CMC Dry Ice in Concord ships about 2 million pounds of dry ice each year. “You’ve got blocks. You’ve got 16-millimeter pellets. You’ve got 10-millimeter pellets. You’ve got three millimeter pellets,” said Mike Coleman, the company’s owner. In 2016, Coleman started his business buying ice from suppliers and reselling it. But after he had a difficult time getting the ice he needed in February and March of this year, he decided to expand his business to include dry ice production. It was fortuitous timing: Dry ice is in high demand now as a COVID-19 vaccine prepares for rollout. Th...