  It has recently been suggested that planets can form by dust coagulation in
the torus of active galactic nuclei (AGN) with low luminosity of $L_{\rm
bol}\lesssim 10^{42} erg s^{-1}$, constituting a new class of exoplanets
orbiting the supermassive black hole called \textit{blanets}. However, large
dust grains in the AGN torus may be rotationally disrupted by the Radiative
Torque Disruption (RATD) mechanism due to AGN radiation feedback, which would
prevent the blanet formation. To test this scenario, we adopt the simple smooth
and clumpy dust/gas distribution inside the torus region to study the effect of
RATD on the evolution of composite dust grains in the midplane of the torus. We
found that grain growth and then blanet formation are possible in the smooth
torus model. However, in the clumpy torus model, grain growth will be strongly
constrained by RATD, assuming the gas density distribution as adopted in Wada
et al. We also found that icy grain mantles inside clumps are quickly detached
from the grain core by rotational desorption, reducing the sticking coefficient
between icy grains and coagulation efficiency. The grain rotational disruption
and ice desorption occur on timescales much shorter than the growth time up to
a factor of $\sim 10^{4}$, which are the new barriers that grain growth must
overcome to form blanets. Further studies with more realistic AGN models are
required to better constrain the effect of RATD on grain growth and blanet
formation hypothesis around low luminosity AGN.
