Tags: ONGC,
'sweetening of gas',
'hydrogen sulphide',
'mixture of hydrocarbons',
'Hazira complex',
'central excise notification',
'power',
'fertilizers',
'tariff entry',
'excise duty (ED)',
'Central Excise Department (CED)',
'ST',
CST,
GAIL,
NTPC,
petrochemicals