CREATE TABLE table_204_909 (id NUMBER, "pollutant" CLOB, "units" CLOB, "emission standard" NUMBER, "coal-fired" CLOB, "petroleum coke-fired" CLOB)

what is the only pollutant that has 0.0 petroleum coke fired ?
SELECT "pollutant" FROM table_204_909 WHERE "petroleum coke-fired" = 0
SELECT "pollutant" FROM "table_204_909" WHERE "petroleum coke-fired" = 0