The only case where it might be viable is burning crop waste; stems of grain and maize, for example. The UK runs Drax on (imported! in oil burning ships!) sawmill waste, but that's greenwashing to me.
It definitely is. Besides that, Drax doesn't only run on waste products (that's what they'd like to make us believe), they mostly run on freshly logged timber.
And even if it only was waste that's burned, it's IMHO incredibly stupid. We should be happy about every single gram of CO2 that's stored somewhere and use this "waste" for building insulation, paper production, soil revitalization or simply bury it.
Burning simply shouldn't happen when we have way better, cheaper, more efficient, more environmentally friendly methods of producing heat and electricity.
In a post-fossil fuel age, that crop waste will be used as a carbonaceous feedstock for things like jet fuel and what are now petrochemicals. Burning it for power will be uneconomical.
