Rotary batch and cullet preheater system and method

A method of producing molten glass, comprising:

• providing a glass melting furnace configured to melt, by burning fossil fuel, glass sample, the glass sample comprising glass batch material comprising soda ash, or cullet or post-consumer cullet, or any combination of batch material comprising soda ash, cullet and post-consumer cullet, said melting producing exhaust gas;
• introducing glass sample into a chamber of a rotary drum heat exchanger having at least one heat exchange tube;
• causing a transfer of heat from said exhaust gas in said at least one heat exchange tube to said glass sample in said chamber to volatize any organic impurities in said glass sample, heat said glass sample and evaporate water from said glass sample to dry said glass sample, said evaporated water forming water vapor in said chamber;
• discharging the dried glass sample from said rotary drum heat exchanger and introducing it into said glass melting furnace;
• combining said water vapor and any volatized organic impurities with said exhaust gas upstream of said rotary drum heat exchanger;
• and introducing said combined water vapor, any volatized organic impurities and said exhaust gas into said at least one heat exchanger tube.