Ships sailing north from Chile are bringing an unusual cargo to the US: chemical factories. Methanex, the Canadian company that's the world's largest producer of methanol, is spending $1.1 billion to disassemble two of its Chilean factories and rebuild them in Geismar, LA. The first plant is scheduled to open next year. A second will be relocated by early 2016. Scores of other companies including ExxonMobil, Chevron, and Sasol plan to spend about $100 billion to build or expand chemical plants in the US, according to a tally kept by Dow Chemical, the biggest US chemical maker by sales. Nationwide, chemical producers added 11,800 jobs in the 12 months through June, according to the US Bureau of Labor Statistics, the biggest 12-month gain since 1988.