Incredible rates of domestic oil production indicate that refinery utilization is running at maximum capacity. Still, refining stocks took a big hit yesterday on news that the price of renewable energy credits skyrocketed, illustrating there is still risk aplenty in this industry. In this video, Motley Fool contributor Aimee Duffy takes a look at three other ways that companies can benefit from increased refining activity: export capacity, maritime services, and sulfur services.