Atmospheric Oxidation of Amines Relevant for Carbon Capture and Storage

Lead Research Organisation: University of Leeds
Department Name: Sch of Chemistry

Abstract

Post combustion CO2 capture from flue gas streams by amine based species will form a major component of the strategy for CO2 mitigation in the short and medium term. The wide spread uptake of this technology necessary to make a significant impact will require the production of many thousands of tonnes of amines with consequent atmospheric release either in small but still significant amounts during production, transport, use, recycling and disposal or in larger amounts following accidental release or plant failure. Very little is known about the atmospheric lifetimes or degradation products of even simple amines or the more complex amines that have been proposed for carbon capture (e.g. monoethanolamine - MEA). The overall objective of this project is to fill this gap in our knowledge on the gas phase oxidation of amines. The very limited studies that have taken place to date show that both gas phase and heterogeneous oxidation is important. The focus of this project is gas phase chemistry, but we have colleagues in Leeds and collaborators in the University of Oslo who are experts on the heterogeneous process, so that there will be a good flow of information between the two communities. The first component of the project is the measure the rate coefficients for the reaction of a variety of amines with important atmospheric oxidants such as the OH, NO3 and Cl radicals and ozone (O3). These rate coefficients will be measured under isolated conditions, focusing on just this first step in the amine oxidation process. The measurements will be performed using techniques such as laser flash photolysis and laser induced fluorescence. The resulting rate coefficients will allow us to calculate the atmospheric lifetimes of the amines and hence the spatial spread of any pollution. The second component of the project will be to determine the chemical mechanism for the production of first and subsequent generation products for selected important amines such as MEA. This will be achieved both by determining the position of the initial radical attack on the amine (i.e. for a simple amine such as CH3NH2, what fraction of the H atoms abstracted comes from the CH3 or NH2 groups?) and by observing the concentrations of the stable products, primarily by IR spectroscopy. Amine oxidation following attack at the RNHR group to form NR2 radicals has the potential to form highly toxic nitrosamines following reaction of NR2 with NO. By determining the rate coefficients for NR2 formed from selected important amines, with NO and O2, the third component of the project will asses the potential for nitrosamine formation. The final component of the project is to combine the above information and incorporate into a comprehensive chemical model of the atmosphere - the Master Chemical Mechanism, MCM - to assess the potential for amines to contribute to ozone production (air quality and climate change implications) and other atmospheric issues. The project will involve interactions with industrial groups and legislative organisations. Whilst the primary focus is on amines from carbon capture, amines are produced from a variety of sources - e.g. marine environment, so the project has wider applications and potential.
 
Description Rates of reactions of a number of reactions of amines relevant for carbon capture and storage with OH have been measured. The results show that gas phase reactions will be competitive with heterogeneous uptake.

The mechanisms of reactions (determination of site specific rate coefficients and product identification) has been undertaken for simpler amines relevant to CCS.

One publication in the high profile Journal of Physical Chemistry Letters (April 2012) and four further manuscripts have been published in PCCP (2015), EST x 2 (2014) and JPCA (2013). The research material has been presented in two international conferences in 2012.
Exploitation Route Knowledge of the reaction rates and primary products of amine oxidation are crucial in determining whether significant concentrations of toxic nitramines and nitrosomines will be formed from any amine release from commercial CCS plants.

We organised a symposium in Leeds in October 2012 which included delegates from interested industrial corporations (e.g. Doosan Power Systems) and government (DECC). Publications -4 publications from 2012 - 2015).

Conferences presentations (3) - International Gas Kinetics Symposium, Boulder USA, June 2012, Atmospheric Chemical Mechanisms Conference, Davis, USA, Dec 2012.

Symposium on CCS, University of Leeds, October 2012.

An oral presentation has been accepted for the International Conference on Chemical Kinetics, Seville July 2013.
Sectors Energy

Environment

 
Title MESMER 
Description MESMER is an open access programme to calculate the pressure and temperature dependence of pressure dependent reactions occurring over complex potential energy surfaces. Significant updates to MESMER have been incorporated during the lifetime of this grant, epitomised by our latest publication (Chem Phys Lett 2016) where we have coupled elementary reactions together and can allow for chemical activation. 
Type Of Material Improvements to research infrastructure 
Year Produced 2009 
Provided To Others? Yes  
Impact MESMER has been picked up by groups around the world. We are aware of an intercomparison exercise including MESMER which should shortly be submitted for publication. There have been several hundred downloads of the programme. 
URL http://www.chem.leeds.ac.uk/mesmer.html
 
Description Accelrys 
Organisation Accelrys
Country United Kingdom 
Sector Private 
PI Contribution On going work with the development of the MESMER programme to model the pressure and temperature dependence of reactions associated with multiple energy wells. Applications in Combustion Chemistry, Atmospheric Chemistry and in understanding fundamental physical processes, particularly energy transfer.
Collaborator Contribution Computation and programming support. Contributions to intercomparisons and publications.
Impact On going upgrades to the MESMER programme. Contributions to an intercomparison of MESMER with the MULTIWELL programme, an alternative approach to calculating temperature and pressure dependences.
 
Description Argonne National Laboratory 
Organisation Argonne National Laboratory
Country United States 
Sector Public 
PI Contribution Joint collaboration for a Science paper.
Collaborator Contribution Provision of theoretical calculations
Impact Publication in Science (Glowacki et al. 2012)
Start Year 2012
 
Description University of Oslo 
Organisation University of Oslo
Country Norway 
Sector Academic/University 
PI Contribution The collaboration involved studies of the branching ratios of OH radicals with amines relevant for the atmospheric decomposition of amines released during Carbon Capture with amine based solvents. Work at Leeds provided the experimental data.
Collaborator Contribution Prof Nielsen lead the theoretical component of this work, calculating the potential energy surfaces for the reactions and from this, the branching ratios for OH radicals with either the C-H or N-H bonds in primary and secondary amines. The results have been compared with experiment.
Impact One publication (Onel et al. JPCA 2013) includes calculations from the Oslo group. The collaboration is still on-going and we are working on a publication on the branching reactions of OH with monoethanol amine, currently the solvent of choice for Carbon Capture. Update for 2017 Submission - Collaboration is still active. On the basis of this collaboration Seakins is an external advisor to a programme led by Nielsen on the atmospheric oxidation of amines and Heard (researcher at Leeds) has been contributing experimentally to this programme. Additionally the collaboration has led to the submission of a Marie Curie Application for Early Career Researchers (Carbon Capture and the Environment H2020-MSCA-ITN-2017) in January 2017.
Start Year 2012
 
Description Seminar on the Atmospheric Effects of Carbon Capture and Storage 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact Hosting a workshop and seminar on Carbon Capture and Storage with participants from Policy (e.g. DECC), Industry (e.g. Babcock) and Monitoring (SEPA). Workshop has lead to on-going collaborations of academics involved with SEPA.

See above - collaborations with SEPA and also pending applications with University of Oslo
Year(s) Of Engagement Activity 2012