Structural information on soil organic matter (SOM) at the molecular level can be obtained on diverse structural units that are amenable to degradation techniques. Chemolytic techniques in combination with colorimetric analyses or GC MS are used to determine amino acids (proteins), sugars (polysaccharides), lipids, or aromatic oxidation products from lignin or charred organic matter. Microbial markers (amino sugars, muramic acid) are analyzed after hydrolysis and gas chromatographic separation. Macromolecular structures can also be subjected to thermochemolytic degradation or pyrolysis and subsequent analysis of the fragments by GC MS. Alternative techniques for the examination of organic matter in heterogeneous macromolecular mixtures are non-destructive spectroscopic methods, such as nuclear magnetic resonance (NMR) spectroscopy. Although this technique can give good results concerning the gross chemical composition, speci®c compounds are hardly identi®ed. The combination of spectroscopic techniques with thermolytic and chemolytic methods will add substantially to the understanding of the nature of refractory soil organic matter. Physical fractionation prior to analysis provides a means to dierentiate between distinct SOM pools that can be further characterized by the methods described above. Studies on SOM structural characteristics have focused mainly on the A horizons of soils under agriculture and litter biodegradation in forest soils and need to be extended to a wider variety of soil types and the subsoil. #

Municipal solid waste generation is a rapidly increasing challenge that is leading to severe pollution and environmental degradation in many urban areas of developing countries. Globally, the solid waste sector accounts for 18% of methane emissions and 3e4% of greenhouse gas emissions overall. Waste handling and disposal systems in most large cities have largely been designed with minimal accounting of environmental issues. This study presents the Waste to Energy Recovery Assessment (WERA) framework, a new quantitative decision support model for initial evaluation and alternative comparisons of different thermochemical treatments of municipal wastes. The framework not only accounts for benefits through electricity generation but also accounts for emissions from facilities and the associated social cost of carbon in a cost-benefit assessment. The assessments are conducted with Monte Carlo simulations that explicitly account for uncertain factors such as future composition and generation of solid waste, technical efficiency of treatment processes, capital and operating costs, as well as future policies. The framework is used to study waste-to-energy (WtE) systems for Abu Dhabi, Riyadh, Tokyo and New York. The results show that WtE systems can fulfill only 1.4e3.6% of 2014 electricity demand in the analyzed cases. Furthermore, the net present value for different technologies can be positive if collection fees and electricity rates (potentially set through feed-in-tariff policies) are sufficiently high. The analysis for Abu Dhabi and Riyadh also reveals that in a limited set of conditions (of technology efficiencies, and waste collection rates etc.) the WtE facilities can be self-sustaining investments.

The rising cost of crude oil affects the asphalt paving industries and this in turns has encouraged researcher to modify or replace asphalt. The numbers of commercial vehicles increase every year. Hence, design, construction and maintenance of asphalt road facilities must be improved in order to provide the highest standards of safety and comfort, but certain areas of the road need some extra attention due to higher stressed than the others. For that reason road paving industry is interested in utilizing alternative and sustainable binder materials for modified asphalt to improve the production, placement and performance of asphalt mixtures. Nonetheless, sources of materials should be considered economically and environmentally viable after applying in pavement. According to previous research, the non crude petroleum binder was derived from the production of bio-oil through fast pyrolysis of biomass. The main source of bio-oil is from biomass industry or renewable organic industry such as timber waste, oil palm waste, rice husk, coconut trunk fibers, municipal waste and sugar cane waste. Alternatively, the bio-oil can be as substitute material as modification of asphalt. This paper presents a review of the source, characterization of bio-oil and the effects of bio-oil on the properties of asphalt.

Vacuum pyrolysis of softwood bark residues yields besides oil, charcoal as second valuable product. The activation behavior of the vacuum pyrolysis charcoal was compared to charcoal produced during conventional, atmospheric carbonization process. Steam activation of charcoal obtained by vacuum pyrolysis yields an activated carbon with a higher surface area than by using charcoal produced during atmospheric carbonization process. This can be related to the more open pore structure of the vacuum pyrolysis charcoal. Steam activation of the vacuum pyrolysis charcoal was studied at temperatures ranging from 760 to 850°C. Activated carbons with surface areas above 1200 m 2 /g and micropore volumes above 0.40 cm 2 /g were obtained.

There are vast resources of oil shale in the western United States. Development of technically and economically effective technologies for the conversion of oil shale to liquid fuels will help provide a long-term and secure source of transportation fuels. Developing good understanding of the decomposition kinetics of oil shale to oil and other products, along with the oil compositional information are important regardless of the process used. Themogravimetric analysis combined with online mass spectrometry (TGA-MS) affords the opportunity to obtain compositional information while the decomposition is being measured quantitatively. In this work we provide data on the TGA-MS analyses of Green River oil shale from Utah. Compounds of about 300 atomic mass units were targeted in the mass spectrometric analyses.

A comparison between different emission rates of various pollutants obtained from various wastes is presented. The studied wastes were the following: polyethylene, tyres, sewage sludge, polyvinyl chloride, cotton textiles, polyester textiles, meat and bone meals, varnish wastes, olive oil solid waste (pomace), waste lube oils, paper waste, tomato plant, pine needles and cones, mobile phones and automotive shredder residue. The decomposition of these wastes was studied in a horizontal laboratory scale reactor at 850 ºC in an inert and an oxidizing atmosphere, and the analysis of the pollutants evolved comprised several compounds such as light hydrocarbons, PAHs and PCDD/Fs.

The pyrolysis of switchgrass (Panicum virgatum) of the cultivar, ''Cave-in-Rock'' harvested at three stages of physiological maturity was studied in a PY-GC/MS system at the 600-1050 8C temperature range. Under these conditions, the decomposition was complete within 20 s yielding char, and two sets of pyrolysis gas, condensable and non-condensable. The former consisted of acetaldehyde (CH 3 CHO), acetic acid (CH 3 COOH) and higher molecular weight compounds possibly from the hydroxyl group and from the methoxy groups of the cell wall components. The non-condensable gases were mainly CO, CO 2 and C 1 -C 3 hydrocarbons. For these, there was a 900 8C temperature boundary where dramatic change occurred in their evolution rates. Below this temperature, CO 2 decreased but CO and the C 1 -C 3 hydrocarbons increased almost linearly with temperature. Above this temperature boundary, the hydrocarbons leveled off but there was a rapid rise in CO and CO 2 evolution at a constant CO/CO 2 ratio. These suggest the appearance of secondary or tertiary pyrolysis reactions involving rearrangement and release of CO and hydrocarbons prior to this temperature boundary and the release of CO and CO 2 from the tightly bond oxygen functionalities including C-C bonds thereafter. At <750 8C, there were modest increases in condensable gas yield and decrease in non-condensable gas due to differences in plant maturity at harvest. However, the effect of switchgrass physiological maturity on gas yield was statistically insignificant at high temperatures. The energy content of the non-condensable gas measured was about 68% of the gross energy content of the biomass for the early harvest crop and 80% for the mature crop. The activation energy for the decomposition, estimated assuming first order reaction kinetics, showed a linear increase with plant physiological maturity. The results demonstrate that physiological maturity at harvest of switchgrass biomass can result in different concentrations of pyrolysis products at different temperatures. These results also demonstrate the need for additional research with a broader array of herbaceous biomass materials to develop a better understanding of the synergies of crop cultivation, harvesting and processing of dedicated herbaceous biomass energy crops during their thermochemical conversion. #

Microcrystalline cellulose was analysed by Curie-point pyrolysis-capillary gas chromatography-mass spectrometry (Py-GC-MS) under electron impact (70 eV) as well as chemical ionisation (isobutane) conditions. Almost all interpretations could be supported by high-resolution mass spectrometric data, obtained by Py-GC-high-resolution MS. The pyrolysis products identified can be classified into several main groups i.e. carbonyl compounds, acids and methyl esters, furans, pyrans, anhydrosugars and hydrocarbons. Altogether 96 compounds have been found, and structural assignments could be given to 94 of them. From these compounds 25 have not been identified earlier in pyrolysates of polysaccharides. Levoglucosan is the major GC amenable pyrolysis product detected. Several formation pathways are proposed to account for the formation of a number of pyrolysis products from levoglucosan and/or cellobiosan. An overview showing the thermal degradation pattern of cellulose through anhydrosaccharides to smaller pyrolysis products is also presented. Carbohydrates; cellulose; gas chromatography; high-resolution mass spectrometry; levoglucosan; mass spectrometry; pyrolysis.

The disposal of 280 million tires generated each year in the U.S. is a great environmental problem. The tires take up large amounts of valuable landfill space and also present fire and health hazards. Tire-pyrolysis plants have been in operation for years, but the economics are poor, and most of these facilities have been shut down. This is mainly due to the low value of the end products, which are usually fuels (oil, pyrolysis gas, char). It is believed that reprocessing of waste tires into value-added products would improve the economic leverage. This study addresses reprocessing of oils derived from waste-tire pyrolysis into carbon black - a valuable feedstock for the manufacture of tires, other rubber products, paints, pigments, ink, powder coating, toner, etc. Such a process would form a recycling loop for the carbon black recovered from waste tires. The objective of this work was to demonstrate the feasibility of the proposed approach in a laboratory scale. More specifically, the goal was to show that carbon black produced in the furnace process (1) using waste-tire oil as a feedstock could possess similar characteristics as the carbon black made from a traditional petroleum-based feedstock. Materials and Experimental Techniques Four oil samples were used in this study: (a) tire-pyrolysis oil prepared at Advanced Fuel Research, Inc. (AFR) in a two-inch diameter packed-bed reactor; (b) tire-pyrolysis oil obtained from a large-scale tire pyrolysis plant operated by Conrad Industries in Chehalis, Washington; (c) tire-pyrolysis oil obtained from a pilot-scale tire pyrolysis facility operated by Metso Minerals (formerly Svedala) in Danville, Pennsylvania; and (d) Exxon bunker oil provided by Caleb Brett. The highly aromatic Exxon oil is a typical high-grade feedstock that carbon-black manufacturers use in their normal operations. This oil was used as a reference for the tire-derived feedstocks. In addition, a sample of the AFR tire oil (a) that had been aged for two years was examined to determine oil stability during extended storage at ambient temperature and pressure.

The chemical structure of the milled-wood lignin isolated from Paulownia fortunei wood was investigated. The lignins were characterized by analytical pyrolysis and two-dimensional NMR that indicated a predominance of guaiacyl (G) over syringyl (S) units, and only showed small amounts of p-hydroxyphenyl (H) units, with a H:G:S molar ratio of 1:59:40. The heteronuclear single quantum correlation (HSQC) NMR spectrum gave additional information about the relative abundances of the different inter-unit linkages present in the lignin structure. Paulownia lignin showed a predominance of -O-4� aryl ether linkages (62% of total side-chains), followed by � resinol-type (12%) and -5 � phenylcoumaran-type structures (11%) and with lower amounts of other condensed structures such as spirodienone (3%) and dibenzodioxocin (2%) structures. The high lignin content (ca. 23% Klason lignin), together with the low S/G ratio and the abundance of condensed (carbon–carbon linked) structures (together with ...

Silicon-rich oxide (SiO x , 0 < x < 2) thin films were deposited using the Low Pressure Chemical Vapor Deposition (LPCVD) method at temperature of 570 °C using silane (SiH 4) and oxygen as the reactant gasses. The films were annealed at temperatures of 800, 900, 1000, and 1100 °C to induce the separation of excess silicon in the SiO x films into nanosized crystalline silicon particles inside an amorphous SiO x matrix. The size of the silicon particles was determined using Raman spectroscopy.

Considerable controversy exists concerning the rate of coal pyrolysis. At 800°C the reported rates derived using a single first-order process to define weight loss vary from < 1 s-1 to ~100 s- 1. In an attempt to resolve this controversy, a new pyrolysis experiment has been designed which allows direct measurement of coal temperature and reaction time. It uses a small-diameter electrically heated tube into which coal and helium are injected. The reaction distance is varied by moving the electrode positions. Temperature is measured inside and outside the tube with a thermocouple. Temperatures of the solids are determined at the tube exit using FT-i.r. emission and transmission spectroscopy. The transit time for a pulse of coal is measured using phototransistors at the top and bottom of the tube. Particle velocities are also determined using FT-IR transmission. Measurements have been made on sieved size fractions of a North Dakota lignite, Rosebud subbituminous coal and Illinois No. 6 bituminous coal in tubes up to 240 cm long at asymptotic tube temperatures of 600, 700, 800 and 935°C. At 800°C primary pyrolysis was completed in a period of 14 ms, during which the maximum coal temperature was increasing from 600 to 740°C. The results are in good agreement with a previously developed functional-group model of coal pyrolysis which employs a distribution of activation energies to describe the evolution of individual pyrolysis species. The results are also in reasonable agreement with predictions of a single first-order model for weight loss which uses a rate constant k=4.28 x 1O4 exp(-228500/RT) Jmol-’ s-1. This rate,which is over 1000 s-l at 800°C, is inconsistent with the low rates. Reasons for discrepancies in reported rates are discussed

Bio-oil and bio-char were produced from corn cobs and corn stover (stalks, leaves and husks) by fast pyrolysis using a pilot scale fluidized bed reactor. Yields of 60% (mass/mass) bio-oil (high heating values are w20 MJ kg À1 , and densities >1.0 Mg m À3) were realized from both corn cobs and from corn stover. The high energy density of bio-oil, w20-32 times on a per unit volume basis over the raw corn residues, offers potentially significant savings in transportation costs particularly for a distributed ''farm scale'' bio-refinery system. Biochar yield was 18.9% and 17.0% (mass/mass) from corn cobs and corn stover, respectively. Deploying the bio-char co-product, which contains most of the nutrient minerals from the corn residues, as well as a significant amount of carbon, to the land can enhance soil quality, sequester carbon, and alleviate environmental problems associated with removal of crop residues from fields.

The paper reviews the pyrolysis of biomass constituents and possible secondary reactions. Biomass pyrolysis yields mostly liquid and solid fuel, easy to store and transport. Relevant working conditions for experiments and large-scale operation are: (i) biomass particles < 200 mm, (ii) a particle heating rate of at least about 80 K min À1 and (iii) a reactor environment where the internal resistance to heat penetration is smaller than the external resistance to heat transfer (Biot-number, Bi < 1). The circumstances of TGA and DSC experiments meet these requirements and fully determine the reaction kinetics and endothermicity of the pyrolysis reaction. The reaction rate constant and the heat of reaction are essential parameters in the design of a pyrolysis reactor. For most of the biomass species tested, the first order reaction rate constant is large and >0.5 s À1. The heat of reaction ranges from 207 to 434 kJ kg À1. All results tie in with literature data, although the reader is cautioned in using literature data since experiments were not always performed under relevant testing conditions.

The conversion of wood-based fiberboard materials into crack-free, monolithic, porous hard carbons is of significant interest due to their ability to perform in a multifunctional capacity. Three varieties of carbonized medium-density fiberboard (c-MDF) were studied for electrical, mechanical, and structural properties. X-ray diffraction data suggested that the volume fraction of large turbostratic crystallites increased with carbonization temperature (T). The volume fraction of large carb turbostratic crystallites had a positive correlation with elastic modulus and electrical conductivity. The c-MDF materials were approximately isotropic with respect to elastic modulus and exhibited increasing stiffness with increasing T (up to 4.5 carb GPa). Between 600 and 1400 8C, the electrical resistivity of c-MDF varied by seven orders of magnitude. The electrical resistivity of the hard carbon material in c-MDF 1400 8C was found to be within about an order of magnitude of polycrystalline graphite.

The smoke formed in the cone calorimeter during the combustion of expanded polystyrene with and without fire retardant has been analysed. Gaseous products were condensed from the smoke and identified by GC-MS. The liquid components adsorbed on solid particles of the smoke were examined by microscopy-FTIR. The solid charred particles were characterised by SEM and X-ray microanalysis. It has been shown that pyrolysis dominates over thermal oxidation during combustion. The charred particles are essentially composed of carbon rich structures with negligible oxidation having occurred. The fire retardant somewhat modifies the characteristics of the combustion of expanded polystyrene and the composition of the smoke. #

A novel fabrication technique for micro proton exchange membrane fuel cells (PEMFCs) based on carbon-MEMS (C-MEMS) was optimized to yield higher performance cells. Polymer manufacturing is relatively easy compared to directly patterning graphite as is typically done to make fuel cell bipolar plates. In a C-MEMS approach, fuel cell bipolar plates are fabricated by first patterning polymer Cirlex ® sheets. By subsequently pyrolyzing the machined polymer sheets at high temperature in an inert atmosphere, carbon bipolar plates with intricate groove structures to distribute the reactants are obtained. Using an improved assembly technique such as polishing the carbonized plates to minimize the contact resistance between gas diffusion layers (GDL) and bipolar plates, better pyrolysis temperature control and a better end plate design, a PEMFC with a 0.64 cm 2 active surface was fabricated using the newly developed bipolar plates. At 1 atm and 25 • C a maximum power density of ∼76 mW cm −2 was obtained, and at 2 atm and 25 • C ∼85 mW cm −2 was achieved. These data are comparable with data reported in the literature for PEMFCs and are a dramatic improvement over earlier results reported for the same C-MEMS based fuel cell. Electrochemical Impedance Spectroscopy (EIS) and cyclic voltammetry were carried out to characterize steady-state and transient characteristics of the novel C-MEMS fuel cell. (Y. Wang). 1 An exchange student from Brazil working at RERL of the UC Irvine. of electrically connecting the adjacent cells while at the same time distributing the reactant gases over the anode and cathode. Carbonbased substrates such as carbon paper and cloth constitute a typical GDL. The GDLs are placed on the membrane electrode assembly (MEA) and perform several functions: gas species transport, heat transport and last but not least the electrical connection between the bipolar plates and the catalyst layers on the proton-conductive membrane. The catalyst layers comprise the C/Pt or Pt alloy catalyst itself, an ionomer, and void space. The electrochemical reactions take place at the triple-phase boundary (TPB) of the catalyst layer, the gas phase and the ionically conductive membrane. The membrane, typically made of Nafion ® , fulfills a dual role, i.e. as the gas/electron separator and for conducting protons. The Nafion ® membrane is characterized by hydrophobic, fluorinated main chains with hydrophilic sulfonic acid pendant groups, allowing for protons to weakly interact with SO 3 − groups and to travel through the hydrated regions associated with those sulfonic groups. Different from the traditional power generation in heat engines, fuel cells are electrochemical devices and their efficiency is not limited by the Carnot heat cycle. Efficiencies of more than 50% have been achieved in many commercial units operating at low currents. Fuel cell efficiency is especially high at smaller scales and in this regard, fuel cells may be ideal for powering portable/micro electrical devices and may have the potential to replace batteries whose 0378-7753/$ -see front matter

This work aimed to study the recovery of two types of waste by the process of pyrolysis. The obtained results show that the adding of a plastic mix improves the overall efficiency of the slow pyrolysis of pine. Therefore, it was possible to achieve higher liquid yields and less solid product than in the classic slow pyrolysis carbonization of biomass. The obtained liquids showed heating values similar to that of heating fuel oil. The gas products had energetic contents superior to that of producer gas, and the obtained solid fractions showed heating values higher than some coals. There were also identified some typical products of fast biomass pyrolysis used as raw material in several industries. The effects of experimental conditions in product yield and composition were also studied. The parameters that showed higher influence were (with its increase): reaction time on gas product composition (increase of the alkane content) and on liquid composition (increase in aromatics content); reaction temperature on product yield (decrease of liquid yield with increase of solids and gases) and on gas product composition (increase in alkane content); initial pressure on liquid composition (increase in the aromatics content) and mainly the pine content of the initial mixture on products yield (increase of gas and solid yield with a decrease in liquids) and on the gas product composition (favouring CO and CO 2 formation).

The Upper Benue rift comprising the Gongola and Yola Basins in Nigeria consist of the Aptian-Albian Bima Formation, the Yolde Formation (Cenomanian-Turonian), Gongila/Pindiga/ Dukul Formation (Turonian-Coniacian) and Gombe Formation (Campanian-Maastrichtian). To evaluate the maturity and source rocks potential, vitrinite reflectance, Rock-Eval pyrolysis and infrared spectroscopy were carried out on 52 shale samples collected from boreholes, mine quarries and outcrop sections. In the Gongola Basin, mean random vitrinite reflectance (Rom) values range from 0.45% in the Gombe Formation to 0.69% in the Pindiga Formation and to 0.82% in the Bima Formation. Reflectance values in the Yola Basin also increase with stratigraphic age ranging from 0.73% in the Dukul Formation to 0.94% in the Yolde Formation and up to 1.37% in the Bima Formation. Total organic carbon (TOC) values in the Pindiga and Gongila Shales are between 0.4 to 2.4% averaging 0.75%. TOC contents from 0.10 to 12.9 averaging 1.2% are contained in the Yolde Formation of the Yola Basin. Tmax values from the pyrolysis of shales in the Gongola Basin range from 419 to 435°C whereas for shales in the Yola Basin they range from 431 to 442°C. Plots of HI vs Tma x for kerogen classification indicate the prevalence of Type III kerogens in the Gongila and Pindiga Shales although there are some indications of Type II-111 kerogens in the Yolde Shales of the Yola Basin. Our preliminary data suggest that Cretaceous successions in the Gongola Basin are thermally immature to marginally mature whereas source rocks in the Yola Basin are thermally mature with respect to hydrocarbon generation. The predominance of Type III kerogens in the Gongola Basin suggest their potential to generate gas in the deeply buried sections. The Dukul and Yolde formations with Type II-III kerogens may have generated some quantities of oil and gas in the deeper non-emergent sections.

Vacuum pyrolysis of 100 g of lignin derived from steam explosion of wood yielded 42.7% oil, 38.0% charcoal, 10.0% gas and 9.3% pyrolytic water (wt. %, moisture and ash-free basis) at 465°C and below 2 kPa absolute pressure. The pyrolysis oil was fractionated into eight fractions, Fl-F8. Fl and F2 were mainly hydrocarbons and accounted for 3.4% of the anhydrous oil. F3 to F7 were mainly mono and diphenols and represented 41.6% of the anhydrous oil. F8 had very low GC/MS response due to its low volatility and/or high polarity. It may be possible to use directly fractions F3 to F7 in phenolic resin formulation.

Vacuum pyrolysis of pure PVC at various temperatures and under a total pressure of 2 kPa has been performed to identify and quantify the main pyrolysis products obtained during the different stages of thermal degradation. A system consisting of a bench scale batch reactor with a condensation train was used to collect the pyrolysis products. The main gaseous and liquid

Hydrogen production from waste tires was investigated using a two-stage pyrolysis-gasification reactor and Ni-Mg-Al (1:1:1) as a catalyst. In addition, the elastomer constituents most commonly used in tires, natural rubber (NR), styrene-butadiene rubber (SBR), and butadiene rubber (BR), were also investigated. Experiments were conducted at a pyrolysis temperature of 500°C and gasification temperature of 800°C. The results showed that the gas and hydrogen yield were increased for the tire and elastomer constituents during pyrolysis-gasification. However, there was a dramatic increase in H 2 and CO concentrations as well as a consequent decrease in CH 4 and C 2 -C 4 concentrations when the Ni-Mg-Al catalyst was applied to the pyrolysis-gasification process. For example, hydrogen production increased from 0.68 to 5.43 wt % for the catalytic steam pyrolysis-gasification of waste tire in the presence of Ni-Mg-Al catalyst. The highest hydrogen production (15.26 wt %) was obtained for the BR feedstock. Reacted catalysts were characterized using a variety of methods, including temperature-programmed oxidation (TPO) and scanning electron microscopy (SEM) with energy dispersive X-ray spectrometry (EDXS). The SEM results showed that large amounts of filamentous carbons were observed for the reacted Ni-Mg-Al catalysts derived from all the feedstocks. The total amount of coke deposition on the reacted catalyst, calculated from TPO experiments, was lowest for the BR feedstock (7.0 wt %) and was 31, 21.8, and 18.4 wt % for the waste tire, NR, and SBR samples, respectively.

The issue of sustainability is a growing concern and has led to many environmentally friendly chemical productions through a great intensification of the use of biomass conversion processes. Thermal conversion of biomass is one of the most attractive tools currently used, and pyrolytic treatments represent the most flexible approach to biomass conversion. In this scenario, microwave-assisted pyrolysis could be a solid choice for the production of multi-chemical mixtures known as bio-oils. Bio-oils could represent a promising new source of high-value species ranging from bioactive chemicals to green solvents. In this review, we have summarized the most recent developments regarding bio-oil production through microwave-induced pyrolytic degradation of biomasses.

The fate of levoglucosan after it forms during cellulose pyrolysis was investigated experimentally using time-resolved thermogravimetric analysis/differential scanning calorimetric combined with mass spectrometry measurements followed by high performance liquid chromatography and gel filtration chromatography of the pyrolysis residue. This study indicates that levoglucosan formed during cellulose pyrolysis is initially a liquid that undergoes two simultaneous, competing processes of evaporation and polymerization. Levoglucosan that evaporates escapes the high temperature pyrolysis zone while levoglucosan that polymerizes is trapped in the pyrolysis zone and dehydrates to low molecular weight volatile products and char. The oligosaccharides that form during polymerization are subject to two simultaneous reaction pathways: direct decomposition to low molecular weight products such as water, carbon dioxide, 5-hydroxymethylfurfural, furfural, furan and acetic acid, and formation of polysaccharides that eventually dehydrate to char and low molecular weight volatiles. Based on the experimental observations and quantitative measurements, a modified cellulose pyrolysis pathway involving levoglucosan as the major intermediate is proposed.

CdS has been proved to be an ideal material for use as the window layer for heterojunction solar cells especially with n-CdS/p-CdTe. CdS, Cd0. 9Sn0. 1S and Cd0. 8Sn0. 2S films were deposited onto glass substrates at 300° C substrate temperature by using ultrasonic spray ...

Municipal Solid Waste (MSW) management is a chronic environmental and economic problem in urban areas worldwide and more specifically in developing countries. Waste-to-Energy (WTE) technologies show a great potential to convert this problem to a revenue source. Pyrolysis is a promising technology and is currently utilized in many regions of the world for MSW disposal and energy generation. The economic value of pyrolysis has been insufficiently evaluated. This paper introduces and discusses the economic value of pyrolysis as MSW management disposal method and energy source. The return period of investments is considered for various pricing policies with respect to end product of process. Hypotheses and conclusions of the model works are briefly reported.

— Algae are gaining broad consideration as a substitute renewable source of biomass for the manufacture of bioethanol, due to this reason categorized under the " third generation biofuels " .İn this work, GC-MS analysis and FTIR has been done of bio-oil obtained from fast pyrolysis of Freshwater Algae(Spirogyra) in this paper we have shown a simple process of converting biomass of fresh water algae to bio-oil through pyrolysis and explained it with the help of graphs and tables. Pyrolysis is a thermal process for converting various biomasses , residues and wastes to produce high-energy-density fuels (bio-oil, biochar). The bio-oil was obtained in two step pyrolysis in which temperature of the system kept 25ºC and then increased up to 650ºC time by time. After pyrolysis these fractions were analyzed by gas chromatography/mass spectrometry (GC-MS) and FTIR which show different peaks and data of different compounds and functional groups present in this bio-oil

Energy is essential for the nature of life and the development of countries. The main demand for the 21st century is to fulfill growing energy needs. Pakistan, through the use of fossil fuels, meets energy demands. There is pressure on the economy of the country due to the massive reliance on fossil fuels, and this tendency is influenced by various environmental impacts. To overcome the burden on fossil fuels, more attention has been drawn to provide fossil fuel substitution. Tire pyrolysis is among the effective substitutes of the fuel technology that generates useful products of liquid oil, char, and pyro gas. This research focuses on the environmental, social, and economic viability of tire pyrolysis oil in Pakistan. This study estimates the production and potential of tire pyrolysis oil (TPO) in Pakistan. Based on the calculations, the potential of tire pyrolysis oil production in Pakistan from 2015–2019 is 468,081 to 548,406 tons. The potential production of TPO in 2018–2019 wa...

The aim of this kinetic work is to provide a better understanding of the pyrolysis of lignin and biomasses not only in terms of devolatilazation rate but also of the volatile species released. The complexity of both lignin structure and its degradation mechanism meant that a lumping approach suitable for handling the huge amount of initial, intermediate and final products had to be used. Despite these simplifications, the proposed semi-detailed kinetic scheme involves about 100 molecular and radical species in 500 elementary and lumped reactions. It has already been proved that this lignin devolatilization model correctly predicts the degradation rates and the detail of the released products. This work constitutes an initial yet significant step towards deriving a complete kinetic scheme of biomass devolatilization.

A number of N,N-dialkylated tryptamines show psychoactive properties in man which resulted in a renewed interest in psychopharmacological research. Attempts to manufacture these derivatives are increasing within a clandestine environment, where literature procedures are adapted and information is exchanged on the Internet. One such example is based on the thermolytic decarboxylation of tryptophan to tryptamine as the precursor to psychoactive derivatives. This procedure was proposed to make use of household solvents such as turpentine substitute and white spirit to facilitate decarboxylation. Discussions on websites also suggested the catalytic use of natural oils in order to accelerate these reactions. In this research, the analytical characterization of this preparation procedure was carried out using gas chromatography-ion trap single and tandem stage mass spectrometry in electron and chemical ionization mode that led to the identification of previously unreported 1-mono and 1,1-disubstituted tetrahydro-␤carboline (THBCs) by-products. The tryptamine product and several THBC by-products were determined quantitatively and a "fingerprint" analysis of the crude products allowed for the differentiation between the essential oil catalysts involved as indicated by the presence of tetrahydro-␤-carbolines and their imine intermediates.

The thermolysis of benzylphenylether (BPE) was examined at 320°C in liquid, vapor, and supercritical methanol phases as a probe of the reaction mechanism. Toluene and phenol were the major products in all cases, but observed selectivities were dependent upon the reaction phase. Isotopic labeling experiments demonstrated that methanol participated in the reaction network as a hydrogen donor through a free-radical mechanism. These results are consistent with free-radical steps for neat BPE primary pyrolysis that include BPE fission followed by hydrogen abstraction and radical recombination reactions. A detailed set of 2 1 free-radical steps quantitatively explains the dependence of the selectivity and conversion on the phase behavior.

The surface morphology and chemistry of CBp obtained by pyrolysis of waste tyres at 500 and 700 -C, respectively was studied compared with a commercial tyre carbon blacks by laser particle size analyzer, X-ray diffractogram (XRD) and electron spectroscopy for chemical analysis (ESCA). The distribution of CBp aggregates was the mixed particle distribution of commercial carbon blacks added to tyres in fabrication. The concentration of inorganic compounds and carbonaceous deposits (the organic compounds deposited on the surface of the CBp) depends on the pyrolysis temperature. The chemical nature of the CBp from pyrolysis at 700 -C was found to be closer to the commercial tyre carbon blacks than the CBp from pyrolysis at 500 -C. D 2005 Elsevier B.V. All rights reserved.

Renewable biomass is considered as an important energy resource all over the world and for an agriculture based economy like that of India, the future prospects of being able to convert widely available biomass materials into various forms of fuel is most attractive. In this study, pyrolysis of groundnut de-oiled cake was investigated with an aim of studying the physical and chemical characteristics of the bio-fuel produced and to determine its feasibility as a commercial fuel. Thermal pyrolysis of groundnut de-oiled cake was done in a semi-batch reactor at a temperature range of 200-500°C and at a heating rate of 20°C/min. The chemical analysis of the bio-fuel showed the presence of functional groups such as alkanes, alkenes, alkynes, aldehydes, ketones, carboxylic acids, esters, amines, nitriles, nitro compounds and aromatics rings. The physical properties of the bio-fuel obtained were close to that of diesel and petrol.

Tribenzyl tin(IV) chloride complexes of morpholine N-thiohydrazide (L1), aniline-N-thiohydrazide (L2),N-(morpholine-N-thio)-1,3-propanediamine (L3) and (aniline-N-thio)-1,3-propanediamine (L4) of the type (C6H5CH2)3Sn(L)Cl (where L=L1, L2, L3 and L4) have been synthesised in dioxane and in H2O and acetone mixture. These were characterized by C,H,N-analysis, UV, IR and 1HNMR spectral studies. In both the complexes ligands act as bidentate, coordinating through sulphur and terminal nitrogen. The complexes are 1:1 metal ligand complexes. Various thermodynamic parameters have been calculated for the decomposition steps using TG/DTA curves in air as well as nitrogen atmosphere.

Municipal solid waste management (MSWM) constitutes one of the most crucial health and environmental problems facing authorities in the Khartoum State (Sudan). The analysis showed that Khartoum State produced around 1,040,250 tons of solid municipal waste annually 12.7% of it plastic which is 132,112 tons. Studies say that the liquid (oil) yield of thermal pyrolysis of plastic waste is between 80-90%. Modification made by Aspen Hysys program for thermofuel process to improve the efficiency of the process.

Thermal decomposition of polypropylene (PP) was studied in the presence of wood flour, lignin, cellulose and charcoal in order to understand the pyrolytic behavior of the mixture of these components occurring in waste. Thermogravimetry/mass spectrometry was applied for monitoring the weight loss and the product evolution profiles under slow heating conditions. The formation of oligomeric products was analyzed by pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). Since the charring reactions of wood are still proceeding during the PP decomposition, the interactions between PP and char devolatilization are expected to be rather pronounced. The effect of the freshly formed pyrolytic chars on the decomposition of PP was simulated by mixing PP with pure activated charcoal. Activated charcoal had the most significant effect on the decomposition profile and the product distribution of polypropylene. In the presence of charcoal the decomposition shifted to lower temperature and the DTG curve became broader. The presence of charcoal promotes the formation of monomer and dimer. The effect of wood flour, lignin and cellulose is less pronounced. Though the decomposition starts at lower temperature in the presence of these additives and the DTG curve became broader, the temperature of the maximum decomposition rate and the char yields did not change significantly.

Pyrolysis of pistachio shell has been carried out in a well-swept fixed bed reactor. The effects of pyrolysis temperature, reaction time and sweeping gas (N 2 ) flow rate on product yields were investigated in the ranges of 350-650°C, 10-50 min and 50-450 ml min À1 , respectively. The results showed that temperature was the most effective parameter on product yields. The liquid product was characterized by FTIR, GC-MS and MALDI-TOF-MS/LD-MS whereas the solid product was subjected to FTIR, SEM and BET surface area analyses as well as heating value determinations. The liquid product was a highly oxygenated complex mixture with 18 identified compounds, and had a higher heating value of 4645 kcal kg À1 . The solid product, as produced, was a valuable solid fuel with an energy content higher than that of subbituminous coal, but was found unsuitable for active carbon applications owing to its low surface area values.