Words to Describe feedstocks

How feedstocks often is described ("________ feedstocks")

• raw
• gaseous
• light
• principal
• organic
• catalytic
• solid
• value
• alternative
• residual
• necessary
• paraffinic
• toxic
• mixed
• various
• boiling
• desirable
• woody
• cost
• containing
• potential
• virgin
• primary
• heavy
• natural
• derived
• renewable
• conventional
• important
• suitable
• excellent
• synthetic
• chemical
• inexpensive
• sulfur
• difficult
• liquid
• based
• crude
• biological
• heavier
• attractive
• basic
• expensive
• domestic
• herbaceous
• aromatic
• cheaper
• lighter
• valuable
• available
• plentiful
• agricultural
• typical
• cheap
• cellulosic
• quality
• rich
• different
• fossil
• traditional
• carbonaceous
• other
• impure
• major
• complex
• alternate
• industrial
• preferred
• content