Pyrolysis Of Pine Research Articles

Co-pyrolysis of pine sawdust with aluminum dross for immobilization of heavy metal and enhancing hydrogen generation

Co-pyrolysis of pine sawdust with aluminum dross (AD) for harvesting energy product and safely treated AD-biochar composite was investigated in this work. The catalytic pyrolysis experiment was carried out in a fixed bed reactor. The pyrolysis products were analyzed by gas chromatography (GC), gas chromatography coupled with a mass spectrometer (GC–MS), and solid C-13 Nuclear Magnetic Resonance (13C NMR). The results show that the heavy metals, such as Cu, were immobilized by organic metal-chelating structures as carbon–oxygen-metal (C–O–M) bonds in the AD-biochar composite. In addition, the hydrogen yield from catalytic pyrolysis of pine on AD reaches 131.86 ml/g, significantly higher than the 98.97 ml/g from pure pine pyrolysis. The enhanced hydrogen production is elaborated by the intermediate hybrid mechanism with formation of C–O–M intermediates between the metallic oxides in AD and the oxygen containing functional groups in biomass. Meanwhile, the CO2 yield decreases from 23.68 ml/g to 16.41 ml/g while the CO yield reduces from 49.72 ml/g to 46.85 ml/g. These results may guide to a new exploration on simultaneous treatment of hazardous industrial wastes and utilization of biomass.

Effect of Temperature on the Pilot-Scale Catalytic Pyrolysis of Loblolly Pine

A pilot-scale biomass catalytic pyrolysis unit with a nominal throughput of one tonne of biomass per day (1TPD) has been in operation since 2013 to investigate the process parameters that have the largest influence on biocrude yield, oxygen content, and chemical composition. A parametric study was conducted to investigate the effect of pyrolysis temperature, ranging from 433 to 581 °C, on biocrude yield and quality. A locally sourced loblolly pine feedstock and a commercially available, spray dried, nonzeolitic γ-Al2O3 catalyst were used in individual experiments conducted at each pyrolysis temperature to achieve a minimum of 4 h of steady-state continuous operation. Typically, 600–800 kg of biomass was fed over a 12-h period, with one experiment extended to almost 29 h (1144-kg biomass fed) and one experiment interrupted by a process upset after just 7 h (411-kg biomass fed). Comprehensive analysis of collected gas, liquid, and solid products were used to calculate carbon balances (77% to 107%) for each experiment. The biocrude yield ranged from 12 to 18 wt % C and, in general, decreased with increasing pyrolysis temperature. The average steady-state biocrude yield as a function of temperature translated to a biocrude production rate between 40 and 50 gallons per dry ton. The biocrude oxygen content varied between 21 and 31 wt %, on a dry basis, and as expected, decreased with increasing pyrolysis temperature. The identified components in the semivolatile biocrude products are mostly methoxyphenols and other multiphenolic compounds. The multiphenolic compounds are demethoxylated at pyrolysis temperatures above 500 °C, producing biocrudes with higher concentrations of monophenols and polycyclic aromatic hydrocarbons. The concentration of anhydrosugars, like levoglucosan in the biocrudes, decreased with increasing pyrolysis temperature from ∼15 to ∼1 vol %.

A two-dimensional distributed activation energy model for pyrolysis of solid fuels

Pyrolysis kinetic models are pivotal for understanding and optimizing the gasification, distillation, and combustion processes. This paper proposes a novel two-dimensional distributed activation energy model (2D-DAEM), which is achieved via extending the classical DAEM to the 2D plane of activation energy E and pre-exponential factor A. The performance of the proposed model was evaluated based upon comprehensive analyses of complex reactions such as co-pyrolysis. The results show that the 2D-DAEM outperforms the classical DAEM in terms of efficiency and accuracy. Specifically, the co-pyrolysis analysis of pine woodchips (PINE) and polyethylene terephthalate (PET), shows that the classical DAEM tends to underestimate the lnA values (i.e., 43.0 for PINE pyrolysis; 42.0 for PET pyrolysis; but 39.2 for PINE&PET co-pyrolysis), while the lnA value of 2D-DAEM (about 43.0 for all) is more reasonable. Additionally, the 2D-DAEM is employed to study the influence of coal particle size on pyrolysis. It is observed that the 25 μm coal has the highest reaction rate under both 500 K and 1500 K iso-thermal processes. As a more normative, reasonable, and accurate model, the proposed 2D-DAEM is bound to enhance the practice of reaction prediction, material analysis, and process design.

Understanding the catalytic upgrading of bio-oil from pine pyrolysis over CO2-activated biochar

To understand the catalytic upgrading of bio-oil over char-based catalyst, pyrolysis of pine sawdust with various char catalysts under different reaction temperatures was performed in a fixed-bed reactor, from which the liquid product was analyzed with gas chromatography-mass spectrometry (GC/MS). The main pyrolytic liquids were ketones and acids in the non-catalytic pyrolysis run, which were mainly derived from the pyrolysis of cellulose and hemicellulose in biomass by ring opening and side chain cracking reactions, while the relative content of phenolic substances obtained from catalytic reaction at 400 °C over CO2-activated char increased from 33.79% to 78.12% with the increasing char activation time from 0.5 to 2.0 h, resulting from the formation of more multiple active sites (including surface active groups and the pore characteristics) on activated char. When the catalytic reaction temperature reached 600 °C, the quality of the bio-oil was further improved since the relative content of aromatic hydrocarbons increased from 7.30% to 21.04% at the expense of elimination of some oxygen-containing compounds (e.g., ketones, acids, aldehydes, etc). Furthermore, the content of phenol in phenolic compounds increased from 26–64% to 51–97%.

Fast pyrolysis of pitch pine biomass in a bubbling fluidized-bed reactor for bio-oil production

The kinetic parameters for the pyrolysis of biomass of the pitch pine (Rigida pine P. Mill) were examined by thermogravimetric analysis in the temperature range 25°C to 700°C, in which the main decomposition was occurred from 250°C to 400°C. Pyrolysis of pitch pine has been investigated in a bubbling fluidized bed reactor. In this system, silica sand and nitrogen were used as the fluidizing bed material and fluidizing medium, respectively. The experimental was systemically performed on different temperature, fluidized velocity, and particle size of biomass. The optimum temperature condition at which the bio-oil yields reached the highest value (65.5%) was 500°C. In addition, the higher heating values of bio-oils from pitch pine biomass were reached in the range 22MJ/kg to 24MJ/kg. Moreover, this bio-oil had high content of useful chemicals including such as levoglucosan, furfural, and guaiacol. The large amount of C5–C11 (gasoline fraction) produced make the pyrolyzed oil originating from pitch pine trees a promising biofuel candidate.

Regulating light olefins or aromatics production in ex-situ catalytic pyrolysis of biomass by engineering the structure of tin modified ZSM-5 catalyst

Valorization of biomass to olefin or aromatics harbours tremendous practical value due to growing concerns about sustainable production of chemicals. Herein, the olefin or aromatics yields of ex-situ catalytic pyrolysis of pine can be regulated by impregnating Sn on hollow-structured ZSM-5 (M-ZSM-5) and microporous ZSM-5 catalysts in fixed-bed reactor, respectively. Results showed that Sn/ZSM-5 catalyst simultaneously increased medium acidic sites and maintained strong acidic sites, which obtained the maximum carbon yield of aromatics (33.77%) due to enhanced cracking and deoxygenation reactions. In addition, Sn boosted alkylation between olefin and aromatics, generating more alkylbenzene. In contrast, Sn/M-ZSM-5 catalyst produced the highest olefins carbon yield (12.39%) because the reduction of strong acidic sites and microporous volume inhibited the olefin aromatization. Moreover, olefins were easier to desorb from Sn/M-ZSM-5 due to the enhanced mass transfer ability, which weakened the alkylation reactions. The synergistic effect harbours great significance to manipulate the distribution of products.

Thermo-catalytic co-pyrolysis of biomass and high-density polyethylene for improving the yield and quality of pyrolysis liquid

The overall goal of this research was to study the effects of temperature and pine-to-HDPE ratios on the pyrolysis products. Catalytic co-pyrolysis of pine and HDPE was carried out in a double-column staged reactor, wherein the temperature was varied as 450 °C, 500 °C, and 550 °C for each pine/HDPE ratio of 0/100, 25/75, 50/50, 75/25, and 100/0. Thermal cracking of the feedstock is initiated at the first column, and the zeolitic-based ZSM-5 catalyst offered secondary cracking at a catalyst-to-feedstock ratio of 1:1 in the second column of the reactor. Catalytic pyrolysis of HDPE produced 31 wt% pyrolysis oil (40 MJ/kg calorific value) with a selectivity of above 90% toward gasoline-range hydrocarbons at 500 °C. Comparatively, pine offered 26.3% wt.% pyrolysis liquid yield with 7.9% dark pyrolysis oil (30 MJ/kg calorific value) that has a gasoline selectivity of 69.3%. Thus, the addition of HDPE increased the gasoline selectivity by increasing the hydrogen/carbon effective (H/Ceff) ratio. At pine/HDPE ratio of 25/75, the pyrolysis oil content was 22.5% at 500 °C, which is 3 times more than that of pine pyrolysis. The optimum yield and higher gasoline selectivity were observed at 500 °C for 0/100 and 25/75 pine to HDPE ratios.

Effect of pyrolysis temperature on pyrolysis of pine saw dust and application of bio-char

Pine saw dust as a typical forest residue is slowly pyrolyzed at 400–800 °C in a fixed bed system. The influence of pyrolysis temperature on the characteristics of bio-gas, bio-oil and bio-char is investigated and then to assess their potential uses. The result indicates that the yield of bio-gas increases as pyrolysis temperature increases, while the yield of bio-char decreases. The pyrolysis temperature does not have much effect on the yield of bio-oil. The bio-gas has high content of combustible gases (H2 + CO) and heating value with increase in pyrolysis temperature. The highest content of combustible gases is 76.96% with the highest heating value of 16.46 MJ/Nm3. The main identified compounds of bio-oil are the furfuran, alkane and phenol, respectively. Therefore, bio-oil can be used as the potential chemical materials in the food, chemical, pharmaceutical and other industries. The physiochemical properties of bio-char such as element content, and BET specific surface area have changed as pyrolysis temperature increases. Besides, bio-char could be potentially applied not only to remove Ag+ from aqueous solutions but also to produce a new value-added nanocomposite.

Optimizing Process Conditions during Catalytic Fast Pyrolysis of Pine with Pt/TiO2—Improving the Viability of a Multiple-Fixed-Bed Configuration

Catalytic fast pyrolysis (CFP) has been identified as a promising pathway for the production of renewable fuels and co-products. However, continued technology development is needed to increase proc...

Sustainable Development of Graphene Oxide from Pine Leaves for Electrochemical Energy Storage and Corrosion Protection

Present investigation demonstrates application of pine leaves as green friendly source for production of biochar (BC) that could to transformed into graphene oxide (GO) for sustained electrochemical energy storage (EES) and corrosion protection in KOH (2.0 M). For this purpose, BC was prepared through pyrolysis of pine leaves (moisture content 78.09 %) at 750 o C over 3 h in nitrogen environment. GO was synthesized through modification in Hammer’s method. Formation of BC and GO was ascertained through Fourier transform infrared, Raman and X-ray diffraction spectra. Working electrodes (WE) were fabricated from BC (WE BC ) and GO (WE GO ) in presence of hydroxy methyl propyl cellulose as binder and their morphologies were compared through scanning electron microscopy. WE were electrochemically analyzed through cyclic voltammetry (CV), electrochemical impedance spectra (EIS) and potentiodynamic polarization in KOH (2.0 M). CV @ 0.005 V/s in potential window of -0.71 V to -0.21 V reveals 390.4 F/g of Cs of WE GO that was 24.49 % improved over WE BC . EIS in frequency response (KHz) ranging 1.0 × 10 -5 Hz to 100 at ± 0.005 V reveals stability of WE over 24 h. Potentiodynamic polarization in the potential ranging -1.5 to 1.0 @ 0.005 V/s reveals corrosion rate (mm/year) of WE GO @ 4.69 × 10 -4 that was much reduced over WE BC (2.27 × 10 -3 ) under identical conditions.

Insight into Tar Formation Mechanism during Catalytic Pyrolysis of Biomass over Waste Aluminum Dross

Tar is one of major products from biomass pyrolysis. Its formation mechanism in a catalytic pyrolysis system comprising pine sawdust and waste aluminum dross (AD) is investigated with the aid of analytical methods including thermogravimetric analysis (TG), Nuclear Magnetic Resonance (NMR), electron paramagnetic resonance (EPR), and gas chromatography coupling with mass spectrometry (GC-MS). The results show that AD plays a vital role in cleavage of C-O bonds to enhance selective formation of furans, ketones, and phenols. The catalytic pyrolysis is initiated by active C-O-M intermediate formation that accelerates C-O bond cleavage and generates great amounts of free radicals to 1020 spins/g at 300–500 °C. Compared with pure pine pyrolysis, the percentage of glucosidic bonds from cellulose decreases from 14.00% to 9.66% at 500 °C; the etherified guaiacyl is more actively ruptured and disappears at 700 °C. Furans and ketones increase from 17.45% to 22.23% and 6.71% to 10.80% at 500 °C, respectively. Phenols increase from 66.75% to 71.57%. The preferential production of higher value-added products via catalytic pyrolysis between biomass and industrial wastes may bring new insight to the simultaneous valorization of agricultural, municipal, and industrial waste.

Catalytic Hydroprocessing of White Pine Pyrolysis Bio-Oil over Cobalt-Molybdenum Carbide in a Continuous Packed-Bed Reactor

Catalytic hydroprocessing of white pine pyrolysis bio-oil over cobalt-molybdenum (CoMo) carbide supported on biochar was carried out in a continuous fixed-bed reactor at a temperature between 350 and 425 °C, hydrogen pressure between 7 and 12.5 MPa, and liquid hourly space velocity (LHSV) of 0.1–1.0 h−1 with a hydrogen flow rate of 500 mL/min. The results showed that the CoMo carbide catalyst can effectively improve the yield and qualities of hydrotreated bio-oil. Under the preferred reaction conditions of 400–425 °C, 10 MPa H2, and LHSV 0.3 h−1, the yield, the carbon content, the carbon recovery ratio, and the higher heating value of the upgraded bio-oil reached 24.2–25.7% of the feed, 86.5–87.4%, 48.1–52.1%, and 41.8–43.9 MJ/kg, respectively. The oxygen content, total acid number, and moisture of the hydrotreated bio-oil decreased to 0.1–1.6 wt%, aromatics > olefins > paraffins > naphthenes.

Activated Carbons from Fast Pyrolysis Biochar as Novel Catalysts for the Post-Treatment of Pyrolysis Vapors, Studied by Analytical Pyrolysis

Biochars are attractive materials for carbon catalysts since their carbon content and surface area are relatively high and minerals present in biochar can act as active sites for catalytic reactions. In this study, biochars from the fast pyrolysis of birch, pine, and unbarked willow were activated and acid washed. These materials were tested as catalysts for a post-treatment of pine wood pyrolysis vapors, aiming at stabilizing the vapors before their condensation. All the unmodified biochars had high content of minerals, those being highest in willow due to the bark. After the activation treatments, the surface areas and pore volumes of all biochars significantly increased. All studied biochars and activated carbon catalysts reduced the oxygen content of the pyrolysis degradation products. This effect was more pronounced for compounds derived from polysaccharides vs. lignin. The most promising catalyst for vapor upgrading was unwashed activated carbon from willow, having high surface areas and pore volumes together with high mineral contents. These properties together promoted the high conversion of polysaccharide-derived products (anhydrosugars, acids, and pyrans) into CO2. Release of highly oxidized degradation products may indicate that reductive stabilization takes place via hydrogen migration from the polysaccharide-derivatives to lignin derivatives, mediated by the carbon catalyst.

Selective conversion of lignocellulosic biomass into furan compounds using bimetal-modified bio-based activated carbon: Analytical Py-GC×GC/MS

Bio-based activated carbon supported Cu, Al, Sn and their bimetals were devised to serve as solid acid catalysts for the pyrolysis of xylan to generate furan compounds, and their catalytic activity was evaluated by Py-GC × GC/MS. The Cu–Al/C catalysts with diverse Cu to Al ratios exhibited better performance in enhancing the content of furans and the selectivity of 2-MF compared with other catalysts. Among the series of Cu–Al/C catalysts, 4Cu–2Al/C achieved a content of furan compounds as high as 80.6%, and 2-MF, FF and furan were the major furan products with selectivity values of 44.0%, 30.0% and 15.8%, respectively. Furthermore, the catalyst also worked well in promoting the pyrolysis of xylose, glucose, cellulose and pine to produce furans, and the highest and lowest contents of furans were obtained from glucose (87.8%) and pine (70.1%), respectively. These results suggest the 4Cu–2Al/C obviously promotes the formation of furans, which is comparable to those of recently reported solid acid catalysts. Characterization with XRD, XPS, NH3-TPD, N2 adsorption-desorption, and SEM, demonstrated that the effective interactions between Cu species and Al species facilitated the dehydration of saccharides and the dehydrogenation of cyclopentanones to increase furan compounds. Al species, mainly Al2O3 were the major contributor to the Lewis acid sites, and Cu specie played an essential role in regulating the acidity and enhancing the selectivity of 2-MF. In addition to furans, 4Cu–2Al/C was found to have positive effects on hindering the formation of acids in the pyrolysis products.

Calcium formate assisted catalytic pyrolysis of pine for enhanced production of monocyclic aromatic hydrocarbons over bimetal-modified HZSM-5

An efficient process was developed to selectively produce monocyclic aromatic hydrocarbons (MAHs) from ex-situ catalytic fast pyrolysis (CFP) of pine assisted with calcium formate (CF) over bimetal-modified HZSM-5. Mo and another metal (Mg, Ga or Zn) were used to modify the HZSM-5, and the as-synthesized bimetal-modified HZSM-5 catalysts were utilized for both pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) and lab-scale CFP tests with CF as a hydrogen donor to selectively obtain MAHs. The results revealed that the presence of CF and Mg-Mo modified HZSM-5 (0.5Mg1Mo/HZ) exhibited excellent capability for MAHs production with tiny generation of polycyclic aromatic hydrocarbons (PAHs). The maximum MAHs yield attained 12.79 wt% at 650 °C from Py-GC/MS with the CF-to-pine (CF-to-PN) ratio of 3 and catalyst-to-pine (CA-to-PN) ratio of 11, and became 9.67 wt% from lab-scale device with CF-to-PN and CA-to-PN ratios of 0.5 and 4, respectively. In addition, compared with HZSM-5, 0.5Mg1Mo/HZ possessed better anti-deactivation ability.

Gas fuel production derived from pine sawdust pyrolysis catalyzed on alumina

AbstractPyrolysis gas release behaviour, including hydrogen, CH4, CO and CO2 from pine pyrolysis, is collected from fixed bed reactor and analyzed by gas chromatography (GC). Pyrolysis tar composition is monitored using GC coupled with a mass spectrometer (GC–MS). The gas generation mechanism of catalytic pyrolysis on alumina is elaborated. The carbon structure of char is quantitatively determined by carbon‐13 nuclear magnetic resonance (13C‐NMR) using curve‐fitting methods. The results show influence of alumina on gas fuel production is mainly embodied in absorption and catalytic effect. Steam reforming reaction to gas fuel is accelerated with alumina added during pine pyrolysis. Alumina addition accelerates the decomposition of carbonate and side chains of aromatic ring in lignin below 500°C and prolong the residence time of second pyrolysis. The CH4 release rate reaches to peak value at 500°C during pyrolysis. The H2 increases from 98.95 to 120.19 ml/g with mass ratio of 1/4 (alumina/pine). The CO release rate has a certain increment with the alumina added. These data are the foundation for putting forward a new direction for the reuse of organic and industrial solid wastes enriched with alumina to achieve the goal on energy regeneration.

Detailed Oil Compositional Analysis Enables Evaluation of Impact of Temperature and Biomass-to-Catalyst Ratio on ex Situ Catalytic Fast Pyrolysis of Pine Vapors over ZSM-5

The impact of upgrading temperature and biomass-to-catalyst mass ratio on upgrading pine pyrolysis vapors over HZSM-5 was studied in a dual fluidized bed reactor system. Increasing the upgrading te...

Selective production of monocyclic aromatic hydrocarbons from ex situ catalytic fast pyrolysis of pine over the HZSM-5 catalyst with calcium formate as a hydrogen source

A new protocol using calcium formate as a hydrogen source for preparing monocyclic aromatic hydrocarbons from biomass has been developed.

Selective preparation of monocyclic aromatic hydrocarbons from ex-situ catalytic fast pyrolysis of pine over Ti(SO4)2-Mo2N/HZSM-5 catalyst

To selectively produce monocyclic aromatic hydrocarbons (MAHs) with low amount of polycyclic aromatic hydrocarbons (PAHs), modified HZSM-5 catalysts (Mo2N/HZSM-5, Ti(SO4)2/HZSM-5 and Ti(SO4)2-Mo2N/HZSM-5) were prepared and employed for ex-situ catalytic fast pyrolysis (CFP) of pine wood. Both analytical pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) and lab-scale pyrolysis experiments were conducted to investigate the effects of catalyst, pyrolysis temperature and catalyst-to-pine ratio on the distribution of aromatic hydrocarbon products. Py-GC/MS results showed that the maximal MAHs yields from the HZSM-5, Mo2N/HZSM-5, Ti(SO4)2/HZSM-5 and Ti(SO4)2-Mo2N/HZSM-5 catalysts were 7.57 wt%, 8.11 wt%, 8.71 wt% and 12.53 wt% at 650 °C and catalyst-to-pine ratio of 7. Corresponding PAHs yields from the four catalysts were 2.55 wt%, 0.97 wt%, 1.47 wt% and 1.10 wt%, which clearly indicated that the Ti(SO4)2-Mo2N/HZSM-5 significantly increased MAHs formation and decreased PAHs formation as compared with HZSM-5. Furthermore, lab-scale experiments were conducted to quantitatively determine the pyrolytic product distribution. Results showed that Ti(SO4)2-Mo2N/HZSM-5 catalyst increased the yield of liquid and gas products, and decreased solid products as compared with HZSM-5. Under optimal conditions of 650 °C and catalyst-to-pine ratio of 4/3, the actual yields of MAHs and PAHs from Ti(SO4)2-Mo2N/HZSM-5 catalyst were 9.71 wt% and 1.45 wt%, respectively. In addition, stability tests confirmed that the Ti(SO4)2-Mo2N/HZSM-5 catalyst possessed better effects on MAHs production as well as anti-deactivation than the HZSM-5.

Isolation and Purification of Monofunctional Methoxyphenols from Loblolly Pine Biocrude

Methoxyphenols (MPs) are valuable chemicals in liquid intermediates from pyrolysis of lignocellulosic biomass. The use of a single technique to recover a high-purity bioproduct of MPs from pyrolysis liquid is challenging. The purpose of this study is to combine distillation and chromatography techniques in sequence to recover exclusively eugenols and guaiacols as monofunctional MPs in biocrude produced from the pyrolysis of loblolly pine with a nonzeolite alumina catalyst. A biocrude containing 11.0 wt % of the targeted monofunctional MPs was first distilled in two stages to recover an MP-rich fraction with 49.3 wt % concentration of MPs at a recovery efficiency of 86.9%. A chromatography separation using silica gel adsorbent was then used to purify the MP-enriched distillate. A final MP bioproduct with average purity of 87.3–93.1 wt % was achieved. The average efficiency of the chromatography separation step varied between 73.9 and 82.5% depending on the silica particle size used.