What was the story of the release of black smoke from the Abadan refinery?

According to Energy Press, the public relations of Abadan Oil Refinery issued a notice referring to emergency repairs in one of the operational units of Abadan Refinery, which apologized to the citizens.
Due to emergency repairs and out of service of one of the equipments of the refinery units, we will witness an increase in flaring and an increase in the height of the burner flame and, naturally, the emission of smoke due to the burning of these gases.
It also informs that with the diligent efforts and continuous presence of the managers and specialists of the refinery, this issue is being followed up and, God willing, the repairs will be done in the shortest time and this issue will be resolved with the full launch of this equipment.