In a refinery, crude oil is first distilled, which separates it into light, medium and heavy fractions. After that, refiners start performing chemical reactions to change the oil’s molecules from their natural form into those needed in modern fuels. But the catalysts used in that process aren’t only expensive, they essentially end up as hazardous waste at the end of their productive life. That helps to explain why there’s been a lot of interest in catalyst recycling, which advocates see as a way for refiners to improve both their profitability and their environmental performance. In today’s RBN blog, we continue our look into catalyst recycling — the technology, economics and trade-offs — and detail some of the pushback against it.