Reuters: Tight margins amid high corn and energy costs and weak ethanol prices will squeeze US ethanol producers in 2008, but the industry will continue to expand, albeit at a slower rate than in recent years, industry experts said Monday. A rapid expansion of US ethanol output over the past year and the lack of comparable growth in the infrastructure necessary to get that fuel to market has produced a glut of the renewable fuel in the Midwest, where most of it is produced. That glut …