  Several efforts are ongoing for the development of spherical gaseous time
projection chamber detectors for the observation of rare phenomena such as
weakly interacting massive particles or neutrino interactions. The proposed
detector, thanks to its simplicity, low energy threshold and energy resolution,
could be used to observe the $\beta\beta0\nu$ process i.e. the neutrinoless
double beta decay. In this work, a specific setup is presented for the
measurement of $\beta\beta0\nu$ on 50~kg of $^{136}$Xe. The different
backgrounds are studied, demonstrating the possibility to reach a total
background per year in the detector mass at the level of 2 events per year. The
obtained results are competitive with the present generation of experiments and
could represent the first step of a more ambitious roadmap including the
$\beta\beta0\nu$ search with different gases with the same detector and
therefore the same background sources. The constraints in terms of detector
constructions and material purity are also addressed, showing that none of them
represents a show stopper for the proposed experimental setup.
