CO2 capture from industrial point sources and further development of amine reclaimer waste handling by incineration and biological treatment

The project has consisted of four work packages, dealing with challenges relevant both for the power sector (gas fired, coal fired power plants), as well as for the process industry sector. There are differences however, between power industry and process industry, as the composition of flue gas from process industry will be different from power plant flue gases. This is one reason for performing a comparison between two CO2 capture technologies: amine based capture and a process using chilled ammonia. Th e project has demonstrated that chilled ammonia is advantageous if the CO2 concentration in the flue gas is relatively high and at the same time access to cold cooling water for the process is satisfactory. Amine based CO2 capture (monoethanol amine, MEA) on the other hand is advantageous if the concentration of CO2 is relatively low, as for instance in flue gas from a natural gas fired power plant. MEA based capture is also shown not to be as dependent on cold cooling water. The use of waste heat from in dustrial processes has also been studied in the project. Amine based CO2 capture can generate waste. This waste is to be classified according to the EU Waste Handling Directive. In the project, we have developed chemical methods to characterize waste and degradation products from the capture process. We have also developed a biological method for handling such waste by utilizing bacterial cultures feeding on the waste. Carefully developed bacterial cultures are shown to break the waste down to non-harmfu l components. Waste from the capture process can also be safely incinerated in a cement kiln. The project has demonstrated that such incineration in addition will contribute to reduced emissions of nitrous oxides from the cement production

Little attention are directed towards CO2 emitting point sources, although contribution from these is significant. Better knowledge is needed on CO2 capture from these industries. Focus is on reducing energy consumption through technology development and optimization. Acidic gases and dust in flue gas cause degradation. During regeneration, waste is collected in a reclaimer. This cause operational/environmental implications. Methods for handling/utilisation of ARW are needed. CO2 capture/energy integrat ion: Power intensive industries will not have sufficient energy available and a separate energy plant is needed. This gives additional CO2 that require capture. Case studies for representative industries: cement, aluminium and petrochemical. Areas address ed: How fuel will influence flue gas composition, the effect on the CO2 capture process and the need for pre-cleaning. A PhD will carry out the bulk of this work with a particular emphasis on the chilled ammonia process. Biodegradation of ARW: Experiment s will be done to promote and determine aerobic/anaerobic biodegradability. Culturing of samples in bioreactors for adaptation to ARW. By using ARW as the main source of organic carbon, bacteria that have ability to degrade the waste will be naturally sel ected. Chemical analyses and eco-toxicity test will be performed. One PhD student at Tel-Tek/TUC will perform the bulk of the work. NOx reduction using ARW in SNCR processes: Determination of to which degree ARW can be used for NOx reduction in cement ki lns/combustion systems. The project will involve lab. experiments at TUC as well as full-scale experiments at Norcem. One post doc fellowship followed by a PhD scholarship will carry out the bulk of the work. It is preferred that the PhD will do part of t he work in collaboration with DTU (Denmark). The goal is to increase the knowledge about CO2 capture, especially in the fields of power intensive industries and handling and utilisation of ARW