Influence of cation on the pyrolysis and oxidation of alginates

Ross, Andrew B.; Hall, Craig A.; Anastasakis, Konstantinos; Westwood, Aidan; Jones, James C. Peyton; Crewe, Robert J.

doi:10.1016/j.jaap.2011.03.012

Cited by 63 publications

(57 citation statements)

References 11 publications

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“…Finally, coupled TGA-FTIR analysis gives insight into aspects of the thermal degradation pathways of H-Alg, Na-Alg and Cu-Alg, and the differences between them. Figure 10 shows that the primary volatile component product for this 'slow' pyrolysis, in all three cases, is CO 2 , as evidenced by the intense absorbance at 2360 cm 21 ; this observation has been reported previously from studies using coupled TGA-gas-chromatography/mass spectrometry (Py-GC-MS) [42,44]. Interestingly, if the intensity of the IR absorbance at 2360 cm 21 is plotted against temperature during the pyrolysis of H-Alg, Na-Alg and Cu-Alg over the temperature range 150 -3008C (figure 11a), the trace can be seen to completely replicate the trend in mass loss shown in the equivalent section of the TGA curve (figure 11b).…”

Section: Rsfsroyalsocietypublishingorg Interface Focus 3: 20120046supporting

confidence: 80%

Copper(II)-mediated thermolysis of alginates: a model kinetic study on the influence of metal ions in the thermochemical processing of macroalgae

et al. 2013

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Thermochemical processing methods such as pyrolysis are of growing interest as a means of converting biomass into fuels and commodity chemicals in a sustainable manner. Macroalgae, or seaweed, represent a novel class of feedstock for pyrolysis that, owing to the nature of the environments in which they grow coupled with their biochemistry, naturally possess high metal contents. Although the impact of metals upon the pyrolysis of terrestrial biomass is well documented, their influence on the thermochemical conversion of marine-derived feeds is largely unknown. Furthermore, these effects are inherently difficult to study, owing to the heterogeneous character of natural seaweed samples. The work described in this paper uses copper(II) alginate, together with alginic acid and sodium alginate as model compounds for exploring the effects of metals upon macroalgae thermolysis. A thermogravimetric analysis–Fourier transform infrared spectroscopic study revealed that, unusually, Cu 2+ ions promote the onset of pyrolysis in the alginate polymer, with copper(II) alginate initiating rapid devolatilization at 143°C, 14°C lower than alginic acid and 61°C below the equivalent point for sodium alginate. Moreover, this effect was mirrored in a sample of wild Laminaria digitata that had been doped with Cu 2+ ions prior to pyrolysis, thus validating the use of alginates as model compounds with which to study the thermolysis of macroalgae. These observations indicate the varying impact of different metal species on thermochemical behaviour of seaweeds and offer an insight into the pyrolysis of brown macroalgae used in phytoremediation of metal-containing waste streams.

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Section: Rsfsroyalsocietypublishingorg Interface Focus 3: 20120046supporting

confidence: 80%

Copper(II)-mediated thermolysis of alginates: a model kinetic study on the influence of metal ions in the thermochemical processing of macroalgae

et al. 2013

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“…The presence of alginate, a carbohydrate consisting of alginic acid associated with an inorganic salt, within the algae cell wall, means that the chemistry of algae is slightly different to that of the other feedstock used in this research. Due to the thermal stability of the alginate it is likely that some of the alginate will have remained in the ash (Ross et al, 2011) and this would have influenced how potassium and sodium behaves the ash. While previous reports of high slagging seaweeds in Ross et al, (2008) appear to be verified, it appears that hydrothermally processes seaweeds may perform significantly better.…”

Section: 4influence Of Htc On Ash Behaviour During Combustionmentioning

confidence: 99%

Fate of inorganic material during hydrothermal carbonisation of biomass: Influence of feedstock on combustion behaviour of hydrochar

Smith

Singh

Ross

2016

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A series of high moisture content biomass have been processed by hydrothermal carbonisation (HTC) in a batch reactor at two temperatures (200 °C and 250 °C). The feedstocks processed include food waste, secondary sewage sludge, AD press cake, microalgae, macroalgae and a fibre derived from municipal derived wastes. In addition, three lignocellulosic biomass including miscanthus, willow and oak wood have been processed under identical conditions. The yields and properties of the resulting hydrochars including their HHV, CHNS, mineral content and ash fusibility properties have been determined and compared with their starting biomass. Typical char yields for lignocellulosic material range between 58-70 wt% at 200 °C and reduce to 40-46 wt% at 250 °C. The behaviour and mass balance is however very feedstock dependent and the higher lignin biomass produce higher yields of hydrochar. There is a significant upgrading of the energy density of the hydrochars with calculated HHV ranging from typically 24 MJkg -1 at 200 °C to 28-31 MJkg -1 at 250 °C for lignocellulosic material. The exception is for sewage sludge and AD press cake which result in a significant solubilisation of organic matter. A significant removal of alkali metals is observed and this in turn changes the ash chemistry upon combustion. This change in ash chemistry has been shown to change the ash melting behaviour and the hemisphere temperatures (oxidizing conditions) were seen to increase substantially. A number of predictive slagging and fouling indices have been used to evaluate the influence of the ash chemistry on the fuel combustion behaviour and this combined with the ash fusion testing has shown that HTC reduces the potential fouling and slagging in some of the resulting hydochars if combusted.

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“…Polysaccharides, whose structures are composed of sugar rings linked by glycosidic bonds and various side functional groups, play fundamental roles in many biological fields [7]. In the past several years, alginate, a kind of polysaccharides, has been interested in alternative sources of polysaccharides as a potential spinning feedstock [8]. Alginate is a kind of polyelectrolytes and polysaccharides derived from algae [9,10], and is a linear copolymer composed of b-1, 4-D-mannuronate (M) and a-1, 4-L-guluronate (G) repeating monomeric units.…”

Section: Introductionmentioning

confidence: 99%

Effect of manganese and cobalt ions on flame retardancy and thermal degradation of bio-based alginate films

et al. 2015

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Bio-based cobalt alginate and manganese alginate films were prepared by a facile ionic exchange and casting approach. Their flame retardancy, thermal degradation, and pyrolysis properties were investigated by vertical burning (UL-94), limiting oxygen index (LOI), thermogravimetric analysis, microscale combustion calorimetry (MCC), thermogravimetric analyzer coupled with Fourier transform infrared analysis (TG-FTIR), and pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS). It showed that cobalt alginate film had much higher LOI value (45.0 %) than those of manganese alginate film (30.7 %) and sodium alginate film (24.5 %). Moreover, cobalt alginate film passed UL-94 V-0 rating, while manganese alginate and sodium alginate films showed no rating. Importantly, peak of heat release rate of cobalt alginate and manganese alginate in MCC test was much lower than that of sodium alginate, suggesting that the addition of cobalt ion and manganese ion decreases the release of combustible gases. TG-FTIR and Py-GC-MS results indicated that cobalt alginate and manganese alginate produced much less gaseous products than that of sodium alginate. Finally, a possible thermal degradation mechanism of cobalt alginate and manganese alginate had been proposed. The results provided useful information for understanding flame-retardant mechanism of alginate as well as for designing bio-based materials with excellent fire-retardant properties.

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Influence of cation on the pyrolysis and oxidation of alginates

Cited by 63 publications

References 11 publications

Copper(II)-mediated thermolysis of alginates: a model kinetic study on the influence of metal ions in the thermochemical processing of macroalgae

Copper(II)-mediated thermolysis of alginates: a model kinetic study on the influence of metal ions in the thermochemical processing of macroalgae

Fate of inorganic material during hydrothermal carbonisation of biomass: Influence of feedstock on combustion behaviour of hydrochar

Effect of manganese and cobalt ions on flame retardancy and thermal degradation of bio-based alginate films

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