[rcxdude]

The first thing to understand is that money at this stage is mostly investment: the goal is to develop the technology and try to scale it up, not to just offset the carbon in the short term (in much the same way as investment in solar was not just to generate electricity but to enable economies of scale to actually get it to be a serious contender for replacing fossil fuels).

Why is such technology important to invest in? Two main reasons: firstly it could very well be the most economical means to make certain carbon-emitting processes carbon neutral, for cases where there is not currently a good means to eliminate the carbon emissions. Think aircraft emissions, for example. Secondly, even if we completely eliminate net carbon emissions, global warming will still continue for a fair few decades, as the climate takes a long time to actually reach equilibrium. If we want to avoid that equilibrium being too hot, we will need to remove carbon from the atmosphere. And while planting trees is generally a good thing, it's not really a feasible way to actually remove enough carbon from the atmosphere to make much of a dent (only growing new forests generally removes much carbon: mature forests are mostly carbon neutral, and the carbon capture process is slow). Technology like this, if it can be scaled and use renewable energy, has a chance of being able to make this difference (though the biggest question, apart from whether the technology can actually work, is who will pay for such removal, if it's not for carbon credits).