Bloomberg: Rio Tinto Group and U.S. utilities are urging the government to spend $20 billion on a technology they say has the best chance for eliminating pollution linked to global warming. The energy companies are lobbying Congress to help create devices that can trap carbon dioxide from coal-fired power plants and bury the gas in underground caverns. Environmental groups, labor unions and members of Congress from coal states say pilot projects won’t begin without U.S. support that is unlikely …