Abstract on EPC2000 Art 056 for the decision T0547/21 of 06.09.2022

In T 547/21 D2 was the closest prior art, the aim of the disclosed process therein being, inter alia, to increase the concentration of solids in skim milk or whey, an aim shared by the application at issue. The board noted that it could only be acknowledged that recirculating the UF permeate as disclosed in the application led to a further increase in the solids content if the skilled person would have implicitly inferred this effect on the basis of common general knowledge. The board accepted this assumption and deemed the objective technical problem was to provide a process that led to a further increase in the solids content. On obviousness, the board agreed with the examination division that "the skilled person would be aware that a valuable product [e.g. lactose] still present in the UF permeate can be recovered by a second pass through the system. Indeed, recirculation loops are known in the art particularly for the purpose of recouping useful products from a first pass through a membrane system" (text in square brackets added by the board). Therefore, in view of the objective technical problem posed, the claimed recirculation would have represented an obvious technical measure that the skilled person starting from D2 would have selected on the basis of common general knowledge. It followed that the subject-matter of claim 1 of the main request would have been obtained without exercising any inventive skill. The appellant argued that recirculating the UF permeate to the RO step was not disclosed in either D2 or any of the other documents referred to in the decision under appeal, which, it argued, were instead aimed at fractionating the skim milk or whey. Therefore, the skilled person would not have contemplated returning the UF permeate to the RO in the system since doing so would have deprived the prior-art processes of one of their purposes, i.e. producing a UF permeate rich in lactose. The board was not convinced by the argument; the fact that recirculating the UF permeate leads to an increase in the solids content of the UF retentate had to be regarded as belonging to common general knowledge. Therefore, no secondary document disclosing this feature was needed. What was relevant for the assessment of inventive step was the general teaching in D2 to increase the concentration of solids in skim milk or whey by using the combination of RO and UF. The board found that the appellant's argument was an attempt to replace the objective technical problem with the one allegedly aimed at in the closest prior art. However, the objective technical problem is the problem solved by the distinguishing feature of the claimed invention over the closest prior art, not a problem allegedly aimed at in that closest prior art. The board further held that the fact that other possibilities would have been known to the skilled person, as argued by the appellant, had no bearing on the conclusion that the claimed solution was obvious to the skilled person on the basis of common general knowledge. The board concluded that, starting from D2, the subject-matter of claim 1 of the main request did not involve an inventive step within the meaning of Art. 56 EPC in view of common general knowledge.