  Quantum thermodynamics can be understood as a resource theory, whereby
thermal states are free and the only allowed operations are unitary
transformations commuting with the total Hamiltonian of the system. Previous
literature on the subject has just focused on transformations between different
state resources, overlooking the fact that quantum operations which do not
commute with the total energy also constitute a potentially valuable resource.
In this Letter, given a number of non-thermal quantum channels, we study the
problem of how to integrate them in a thermal engine so as to distill a maximum
amount of work. We find that, in the limit of asymptotically many uses of each
channel, the distillable work is an additive function of the considered
channels, computable for both finite dimensional quantum operations and bosonic
channels. We apply our results to bound the amount of distillable work due to
the natural non-thermal processes postulated in the Ghirardi-Rimini-Weber (GRW)
collapse model. We find that, although GRW theory predicts the possibility to
extract work from the vacuum at no cost, the power which a \emph{collapse
engine} could in principle generate is extremely low.
