Characterization of organic compounds in biochars derived from municipal solid waste
- Authors: Taherymoosavi, Sarasadat , Verheyen, Vincent , Munroe, Paul , Joseph, Stephen , Reynolds, Alicia
- Date: 2017
- Type: Text , Journal article
- Relation: Waste Management Vol. 67, no. (2017), p. 131-142
- Full Text: false
- Reviewed:
- Description: Municipal solid waste (MSW) generation has been growing in many countries, which has led to numerous environmental problems. Converting MSW into a valuable biochar-based by-product can manage waste and, possibly, improve soil fertility, depending on the soil properties. In this study, MSW-based biochars, collected from domestic waste materials and kerbsides in two Sydney's regions, were composted and pyrolysed at 450 °C, 550 °C and 650 °C. The characteristics of the organic components and their interactions with mineral phases were investigated using a range of analytical techniques, with special attention given to polycyclic aromatic hydrocarbons and heavy metal concentrations. The MSW biochar prepared at 450 °C contained the most complex organic compounds. The highest concentration of fixed C, indicating the stability of biochar, was detected in the high-temperature-biochar. Microscopic analysis showed development of pores and migration of mineral phases, mainly Ca/P/O-rich phases, into the micro-pores and Si/Al/O-rich phases on the surface of the biochar in the MSW biochar produced at 550 °C. Amalgamation of organic phases with mineral compounds was observed, at higher pyrolysis temperatures, indicating chemical reactions between these two phases at 650 °C. XPS analysis showed the main changes occurred in C and N bonds. During heat treatment, N-C/C=N functionalities decomposed and oxidized N configurations, mainly pyridine-N-oxide groups, were formed. The majority of the dissolved organic carbon fraction in both MSW biochar produced at 450 °C and 550 °C was in the form of building blocks, whereas LMW acids was the main fraction in high-temperature-biochar (59.9%). © 2017 Elsevier Ltd
Comparison of sample preparation methods for the GC–MS analysis of monoethanolamine (MEA) degradation products generated during post-combustion capture of CO2
- Authors: Reynolds, Alicia , Verheyen, Vincent , Adeloju, Samuel , Chaffee, Alan , Meuleman, Erik
- Date: 2016
- Type: Text , Journal article
- Relation: International Journal of Greenhouse Gas Control Vol. 52, no. (2016), p. 201-214
- Full Text: false
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- Description: As the development of chemical absorption technology for post-combustion capture (PCC) of CO2 from coal-fired power station flue gases proceeds towards commercial deployment, the focus on establishing a thorough understanding of the degradation of the aqueous amine absorbents is increasing. However, there is a need to develop and demonstrate robust analytical methods that are capable of measuring the concentrations of amine degradation products in aqueous monoethanolamine (MEA) matrix during pilot-scale PCC. In this study, sample cleanup and derivatisation methods that enable reliable and robust analysis of MEA degradation products by GC–MS are described. Two sample cleanup methods were evaluated: dehydration (by rotary evaporation and molecular sieves) and cation exchange. The cation exchange sample preparation method was preferred for the analysis of organic degradation products in these samples because it achieved higher recovery and repeatability of GC–MS measurements than those obtained with the dehydration method. Furthermore, the cation exchange method resulted in less continued amine degradation during subsequent analysis steps because of its ability to separate acidic analytes from basic analytes, as well as to remove some inorganic interferences. Further improvement of the sensitivity, repeatability and accuracy of this GC–MS analytical method can be accomplished by: (a) increasing the scale of the cation exchange and/or derivatisation procedures; (b) optimizing the derivatisation reaction conditions; and (c) using a narrower bore (e.g. 0.25 mm ID) GC–MS column. The proposed cation exchange and derivatisation procedures can be readily adopted for the quantification of organic degradation products in other aqueous amine absorbents to provide important insights into the degradation of amine absorbents during PCC of CO2. © 2016 Elsevier Ltd
Degradation of amine-based solvents
- Authors: Reynolds, Alicia , Verheyen, Vincent , Meuleman, Erik
- Date: 2016
- Type: Text , Book chapter
- Relation: Absorption-Based Post-Combustion Capture of Carbon Dioxide Chapter 16 p. 399-423
- Full Text: false
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- Description: Degradation of aqueous amines during post-combustion capture (PCC) of CO2 from fossil-fuel flue gases by wet gas scrubbing can lead to reduced energy efficiency, operational instability, increased corrosion, and unwanted emissions to the environment. Oxidative amine degradation and the accumulation of heat-stable salts primarily occur during absorption of CO2, whereas carbamate polymerization (also called thermal degradation) primarily occurs during desorption of CO2 and thermal amine reclamation. Oxidative degradation is closely related to corrosion, catalyzed by dissolved metal ions, and can be exacerbated by intermittent operation of PCC. Other important reactions, such as nitrosation, occur at much slower rates but can produce environmentally sensitive compounds. The ability to measure the concentrations of individual compounds or monitor amine degradation during PCC is important for managing amine degradation during PCC and demonstrating compliance with environmental regulations. Although some suitable analytical methods are available, further work is needed before they could satisfy the rigorous statutory and legal requirements. Strategies for avoiding and managing amine degradation need to be integrated into all PCC activities including: selecting degradation-resistant amines, ensuring adequate pretreatment of CO2-rich flue gas, avoiding severe CO2 absorption and desorption conditions, and the use of anticorrosion and antioxidation additives. Avoiding intermittent operation of PCC processes and choosing nonmetal column packing may also assist in minimizing amine degradation. © 2016 Elsevier Ltd All rights reserved.
Evaluation of methods for monitoring MEA degradation during pilot scale post-combustion capture of CO
- Authors: Reynolds, Alicia , Verheyen, Vincent , Adeloju, Samuel , Chaffee, Alan , Meuleman, Erik
- Date: 2015
- Type: Text , Journal article
- Relation: International Journal of Greenhouse Gas Control Vol. 39, no. (2015), p. 407-419
- Full Text: false
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- Description: Amine degradation is an important and current focus in the development of chemical absorption technology based on the use of aqueous amines for post-combustion capture (PCC) of CO
IR monitoring of absorbent composition and degradation during pilot plant operation
- Authors: Puxty, Graeme , Bennett, Robert , Conway, Will , Webster-Gardiner, Mike , Yang, Qi , Pearson, Pauline , Cottrell, Aaron , Huang, Sanger , Feron, Paul , Reynolds, Alicia , Verheyen, Vincent
- Date: 2020
- Type: Text , Journal article
- Relation: Industrial and Engineering Chemistry Research Vol. 59, no. 15 (2020), p. 7080-7086
- Full Text: false
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- Description: The monitoring of the absorbent during the operation of CO2 separation processes is a necessary and challenging task. The most common absorbent used is an aqueous amine solution. Traditional approaches to analysis such as titration and chromatography are time-consuming and only provide limited information. This hinders the ability of process operators to rapidly respond to changes in operating conditions. In this work, a combination of infrared (IR) spectroscopy and principle component regression (PCR) analyses have been demonstrated as a rapid and reliable technique to determine the composition of an absorbent during a pilot plant campaign at a brown coal power station. The concentration of amine, a degradation product, CO2, and water was monitored throughout the campaign by a method that provided results in minutes. The results were verified by independent sample analysis using acid-base titration, high-performance liquid chromatography (HPLC), and 13C NMR spectroscopy. It was necessary to use spectral windowing when building the IR-PCR model, but this resulted in a robust and reliable method that has been demonstrated to work in a real-world process environment. © 2019 American Chemical Society.
- Description: The authors wish to acknowledge the financial assistance provided by the Brown Coal Innovation Australia, Ltd., a private member-based company with funding contracts through the Australian National Low Emissions Coal Research and Development, Ltd. (ANLEC R&D) and the Victorian State Government. The work described here was made possible through the PICA project, a collaboration between AGL Loy Yang, IHI, and CSIRO that aims to advance post-combustion CO 2 -capture technology in Australia.
Isolation and characterisation of recalcitrant organic components from an estuarine sediment core
- Authors: Mylotte, Rosaleen , Verheyen, Vincent , Reynolds, Alicia , Dalton, Catherine , Patti, Antonio , Chang, Rung , Burdon, James , Hayes, Michael
- Date: 2015
- Type: Text , Journal article
- Relation: Journal of Soils and Sediments Vol. 15, no. 1 (2015), p. 211-224
- Full Text: false
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- Description: Purpose The purpose of this research was to isolate humic substances and humin from an estuarine sediment core using a novel sequential extraction procedure to characterise the isolates, to determine their compositions and to understand how the organic matter (OM) changes with time. Materials and methods The sediments were exhaustively extracted using the following media: 0.1 M NaOH; 0.1 M NaOH + 6 M urea; and dimethylsulphoxide (DMSO) + H2SO4 (94:6 v/v). Pyrolysis gas chromatography mass spectroscopy (pyGC/MS), and nuclear magnetic resonance (NMR) spectroscopy were the analytical tools that gave the most significant data for the characterisation of the organic isolates. Results and discussion The results indicate subtle molecular compositional differences in relation to the alkaline and alkaline-urea isolates. The humic acids (HAs) and fulvic acids (FAs) are readily solvated in aqueous alkaline media compared to the aqueous insoluble hydrophobic humin (HU) components. In addition to aliphatic hydrocarbons, peptide materials make considerable contributions to the component structures of the isolates. Aryl and O-aryl C units characteristic of lignin, and of cutan structures from plants, indicate contributions from terrestrial OM to the organic components in the HU, especially from the base of the core. The evidence suggests that components of terrestrial plant materials and of microbial biomass are preferentially preserved with time and make the major contributions to the OM retained over long time scales. The data acquired provide detailed information about the origins, compositions, nature and the associations of the OM in the estuarine sediment core. Such information provides a greater understanding of the role of these organic components in the carbon (C) sink. Conclusions Humic acids and FAs are mineralised with time whereas HU is highly recalcitrant and represents a long-term sink for organic C. Humin is a separate organic entity and does not conform to the definitions of a humic substance. Terrestrial OM is preserved over long time scales in the environment. Protein makes significant contributions to all the organic isolates and its preservation suggests encapsulation in hydrophobic domains, or interactions with clay minerals.
Monoethanolamine degradation during Pilot-Scale post-combustion capture of CO₂ from a brown coal-fired power station
- Authors: Reynolds, Alicia , Verheyen, Vincent , Adeloju, Samuel , Chaffee, Alan , Meuleman, Erik
- Date: 2015
- Type: Text , Journal article
- Relation: Energy & Fuels Vol. 29, no. 11 (2015), p. 7441-7455
- Full Text: false
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- Description: The use of aqueous amines, such as monoethanolamine (MEA, 2-aminoethanol), for post-combustion capture (PCC) of CO2 from fossil-fuel-fired power station flue gases leads to undesirable reactions with oxygen, SO2, and NO2. This study has used a gas chromatography with mass spectrometry detection (GC-MS) method to measure the changes in concentrations of organic compounds in samples of a 30% (w/w) aqueous MEA absorbent obtained from CSIRO's PCC pilot plant operating at AGL's Loy Yang brown coal-fired power station in Latrobe Valley, Victoria, Australia. This aqueous MEA absorbent was previously used for more than 700 h of PCC, and the collected samples represent a further 834 h of PCC operation. These data provide a new perspective on the close, interdependent relationships between corrosion and amine degradation reactions. Other important outcomes include confirmation that (a) organic degradation products identified during laboratory-scale trials were also produced during pilot-scale PCC and (b) N-(2-hydroxyethyl)imidazole (HEI) is a suitable molecular marker for oxidative degradation of MEA. This investigation has also highlighted areas that require further research, including (a) determination of oxidative degradation mechanisms in both the presence and absence of dissolved transition metals, (b) determination of parameters that limit oxidative degradation during pilot-scale PCC, (c) investigation of the antioxidative or oxygen-scavenging properties of partially oxidized amine absorbents during PCC, and (d) measurement of the concentrations of glycine, glycolic acid, and other potential organic acids during PCC. [ABSTRACT FROM AUTHOR]
- Description: The use of aqueous amines, such as monoethanolamine (MEA, 2-aminoethanol), for post-combustion capture (PCC) of
Primary sources and accumulation rates of inorganic anions and dissolved metals in a MEA absorbent during PCC at a brown coal-fired power station
- Authors: Reynolds, Alicia , Verheyen, Vincent , Adeloju, Samuel , Chaffee, Alan , Meuleman, Erik
- Date: 2015
- Type: Text , Journal article
- Relation: International Journal of Greenhouse Gas Control Vol. 41, no. (2015), p. 239-248
- Full Text: false
- Reviewed:
- Description: Post-combustion capture (PCC) of CO2 from fossil fuel-fired power station flue gas is one of many technologies that are being developed to reduce anthropogenic greenhouse gas emissions in the medium term. Wet-gas scrubbing using aqueous amines is currently the most mature PCC technology suitable for separating CO2 from coal-fired power station flue gases. In this study, a series of twelve samples of a degraded 30% (w/w) MEA absorbent were obtained over a six month pilot scale PCC campaign at a brown coal-fired power station in Australia. These samples were used to investigate the accumulation of heat-stable salts, inorganics and minerals. The heat-stable salts concentration increased from 0.80 to 2.29% (w/w, as MEA) and organic acids from the oxidative degradation of MEA were the largest component of heat-stable salts. Acid gases such as SOx and NOx, make-up water, ultra-fine fly-ash and corrosion were all sources of the minerals and inorganics that accumulated in the aqueous MEA absorbent. Corrosion was the single biggest contributor of transition metals and the abrupt change in ratios of Fe, Cr and Mo suggests that the dominant corrosion mechanism may have changed towards the end of the campaign. The rapid accumulation of minerals and inorganics during this PCC campaign highlights the importance of continuing research into the interactions between amine absorbents and inorganic or mineral contaminants. The data presented in this study are an important resource for design of laboratory scale experiments to investigate these physical and chemical interactions between aqueous amines, minerals and inorganics.
Quantification of aqueous monoethanolamine concentration by gas chromatography for postcombustion capture of
- Authors: Reynolds, Alicia , Verheyen, Vincent , Adeloju, Samuel , Chaffee, Alan , Meuleman, Erik
- Date: 2014
- Type: Text , Journal article
- Relation: Industrial and Engineering Chemistry Research Vol. 53, no. 12 (2014), p. 4805-4811
- Full Text: false
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- Description: The availability of reliable analytical methods for measuring amine concentrations is necessary for optimum operation of aqueous amine CO 2 separation systems being employed for postcombustion capture (PCC) of CO2. A GC-FID (gas chromatography with flame ionization detection) method is described for the reliable quantification of 30% (w/w) monoethanolamine (MEA) in severely degraded solvent samples. The observation of intermittent splitting of the MEA peak was a major concern with this approach. The use of a wide-bore column led to improved MEA peak resolution and peak shape. The reliability and robustness of the GC-FID method were assessed by analyzing degraded 30% (w/w) MEA solvent samples from CSIRO's pilot plant at AGL's Loy Yang power station in Victoria, Australia. The results were compared with those obtained by titration and total organic carbon (TOC) measurements of the same samples. The MEA concentrations obtained by the GC-FID and titration methods were statistically similar. In contrast, the MEA concentrations calculated from TOC were consistently higher than those obtained by both GC-FID and titration. © 2014 American Chemical Society.
Use of MEA oxidation intermediates to monitor oxidation conditions during post-combustion capture of CO2
- Authors: Reynolds, Alicia , Verheyen, Vincent
- Date: 2019
- Type: Text , Conference paper
- Relation: 14th Greenhouse Gas Control Technologies Conference (GHGT-14); Melbourne 21-26 ; October 2018 p.
- Full Text:
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- Description: Amine oxidation is a serious concern for post-combustion capture (PCC) of CO2 from fossil-fuel fired power stations. Organic acids are important oxidation products and have been measured in different ratios at different pilot plants. The concentrations of acetate, formate, glycolate and oxalate were measured in samples of degraded monoethanolamine from a variety of PCC pilot plants as well as laboratory-scale degradation experiments. The results suggest that the ratios of monoethanolamine oxidation intermediates (particularly glycolate and oxalate) have potential as process monitoring tools. Ultimately, ratios of these oxidation intermediates could be used to proactively manage and minimise oxidation of amine-based PCC absorbents by indicating the need for oxygen-scavenger addition or alerting operators to imminent increases in oxidative degradation rates.