Two model coals, one containing pyrrolic nitrogen and another containing pyridinic nitrogen,have been used to study N
2 formation from different nitrogen structures during coal pyrolysis.The formation of N
2 during pyrolysis of the model coals with and without a catalyst has beeninvestigated in a fixed-bed reactor at 2.5-10
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C/min up to 1000
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C. The pyrolysis results showthat calcium and iron catalyze both pyrrolic and pyridinic nitrogen in model coals to N
2. Calcium-catalyzed N
2 formation occurs at temperatures higher than 800
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C; however, the iron catalyzesN
2 formation at temperatures below 800
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C. The remarkable formation of N
2 results in lowresidual nitrogen in char. It is suggested that the calcium and iron catalysts catalyze N
2 formationmainly through solid-phase reactions of pyrrolic and pyridinic nitrogen forms in char.