World Congress on Biosensors 2014

World Congress on Biosensors 2014
Biosensors 2014

Tuesday 29 January 2013

Just Published: Journal of Analytical and Applied Pyrolysis


A new issue of this journal has just been published. To see abstracts of the papers it contains (with links through to the full papers) click here:
Journal of Analytical and Applied Pyrolysis
http://rss.sciencedirect.com/publication/science/5247
Selected papers from the latest issue:

Hydrotreating of Low Temperature Coal Tar to Produce Clean Liquid Fuels

29 January 2013, 09:48:43
Available online 24 January 2013
Publication year: 2013
Source:Journal of Analytical and Applied Pyrolysis

Clean liquid oil was obtained from low temperature coal tar (LCT) via hydrotreating in trickle-bed reactor (TBR) system filled with commercial catalysts. The effects of hydrogen pressure (10–16MPa), reactor temperature (350–410°C) and liquid hourly space velocity (LHSV) (0.25–1h−1) on hydrotreating performance were investigated while hydrogen to oil volume ratio was maintained constant at 1600 LN/L in all cases. The degree of sulfur removal was greater than nitrogen removal with increasing temperature, pressure and contact time over the commercial catalyst. The TBR system was capable of removing nitrogen and sulfur from 1.14 and 0.34wt % in the feed to 63μg·g−1 and 8μg·g−1, respectively in the products. Gasoline (<180°C) and diesel (180–360°C) fraction were separated from the oil products and analyzed. The gasoline fraction produced from LCT by hydrotreating comply with gasoline specifications for distillation range, sulfur content, induction period and gum presence. But it did not meet the specifications for RON (Research Octane Number) specifications. Diesel fraction produced from LCT meet all quality tests as fuels which could be directly used as motor fuels without upgrading. The results indicated that the raw LCT could be considerably upgraded through catalytic hydrotreating and high-quality fuels were obtained.

Highlights

► Clean liquid oil was obtained from low temperature coal tar (LCT) via hydrotreating in trickle-bed reactor (TBR) system filled with commercial catalysts. ► The TBR system was capable of removing nitrogen and sulfur from 1.14 and 0.34wt % in the feed to 63μg·g−1 and 8μg·g−1, respectively in the products. ► Gasoline (<180°C) and diesel (180–360°C) fraction were separated from the hydrotreating products. Gasoline fraction has an aromatics content that is much less than its straight-run equivalent derived from crude oil, being a good feedstock for catalytic reforming. Diesel fraction meet all quality tests as fuels which could be directly use as motor fuels without upgrading.

Adsorption of p-chlorophenol onto microporous activated carbon from Albizia lebbeck seed pods by one-step microwave assisted activation

29 January 2013, 09:48:43
Available online 24 January 2013
Publication year: 2013
Source:Journal of Analytical and Applied Pyrolysis

Agricultural wastes, Albizia lebbeck seed pods, have been utilized as precursors for production of a microporous activated carbon using one step microwave assisted K2CO3 activation. The sorption performance of prepared carbon for p-chlorophenol (PCPh) was investigated by batch adsorption technique. Effects of radiation time, radiation power, and impregnation ratio on the sorption performance were studied to determine the best preparation conditions. Carbon with 26.2% yield and 247.9mg/g PCPh uptake has been obtained at conditions of 8min radiation time, 540W radiation power and 1.5g/g impregnation ratio. The surface area, micropore volume, and mesopore volume of prepared carbon at best conditions were 1676.6 m2/g, 0.527cm3/g, and 0.181cm3/g, respectively. The best fitting for PCPh equilibrium isotherm data was achieved by the three-parameter Sips isotherm with a maximum adsorption capacity of 300.6mg/g. The experimental kinetic data were well represented by the pseudo-second order model.

Highlights

► Microporous carbon was prepared from Albizia lebbek seed pods. ► One-step microwave activation was adopted for preparation. ► High surface area of 1676.6 m2/g was characterized. ► Maximum capacity of 300.6mg/g was reported for p-chlorophenol. ► Sorption mechanisms of p-chlorophenol were illustrated.

Experimental and theoretical studies of pyrolysis of chrysophanol and its derivatives

29 January 2013, 09:48:43
Available online 23 January 2013
Publication year: 2013
Source:Journal of Analytical and Applied Pyrolysis

Rhubarb has been used as a tobacco additive recently. In order to understand the smoke emissions of herbal cigarettes with rhubarb additive, the pyrolysis of major components of rhubarb: chrysophanol and its derivatives (emodin, rhein and aloe-emodin) have been studied by synchrotron VUV photoionization mass spectrometry (SVUV-PIMS) combined with molecular-beam sampling technique. Various pyrolysis products are observed due to the different substituent groups. The main pyrolysis products of chrysophanol come from the CO and H2O elimination reactions. The CO, CO2 and HCOOH elimination reactions are the primary pyrolysis processes for rhein. Besides, elimination of H2 from aloe-emodin and loss of OH radical from both emodin and rhein also occur in the pyrolysis process. Furthermore, theoretical calculations are used to deduce the decomposition pathways and determine the geometries of pyrolysis products. Our work shows that the combination of SVUV-PIMS measurements and theoretical calculations is powerful to study pyrolysis behavior of complex organic compounds.

Highlights

► Pyrolysis behavior of chrysophanol and its derivatives was studied by SVUV-PIMS. ► Tunable SVUV photoionization benefits the measurement of pyrolytic products. ► The initial formation temperatures of all pyrolytic products have been determined. ► Theoretical calculations validated the decomposition pathways of studied compounds. ► SVUV-PIMS combined theoretical calculations perform well in pyrolysis analysis.

Use of thermogravimetry for single characterisation of samples of the composting process from sewage sludge

29 January 2013, 09:48:43
Available online 23 January 2013
Publication year: 2013
Source:Journal of Analytical and Applied Pyrolysis

Pyrolysis and combustion of different samples from a sewage sludge composting tunnel plant were studied by thermogravimetry. Two series of samples were analyzed: initially, 8 samples were taken at 8 different points from different stages of the process; later, 5 samples from different points at the end of the composting tunnel were taken. The experiments were carried out at 10°Cmin−1, in N2 atmosphere and N2:O2 4:1 atmosphere. The results were discussed to analyze the heterogeneity of the samples. In addition, the compositions of the samples taken for the analysis were deduced using the decomposition kinetics as correlation of weight loss vs. time. The fractions considered were sewage sludge, straw and sawdust. The compositions deduced were compared with the toxicity concentration of dioxins, in order to analyze the possible variations of toxicity determined.

Highlights

► TG, DTG and kinetics have been useful for analyzing the uniformity. ► The determination of dioxin concentration in compost samples is not easy. ► There is a great variation of dioxin concentration in similar samples.

Formation of nanoporous carbon materials in conditions of thermocatalytic synthesis

29 January 2013, 09:48:43
Available online 23 January 2013
Publication year: 2013
Source:Journal of Analytical and Applied Pyrolysis

A study of the volatile products formed in the process of thermocatalytic destruction of a hardwood and the carbonizates on its basis in the presence and absence of acidic (H3PO4) and alkaline (NaOH) activators was performed by thermogravimetry/mass spectrometry (TG/MS) method. Ranges of formation temperatures and the amount of water and the main gaseous products were determined. It is shown that, in the case of activation with alkali, the chemical composition and structure of the precursor have a pronounced effect on the process. Nanoporous carbon materials with high indices of the porous structure were obtained.

Highlights

► Volatiles of wood and carbonizates catalytic destruction were tested by TG/MS ► H3PO4 and NaOH were used as activation agents ► Nanoporous activated carbons were synthesized ► Porous structure of activated carbons were tested by N2 sorption.

Thermal kinetic parameters and evolved gas analysis (TG-FTIR-MS) for thiourea-formaldehyde based polymer metal complexes

29 January 2013, 09:48:43
Available online 18 January 2013
Publication year: 2013
Source:Journal of Analytical and Applied Pyrolysis

Two polymer metal complexes with a general formula of TUF-M(II) (M=Co, Cu) were synthesized by the reaction of a thiourea-formaldehyde resin (TUF) and transition metal ions. The thermal degradation of TUF-M(II) was investigated using thermogravimetric analysis (TGA) and differential thermal analysis (DTA) during pyrolysis and combustion. The kinetic parameters for the thermal degradation were evaluated using the Coats–Redfern and Friedman equations. An evolved gas analysis (EAG) during the thermal decomposition of TUF-M(II) was performed for the pyrolysis and combustion up to 800°C using both online coupled TG-FTIR and simultaneous TG-MS. The emissions of CS2, NH3, SO2, COS, HCN, H2NCN and HNCS were identified during the thermal degradation of TUF-M(II). The total mass loss resulting from the pyrolysis of TUF-Cu(II) at 775°C was 73.26%, while 44.02% of the original mass was lost at 225°C - 325°C. The activation energy for the second stage of degradation of the combustion (189.2 KJ mol−1, 184.5 KJ mol−1) was higher than that of the pyrolysis (179.8 KJ mol−1, 175.1 KJ mol−1) at a similar stage for both complexes using the Coats-Redfern method.

Highlights

► The thermal degradation of TUF-M(II) was investigated using TGA and DTA technique. ► The thermal kinetic parameters during pyrolysis and combustion were evaluated using Coats–Redfern and Friedman equation. ► The evolved gas analysis (EAG) during thermal decomposition of polymer metal complexes was determined using TG-FTIR-MS technique.

The GRAUTHERMIC-Tyres process for the recycling of granulated scrap tyres

29 January 2013, 09:48:43
Available online 12 January 2013
Publication year: 2013
Source:Journal of Analytical and Applied Pyrolysis

The influence of thermolysis temperature (range 500–700°C) on the products produced from granulated scrap tyres (GST) (2–6mm Ø) in a semi-batch pilot plant that uses several fixed bed reactors in parallel (GRAUTHERMIC-Tyres® process) was examined. This pilot unit consisted of six vertical fixed bed reactors in parallel, each with a capacity of 12kg GST. Thermolysis proceeded in a normal air atmosphere. The solid (char), liquid (tyre-derived oil [TDO]) and gaseous products generated at each temperature were characterised. The incondensable gas fraction was used to produce electricity via a gas turbine. The yields of the gas, TDO and char fractions were 15–22wt.%, 34–46wt.% and 39–44wt.% respectively, values that represent major recoveries from the GST feedstock. The TDOs were mainly a mixture of aliphatic and aromatic hydrocarbons and had very high GCVs (41–43MJ/kg), higher than those of conventional liquid fuels. A large increase was seen in the polycyclic aromatic hydrocarbon content above 550°C. The non-condensable gases obtained had a high GCV value (64–83MJ/Nm3), and produced 4.1–6.5kWhelectricity/g of GST in a gas turbine. The chars had a GCV of 27–28MJ/kg, high ash (17–21wt.%) and zinc contents, and an essentially macroporous texture with a low BET surface area (46–78m2/g). The thermolysis of GSTs with co-generation of gases by the GRAUTHERMIC-Tyres® method would appear to be a viable means of valorising GST.

Highlights

► We performed the thermolysis of granulated scrap tyres in a pilot scale. ► We examine changes in the oils, gases and chars composition about temperature. ► We examine the electricity production in gas turbine.

Characteristics of activated carbon prepared from waste PET by carbon dioxide activation

29 January 2013, 09:48:43
Available online 11 January 2013
Publication year: 2013
Source:Journal of Analytical and Applied Pyrolysis

Poly(ethylene)terephthalate (PET) waste was subjected to carbonization in a nitrogen stream at 1098K. The coke was then activated in a carbon dioxide stream under various conditions: temperatures of 1173, 1198 and 1213K as well as process times of 4, 5, 6 and 8h. The activated carbons were characterized using various methods: the structure from Raman and XRD measurements, the porosity from low temperature nitrogen adsorption, the surface properties from cyclic voltammetry and the hydrogen storage capacity from the low temperature adsorption isotherm of H2. The results demonstrated the importance of the temperature and the duration of the process. Higher temperatures results in the etching of graphitic domains of better crystallinity. A relatively small increase in activation time at the highest temperature used yielded a significant increase in the degree of burn-off and porous structure development. The microporosity of these carbons is similar to that of commercial activated carbons. They also have a similar capacity to adsorb water pollutants (e.g. 4-chlorophenol). The PET carbon sample with maximum burn-off exhibited higher values of the microporous structure parameters and the electric double layer capacity in electrolyte solution than the other three samples. The same sample exhibits a sufficient hydrogen storage capacity, which after optimization of the activation conditions should yield an effective storage material. This confirms the possibility of producing activated carbon from waste PET with satisfactory properties by the simple processes of carbonization and activation. The activated carbons obtained have potential use as water pollutant adsorbents, low-cost materials for hydrogen storage and electrode materials in supercapacitors or fuel cells.

Highlights

► Activated carbon was obtained from waste PET by carbonization and activation. ► Its porous structure can be regulated by the temperature and/or activation time. ► It is a low-cost material for water pollutant adsorption and hydrogen storage. ► Another use is as an electrode material in supercapacitors or fuel cells.

Feasibility of monomer aromatic substances as calibration standards for lignin quantitative analyses in Pyrolysis-GCMS

29 January 2013, 09:48:43
Available online 11 January 2013
Publication year: 2013
Source:Journal of Analytical and Applied Pyrolysis

In this paper, the feasibilities of five different monomer aromatic substances as calibration standards by analytical pyrolysis with gas chromatographic separation and mass selective detection (Py-GC/MS) were applied for the quantification of lignin in paper and pulp. The stabilities of these substances in the pyrolysis process were evaluated and the curves of peak response area to mass also were obtained. The results showed that the substances with exact same substituions on the benzene ring as lignin units had good stablities in the pyrolysis process with good lineabilities of peak response area to the mass curves, which implicated these substances can be applied as calibration standards in the liginin quick quantitative analyse without tedious pretreatments and structure changes.

Highlights

► Good linearlities of selected monommers in GCMS without Pyrolysis ► Better stablities of monomers with same substitutions on the ring as lignin units ► Feasilble and reliable for lignin analyse with greater enthalpy calibration standards.

Thermal degradation and combustion behavior of reconstituted tobacco sheet treated with ammonium polyphosphate

29 January 2013, 09:48:43
Available online 5 January 2013
Publication year: 2013
Source:Journal of Analytical and Applied Pyrolysis

In this paper, the APP-modified reconstituted tobacco sheet (RTS) was prepared by a paper-making process. Thermogravimetric analysis coupled to Fourier transform infrared spectrometer (TG-FTIR) had been used to investigate the influences of APP on the thermal degradation and the formation of evolved volatile products of RTS. TG-FTIR results illustrated that the incorporation of APP into RTS could retard the thermal degradation of the major components of RTS and meanwhile lead to the formation of more thermally stable char. Moreover, the main gases released during the pyrolysis of RTS and APP-modified RTS were H2O, CO2, CO, NH3, carbonyl compounds, alcohols and alkanes. The presence of APP changed the formation of evolved volatile products of RTS obviously. The effects of APP on the combustion behavior of RTS were studied by micro-scale combustion calorimetry (MCC), cone calorimetry (CCO) and infrared thermography (IRT). Results demonstrated that the formation of combustible gases was mainly determined by the thermal decomposition stage occurred in the temperature range of 150–600°C. The incorporation of APP into RTS influenced the release of fuel gases and the char formation in the process of the thermal decomposition of RTS, and eventually retarded the flammability of RTS. In addition, it had been found that the maximum firecone temperature of untreated RTS was higher than that of APP-modified RTS.

Highlights

► The APP-modified reconstituted tobacco sheet (RTS) has been prepared successfully by a paper-making process. ► APP can retard the thermal degradation of the major components of RTS and change the formation of evolved volatile products of RTS obviously. ► APP can influence the release of fuel gases and the char formation in the process of the thermal decomposition of RTS, and thus retard the flammability of RTS.

Properties of spray deposited Cu2ZnSnS4 (CZTS) thin films

29 January 2013, 09:48:43
Available online 5 January 2013
Publication year: 2013
Source:Journal of Analytical and Applied Pyrolysis

A new solar absorber material, Cu2ZnSnS4 (CZTS) in thin film form has been deposited onto glass substrates using spray pyrolysis technique. The thickness dependent (244–754nm) structural, morphological, optical and electrical properties of CZTS films have been studied. The X–ray diffraction studies revealed the formation of polycrystalline CZTS films. The surface morphological studies revealed the formation of smooth, compact and uniform CZTS surface. Absorption coefficient was of the order of 104 cm−1 and depending on film thickness the direct transition was observed with band gap in the range from 1.6 to 1.67eV. The thermoemf measurement revealed that the CZTS films exhibit p–type electrical conductivity.

Highlights

► Detail film formation mechanisms of CZTS thin film. ► Simple and inexpensive method is for the synthesis of CZTS films. ► The Structural, morphological and optical properties. ► In the present manuscript, the work is novel in the context that for the first time, the effect of different film thickness [244-754nm] on physicochemical properties of CZTS thin films.

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