He is one of a small number of people who has made it to both the North Pole and the South Pole. He runs ultramarathons. He climbs mountains. Oh, and he is a billionaire, one of the country's richest men, who has reluctantly been making the headlines. Jim Ratcliffe, who recently threatened to close the huge Grangemouth petrochemical plant in Scotland - which he owns through his company Ineos - is often described as 'reclusive'. Certainly he doesn't seek publicity. In Profile this week, Jo Fidgen talks to those who know him best, to find out what makes Jim Ratcliffe tick.