Reforming of Cracker Fuel Gas

The high CO₂ emissions from ethylene plants is well documented, which stems from the use of internally produced fuel gas, which is combusted in the furnaces and boilers to provide reaction energy and to raise steam for internal compressor drivers and process heating duties.

Gas crackers are inherently lower CO₂ emitters since they have both lower furnace heat duties, plus the internally produced fuel gas is higher in hydrogen content. Therefore, maximum CO₂ reduction will occur when the hydrogen content of the fuel gas is maximised.

In the decarbonised cracker concept, combining a cracker with a hydrogen reformer, the cracker combustion energy demand is supplied purely from the firing of high purity hydrogen, with the principal source of this hydrogen being from the reforming of the entire cracker fuel gas product.

Technip Energies has recently announced a suite of blue hydrogen technologies under the BlueH2 by T.EN^TM banner. In the blue hydrogen process, the CO₂ produced from reforming process is captured. The high purity hydrogen product is then utilised to provide the fuel for both the Blue Hydrogen unit and the cracker as furnace and boiler fuel gas.

The decarbonized cracker will produce significantly lower direct (Scope 1) CO₂ emissions, with the majority of equivalent CO₂ emissions coming from the CO₂ burden associated from electrical power generation (Scope 2).

The paper will address whether the cracker and reformer combination can effectively be applied to liquid and gas crackers and provide an indication of the overall cost of CO₂ emission reduction. It will also provide an overview of the different types of reforming available and their merits when compared to the green hydrogen production route via the electrolysis of water.