Crude oil prices added 47 cents and reached $91.48 per barrel Thursday morning on the New York Mercantile Exchange. Prices rose but recent economic data from the United States and China suggest slowing demand, market analyst Dominick Chirichella said. \"From a fundamental viewpoint oil remains driven by a weakening demand picture. In addition supply remains robust,\" he wrote in a research note Thursday. Overnight, energy prices rose. Gasoline prices added 0.2 cents to $2.7172 a gallon. Home heating oil gained 1.81 cents to $2.8047 a gallon. Natural gas climbed 3.3 cents to $4.349 per million British thermal units. At the pump, the average price of a gallon of regular unleaded gasoline was $3.522 Wednesday, up from Tuesday\'s $3.508, the AAA Fuel Gauge Report said.