JUDGMENT

A.K. Sikri, J.

1. The issue involved in the present case pertains to the applicability of the doctrine of unjust enrichment in the case of refund of duty paid on 'capital goods' used captively. The factual matrix under which the aforesaid issue arises for consideration is taken note of, in short, hereinbelow:

2. The Respondent herein purchased Electro Static Precipitators (ESPs for short) from M/s. BHEL, Ranipet. In terms of Notification No. 78/1990-CE dated 20.3.1990, the Respondent was entitled to buy the said ESPs at concessional rate of duty which was 5% ad valorem in contra distinction to the normal rate of 15% ad valorem duty. This concession rate becomes payable on the condition that an officer not below the rank of Deputy Secretary in the Ministry of Environment and Forests (MoEF) certifies that the goods manufactured are meant for pollution control purpose. The dispute arose as to whether the Respondent was entitled for concessional rate of duty or not. It paid the duty at normal rate and fought for refund of the extra duty paid on the ground that only concessional rate of duty at 5% could have been charged. Respondent succeeded in its attempt before the judicial for