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Introduction
Dr. Christian Roy is CEO of a company called Pyrovac Inc. located in Quebec City, QC, Canada. Pyrovac is a technology provider in the area of pyrolysis. We design and build industrial pyrolysis plants in the area of biomass, used tires and plastic pyrolysis. My e-mail is croy@pyrovac.com.
Publications
Publications (213)
Pyrolysis of solid fuels such as coal, peat and biomass enables conversion into solid and liquid products, with noncondensable gas being a by-product. The present study evaluates conversion characteristics of Brazilian coal, peat and biomass samples using vacuum pyrolysis techniques. Feedstock and their respective solid residues (chars) and pyrolyt...
The treatment of bituminous roofing waste materials by vacuum pyrolysis was tested in a pilot plant. The pyrolysis experiment was carried out batchwise at a temperature of 500°C and a total maximum pressure of 16 kPa. The amount of feedstock tested was 37 kg. Pyrolysis product yields were 52.3 wt.% oils, 31.2 wt.% solids, 14.4 wt.% pyrolysis gas, a...
Vacuum pyrolysis of wood furnishes high yields of oils which are a source of liquid fuels and chemicals. Wood charcoal is a solid residual by-product. Solid residues produced at 200, 263, 327, 363, 401, and 448 °C in a Process Development Unit were analyzed using wet chemical methods and chromatography and infrared spectrometry.A Diffuse Reflectanc...
The surface fractal dimension (Ds) of pyrolytic carbon blacks (CBp) was determined using small angle X-ray scattering (SAXS). The CBp were produced by vacuum pyrolysis of used tires at different temperatures and pressures. For the CBp a dependence of the pyrolysis conditions on the fractal dimension was observed. The fractal dimension decreases, su...
Distillation/dehydration represents the largest fraction of the energy used in the production of ethanol. The Siftek technology introduced in this paper carries the potential of reducing energy consumption of distillation/dehydration by up to 50% through the single pass removal of water from the water/ethanol stream at the beer column outlet, using...
A phenol-formaldehyde (PF)-resin designed to penetrate wood and immobilize copper and boron in wood cells for protection against decay was investigated. The phenol portion of the PF-resin was partially substituted with pyrolysis oil derived from softwood bark. The objective was to reduce the environmental impact associated with the production of pe...
A comprehensive, unified approach, using the Linear Packing Theory and Unit Cell Model, is proposed for calculating of the effective thermal conductivity of polydispersed packed beds. In this new approach, the effect of packing density is incorporated by the use of (i) an initial porosity to take into account the packing of mono-sized particles, an...
Producing fuel ethanol can be expensive, but with the right technology a company can reduce costs and save energy. A designer and manufacturer of gas separations systems created a membrane separation technology as an alternative to distillation and molecular sieve dewatering solutions. The company decided to put it to the test at an ethanol manufac...
Jack pine and sugar maple wood samples were treated in a two-step process that involved first a copper chloride or a copper chloride-sodium borate mixture and then a phenol-formaldehyde resin containing a certain percentage of softwood bark pyrolytic oil. Various controls were also prepared for comparison. The modulus of rupture (MOR) of jack pine...
The paper studies the motion of scrap tire shreds in a moving and stirred bed vacuum pyrolysis reactor. The reactor configuration is a novel concept. The pattern and the residence time distribution (RTD) of the particle motion in the reactor were investigated using tracers, for different feed rates and blade speeds. It was shown that the particle m...
Phenolic compounds with potential industrial applications are major pyrolysis products of biomass lignin. Fractional pyrolysis allowed the evolution of chemical compounds such as phenols to be monitored as a finction of temperature. Due to the less restrained pyrolysis conditions, phenolic compounds were produced in high yields by fractional pyroly...
A novel reactor configuration has been developed in our laboratory which addresses the heat transfer limitations usually encountered in vacuum pyrolysis technology. In order to scale-up this reactor to an industrial scale, a systematic study on the heat transfer, the chemical reactions and the movement of the bed of particles inside the reactor has...
IntroductionExperimentalResults and DiscussionConclusion
AcknowledgementsReferences
The rheological properties of a phenol–formaldehyde resin containing various ratios of softwood pyrolytic oil as phenol substitute were investigated using the simple Bingham rheological model for viscoplastic fluids. Flow activation energy was determined for the various resin blends and the pyrolytic oil between room temperature and 50°C and correl...
Sapwood blocks of white pine and American beech were impregnated in a two-step treatment with either a 5 percent copper chloride solution or a mixture of 5 percent copper chloride and 2 percent sodium borate followed by impregnation with a phenol-formaldehyde resin containing various concentrations of a softwood-bark-derived pyrolytic oil. The trea...
This paper describes an analytical approach to determine the chemical composition of bio-oils in terms of macro-chemical families. Bio-oils from the vacuum pyrolysis of softwood bark and hardwood were first fractionated using solvent extraction. Fractions obtained were then characterized using GC-MS, thermogravimetric techniques (TG) and Gel Permea...
Softwood bark (SWBR) and hardwood rich in fibres (HWRF) biomass samples were used as model feedstocks to study the properties of bio-oils obtained by vacuum pyrolysis. The content and composition of extractives in the feedstocks were determined after fractionation into different classes of compounds using solvents of different polarities followed b...
Softwood bark (SWBR) and hardwood rich in fibres (HWRF) biomass samples were used as model feedstocks to study the properties of bio-oils obtained by vacuum pyrolysis. The content and composition of extractives in the feedstocks were determined after fractionation into different classes of compounds using solvents of different polarities followed b...
The thermal stability of bio-oils obtained from softwood bark (SWBR) and hardwood rich in fibers (HWRF) residues was studied under aging conditions at 80 °C in sealed glass bottles in the presence of stainless steel and copper. SWBR-derived bio-oil separated into oily and aqueous phases during aging, while HWRF-derived oil remained as a single phas...
The multiphase complex structure of biomass pyrolysis oils can be attributed to the presence of char particles, waxy materials, aqueous droplets, droplets of different nature, and micelles formed of heavy compounds in a matrix of hollocellulose-derived compounds and water. Bio-oil complexity is illustrated by use of two oils produced from the vacuu...
Thermal decomposition of balsam fir and white spruce mixed bark residues at 450°C and under vacuum <20 kPa abs.) results in high yields of pyroligneous liquors rich in phenols. The pyrolytic aqueous condensate fractionation in four distinct parts was accomplished by a liquid-liquid extraction method. Each fraction was tested for its anti-fungal pro...
By vacuum pyrolysis, the rubber portion of used tires is transformed into oil and gas and the carbon black filler is recovered as pyrolytic carbon black (CB P). Several commercial applications for the different products have been investigated and are reported in this article. CB P surface chemistry and activity are similar to those of commercial ca...
For Abstract see ChemInform Abstract in Full Text.
A kinetic study of the pyrolysis of the five main plastics contained in a typical municipal plastic waste (MPW) stream revealed that some interactions occur between the plastics during the mixture pyrolysis. A comparison of the kinetic parameters showed that the activation energy of each polymer in the mixture changed only slightly when compared wi...
Sorption and transport behavior of water vapor in two copolyimide dense films and their asymmetric capillary membranes were studied at 30°C. Water vapor permeation and separation behavior in the copolyimide dense and asymmetric membranes were also investigated in vapor feeds of pure water, 1-propanol/water, and acetic acid/water with concentration...
The objective of this study is to provide background information on pyrolysis oil for gas turbine applications. The bio-oil investigated consists of an upper layer and a bottom layer. It has been produced by vacuum pyrolysis of softwood bark. The storage stability and the thermal behavior of the whole bio-oil, the upper layer, and the bottom layer...
The corrosion of three metals (aluminum, copper, and austenitic steel (SS 316)) at 80 °C by bio-oil obtained by vacuum pyrolysis of softwood bark residue was studied using X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES) depth profiling. The bio-oil is very acidic (pH value of 3) and contains significant amounts of water...
Crude bio-oils obtained via the pyrolysis of bark residues are dark, viscous, and sticky materials that visually appear similar to homogeneous liquids. However, microscopic tests revealed the presence of tridimensional compounds (agglomerates) and solid particles that are dispersed in the continuous bio-oil medium. These materials are responsible f...
Experiments were conducted in a moving and stirred bed vacuum pyrolysis reactor handling polydispersed softwood bark feedstock to study flow characteristics as functions of feed throughput, agitation speed, particle size and shape. A new idea of polydispersed fluorescent tracers was employed for the first time to investigate the residence time dist...
Wood adhesives derived from softwood bark pyrolysis oils (PO) and isocyanates (pMDI) have been developed for particleboards with a non-conventional blending system. The PO produced by the vacuum pyrolysis Pyrocycling(TM) process was used to replace between 30 and 40% by weight of the pMDI in a 4% adhesive-containing particleboard. Results showed th...
A common denominator of modern tire recycling methods is that they are generally subsidized by governments through tipping fees. The paradigm however is that the compounds composing a tire, i.e. carbon black, oil and steel, are pricy materials. A technology that could enable the recapture of the above valuable materials may ultimately sustain itsel...
Commercial furnace carbon blacks with a low oxygen concentration at the surface were studied using X-ray photoelectron spectroscopy. Oxygen-containing groups and the basal planes of graphene layers were investigated. The highest concentration of basic sites was found for the samples with the narrowest graphite peaks. The ability of graphene layers...
This chapter describes the surface and pore structures of CMK-5 ordered mesoporous carbons investigated by nitrogen adsorption and surface spectroscopic methods. The matrices used for the ordered mesoporous carbons (OMC) synthesis were characterized by nitrogen adsorption. The OMCs were studied by X-ray photoelectron spectroscopy (XPS) and by nitro...
Bio-oil obtained via the vacuum pyrolysis of softwood bark residues is a multiphase, viscous, unstable system composed of water-soluble and water-insoluble fractions. Using centrifugation, the bio-oil can be separated into an upper layer (ca. 16 wt %) and a bottom layer (ca. 84 wt %). The upper layer exhibits low contents of water, solid, and ash,...
Due to the recent bovine spongiform encephalopathy (BSE) crisis in the European beef industry, the use of animal-derived products to feed cattle is now severely restricted. Large quantities of waste animal meat and bone meal (MBM), also known as animal flour, have to be safely disposed of or transformed. One disposal option is pyrolysis. Vacuum pyr...
The reaction of polymethylene diphenyl diisocyanate (pMDI) with pyrolysis oils (PO) was studied by differential scanning calorimetry (DSC) and rheology. Chemical reactions between pMDI and PO occur under 100°C, as shown in DSC scans. DSC analysis showed that the peak temperature of the reaction decreased as the PO content of the PO–pMDI blends incr...
A bench-scale study was undertaken to investigate the potential of vacuum pyrolysis for the production of upgraded bitumen from Alberta tar sands. Vacuum pyrolysis limits the secondary decomposition reactions which results in high yield of transportable oil and low yield of gas. The objectives of this study were (i) to study the influence of the re...
Ordered mesoporous carbons (OMCs) were synthesized in the pore system of SBA-15 aluminosilicates with different Si/Al ratios ranging from 5 to 80. Nitrogen adsorption was used to characterize the pore structure of the aluminosilicates and of the OMCs, whereas the OMC surface chemistry was studied by X-ray photoelectron spectroscopy and static secon...
Conductive carbon blacks from different manufacturers were studied in order to obtain some insight into the relation between their electrical conductivity and their surface properties. The surface chemistry was studied by X-ray photoelectron spectroscopy (XPS) and static secondary ion mass spectroscopy (SIMS), whereas the topology of the carbon bla...
Ordered mesoporous carbons (OMCs) were produced by pyrolysis of sucrose adsorbed in two different silica matrices (MCM-48 and SBA-15), followed by dissolution of the matrix in hydrofluoric acid. Subsequently, some of these OMCs were heat-treated at temperatures of up to 1600 °C. The OMC pore structure was studied by low-pressure nitrogen adsorption...
Very few data exist regarding the thermal properties of softwood bark and therein derived softwood chars. This work describes the measurement of specific heat and particle thermal conductivity of softwood (SW), softwood bark (SB) and therein derived softwood char (SC). Differential scanning calorimetery (DSC) was used to measure the specific heat....
Water vapor permeation and separation behavior in solvent-resistant polyimide dense membranes was investigated. Model mixtures of 1-propanol (1-PrOH)/H2O, and acetic acid (AA)/H2O with concentration of 10wt.% of organic compounds, as well as a pyrolysis aqueous phase containing 11wt.% organic compounds were used as vapor feeds. Solvent-resistant po...
The sorption and transport of water vapor in five dense polyimide membranes were studied by thermogravimetry. The sorption isotherms of water vapor in the polyimides could be successfully interpreted by both the dual-mode sorption model and the Guggenheim–Anderson–de Boer equation. The water vapor diffusion behavior was found to be nearly Fickian a...
In this paper, the effective thermal conductivity (ETC) of softwood bark and softwood char particle beds which are highly polydispersed has been studied theoretically and experimentally. Use of the linear packing theory and unit cell model of heat conduction enabled to express ETC of polydisperded beds as a function of particle size distribution. E...
Truck tire particles were pyrolysed at 490 °C at atmospheric pressure and under vacuum, respectively. The recovered pyrolytic carbon black (CBP) was heated in a post-pyrolysis process at temperatures ranging from 670 to 860 °C. The CBP were studied in comparison to a commercial tire carbon black by low-pressure nitrogen adsorption and surface spect...
Isolation of betulin from Betula papyfera bark can be performed both by chemical extraction or thermal sublimation. With the thermal sublimation method, no toxic nor expensive solvent is used. The scientific literature, however, reports very limited information about the sublimation method. In this work, a thermogravimetric study has been performed...
Ordered mesoporous carbons (OMC) were produced by pyrolysis of hydrocarbons adsorbed in two different silica matrices (MCM-48 and SBA-15), followed by dissolution of the matrix in either hydrofluoric acid or sodium hydroxide. Some carbons were subsequently heat treated at temperatures of up to 1600 °C. The chemistry of the external surface was stud...
The objective of this study was to provide background data on sugarcane bagasse vacuum pyrolysis. Product yields and properties were investigated. Vacuum pyrolysis tests were performed at bench and pilot plant scales. The bagasse finest particles with a diameter smaller than 450 μm were removed in order to overcome difficulties caused by their low...
The surface morphology of various carbon blacks was studied by low-pressure nitrogen adsorption. The shape of their low-pressure nitrogen isotherm depends on the concentration of surface defects. This defect concentration on the surface is different for thermal blacks, even for those of the same grade Different surface morphologies were also observ...
Attempts were made to develop solvent-resistant polyimide capillary membranes with integrally skinned asymmetric structure to be used for the treatment of wood dryer emissions or vacuum pyrolysis aqueous effluents. Model mixtures of 1-propanol (1-PrOH)/H2O and acetic acid (AA)/ H2O, with concentrations of 10–90 wt % of organic components, were used...
Particle density plays an important role in the design and operation of thermoconversion reactors fed with bed of particles such as softwood bark (SB). Little information is available on the single particle density of SB and charcoal derived. As SB and softwood char (SC) particles are highly irregular in shape and size, conventional methods of part...
The main objective of the present work was to study the pyrolysis under vacuum of sugarcane bagasse combined with petroleum residue (PR), in terms of yields and properties of the products obtained. Important synergetic effects were observed during the co-pyrolysis in a fixed bed reactor leading to an increase in charcoal yield. Maximum charcoal and...
The steam activation of charcoal obtained by vacuum and atmospheric pyrolysis of softwood bark residue was studied by thermogravimetry (TG). Carbons activated in the thermobalance were characterised by gas adsorption. Furthermore, the differential weight loss (DTG) curves were correlated with the specific surface area and surface spectroscopic resu...
Wood adhesives derived from softwood bark residues pyrolysis oil have been developed for oriented strandboard (OSB), an exterior grade wood composite product. The phenolic-rich oil produced by the vacuum pyrolysis Pyrocycling™ process was used to replace part (25% and 35% by weight) of the phenol in phenol-formaldehyde (PF) resin formulations. Some...
Phenol-formaldehyde (PF) resols were prepared with different proportions of phenol replaced with softwood bark pyrolysis oils under varying formaldehyde to phenolics molar ratios and sodium hydroxide contents. Propylene carbonate (PC) was added to these adhesives to improve the cure of resins. The cure behavior was characterized by differential sca...
Cure behavior of resins formulated with petroleum phenol replaced by 25 and 50 wt % of softwood bark-derived pyrolysis oils, using various formaldehyde to phenolics molar ratios and alkalmitv content, was characterized by Differential Scanning Calorimetry (DSC). Kinetic parameters were obtained by the Borchart-Daniels method and the model-free (Vya...
Separation of betulin from the outer bark of Betula papyrifera birch tree by sublimation in a batch vacuum pyrolysis reactor was studied in the temperature range of 250–300°C and under a total pressure of 0.7 kPa. Yield of 9.5% by weight of betulin on an anhydrous bark basis was obtained. The total yield of extractives was in the range of 28–32%. T...
Bark residues generated by the pulp and paper and wood industries represent a threat to the environment due to leaching of chemicals such as phenolics and resin acids which are being currently regulated by governments. Vacuum pyrolysis of resinous bark produces phenolic-rich oils which represent a potential raw material to replace petroleum-based p...
Vacuum pyrolysis of individual plastics including high density polyethylene (HDPE), low density polyethylene (LDPE), polypropylene (PP) and polystyrene (PS) has been performed at a final temperature of 500°C and under a total pressure of 2 kPa. A PVC sample and a commingled plastic sample composed of HDPE/LDPE/PP/PS/PVC have been pyrolyzed in two c...
A new method, called the DTG curve fitting method, has been used to determine the kinetic parameters of six major plastic materials found among urban refuse: high-density polyethylene, low-density polyethylene, polystyrene, polypropylene, poly(vinyl chloride), and poly(ethylene terephthalate). This method involves first measuring the weight loss be...
Hydration of alpha-pinene under various conditions was studied and compared with the literature. Optimal reaction conditions have been established for the hydration of alpha-pinene and crude turpentine oil in the absence of catalyst and using a low volume of acetone. A detailed reaction product analysis is reported. The main hydration product, alph...
Biomass is a renewable and alternative source for the production of fuels and chemicals. This paper provides a brief survey of lignin precursors as well as thermogravimetric and pyrolysis studies of lignin with special reference to the production of phenols. Thermogravimetric analysis provides information on pyrolysis kinetics while thermogravimetr...
One-step and stepwise laboratory batch vacuum pyrolysis of a mixture of birch bark (ca. 46%) and birch sapwood (ca. 54%) was carried out in the temperature range 25–550°C. The pyrolysis oil (defined as the total condensates, including water and organics) was analyzed by GC–MSD and the quantity of phenols (referred to monolignols in this paper) was...
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 surf...
The electrical conductivity of thermal and conductive carbon blacks with different chemistry was determined by impedance spectroscopy. Thermal blacks are suitable compounds for studying the influence of the chemistry on the conductivity since they have similar structures and surface areas, which strongly influence the conductivity. The conductivity...
Thermal decomposition under nitrogen of sugarcane bagasse, petroleum residue and their blends was studied by thermogravimetry (TG) at different heating rates (10, 20, 40 and 60°C/min). Thermal decomposition kinetic parameters were determined. Sugarcane bagasse pyrolysis was described as the sum of cellulose, hemicellulose, and lignin individual con...
A birch wood sample (Betula papyrifera) composed of 54% sapwood and 46% bark was pyrolyzed in a pilot plant reactor. The products were 53.9% condensates (pyrolysis oil including 8% reaction water), 24.0% gas and 22.1% wood charcoal (anhydrous initial feed basis). The pyrolysis oil was steam distilled and the recovery of phenols at various steam pyr...
Thermal decomposition of commingled plastics comprising high and low density polyethylene, polystyrene, polypropylene and poly(vinyl chloride) was investigated under vacuum conditions by dynamic thermogravimetric analysis in the temperature range of 25–600°C. The mixtures were representative of the major polymeric materials found in a municipal pla...
A research program was undertaken to evaluate the overall performance of a vacuum pyrolysis process applied to the treatment of Automobile Shredder Residues (ASR). North American and European ASR samples were tested. Vacuum pyrolysis experiments were carried out in the temperature range of 496–536°C and a total pressure of approx. 1–5 kPa. Pyrolysi...
Defects on carbon black surfaces are studied by low-pressure nitrogen adsorption at 77 K. The shape of the experimental carbon black isotherms and simulated isotherms on defect graphite surfaces [Carbon 36 (1998) 1439] are in good agreement. Surface defects cause a reduced nitrogen adsorption for P/P0 from ∼5×10−5 to ∼0.1. This decrease can be used...
Vacuum pyrolysis of sugar cane bagasse (5.7% moisture) at 500°C and 8 kPa yielded 19.4% charcoal, 34.2% pyrolytic oil, 27.8% water and light organic compounds and 17.6% gases. High surface area (∼1950 m2/g) activated carbon was obtained from the chars by steam activation. It was earlier observed that the properties of bagasse-derived pyrolytic oil...
Various samples of used car and truck tires were pyrolyzed in a batch mode under vacuum and in a continuous feed reactor. The pyrolysis temperature varied in the range of 440–570°C. dl-limonene is a major product formed during the thermal decomposition of rubber under reduced pressure conditions. The pyrolysis oils were distilled to obtain a dl-lim...
The bulk chemistry of commercial carbon blacks and carbon blacks obtained by vacuum pyrolysis (CBP) of used tires was investigated by 13C-NMR spectroscopy with and without magic angle spinning of the sample. Two different kinds of carbon atoms can be distinguished: Graphite like carbon atoms in poly-condensed aromatic rings and carbon atoms in a le...
This paper completes a study the ultimate objective of which was to provide background information on biomass pyrolysis oils (bio-oils) regarding their use as a gas turbine liquid fuel. The bio-oil was obtained by vacuum pyrolysis of softwood bark residues. The stability and ageing of the bio-oil and mixtures thereof were evaluated. The samples wer...
The objective of this study was to provide background information on biomass pyrolysis oils (bio-oils) regarding their use as a liquid fuel for gas turbine applications. The bio-oil was obtained by vacuum pyrolysis of softwood bark residues. Alkali metal content, viscosity, solid content, heating value, surface tension, moisture content and density...