Fast Pyrolysis Of Pine Wood Research Articles

Optimising ex-situ catalytic fast pyrolysis of pine wood at pilot scale: Impacts on the energy content, chemical composition and stability of the liquid fuel product

A central composite design was used to optimise the yield and higher heating value (HHV) of the liquid fuel produced through ex-situ catalytic fast pyrolysis of pine wood. The variables were the temperature and loading of H-ZSM-5 zeolite catalyst. GC/MS, 1H NMR and stability tests were undertaken to compare the fuel properties of organic phases with similar HHVs, generated from catalytic treatments at low (≤ 370 °C) and high (≥ 470 °C) temperatures. When targeting an HHV of 32 MJ/kg, higher yields were obtained at low temperature and high catalyst loading, despite higher coke yield. Treatment at low temperature preserved more alkyl groups and made the fuel less aromatic (−13 % of aromatic hydrogen and lower content of Crich hydrocarbons). Undesirable catalytic cracking of alkyl groups at higher temperature was evidenced by a 60 % increase in the production of hydrocarbon gases. Despite a higher oxygen content, the fuel produced at low temperature was also found to be more stable.

Influences of zinc chloride on fast pyrolysis of pinewood

Fast pyrolysis is a thermochemical process which converts biomass into intermediate bio-oil and biochar products, which can be further processed to produce end products. Bio-oil is an organic liquid containing myriads of organic chemicals derived from the decomposition of cellulose, hemicellulose, and lignin components in lignocellulosic biomass. There are chemicals in bio-oil which are highly valuable as specialty chemicals, such as furfural, levoglucosan and levoglucosenone. Unfortunately, the amounts of these chemicals are typically too small, which makes it uneconomical to extract them from bio-oil. This work is focused on fast pyrolysis of pinewood, a well-known softwood used in paper industry. In this work, it was demonstrated that bio-oil containing higher fractions of furfural and levoguclosenone can be produced by treating pinewood feedstock with zinc chloride prior to pyrolysis. The batch pyrolysis studies by using a micropyrolyzer, a batch tubular reactor, and a thermogravimetric analyzer showed that the amounts of zinc chloride impregnated to pinewood feedstock significantly affect the yields of bio-oil and biochar products and the composition of chemicals in bio-oil. Increasing the concentration of zinc chloride solution used for pretreating the feedstock resulted in higher yields of biochar containing higher amount of the salt. Optimum concentrations of furfural and the two sugars in bio-oil product seemed to be obtained from pyrolysis of pinewood that was pretreated with 5wt% zinc chloride solution. Pretreatment with higher salt concentration reduced the concentration of levoglucosan but did not affect the other two valuable chemicals.

Experimental study of fast pyrolysis vapors fractionation through different staged condensation configurations

The quality of biocrudes from fast pyrolysis of lignocellulosic biomass can be improved by optimizing the downstream condensation systems to separate and concentrate selected classes of compounds, thus operating different technological solutions and condensation temperatures in multiple condensation stages. Scientific literature reports that fractional condensation can be deployed as an effective and relatively affordable step in fast pyrolysis. It consists in a controlled multiple condensation approach, which aims at the separated collection of classes of compounds that can be further upgraded to bio-derived chemicals through downstream treatments. In this study, fractional condensation has been applied to a fast pyrolysis reactor of 1 kg h-1 feed, connected to two different condensation units: one composed by a series of two spray condensers and an intensive cooler; a second by an electrostatic precipitator and an intensive cooler too. Fast pyrolysis of pinewood was conducted in a bubbling fluidized bed reactor at 500 °C, while condensable vapours were collected by an interchangeable series of condensers. Using the first configuration, high boiling point compounds – such as sugars and lignin-derived oligomers – were condensed at higher temperatures in the first stage (100 – 170 °C), while water soluble lighter compounds and most of the water were condensed at lower temperatures and so largely removed from the bio-oil. In the first two condensing stages, the bio-oil water content remained below 7 wt % (resulting in 20 MJ kg-1 of energy content) maintaining about 43% of the liquid yield, compared to the 55% of the single step condensation runs. The work thus generated promising results, confirming the interest on upscaling the fractional condensation approach to full scale biorefinering.

Fast Pyrolysis of Pine Wood Pretreated by Large Pilot-Scale Thermomechanical Refining for Biochemical Production

Pretreatments of lignocellulosic biomass prior to fast pyrolysis need to give a better yield and quality of pyrolysis oil and be practical to implement at a commercial scale. This study demonstrate...

Effect of pine wood biochar mixed with two types of compost on growth of bell pepper (Capsicum annuum L.)

The purpose of this study was to evaluate the biochar from fast pyrolysis of pine wood mixed with manure compost or vermicompost as a potential container substrate to replace peat moss. Seven biochar substrates were compared to the control (a commercial substrate; 0B) in container cultivation of bell pepper (Capsicum annuum L.): 100% biochar (100B), 90% biochar + 10% manure compost (90B10C; by volume), 80% biochar + 20% manure compost (80B20C), 70% biochar + 30% manure compost (70B30C), 90% biochar + 10% vermicompost (90B10V), 80% biochar + 20% vermicompost (80B20V), and 70% biochar + 30% vermicompost (70B30V). The physical characteristics of the container substrate (total porosity, container capacity, air space, and bulk density) were tested using NCSU porometers. The electrical conductivity (EC) and pH of container substrate leachates were measured according to the pour-through method on 34, 41, 62, and 83 days after planting (DAP). Growth index was measured on 34, 41, 48, 55, 62, 69, 76, and 83 DAP. Leaf SPAD value, net photosynthesis rate, total leaf area, and stem diameter were measured at week 11. Dry weight and yield were measured at the flowering (72 DAP) and harvesting (113 DAP) stages. The control showed the highest container capacity (59.2%) and the lowest air space (14.1%), with the opposite results observed on 100B. Control had pH values within 6.0–7.0 for optimum pepper growth, while container substrates with biochar resulted in a pH less than 6.0 from 41 to 83 DAP. EC in control at 34 DAP was approximately four times greater than values observed on the other substrates. EC of 70B30V slightly increased between 34 and 41 DAP, and the lowest EC was observed on 100B. SPAD value and net photosynthesis rate were the greatest on plants grown in control. The total leaf area, stem diameter, growth index, vegetative (stem + leaf) and flower dry weights, and yield were the highest in control, followed by 70B30V, 80B20V, and 90B10V, with the lowest in 100B.

Fast pyrolysis bio-oil from lignocellulosic biomass for the development of bio-based cyanate esters and cross-linked networks

Fast pyrolysis of pine wood was carried out to yield a liquid bio-oil mixture that was separated into organic and aqueous phases. The organic phase (ORG-bio-oil) was characterized by gas chromatography–mass spectroscopy, 31P-nuclear magnetic resonance spectroscopy, and Fourier transform infrared (FTIR) spectroscopy. It was further used as a raw material for producing a mixture of biphenolic compounds (ORG-biphenol). ORG-bio-oil, ORG-biphenol, and bisphenol-A were reacted with cyanogen bromide to yield cyanate ester monomers. Cyanate esters were characterized using FTIR spectroscopy and were thermally cross-linked to develop thermoset materials. Thermomechanical properties of cross-linked cyanate esters were assessed using dynamic mechanical analysis and compared with those of cross-linked bisphenol-A-based cyanate ester. ORG-biphenol cyanate ester was observed to have a superior glass transition temperature (350–380°C) as compared to bisphenol-A cyanate ester (190–220°C). Cyanate esters derived from bio-oil have the potential to be a sustainable alternative to the bisphenol-A-derived analog.

The effect of biomass pretreatment on catalytic pyrolysis products of pine wood by Py-GC/MS and principal component analysis

Non-catalytic and catalytic pyrolysis of pretreated pine wood was conducted using pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). Biomass pretreatment included acid-leaching, torrefaction, and acid-leaching followed by torrefaction. Forty-five pyrolysis products were identified in the Py-GC/MS chromatograms and their peak area data evaluated by principal component analysis. In non-catalytic pyrolysis, acid-leaching pretreatment enhanced the levels of levoglucosan, while torrefaction pretreatment enhanced the proportion of catechols in the volatile products. Increasing both the temperature and catalyst loading in catalytic pyrolysis promoted the formation of aromatic hydrocarbons. At lower pyrolysis temperatures (450–500 °C), acid-leaching pretreatment resulted in slightly lower proportions of aromatics, while torrefaction pretreatment had the opposite effect. Overall, temperature and catalyst loading were considerably more important factors in catalytic fast pyrolysis of pine wood than biomass pretreatment as studied by Py-GC/MS.

Selective Production of Formic Acid by Wet Oxidation of Aqueous-Phase Bio-oil

Fractionation of bio-oil is an important step in the development of an effective upgrading strategy of bio-oil to transport fuels and chemicals because it reduces bio-oil complexity and side reactions; however, the strategy should preferably make use of all fractions. We therefore fractionated bio-oil from fast pyrolysis of pine wood using water addition and liquid–liquid extraction and studied its aqueous-phase oxidation to formic acid. One potential use of formic acid is as a hydrogen source for upgrading of the organic phase. The effects of the temperature, oxygen pressure, and concentration of substrates and phenolic compounds on the yield and selectivity of formic acid were investigated. Batch experiments revealed a yield of up to 56 wt % (dry basis) and high selectivity, after 30 min at 170 °C and 5.0 MPa. However, the presence of phenolic compounds in the aqueous phase and substrate concentrations greater than 3% were detrimental. Extraction of the aqueous phase with butyl acetate was effective for...

Chemical and ecotoxicological properties of three bio-oils from pyrolysis of biomasses

In view of the potential use of pyrolysis-based technologies, it is crucial to understand the environmental hazards of pyrolysis-derived products, in particular bio-oils. Here, three bio-oils were produced from fast pyrolysis of pine wood and intermediate pyrolysis of corn stalk and poultry litter. They were fully characterized by chemical analysis and tested for their biodegradability and their ecotoxicity on the crustacean Daphnia magna and the green alga Raphidocelis subcapitata. These tests were chosen as required by the European REACH regulation. These three bio-oils were biodegradable, with 40–60% of biodegradation after 28 days, and had EC50 values above 100mgL−1 for the crustacean and above 10mgL−1 for the alga, showing low toxicity to the aquatic life. The toxic unit approach was applied to verify whether the observed toxicity could be predicted from the data available for the substances detected in the bio-oils. The predicted values largely underestimated the experimental values.

Production of gaseous and liquid bio-fuels from the upgrading of lignocellulosic bio-oil in sub- and supercritical water: Effect of operating conditions on the process

This work analyses the influence of the temperature (310–450°C), pressure (200–260bar), catalyst/bio-oil mass ratio (0–0.25g catalyst/g bio-oil), and reaction time (0–60min) on the reforming in sub- and supercritical water of bio-oil obtained from the fast pyrolysis of pinewood. The upgrading experiments were carried out in a batch micro-bomb reactor employing a co-precipitated Ni–Co/Al–Mg catalyst. This reforming process turned out to be highly customisable for the valorisation of bio-oil for the production of either gaseous or liquid bio-fuels. Depending on the operating conditions and water regime (sub/supercritical), the yields to upgraded bio-oil (liquid), gas and solid varied as follows: 5–90%, 7–91% and 3–31%, respectively. The gas phase, having a LHV ranging from 2 to 17MJ/m3 STP, was made up of a mixture of H2 (9–31vol.%), CO2 (41–84vol.%), CO (1–22vol.%) and CH4 (1–45vol.%). The greatest H2 production from bio-oil (76% gas yield with a relative amount of H2 of 30vol.%) was achieved under supercritical conditions at a temperature of 339°C, 200bar of pressure and using a catalyst/bio-oil ratio of 0.2g/g for 60min. The amount of C, H and O (wt.%) in the upgraded bio-oil varied from 48 to 74, 4 to 9 and 13 to 48, respectively. This represents an increase of up to 37% and 171% in the proportions of C and H, respectively, as well as a decrease of up to 69% in the proportion of O. The HHV of the treated bio-oil shifted from 20 to 35MJ/kg, which corresponds to an increase of up to 89% with respect to the HHV of the original bio-oil. With a temperature of around 344°C, a pressure of 233bar, a catalyst/bio-oil ratio of 0.16g/g and a reaction time of 9min a compromise was reached between the yield and the quality of the upgraded liquid, enabling the transformation of 62% of the bio-oil into liquid with a HHV (29MJ/kg) about twice as high as that of the original feedstock (17MJ/kg).

Exploring the Products from Pinewood Pyrolysis in Three Different Reactor Systems

The product yields and selectivity from fast pyrolysis of biomass are highly dependent upon the physicochemical properties of the biomass feedstock and the process conditions. The objective of this study was to compare the product yields and selectivity from fast pyrolysis of pinewood using three different reactors systems typically used in research laboratory settings for studying biomass pyrolysis: a micropyrolyzer coupled to a gas chromatography/mass spectrometry system, a batch tubular reactor, and a fluidized-bed (FB) continuous reactor. The pyrolysis of pinewood using the three reactors gave different bio-oil yields, altered the amounts and compositions of the non-condensable gases, and gave rise to variations in the amount and types of chemicals in bio-oil produced. The variability in residence times of the three reactors and mechanical factors within the FB reactor altered the degree of secondary reactions of the primary pyrolysis vapor, leading to the observed changes in composition. Lower yields...

Effect of biomass ash in catalytic fast pyrolysis of pine wood

Fast pyrolysis experiments of pine wood have been performed in a continuously operated mechanically stirred bed reactor at 500°C. The effects of the pine wood ash were studied by comparing non-catalytic and catalytic experiments (using a ZSM-5 based catalyst) with their ash-added counterparts. To show the case of ash accumulated from the biomass feeding, the results of catalytic fast pyrolysis obtained after eight reaction/catalyst regeneration cycles were included as well. The objective was to distinguish between the ash-catalyst interactions and the catalyst deactivation. The latter may be caused by thermo-mechanical, chemical and/or structural changes in the catalyst; such as poisoning, fouling, and attrition, as well as by coke deposition. Ash concentrations up to ca. 3wt.% relative to the amount of pine wood fed, and ca. 0.002wt.% relative to the amount of bed material, were found to be sufficient to change the distribution and the composition of pyrolysis products. The addition of ash to the catalytic fast pyrolysis, caused a reduction in the yields of both the organics and coke by 2wt.% (on feed basis), while increases of 1wt.% and 4wt.% in the water and non-condensable gases were observed, respectively. The total yield of CO plus CO2 was boosted by more than 10%, while the CO2 production (decarboxylation reactions) was favoured clearly. Moreover, the presence of added-ash suppressed the conversion of sugars and acids – these were more pronounced in the case of accumulated-ash – as well as of the phenols. The catalyst deactivation during the reaction/regeneration cycles is not only related to the presence of ash but also to changes in the structure and composition of the catalyst. To overcome the drawbacks of biomass ash in catalytic fast pyrolysis, either the biomass feedstock has to be leached (ash removal) before being introduced to the process, or the char (which contains a vast majority of the biomass ash) has to be physically removed from the catalyst before the regeneration step.

Catalytic Fast Pyrolysis of Pine Wood: Effect of Successive Catalyst Regeneration

The main product of biomass fast pyrolysis is a liquid mixture of numerous organic molecules with water that is usually called pyrolysis oil or bio-oil. The research discussed in this paper was meant (1) to validate a new, semicontinuously operated pyrolysis setup and (2) to investigate the effect of a repeatedly regenerated ZSM-5-based catalyst (eight reaction/regeneration cycles in total) on the yields and compositions of the pyrolysis products in relation to the applied process conditions and on the catalyst itself. The reliability of the setup has been proven by multiple repetition of noncatalytic and catalytic (in situ) pyrolysis experiments for pine wood at 500 °C under identical conditions. As a result, the mass balance closures for all experiments varied from 92 to 99 wt %, while the scatter in measured data was always less than 5%. Changes in the performance of the repeatedly regenerated catalyst have been observed via detailed analysis of the bio-oil (GC × GC-FID and GC × GC-TOF-MS, Karl Fischer), the noncondensable gases (micro-GC), and the carbonaceous solids (elemental analyzer, BET surface area). Along the reaction/regeneration sequence, the yield of organics increased, while water, carbonaceous solids, and noncondensable gases decreased. Trends in pyrolysis product yields converging to that of noncatalytic levels were observed, which revealed that the influence of the catalyst slowly declined. The main observation was that the catalyst partially loses its activity in terms of the product distribution along the reaction/regeneration sequence, while retaining sufficient activity in producing the target chemical compounds.

Secondary Vapor Phase Reactions of Lignin-Derived Oligomers Obtained by Fast Pyrolysis of Pine Wood

In this paper, the effect of secondary reactions in vapor phase on the yield and composition of pyrolytic lignin (PL) oligomers was investigated. The Pine wood material was pyrolyzed at 500 °C in a fluidized bed reactor, and the vapors were transferred to a downstream tubular reactor operated at residence times between 0 and 15 s and temperatures of 400, 500, and 550 °C. Relatively small changes in yield and composition of PL oligomers were observed when the tubular reactor was operated at 400 °C. However, as the temperature in the tubular reactor increased (500 and 550 °C), the effect of residence time became more pronounced and the rate of thermal degradation of pyrolytic lignin increased. The pyrolytic lignin fraction was isolated from the bio-oil and analyzed by UV-fluorescence, TGA, Py-GC/MS, FTIR, ESI-MS, and 1H NMR. The main change observed in the composition of PL oligomers (by Py-GC/MS and 1H NMR) as a function of the vapor phase reaction time and temperature was the removal of methoxyl groups. F...

Iron nanoparticles in situ encapsulated in biochar-based carbon as an effective catalyst for the conversion of biomass-derived syngas to liquid hydrocarbons

Biochar, a by-product from the fast pyrolysis of pine wood, was used as the support material for the synthesis of carbon-encapsulated iron nanoparticles. The nanoparticles were characterized for physicochemical properties by multiple morphological and structural methods (e.g., SEM, TEM, XRD, FTIR, and TPD). The Fischer–Tropsch synthesis (FTS) process was carried out to evaluate the catalytic activity of the nanoparticles on conversion of biomass-derived synthesis gas (bio-syngas) to liquid hydrocarbons. Characterization results revealed that the nanoparticles had core–shell structures with iron in situ encapsulated within a graphitic shell. Moreover, significant amounts of iron carbide (mainly Fe3C) were formed as an interface between the carbonaceous shell and the iron core. FTS tests indicated that such carbon-encapsulated iron nanoparticles possessed a high activity on conversion of bio-syngas and good selectivity towards liquid hydrocarbons (of which olefins were the dominant product). Over a 1500 h testing period, the nanoparticles showed striking stability against deactivation, with CO conversion maintained at about 95% and liquid hydrocarbon selectivity at about 68%.