Refinery gas combustion

PCK Raffinerie GmbH, Schwedt (Germany)

The PCK Raffinerie GmbH in Schwedt converts crude oil into gasoline, diesel and aircraft fuels. A combustion plant which makes thermal use of the substances in the production process is to be used to reduce costs and increase the eco-friendliness of the plant.

During the production of fuels, a large proportion of the crude oil can be utilized, but refinery gases and heavy constituents are still left over. The "reraffinate" forms part of these heavy oils and makes particular demands on the combustion, as does the refinery gas which consists of around 70% hydrogen and differs significantly during combustion from the standard fuel, natural gas. It also fluctuates very widely in the composition and heat value, so that high demands are made on the control technology and the stability of the burner. The solution installed by SAACKE now enable a number of these refinery by-products to be used thermally to provide both heat and electricity for the production process.

The benefits of the SAACKE TF-DDZG are immediately apparent:

• The utilization of the available refinery gas guarantees not only an enormous cost benefit, but also a low emission level. The integrated air preheating system increases the efficiency of the plant and also saves fuel.

• As residual oil is also used as a second fuel alongside the refinery gas, the SAACKE TF-DDZG offer sufficient reserves to comply with all the limits - even with fluctuating grades of the oil.

• Compared with the old plant, the new SAACKE installation requires only 6 instead of 8 burners and thus reduces investment costs and maintenance.

• The ultra-low NO_x technology is a further development of the proven DDZ burners and has a number of benefits compared with conventional measures for NO_x reduction. The burner is suitable in principle for practically all fuels and with a recirculation rate of approx. 50% achieves extremely low emission values so that an external recirculation is frequently superfluous.

The combustion plant in Schwedt shows: The SAACKE TF-DDZG burner is a high-availability solution which burns refinery gases reliably and efficiently even under extreme conditions.

The installed plant consists of two steam boilers with a total capacity of 240 t/h at a boiler pressure of 90 bar and a mean boiler temperature of  520°C. A total of 6 SAACKE TF-DDZG burners with air preheating replace the previous 8-burner heavy oil combustion system and use refinery gas as main fuel.

The combustion system consists of 6 modified SAACKE TF-DDZG. These steam pressure atomizers combine the benefits of sturdy steam pressure atomizer technology with an internal recirculation system and hence very low NOx emissions.