Well, all depends on what the definition of 'clean' is. Too often it's used as 'marginally improved emissions levels compared to burning brown coal at Hazelwood, but still not even approaching a point that'll actually have an impact on averting AGW, but we'll call it clean anyway because we want to pretend it's environmentally sustainable so we can keep selling coal'
I have no faith at all in any sort of carbon sequestration. I was involved in research in the field at CSIRO back in the day. It's hugely energy-intensive, unreliable, limited, and has potential for cataclysmic failures involving massive fatalities. They've been researching it since the early 90s and it still isn't used meaningfully anywhere, the technical problems are just too great. It's a dead end.