Abstract: Coal gasifiers using technology developed by Texaco Development Corporation, use coal slurry and oxygen as feed stocks. During start-ups, the raw gas produced in the gasifier must be flared until the downstream clean-up and recovery plants can be started. In order to reduce emissions through the flare during start-up, a technique was developed to start the gasifiers and downstream plants on a sulfur free, liquid, organic fuel. Once downstream plants are on-line, the fuel feed is switched to coal slurry on the same burner. The switch is accomplished while maintaining pressure and without interrupting to the fuel feed.