I know that you need industrial facilities to compost compostable plastics within a reasonable timeframe. But how does this process work exactly? How long does it take? Is it simply a matter of doing hot composting and maintaining high temperatures? Are any extra resources (e.g. water or energy) needed? Is the end product ready-to-be used compost?

I suspect the exact method may depend on the type of compostable plastic. I'm mainly interested in composting PLA-based plastic since they form the majority of all compostable plastics.

EDIT: I've learned that here in The Netherlands compostable plastic isn't recycled, but incinerated instead. Perhaps this is the same elsewhere and no compostable plastic is recycled?