what are the major constraints?

Just started to get interested in this stock and have really enjoyed the rolling battle between Sdaji and the rest! I haven't done a great deal of research on this, but it appears to be great technology which goes somewhere to solving CO2 emissions/ carbon tax issues, and producing a renewable fuel.
But what I can't get a sense of is whether the technology is proven, reliable, and repeatable? If it is, then I assume the major constraints are industry acceptance and access to capital to build facilities?