Ending petroleum dependence is the big, fat target of most cleantech startups. But one startup thinks it can make today’s dominant energy source for transportation greener.

Petroleum refining catalyst maker Rive Technology announced today a $25 million round to commercialize its technology, which helps oil refiners squeeze better yields of high-quality fuel out of crude oil.

Rive’s catalysts can increase the amount of fuel usable for transport that refiners can get out of crude oil, and can be dropped in to replace current catalysts used in refineries. The company explains its cleantech peg as this: catalysts that improve efficiency in oil refining can eventually cut down on the overall amount of crude oil used or mined, increasing profits for refiners and also leaving less of an environmental footprint.

“Refiners can produce a fixed amount of fuel while emitting less CO2,” said Andrew Dougherty, the company’s marketing and finance chief, noting the technology could also be used in biofuels.

As an investment, the company certainly seems to be a good bet, considering that the oil refining market that Rive’s catalysts will play in is worth about $2 billion globally. Winning over  Blackstone is no small feat, either — Blackstone executive Jamie Kiggen called Rive “poised to have major impact on the refining industry” in a statement. Still, at first blush, Rive’s self-described clean-energy angle does seem to be a bit of a stretch considering how it’s working with, well, oil.

And in fact, Rive’s technology aims to make the oil business more profitable. It brings to mind how some long-time green investors bristle at the term “cleantech” since it’s become a catchall for things that are only vaguely clean energy-related. (The term “green” has the same problem in packaging marketing, which has led the Federal Trade Comission to crack down lately.)

But then again, Rive’s appeal is an example of new technology efforts that mitigate or adapt to global warming rather than stop it entirely, a trend that Earth2Tech recently pointed out. It’s a line of thinking that reflects a sharp edge of pragmatism and reality. Exciting hype aside, electric cars are set to make only modest gains in the overall car market in the next few years, and despite gains in biofuels and larger percentages of ethanol-blended gasoline approved for cars in the U.S., oil is far from going away any time soon — so making the refining process greener isn’t a bad way to go.

Possibly the bigger takeaway here is that despite buzz and generous government support in recent years for renewable energy and energy efficiency projects, fossil fuels are here to stay. As we’ve previously reported, the rising popularity and relative cheapness of natural gas will likely challenge solar and wind for financing, as well as replace its dirtier fossil-fuel cousin, coal. And all the green buzz aside, major investors like Blackstone Group think improved oil refining is a good bet in any market, bull or bear, according to Dow Jones Newswires.

Other investors in this round, which was led by Blackstone, include Charles River Ventures, Advanced Technology Ventures and Nth Power. The company’s technology was developed at MIT. Rive has raised $47 million to date.

[Image from Flickr/tsuda]