This mod alters both the tech and recipe requirements for the bio-boiler in the bio-industries mod, allowing it to be unlocked significantly earlier for use in steam setups. In the startup settings, you'll find a setting to still require a bio industries research to unlock the bio-boiler (research requires red/automation science), which is enabled by default. Disabling his will unlock the bio-boiler at the game's start. There are a couple reasons why I felt this change was necessary, as follows:

-Firstly, the tech that unlocks bio-boilers requires automation/logistic/chemical science to unlock, which puts it being unlocked well after solar and accumulator techs are available. Initially thinking this was just a more space efficient boiler, I felt this was off, asking myself "Why not forego it and just work on renewable and completely clean solar energy instead?" As such, I felt reducing its tech requirement to be before solar and adjusting its recipe to compensate was necessary.

-Secondly, the bio-boiler is still a fuel-burning entity which produces steam in a more compact space, but at the same efficiency as the normal boiler fuel-wise. Since it offers no particular efficiency upgrade over the normal boiler other than in space (and pollution, thanks to a tip by Pi-C), I saw no reason that it should require significant research to unlock compared to the normal boiler, which is available at the game's start.