WP3 - Closing Degradation Knowledge Gaps

The main objective of WP3 is to close knowledge gaps related to solvent degradation and its impacts. WP3 will provide fundamental understanding of the connection between degradation, corrosion and foaming.

The volatility of degradation compounds of second and third generation solvents will be tested, allowing the prediction of resulting emissions and quantifying the impacts of such emissions.

Data on degradation of novel solvents will be generated, closing an important knowledge gap towards the further development of solvents. Results from this work package will set a benchmark and target for WP2, deliver essential data for WP1, and act as a de-risking mechanism before solvents can be tested at larger scale.

WP3 is divided into 3 key tasks:

  • Task 3.1 Connection between corrosion, foaming and degradation
  • Task 3.2 Degradation of second and third generation solvents
  • Task 3.3 Volatility of degradation compounds and novel solvents

Coordinator profile

Hanna K. Knuutila, Coordinator of WP3
Coordinator Name: Hanna K. Knuutila
Coordinator Job Role: Deputy of Education, Chemical Engineering, NTNU
Professor Hanna K. Knuutila is Deputy of Education at the Department of Chemical Engineering at NTNU. She has been involved in several EU and national projects and is currently the main supervisor of 5 PhD students and 1 post-doc in the field of acid gas removal. Current activities include solvent degradation and corrosion studies, modelling and measurement of absorption kinetics, and development of second and third generation solvents for both traditional absorption processes and membrane contactors.

Results

D3.1.1 Effect of PZ degradation on corrosion of carbon and stainless steel
Current obstacles that prevent commercial implementation of amine-scrubbing CO₂ capture are the high costs. Reducing capital costs by appropriate selection of construction materials, which requires knowledge of material corrosion performance for the process, will improve the economic feasibility of this technology. Corrosion was evaluated in three pilot plant campaigns using aqueous piperazine with the Advanced Stripper (PZAS)
D3.1.2 Corrosion Tendencies of 2nf and 3rd generation solvents
In this study, corrosion tendencies of amines in water-lean solvents have been studied. This was done through measurements of the metal content in the solvents after a finished thermal degradation experiment. In these experiments, the water content was reduced both by increasing the amine concentration, and by introducing organic solvents as replacements for the water as diluents.
D3.1.3 Foaming in PZ affected by degradation en impurities
Experiments were conducted to measure foaming and foam break time of 5 m piperazine (PZ) in two recent lab campaigns. This report summarizes those measurements made during April-May 2022 (Y.L. Chen) and October-November 2022 (Carter) and benchmarks them to those made by Xi Chen [1]. Foaming and foam break time were measured in 5 m PZ at a loading of 0.3 mole CO₂/mole alkalinity. Additional experiments were conducted with varying concentrations of formaldehyde added to the solvent to simulate changes in foaming behavior with degradation. The calculated foaminess of the test solutions as measured by Y.L. Chen differed from the 2011 findings of X. Chen with no clear trend. However, foam break time trends followed those of X. Chen up to the addition of 150 mM formaldehyde, when the data points diverged. The October- November 2022 measurements made by Carter generally matched the April-May 2022 measurements with the exception of the extremes of 0 and 150 mM formaldehyde additions.
D3.1.4 Report describing the foaming tendencies and results from the iron solubility measurements
While amine-based carbon capture has been shown to be effective in capturing CO2, there are several challenges associated with this technology. One of the main challenges is solvent degradation, which refers to the chemical decay of the amine solution over time. This degradation can reduce the effectiveness of the amine in capturing CO2 and increase the cost of the process. One factor that can impact amine degradation is the presence of iron in the amine solution potentially catalysing the oxidative degradation. Another potential challenge with amine-based carbon capture is foaming in the absorber, which refers to the formation of small bubbles in the amine solution. Foaming, which depends on the solvent, and typically occurs after some time and is often thought to be caused by some degradation compounds, can reduce the efficiency of the process and increase its cost by increasing pressure drop and requiring regular addition of anti-foaming agents to mitigate the formation of bubbles. This work aims to investigate these two related phenomena that affect the performance of the capture process. This report briefly describes this work's motivation and experimental methodology, which focuses on the influence of many parameters on the solubility of iron or other metals.
D3.2.2 Manuscript to be submitted on thermal degradation of second and third generation solvents
This deliverable describes the work done on degradation of second and third generation solvents in LAUNCH. The work has been published, and the publication including supplementary information is available here: https://pubs.acs.org/doi/10.1021/acs.iecr.2c01934
D3.3.2 Thermal degradation of second and third generation solvents
Absorption-based carbon capture with amine solvents is now a proven technology. However, potential emissions of amine solvent and volatile degradation compounds are real problems; therefore, it is essential to control them [1]. These emissions formed in the absorber depend on the solvent composition (volatility of the solvent and its degradation products), the absorber design, and operating conditions. Concerning MEA, a considerable amount of (volatile) degradation compounds are known [2]. Some of these degradation products are known to be volatile, but this knowledge is the result of years of research. In the race to develop the next generation solvents, it is essential to identify the volatile degradation compounds of potential solvent candidates in the early stage of development, in a short time and before piloting. This public summary summarizes the work performed in the LAUNCH project in task T3.3.2 related to developing a simple and quick method to identify the volatile degradation products of a given (novel) solvent in a qualitative and semi-quantitative way. This summary describes the tested experimental approach.
D3.3.3 Volatility testing of degradation compounds
This document gives a brief description of the two different methods used in the reports D.3.3.1 and D.3.3.2 and compares the results and applications of these in assessing potential emissions for amine solvents for CO₂ capture. One of the challenges of amine scrubbing for CO₂ removal from post-combustion flue gases, is that the process may cause emissions of other compounds if a rigorous mitigation system is not in place. These emissions may consist of the amine components which are performing the chemical absorption of CO₂ themselves, or their degradation products. Since emission control is of such high environmental importance, it is beneficial to be able to assess this in an early stage of solvent development. A method for identifying the volatility of the solvent and its degradation products is, therefore, necessary to qualify a new solvent. These two methods were tested in LAUNCH WP3.3 for the purpose of finding a fast way to assess the potential emissions of various amine solvents.

More About the Project

Work Packages

WP0

Management, Dissemination and Exploitation

WP1

Predicting Degradation

WP2

Controlling Degradation

WP3

Closing Degradation Knowledge Gaps

WP4

Development of Solvent Qualification Programme

WP5

Demonstration of Solvent Qualification Programme

WP6

Techno-economic Evaluation

Objectives

The primary objective of the LAUNCH project is to accelerate the implementation of CO2 capture across the energy and industry sectors by developing novel solvents and establishing a fast-track, cost-effective de-risking mechanism to predict and control degradation of capture solvents.

Outcomes

The LAUNCH project will deliver the necessary knowledge and tools to allow CO2 capture plants to operate in a more controlled and cost-efficient way. The project will also provide solvent developers with the tools to assist in designing and validating novel solvents. By avoiding uncontrolled build-up of degradation products, LAUNCH will improve the performance and economics of CO2 capture.

Publications

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