the negative expression has been changed, rendering it more general in terms of the carbon dioxide recovery steps to be excluded.

5.2 This particular amendment, which due to the broader wording of the negative expression excludes even more subject-matter than the amendment carried out in claim 1 according to the main request, also does not find a basis anywhere in the application as filed. Therefore, the reasoning under points 2.2 to 2.9.2 above applies mutatis mutandis to claim 1 according to the instant request.

5.3 Consequently, the second auxiliary request is not allowable either (Article 123(2) EPC).

Third auxiliary request

6. Compared to claim 1 of the second auxiliary request, claim 1 of the third auxiliary request was further amended by incorporating the features "having a molar ratio of H2/(CO + CO2) which is suitable for the synthesis of methanol".

7. Admissibility of the third auxiliary request

7.1 It has to be noted that the amendment consisting in the incorporation of said additional features into claim 1 would appear to find support only in the description of the application as filed, if at all.

7.2 The amendment in question prima facie gives rise to concerns concerning the clarity (Article 84 EPC) of the wording of the resulting amended claim.

7.2.1 In particular, it has to be noted that present claim 1, according to one alternative (see "... to the upstream side and/or the downstream side ..."), expressly comprises feeding the carbon dioxide recovered from the combustion exhaust gas downstream of the reformer. Having regard to this alternative of the claimed method, a question immediately arises due to said amendment, namely whether the gas as "produced in the reformer" must have the suitable molar ratio, or whether a further addition of recovered carbon dioxide may also be performed to achieve the suitable molar ratio.

7.2.2 At the oral proceedings, prompted by the board to take position on this aspect, the appellant merely argued that claim 1 referred to feeding the recovered carbon dioxide upstream of the reformer and that the alternative "or downstream" could be deleted. However, the above-mentioned concerns are in no way dispelled by this reaction of the appellant.

7.2.3 The board, having to decide on the requests as submitted, thus considers that the amendment in question is not clearly allowable under Article 84 EPC.

7.3 In view of the above circumstances, the late filed third auxiliary request was not admitted pursuant to Article 13(1) RPBA.

Fourth auxiliary request

8. Admissibility of the fourth auxiliary request

8.1 The amended claims according to this request can be regarded as a further attempt to overcome previous objections raised by the respondent and the board by reverting to the narrower definition of the invention (integrated process comprising synthesis gas production and methanol synthesis). The ambit of the instant claim 1 is substantially restricted in comparison to claim 1 according to the second auxiliary request.

8.2 Pursuant to Article 13(1) of the RPBA, the board thus admitted this request despite its late filing.

9. Allowability of the amendment (Article 123(2) EPC)

9.1 Present claim 1 is based on claim 5 of the application as filed and relates to an integrated process comprising the production of synthesis gas and the production and distillation of methanol.

9.2 The characterising part of instant claim 1 comprises all the features of claim 1 according to the second auxiliary request, including the negative expression "without being subjected to CO2 absorption in a carbon dioxide absorbing tower in a carbon dioxide recovery apparatus" concerning the hot synthesis gas produced.

9.3 Present claim 1 is more specific than claim 1 according to auxiliary request 2, since it is directed to an integrated process for the production of the final product methanol from the synthesis gas produced as an intermediate product. An example of such an integrated production method is schematically illustrated by Figure 1 of the application as filed. As already indicated above (points 2.3 ii) and 2.5), Figure 1 and the corresponding parts of the description describe a process which does not comprise an absorption step for carbon dioxide recovery from the synthesis gas, without, however, excluding or mentioning the absence of such a step. It is however noted that Figure 1 does not illustrate the claimed alternative according to which recovered carbon dioxide is fed downstream of the reformer. Neither does the description contain further information concerning this alternative.

9.4 Instant method claim 1 does not recite all the features of the process schematically illustrated by Figure 1, which includes further heat-exchanges of the hot synthesis gas (see reference numbers 41 and 12), a specific arrangement of the distillation column heat exchangers (reference numbers 811, 812 and 813) relative to a specific heat exchanger (reference number 104) for heat exchange between the hot synthesis gas and the regenerated absorbing liquid and only comprises feeding recovered CO2 upstream of the reformer. Moreover, claim 1 in its present wording (see "comprising...") does not exclude the presence or absence of further process steps.

9.5 The board acknowledges that the incorporation into a claim of a negative feature not contained verbatim in the application as filed may be allowable under specific circumstances, such as in the case underlying the decision T 0278/88 referred to by the appellant. The board however notes that in the particular case underlying said decision (see points 3.2.3 and 3.2.4 of the reasons), the absence of a feature in the figures was corroborated by an implicit disclosure of the absence of this feature in the text of the description.

9.6 However, in the present case, there is no such corroborating implicit disclosure in the description, not even on page 23, lines 17 to 29, of the absence of said CO2 recovery step in the broader context of a methanol production process as defined by the positive features of claim 1, at least for the alternative wherein CO2 is fed downstream of the reformer.

9.7 The reasoning under points 2.7 to 2.7.4 thus applies mutatis mutandis to present claim 1. The subject-matter of present claim 1 is defined in terms which provide a definition of the methanol production method which is generic compared to the process described in Figure 1. In other words, the absence of a step for recovering carbon dioxide from the synthesis gas has been extracted from the total information provided by Figure 1 and has been incorporated into claim 1 in the form of a negative expression. However, there are many other conceivable process steps which can be considered to be absent from Figure 1 of the application as filed. In particular since the mass and heat streams involved in the method claimed depend on the relative arrangement and the interaction of unit operations (e.g. heat exchangers) and piping (recycling of carbon dioxide), not all of which are detailed in claim 1, the board considers that the skilled person would not directly and unambiguously derive the absence of said carbon dioxide recovery step as a salient feature of the invention. In the absence of a corresponding teaching in the description, an amendment based on arbitrarily choosing one of many possible negative features (in the present case: the absence of a process feature which is not shown in Figure 1), is not permissible (see e.g. decision T 1120/05, point 2.2.2 of the reasons).

9.8 For the board, the combination of, on the one hand, the positive features of a method for the production of methanol as previously comprised in claim 5 as granted, with, on the other hand, the negative feature excluding carbon dioxide recovery from the synthesis gas, thus generates a subset of methods for the production of methanol, which subset constitutes subject-matter not directly and unambiguously disclosed in the application as filed (intermediate generalisation).

9.9 Since instant claim 1 is directed to subject-matter extending beyond the content of the application as filed, the amendment in question does not meet the requirements of Article 123(2) EPC.

9.10 The appellant also argued that incorporating all the features of Figure 1 into claim 1 would unduly limit the scope of protection conferred. This may be the case from a subjective point of view; however, the question to be answered in the present case is whether the amendments requested by the appellant meet the requirements of Article 123(2) EPC.

9.11 Therefore, the fourth auxiliary request is not allowable either (Article 123(2) EPC).

Fifth auxiliary request

10. Admissibility of the fifth auxiliary request

10.1 The board accepts that the amendments requested may be considered as an attempt to overcome various objections under Articles 123(2) and 84 EPC raised earlier by the respondent as well as by the board, in particular against the negative expression incorporated into the independent claims.

10.2 However, the request was filed at an extremely late stage of the proceedings, namely at the beginning of the oral proceedings. Moreover, the appellant did not put forward convincing reasons justifying why the request could not have been filed earlier.

10.2.1 In particular, the board observes that its second communication did not deal with outstanding objections under Article 123(2) EPC, but merely drew the parties' attention to the contents of some prior art documents.

10.2.2 Therefore, the amendment to claim 1 consisting in the deletion of the negative feature present in the respective claim 1 according to all requests previously on file cannot be regarded as a reaction to the said second communication.

10.2.3 A negative feature (exclusion of CO2 recovery by absorption from the synthesis gas) was already contained in the claims filed as the main request with the appellant's statement of grounds of appeal, and this negative feature was objected to under Article 123(2) EPC by both the respondent and the board. Nevertheless, the appellant maintained such a negative expression in each of the independent claims according to the new main request and the new auxiliary requests filed in response to the summons to oral proceedings and the board's first communication, and did not file a request comprising no such negative expression till the date of the oral proceedings.

10.3 It is also noted that the fifth auxiliary request cannot be considered as a "converging" request in the sense of decision T 1685/07 of 4 August 2010; see "Leitsatz" and "Reasons", points 6 to 6.8. In particular, although some further limiting (positive) features setting out details of synthesis gas heat utilisation were incorporated into claim 1, the negative expression previously contained in claim 1 according to all requests was dropped altogether, leading to a broadening of the claimed subject-matter in this respect. Moreover, whereas claim 1 according to the preceding fourth auxiliary request was limited to methanol production, in claim 1 according to the present fifth auxiliary request the appellant reverts to a broader claim directed to the manufacturing of synthesis gas in general, i.e. not necessarily within the context of methanol synthesis.

10.4 Moreover, present claim 1 is not based on a straightforward combination of claims 1 and 4 as granted, but also comprises additional features which according to the appellant find their basis in the description as filed and comprise minor adaptations in wording.

10.4.1 It is noted that the passages of the application as filed (page 13, line 33 to page 14, line 2) pointed out by the appellant as forming a basis for the amendment in question relate to the specific embodiment represented in Figures 1 and 2 of the patent in suit, i.e. to a specific example of an integrated process for the production of synthesis gas and methanol.

10.4.2 The proposed amendment thus consists in the incorporation of features isolated from the description of said specific example into the broader method (production of synthesis gas in general) according to claim 1 as granted. An assessment of the allowability of this amendment under Article 123(2) EPC requires inter alia a careful check of whether or not the skilled person could directly and unambiguously derive from the application as filed a disclosure of the set of methods constituting the subject-matter of claim 1 as amended. Moreover, the minor adaptations of the wording used would also have to be checked for possible implications in terms of allowability under Articles 123(2) and 84 EPC. Finally, considering that some of the added features were not previously present in the claims but were taken from the description, it could not be ruled out that a review of the entire prior art on file would possibly become necessary in the context of the evaluation of inventive step.

10.5 In view of all the above circumstances, the board does not consider the instant request to be clearly allowable in the sense that no extensive examination would be required as to whether or not the amendments meet the requirements of Articles 123(2), 84 and 56 EPC.

10.6 Consequently, the fifth auxiliary request filed at the oral proceedings was not admitted pursuant to Article 13(1) RPBA.

11. In summary, the appellant's pending requests are either not admissible in view of their late filing or not allowable under Article 123(2) EPC.