Suggestion - when K2 is installed, make the recipe for a chemical plant include the basic chemical plant. Potentially reduce some of the ingredients needed in the chemical plant as a result (e.g. replace the pipes with a single basic chemical plant).
K2 tends to have a very strict hierarchy when it comes to using one building in the next of its tier (e.g. the lowest electric tier labs, inserters, and assembling machines all require their burner counterpart as an ingredient). When Natural Gas is installed, the basic chemical plant seems to basically function as a burner chemical plant, so the progression of using the basic chemical plant in the chemical plant makes sense.
Optionally, rename the basic chemical plant to a burner chemical plant (perhaps also only when K2 is installed).
Suggestion - when K2 is installed, make the recipe for a chemical plant include the basic chemical plant. Potentially reduce some of the ingredients needed in the chemical plant as a result (e.g. replace the pipes with a single basic chemical plant).
K2 tends to have a very strict hierarchy when it comes to using one building in the next of its tier (e.g. the lowest electric tier labs, inserters, and assembling machines all require their burner counterpart as an ingredient). When Natural Gas is installed, the basic chemical plant seems to basically function as a burner chemical plant, so the progression of using the basic chemical plant in the chemical plant makes sense.
Optionally, rename the basic chemical plant to a burner chemical plant (perhaps also only when K2 is installed).
(Source: Xynariz)