Thermogravimetry has been widely used for the characterization of several biomasses but the most useful information given by this technique has been normally concerned to the relative amounts of humidity, hemi-cellulose, cellulose and lignin present in the biomass. TG-FTIR has been used to yield qualitative data about the pyrolysis products, in an exploratory way, by some authors. In the present paper, this technique was employed to reach comparative data about the products of pyrolysis of biomasses that are potentially available at economic bases for the production of biofuels. Agricultural residues such as coconut shell, sugarcane bagasse, corn stalks and peanut shell were chosen to be investigated. For all samples, the thermogravimetric curves showed a mass loss between 35 and 400 °C changed up to 73%, while that the loss between 400 and 800 °C changed up to 26%. TG-FTIR indicated tendencies in the rate of the formation of important species during the pyrolysis process of the four biomasses studied. The interpretation of the spectra allowed the proposition of characteristic absorbance ratios and the comparison of these values allowed inferences about the relative abundances of components formed in the pyrolysis of the biomasses. As an example of the possible inferences reached, among the species formed in the pyrolysis condensate, called bio-oil, the formation of carboxylic acids has to be specially considered due to their corrosivity. Thus, the data produced indicated that a bio-oil derived from peanut shell should be a little less acidic while the one derived from sugarcane bagasse should be showed more acidic among the biomasses studied.
Csontszénnel és növényi eredetű bioszénnel tenyészedényes modellkísérletet állítottunk be, hogy feltárjuk a kiválasztott magyarországi talaj fizikai és kémiai tulajdonságaira gyakorolt hatásokat. A tenyészedényes modellkísérletben a kezeléseknek megfelelően (0, 1, 2,5, 5 és 10%) 500 cm3-es műanyag edényekbe 200 g talajkeveréket tettünk. Vizsgáltuk a minták AL-oldható P- és K-tartalmát, vízoldható összes sótartalmát, desztillált vizes pH-ját, kötöttségét és szerves-C-tartalmát (Tyurin módszerével).A kísérlet eredményeképpen megállapítható, hogy a csontszén (ABC) bekeverés hatására jelentősen megnőtt az AL-oldható P2O5-tartalom a talajkeverékekben, köszönhetően a csontszén eredendően nagy P-tartalmának.A pH és az összes sótartalom jelentősen nőtt a csontszén (ABC) kezeléseket követően, elsősorban a csontszén nagy ásványianyag-tartalma miatt. A növényi eredetű bioszén (BC) kezelések esetében azonban pH-növekedés csak a nagyobb koncentrációnál volt tapasztalható, az összes sótartalomban pedig nem tapasztaltunk változást. A sótartalom- és pH-növekedés egyik kezelés során sem okozott túlzott sófelhalmozódást. A sótartalom 0,07% körül alakult a legnagyobb dózis esetében is, azonban hosszú távon érdemes figyelmi a sótartalom változását.A növényi eredetű bioszén (BC) bekeverése növelte a kezelt talaj víztartó képességét, kálium- és szerves-szén-tartalmát, míg a csontszén esetében nem tapasztaltunk hasonló hatást. További kutatások szükségesek, hogy újabb információkat kapjunk a bioszenek mezőgazdasági felhasználásáról. Fokozottan igaz ez a csontszénre, mivel a jövőben a foszforutánpótlás alternatívája lehet.
Tris(1,10-phenanthroline) iron(II) ([Fe(phen)3]2+) ion synthesized in the supercage of zeolite Y has been characterized by Mössbauer, UV-VIS reflectance, and X-ray diffraction methods. The complex in the supercage may be significantly distorted by interaction between the complex and the supercage wall. Pyrolysis mechanism under air of the complex in the supercage was studied on the basis of Mössbauer spectra.
The thermal degradation of copolymers based on butyl acrylate-methyl acrylate-acrylic acid used as acrylic pressure-sensitive adhesives, especially for bonding of plasticizer containing materials, has been investigated using thermogravimetry and pyrolysis-gas chromatography at 250°C. It was observed that during the pyrolysis of butyl acrylate-methyl acrylate-acrylic acid copolymers unsaturated monomers as methyl acrylate, methyl methacrylate, butyl acrylate and butyl methacrylate were formed. During the side-chain butyl acrylate-methyl-acrylate-acrylic acid-copolymer degradation the presence of methyl alcohol and butyl alcohol was observed.
Thermal decomposition of acrylamide from polyacrylamide
Time-resolved pyrolysis with ion-attachment mass spectrometry
increased by heating the probe from 50 to 500 °C at a rate of 20 °C min −1 . The temperature is then held at 500 °C for 10 min. The pyrolysis products formed are ionized and then detected. The advantage of this technique is that the degradation occurs close
-PVC composites was further investigated by Py–GC/MS. The principle pyrolysis products of PVC and WF-PVC at 500 °C are listed in Table 4 . In order to interpret the results obtained, pyrolysates were grouped on the basis of their chemical
The thermal decompositions of dehydrated or anhydrous bivalent transition metal (Mn, Fe, Co, Ni, Cu, Zn, Cd) and alkali rare metal (Mg, Ca, Sr, Ba) methanesulfonates were studied by TG/DTG, IR and XRD techniques in dynamic Air at 250–850 °C. The initial decomposition temperatures were calculated from TG curves for each compound, which show the onsets of mass loss of methanesulfonates were above 400 °C. For transition metal methanesulfonates, the pyrolysis products at 850 °C were metal oxides. For alkali rare metal methanesulfonates, the pyrolysis products at 850 °C of Sr and Ba methanesulfonates were sulphates, while those of Mg and Ca methanesulfonate were mixtures of sulphate and oxide.
To develop thermal stable flavor, two glycosidic bound flavor precursors, geranyl-tetraacetyl-β-D-glucopyranoside (GLY-A) and geranyl-β-D-glucopyranoside (GLY-B) were synthesized by the modified Koenigs–Knorr reaction. The thermal decomposition process and pyrolysis products of the two glycosides were extensively investigated by thermogravimetry (TG), differential scanning calorimeter (DSC) and on-line pyrolysis-gas chromatography mass spectroscopy (Py-GC-MS). TG showed the T p of GLY-A and GLY-B were 254.6 and 275.7°C. The T peak of GLY-A and GLY-B measured by DSC were 254.8 and 262.1°C respectively.
Py-GC-MS was used for the simply qualitative analysis of the pyrolysis products at 300 and 400°C. The results indicated that: 1) A large amount of geraniol and few by-products were produced at 300°C, the by-products were significantly increased at 400°C; 2) The characteristic pyrolysis product was geraniol; 3) The primary decomposition reaction was the cleavage of O-glycosidic bound of the two glycosides flavor precursors. The study on the thermal behavior and pyrolysis products of the two glycosides showed that this kind of flavor precursors could be used for providing the foodstuff with specific flavor during heating process.
The thermal degradation of selected poly(alkyl methacrylates) at temperatures between 300 and 800 °C was investigated by pyrolysis gas chromatography. Quantitative characterization of the pyrolysis products yields insights into the mechanism for thermal degradation of poly(alkyl methacrylates) under these conditions. Unsaturated monomeric alkyl methacrylates, carbon dioxide, carbon monoxide, methane, ethane, methanol, ethanol, and propanol were formed during thermal degradation of poly(alkyl methacrylates).
A combination of pyrolysis and gas chromatography were used to investigate thermal degradation products formed from acrylic copolymers containing alkyl acrylate and methacrylate. The method provided an analytical tool for characterizing the chemical composition and structure of the degradation products. Thermal degradation of the synthesized copolymers was analyzed using isothermal (250 °C) pyrolysis–gas chromatography. The degradation process, and the nature and amount of pyrolysis products, provides relevant information about the thermal degradation of acrylic copolymers and the mechanism of pyrolysis. During pyrolysis, the formation of corresponding olefins, alcohols, acrylates and methacrylate was observed.