Texas’s refining complex is mostly back from last month’s crippling cold blast, but lingering freeze-related issues continue to plague a number of production units. More than six weeks after the Arctic storm took down at least 18 of the state’s 30 refineries, and almost 5 million barrels a day of crude-processing capacity, two of the plants still haven’t restored operations. But at a number of sites, equipment ranging from fluid catalytic crackers to crude units are still struggling. It’s an old story: Refineries don’t respond well to being restarted after unplanned total shutdowns, be it from winter storms, hurricanes or flooding. Refiners are anxious to restart because after cutting processing rates for more than a year due to the pandemic, the market now beckons with gasoline demand at its highest since October and profit margins rising. […]