Operators in a Conflicting Situation – Energy Supply Versus CO2 Capture

Since being included in the Fuel Emissions Trading Act (BEHG), which regulates the trading of certificates for CO2 emissions, German waste incinerators have been in the situation of having to pay money for every ton of CO2 emitted. The current certificate price of 45 EUR per ton of CO2 emitted is still at a level that is justifiable in terms of operating costs. However, if the certificate price rises rapidly, as politicians envisage, the construction and operation of a CO2 capture stage can have economic advantages.

by Rudi H. Karpf and Sophie Kreuz

 For this reason, some plant operators are currently conducting studies to determine which processes for CO2 capture are generally possible. It must be checked whether the necessary space is available for any retrofitting and what impact the operation of a capture facility might have on the site‘s energy infrastructure. The latter in particular puts operators in a conflict between CO2-free or CO2-neutral operation and their additional role as a regional heat supplier. This applies in particular to the CO2 capture technology that is most frequently considered and most advanced today, amine scrubbing. This process is classified as a chemical absorption process and requires heat energy within the capture process for the regeneration of the amine solution or desorption of the CO2. The energy consumption when using Monoethanolamine (MEA), the most widely used amine today, is approximately 1 MWh of thermal output per 1 ton of captured CO2. Since the energy provided by combustion at German waste incineration plants is used to supply electricity or district heating, amine scrubbing reduces the electricity and heat output provided by the plant. In addition, the question arises as to what to do with the captured CO2. There is currently no infrastructure for the transport routes, regardless of whether CO2 recovery/use (CCU) or storage (CCS) is being pursued. In addition to the aspects already outlined, the space available at many waste incineration plant locations also plays a decisive role in considering CO2-neutral or CO2-free operation. Waste incinerators, whose original task is the safe and environmentally friendly recycling/disposal of waste, are operating in this area of tension.