A little reminder on rounding and novelty …
Claim 1 on file read:
A process for the oxidation of a C2 to C4 alkane to produce the corresponding alkene and carboxylic acid which process comprises contacting in an oxidation reaction zone, said alkane, molecular oxygen-containing gas, and the corresponding alkene and water, in the presence of at least one catalyst active for the oxidation of the alkane to the corresponding alkene and carboxylic acid, to produce a product stream comprising alkene, carboxylic acid and water, wherein in said process the molar ratio of alkene to carboxylic acid produced in said oxidation reaction zone is adjusted or maintained at a pre-determined value by controlling the concentrations of the alkene and water in said oxidation reaction zone and optionally by also controlling one or more of the pressure, temperature and residence time of the oxidation reaction zone and in which the alkane is ethane, the corresponding alkene is ethylene, the corresponding carboxylic acid is acetic acid and wherein ethylene and water are fed into the oxidation reaction zone in a ratio or 1 to 0.1 - 10 by weight, the molar ratio of ethylene to acetic acid produced is in the range 0.8 : 1 to 1.4 :1 and the product stream from the oxidation reaction zone also comprises carbon oxides in an amount of less than 15 mol%. (my emphasis)
 It has not been challenged by the [patent proprietor] that example 3 of document D5 […] discloses a process for the oxidation of ethane to a mixture of ethene and acetic acid over a catalyst containing Mo, V, Nb and Au […] wherein ethylene and water are fed to the reaction zone in a relative ratio of 1:2 by weight ([…] 5% v/v ethylene and 10% v/v water). The molar ratio of ethylene to acetic acid obtained is 1.42:1 (results from dividing the selectivity of ethylene, 55.8 mol% by the selectivity of AcOH, 39.3 mol% as disclosed in table 2 of D5), and hence falls within the claimed range, since 1.42 shall read 1.4 when rounded to a significant figure less (see decision T 871/08 [2.3]). The amount of carbon oxides in the product stream is 4.8 mol%, and thus less than 15 mol% as required by claim 1.
NB: In T 871/08 [2.3] we read:
[2.3] The [patent proprietor] argued that the claimed subject-matter was novel, because the value 2.996 was lower than the lower limit of 3:1 defined in claim 1 at issue.
This argumentation is not accepted by the board. When comparing a value from the state of the art (in the present case the value “2.996”) - with those claimed (here the range of values of “from 3:1 to 9:1”), the state of the art value has to be given the same accuracy as the one claimed. In the case at issue, the values in the claims have been quoted without any digit after the comma, which means that for comparison purposes, the value 2.996 has to be rounded up to 3, which thus falls into the range of the claimed values. This judgement is in agreement with the jurisprudence of the boards of appeal (in particular T 1186/05 [3.6.1-5]; T 708/05 ).
Should you wish to download the whole decision, just click here.
The file wrapper can be found here.