Base scenario and CO₂ emitters

Regional cluster of eleven emitters (red circles) and connecting pipeline network (blue and brown lines) as well as beginning of trunk line (black line) in base scenario Source: DBI-GUT

In this work package following aspects were investigated:

• definition of a base scenario (regional cluster of CO₂ emitters, transport settings, characteristics of storage reservoir),
• definition of typical CO₂ stream compositions of different emitters in regional cluster,
• description and accounting of CO₂ production of different emitters,
• set-up of a geological model for a fictive storage site in the base scenario.

Base scenario: All work in the project was based on a scenario of a regional cluster of eleven CO₂ emitters (power stations and industrial plants) whose CO₂ streams contain different impurities. In the scenario, captured CO₂ streams of individual emitters are collected in a regional pipeline network, jointly transported and injected into a geological storage reservoir. Parameters of the scenario are fictive, referring to real settings in and features of Germany. Considered emitters comprise seven fossil-fuelled power stations (fueled by hard coal, lignite or natural gas) equipped with post-combustion or pre-combustion capture or employing the oxyfuel technology. In addition, four industrial plants (one steel mill, two cement plants and one refinery) are part of the cluster. The spatial array of the different emitters is schematically depicted in the figure on the right. In the scenario, the joint CO₂ streams of the cluster (19.35 Mio t CO₂ annually) are transported in a 400 km long trunk line (300 km onshore and 100 km offshore) to the injection site. A generic saline aquifer (Buntsandstein, depth of 1600 m) in the North Sea area is chosen for injection and geological storage.

A cement plant – a CO2 emitter to be considered for CCS (here: in Brevik, Norway) Source: BGR

Emitters: The CO₂ production by the individual emitters, in particular the complex carbon flow of industrial plants, was accounted and modelled in detail. The average CO₂ stream composition and the temporal variation of the CO₂ mass flow rates of the different emitters were used to define the starting point for considering potential impacts of variable CO₂ mass flow rates and CO₂ stream compositions on the consecutive steps of the CCS process chain.

In addition, a measurement concept was developed for reliable, accurate and cost-effective accounting/quantification of the CO₂ production of the individual emitters. This allows deducing the respective proportionate usage of the joint CO₂ transport and storage infrastructure by each individual emitter.