Patrick Pouyanne has been elected as the new chief executive of Total following the death of Christophe de Margerie in a plane crash earlier this week.The French oil company also elected Thierry Desmarest as its chairman, according to an announcement from its union, returning to a role he held for fifteen years between 1995 and 2010.Pouyanne has been head of the company's refining and chemicals unit since 2012 and a member of the executive committee.Margerie was killed whilst his jet was trying to take off from an airport in Moscow on Monday evening. The jet collided with a snow plough and became engulfed in flames.The 63-year-old has since been praised for his "devotion" to France by the country's president, Francois Hollande. He had stood at the helm of Total for seven years."Christophe de Margerie dedicated his life to French industry and to building up the Total group. He made it into one of the very top global companies."He was the only passenger on the jet, along with three crew members who also died.Meanwhile, the lawyer of Vladimir Martynenkov, the driver of the snow plough, has defended his client against accusations that he caused the crash by going behind the wheel whilst drunk.Other lines of inquiry are also being investigated, including the possibility of an error by air traffic control.