Chemical characterization of MEA degradation in PCC pilot plants operating in Australia
- Authors: Cruickshank, Alicia , Verheyen, Vincent , Adeloju, Samuel , Meuleman, Erik , Chaffee, Alan , Cottrell, Aaron , Feron, Paul
- Date: 2013
- Type: Text , Journal article
- Relation: Energy Procedia Vol. 37, no. (2013), p. 877-882
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- Description: An important step towards commercial scale post-combustion CO2 capture from coal-fired power stations is understanding solvent degradation. Laboratory scale trials have identified three main solvent degradation pathways for 30% MEA: oxidative degradation, carbamate polymerization and formation of heat stable salts. This paper probes the semi-volatile organic compounds produced from a single batch of 30% MEA which was used to capture CO2 from a black coal-fired power station (Tarong, Queensland, Australia) for approximately 700 hours, followed by 500 hours at the brown coal-fired power station (Loy Yang, Victoria, Australia). Comparisons are made between the compounds identified in this aged solvent system with MEA degradation reactions described in literature. Most of semi-volatile compounds tentatively identified by GC/MS have previously been reported in laboratory scale degradation trials. Our preliminary results show low levels of degradation products were present in samples after its use in the pilot plant at Tarong (black coal) and consequent 13 months storage, but much higher concentrations were later found in the same solvent during its at use in the pilot plant at Loy Yang Power (brown coal). Further work includes identifying the cause of poor GC/MS repeatability and investigating the relative rates of reactions described in literature. The impact of inorganic anions and dissolved metals on MEA degradation will also be explored.
Structural characterisation of Middle Jurassic, high-volatile bituminous Walloon Subgroup coals and correlation with the coal seam gas content
- Authors: Chaffee, Alan , Lay, Galinda , Marshall, Marc , Jackson, William , Fei, Yi , Verheyen, Vincent , Cassidy, Peter , Scott, Steven
- Date: 2010
- Type: Text , Journal article
- Relation: Fuel Vol. 89, no. 11 (2010), p. 3241-3249
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- Description: The structure of a suite of high-volatile, bituminous Surat Basin, Queensland coals has been investigated by a combination of analytical probes. These included elemental analyses, pyrolysis-gas chromatography-mass spectroscopy and Fourier transform infrared spectroscopy, together with a study of their liquefaction products in both tetralin and solvent free-tin catalysed hydrogenations. Samples were gathered across a 300 m depth interval intersected by the sampling well. Most techniques revealed clear but subtle differences in structure as a function of depth. The oils produced by solvent free-tin catalysed hydrogenation, however, showed very distinct dependence with depth and the waxy content, as indicated by 1H-NMR, could be correlated with the coal seam gas content
MTE water remediation using Loy Yang brown coal as a filter bed adsorbent
- Authors: Butler, Craig , Green, Alison , Chaffee, Alan
- Date: 2008
- Type: Text , Journal article
- Relation: Fuel Vol. 87, no. 6 (2008), p. 894-904
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- Description: The future development of a non-evaporative brown coal dewatering technique called Mechanical Thermal Expression (MTE) will produce large volumes of acidic, salty and organic rich product water. The overall viability of the MTE process will, in turn rely on the availability of a simple and energy-efficient water remediation strategy. Water treatment using the feed coal itself as an adsorbent may provide such an option. In this study a fixed-bed configuration of raw Loy Yang coal was employed. When the adsorbent was first exposed to MTE water, most of the dissolved organic carbon (DOC) and most of the multivalent cations in solution were adsorbed. However, breakthrough of monovalent cations occurred after a volume of MTE water equivalent to just two times the volume of the adsorbent bed itself (2 bed volumes (BVs)) had passed, with only small proportions of Na and K being retained. About 60% (30 mg/g, db) of the dissolved organic carbon (DOC) and about 25% (0.16 mmol/g, db) of the total cations were removed after passing 20 BV of MTE water through the adsorbent bed. This corresponds to an adsorbent requirement that is 1.4% of the amount of coal to be dewatered. Thus, the use of brown coal adsorbent beds may be an effective primary water treatment option. However specific organic and inorganic components are likely to require further reduction prior to discharge to the environment
Ambient temperature solubilisation of brown coal in ammonium carbamate ionic liquids
- Authors: Qi, Ying , Verheyen, Vincent , Vijayaraghavan, Ranganathan , MacFarlane, Douglas , Chaffee, Alan
- Date: 2016
- Type: Text , Journal article
- Relation: Fuel Vol. 166, no. (2016), p. 106-115
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- Description: Coal solubilisation is often a necessary step for the alternative utilisation of the cheap and abundant brown coal resources in the State of Victoria, Australia, such as producing high quality fuel or chemicals. A series of ionic liquids (ILs), ammonium carbamates, formed by the association of carbon dioxide (CO2) with low molecular weight secondary amines, were investigated as solvents for the solubilisation of Victorian brown coal. The ionic liquid was mixed with a Loy Yang coal at a mass ratio of 20 to 1 (dry basis) for 24 h at ambient temperature. The solubilisation yields of the coal using three such ILs from dimethyl-, diallyl- and dipropyl-amines, respectively, were between 18% and 23%. Repeated solubilisation of the coal with fresh solvent achieved higher yields, with the highest at 66% by the carbamate formed from dimethylamine (DIMCARB). The variations in chemical structure between the products were compared by elemental analysis and a variety of spectroscopic techniques (FTIR, Solid State 13C NMR and Py-GC-MS). The soluble products of the initial solubilisation were more aliphatic than their parent coal. The less polar ILs formed from diallyl- and dipropyl-amines (DACARB and DPCARB) appeared to be more selective for high molecular weight triterpenoids than DIMCARB. Subsequent treatment tended to dissolve more aromatic components. © 2015 Elsevier Ltd. All rights reserved.
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
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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
Structural elucidation of humic acids extracted from Pakistani lignite using spectroscopic and thermal degradative techniques
- Authors: Nasir, Saqib , Sarfaraz, Tahira , Verheyen, Vincent , Chaffee, Alan
- Date: 2011
- Type: Text , Journal article
- Relation: Fuel Processing Technology Vol. 92, no. 5 (2011/05/01/ 2011), p. 983-991
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- Description: The present paper describes the characterization of Pakistan lignite coal, derived humic acids (HAL) and nitrohumic acids (NHA) along with the standard leonardite humic acids (LHA). The study utilized chromatographic and spectroscopic techniques to characterize the structure of coal and derived materials. Pyrolysis coupled to gc/ms was conducted with and without methylating agent (tetramethyl ammonium hydroxide). The pyrolysis study resulted in releasing mainly fatty acid methyl esters, different series of hydrocarbons and α, ω-dicarboxylic acid methyl esters. Triterpenoids, syringic and ρ-coumaric compounds and aromatic compounds derived from lignin moieties were also detected. Fourier transform infrared (FT-IR) and NMR data helped to evaluate the influence of coal rank on regeneration and nitration processes with respect to chemical structural composition of coal and derived materials. FT-IR spectra of four materials were similar except that NHA showed an absorption band at 1532cm−1, thus confirming the presence of -NO2 groups. 13C NMR indicated higher aromaticity and less hydroxylalkyl material in HAL than NHA. The elemental composition and acid functional group content of four materials were also reported. The combination of results from different analytical techniques gives an improved understanding of the Pakistan coal nature and helpful for its future utilization.
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
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
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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
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- 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
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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.