Reuters: Continental Airlines said a blend of biologically derived fuel and jet fuel performed slightly better than jet fuel alone during a test flight by the world’s fifth-largest airline. During some parts of a 90-minute test flight in January, the blended fuel displayed a 1.1 percent increase in fuel efficiency over traditional jet fuel alone, the Houston, Texas-based airline said in a statement on Wednesday. Continental estimates greenhouse gas emissions were cut at least 60 percent …