Show summary
Amine-based post-combustion carbon capture is a method used for reducing CO2 emissions from industrial point sources. During this process, amines can be released into the environment and form carcinogenic nitrosamines and nitramines. Consequently, the location where it is safe to build carbon capture facilities depends on the levels of carcinogens, and where in the atmosphere they are formed. In this project, power plant plume fields simulated using the plume chemistry model SCICHEM were compared to published results obtained with the Fluidity-Chem model. Following this, SCICHEM was used to understand the influence of the atmospheric chemical background, the applied atmospheric chemistry scheme and NO emission strength on the chemical evolution of an isolated ship plume. Subsequently, NO, NO2, O3 and OH fields were simulated after NO emission from a hypothetical Waste-to-Energy plant using SCICHEM, first without and later with the emission of the amine piperazine. It was found that SCICHEM cannot simulate plume edge details well, thereby emphasizing the need for more detailed models like the Volumetric Particle Approach model, currently under development at NILU, that was also tested for comparison. Moreover, the application of different chemistry schemes was found to lead to different results. Processes such as ozone titration, HNO3 formation and HONO formation, should be included in the chemistry scheme. The atmospheric chemical background and especially the peroxy radicals therein, e.g. HO2 and CH3C(O)O2, were found to play an important role in OH depletion or formation close to the source. Under low NO emission (i.e. 3.02 g/s), the conventional conception of OH being depleted near the source was found not to be valid. On the contrary, the OH chemistry starts close to the source, resulting in OH formation beginning at 2 km downwind from the source. As a result, piperazine nitrosamine and nitramine levels were found to be highest close to the source. With an emission of 0.032 g/s of piperazine, maximum nitrosamine and nitramine concentrations of 0.97 ng/m3 and 0.72 ng/m3, respectively, were found at surface level approximately 1 to 1.5 km downwind from the source. In the case of additional direct nitrosamine emission, the nitrosamine level increased to up to 1.54 ng/m3 close to the source. Higher NO emissions of 30.2 g/s were found to lower the nitrosamine and nitramine concentrations, and shift the maximum concentration further downwind from the source due to increased OH depletion. Meteorological parameters and background conditions were simplified and kept constant throughout the entire run, which is not realistic. Therefore, improved simulations should be performed using varying background and meteorological conditions that are valid for the locations of interest.
