Tiny German oil firm strikes black gold on the Rhine Outside the small town of Riedstadt, near Frankfurt, a bright green derrick pumping oil from deep underground marks a rare rural German site where that is still a profitable business. As Berlin battles to reach climate neutrality by 2050, minnow Rhein Petroleum sees a niche for its unusually pure crude during the transition phase, although its output is dwarfed by the more than two million barrels a day still consumed by Europe's top economy. IMAGES AND SOUNDBITES