Pyrolysis Characteristics Of Biomass Research Articles

Evaluation on thermal pyrolysis of biomass straw waste: Focusing aspects of products yields, syngas emissions and solid products characterization

AbstractIn this study, a systematic and quantitative investigation of the pyrolysis characteristics of biomass was conducted in a fixed‐bed tubular reactor, and the influence of pyrolysis temperature on product yields, gas emission characteristics, and syngas compositions as well as physicochemical characterization of resulting solids (i.e., char/ash morphologies, mineral transformations, and elemental compositions) was explored in detail. The pyrolysis experiments were performed under N2, and the resulting solid characterization was detected by XRD, SEM, and EDX. The results indicated that with increasing the pyrolysis temperature from 400 to 800°C, the gaseous product yields increased from 54.9% to 66.7%, while the solid product yield showed a reverse trend, varying within 27.7%–40.5%. Meanwhile, the volume fraction of H2 in syngas increased from 7% to 33%, while the CO2 presented an opposite trend, suggesting that high temperature favored H2 formation and inhibited CO2 formation. On the whole, the CO and CO2 emissions were prior to CH4, H2, and CnHm in sequence. A large amount of sylvite (KCl), quartz (SiO2), dolomite (CaMg(CO3)2), and pyroxene (CaMgSi2O6) in the resulting solids were identified in crystal phases. Higher pyrolysis temperature had a significant influence on solid microstructures, resulting in a relatively higher slagging tendency due to low melting eutectics containing K‐rich and Ca‐rich minerals.

Effect of aqueous phase bio-oil and its typical organic matter washing pretreatment on catalytic pyrolysis characteristics of biomass

In this work, APBO and its typical organic matter (HAc, Phenol, Guaiacol) were used to pretreat wheat straw separately, and CFP characteristics of wheat straw before and after the pretreatment were investigated. Washing with four different solutions removed more than 95% of K+ and over 86% removal of Na+; the removal effect of APBO on Ca2+ and Mg2+ is more evident with more than 84%. Washing reduced AAEMs, thereby reducing acids and ketones and increasing sugars in the bio-oil. TGA demonstrated that different washing significantly increased wheat straw's maximum weight loss rate and overall weight loss rate. After the subsequent addition of HZSM-5 catalyzed pyrolysis, the level of oxygen-containing compounds in bio-oil was significantly reduced and the aromatic hydrocarbon level increased from 2.19% (R) to 14.89% (CR), 31.28% (APBO-CR), 25.9% (HAc-CR), 24.74% (Phenol-CR), 15.81% (Guaiacol-CR), and the highest selectivity was 54.57% for BTX (APBO-CR). The combined APBO washing and HZSM-5 is a potential technology for upgrading biomass and the liquid products of pyrolysis because it can effectively raise bio-oil quality.

Kinetics and thermodynamic study of Calligonum polygonoides pyrolysis using model-free methods

Pyrolysis kinetics was carried out for Calligonum polygonoides (C. Polygonoides) in an inert atmosphere at three different heating temperatures such as 10, 15, and 20 °C/min using thermogravimetric analysis. Physicochemical properties were studied using bomb calorimeter, elemental analyzer, and Fourier Transform Infrared Spectroscopy. C. Polygonoides have a calorific value of 16.33 MJ/kg. Gas chromatography–mass spectrometry was used to identify gases produced during pyrolysis. Thermogravimetric analysis was used to investigate the pyrolysis characteristics of biomass. Activation energy for the three zones of pyrolysis were determined using Kissinger and Ozawa model-free methods. Activation energy calculated for zone I, zone II and zone III using Ozawa and Kissinger model was 133.73, 164.50, 254 KJ/mol and 135.61, 165.88, and 253.00 KJ/mol, respectively. Thermodynamic parameters such as enthalpy, entropy, and Gibbs free energy were calculated for the three different zones. Kinetic and thermodynamic study confirmed that C. Polygonoides can be used as useful and potential bioenergy feedstock.

Product characteristics of rice straw pyrolysis at different temperature: Role of inherent alkali and alkaline earth metals with different occurrence forms

The inherent alkali and alkaline earth metals (AAEMs) in biomass have a significant impact on biomass pyrolysis. However, the catalytic effects of water-soluble (WAM), ion-exchanged (IAM) and acid-soluble alkali metals (AAM) on properties of products are still unclear. In this study, pyrolysis characteristics of biomass containing different intrinsic AAEMs were performed in a fixed-bed reactor at different temperatures. The results showed that the effects of AAEMs on char characteristic and on bio-oil composition were influenced by temperature, but their effects on product yield were independent of temperature. Almost all the Na released in water-soluble form below 400 °C, but part of K element still remained in the chars even at 750 °C, which played a catalytic role in the release of volatiles at high temperature. IAM promoted the formation of C–O groups and reduced the production of CO groups in chars prepared at low temperature. At the range of 400–750 °C, WAM and IAM suppressed the formation of esters, while AAM promoted the production of ketones and aldehydes. WAM had a positive effect on the formation of phenols, while IAM and AAM showed negative influence on phenol production at 750 °C. In addition, WAM, IAM and AAM had different effects on gas composition at different temperatures.

Pyrolysis kinetics of potassium-impregnated rubberwood analyzed by evolutionary computation

To explore the catalytic effect of potassium on pyrolysis characteristics of biomass, the rubberwood is pyrolyzed by a thermogravimetric analyzer. The samples are impregnated by three concentrations of potassium carbonate (0.004 M, 0.008 M, and 0.012 M). The pyrolysis kinetics is analyzed by an independent parallel reaction (IPR) model to describe the catalytic effect on the four-pseudo components model in the rubberwood. The particle swarm optimization (PSO) is adopted to optimize the fit quality between the established kinetic models and experimental data. It is found that the pyrolysis of rubberwood impregnated with 0.012 M concentration of K2CO3 can reduce the activation energy of cellulose from 223.86 to 204.14 kJ mol−1, whereas there is no obvious effect on the activation energies of hemicelluloses and lignin. The starting temperature and ending temperature of cellulose thermodegradation also move toward lower temperatures, indicating that the addition of potassium enhances the degradation of cellulose.

Pyrolysis of saw dust with co-feeding of methanol

Abstract Reaction atmosphere is one of the principle parameters affecting pyrolysis characteristics of biomass. In this study, instead of feeding reactive gases, methanol was co-fed in the pyrolysis of saw dust, aiming to understand the impacts of methanol on evolution of functionalities/structures of the major pyrolysis products. The results showed that at low pyrolysis temperature of 350 °C, methanol did not affect much on the charring reactions but promoted the formation of the heavier organics. At 500 or 650 °C, the co-feeding of methanol enhanced the yields of both char and the heavy components of bio-oil, resulting from the reaction of methanol or its derivatives with the organic components on surface of biochar via recombination/condensation reactions. In addition, methanol enhanced evolution of the organics with π-conjugated structures. The co-feeding of methanol also enhanced crystallinity and sizes of the crystal carbon in the biochar, but led to their lower thermal stability. The in situ Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS) characterization of saw dust pyrolysis indicated that methanol promoted the aliphatic structures formation on surface of the biochar, leading to the low thermal stability.

Thermogravimetric analysis and reaction kinetics of lignocellulosic biomass pyrolysis

The elucidation of the biomass pyrolysis characteristics will provide valuable guidance for the design of pyrolysis devices. The pyrolysis kinetics characteristics of lignocellulosic biomass were studied by thermogravimetric analysis, and the main influencing factors, including biomass particle size, heating rate, and metal ion, were investigated. With a decrease in the particle size of rice straw and pine sawdust, the initial and final pyrolysis temperatures and the temperature of the maximum weight loss ratio decreased. Opposite results were obtained for Phoenix tree leaves. Furthermore, the initial release temperature of volatile matter and the temperature corresponding to the peak of the derivative thermogravimetric curves increased with an increase in heating rate. Moreover, the pyrolysis activity of rice straw decreased significantly after deashing but increased with the addition of potassium. The pyrolysis kinetics parameters were calculated by the Coats–Redfern, Doyle, and the distributed activation energy model (DAEM) methods. The apparent activation energy of pyrolysis was the lowest, varying between 30 and 70 kJ/mol, according to the fitting results of the Coats–Redfern method. The apparent activation energies calculated by the DAEM and Doyle methods are similar, and are 67.6, 245.8, and 271.8 kJ/mol for rice straw, pine sawdust and Phoenix tree leaves, respectively.

Pyrolysis Characteristics of Biomass Impregnated with Cadmium, Copper and Lead: Influence and Distribution

It is critical to dispose and reuse metal-contaminated biomass. In this study, pyrolysis technology was used for processing metal contaminated biomass from Arundo donax and Broussonetia papyrifera impregnated with cadmium (Cd), copper (Cu) and lead (Pb). The results showed that metal-impregnated biomass can be pyrolyzed completely, as confirmed by a thermal gravimetric analyzer analysis. From the start to 200 °C, a dehydration reaction occurred. The decomposition of biomass reacted extensively from 200 to 450 °C, and more than 60% of the mass was lost. The mass of solid residue of the biomass loaded with Cd, Cu and Pb was 4.7% (A. donax ) and 7.5% (B. papyrifera) respectively lower than that of the unloaded biomass, which could have contributed to the lowering of the activation energy of the pyrolyzed biomass. The activation energy of A. donax pyrolyzed was reduced by approximately 1.85–3.84 kJ/mol, while that of B. papyrifera was 0.93–13.28 kJ/mol. More than 67.76% of the heavy metals in the biomass were retained in the solid phase, and uniformly distributed in the pore structure. However, the cellulose crystallinity of the biochar was decreased, therefore causing the disordering of the amorphous carbon phase of the carbon structure. The results suggested that heavy metals in biomass can lower the difficulty of the reaction, and most of the heavy metals remained in the solid phase, indicating that pyrolysis is an interesting technology to process metal-contaminated biomass.

Effects of the cellulose, xylan and lignin constituents on biomass pyrolysis characteristics and bio-oil composition using the Simplex Lattice Mixture Design method

In order to clarify the relationships between biomass pyrolysis mechanism and its main constituents. The effects of main constituents on biomass pyrolysis characteristics were firstly determined by thermo-gravimetric analysis based on the Simplex Lattice Mixture Design to investigate that whether the prediction of the pyrolysis behavior of a certain lignocellulosic biomass is possible when its main constituent contents are known. The results showed that there are constituent interactions in the pyrolysis process, which can be intuitively reflected through the change laws of kinetics parameters. The mathematical models for calculating kinetics values were established, and the models were proved to be valid for predicting lignocellulosic biomass pyrolysis behavior. In addition, the effects of biomass constituents on bio-oil compositions were explored by subsequent vacuum pyrolysis experiments. The xylan pyrolysis had a certain inhibitory effect on the pyrolysis of cellulose, and the pyrolysis products of lignin might promote the further decomposition of sugars from cellulose pyrolysis, while the interaction between xylan and lignin had a little effect on the bio-oil composition.

TC2015] fast pyrolysis characteristics of biomass in a conical spouted bed reactor

In this study, the hydrodynamics of the conical spouted bed reactor was examined to find out stable spouting regime and appropriate gas residence time. And the effects of pyrolysis reaction temperature for the production of the bio‐oil in a conical spouted bed reactor were scrutinized by fast pyrolysis experiment. Stable hydrodynamic operating ranges were identified by evaluation of the pressure drop curve and RMS analysis. The yield of the bio‐oil reached a maximum of 50.8 wt % at reaction temperature of 500°C, while the yield of the char decreased as the reaction temperature increased. Also, the yield of the non‐condensable gas increased when the reaction temperature increased. The water content of the bio‐oil was lowest, 26.1wt %, at 500°C, and the high heating value was highest, 18.4 MJ/kg, at 500°C. © 2016 American Institute of Chemical Engineers Environ Prog, 36: 685–689, 2017

Study on Pyrolysis Characteristics of Biomass with TG-FTIR

The thermal gasification characteristics of biomass straw would be studied with thermo gravimetric (TG), and Fourier Transform Infrared Spectroscopy (FTIR) is used for the real-time monitoring on gasification products during biomass pyrolysis. By the method of thermo gravimetric analyzer combined with Fourier Transform Infrared Spectroscopy experiment. Pyrolysis characteristics and products of biomass straw were experimental explored and analyzed to get pyrolysis characteristics of experimental samples and reaction products, which provided based professional information for effective utilization of biomass straw.

Experimental Research of Biomass Pyrolysis Characteristics at Low Temperature

The pyrolysis characteristics for two types biomass material was tested at 230°C~250°C, and the pyrolysis product component was on-line analyzed by using moisture micro-detection teller, gas chromatograph-mass spectrometer computer and fourier transform infrared spectroscopy. Besides, two different algorithms were used to evaluate the test error. In addition, the generated tar gas was secondary decomposed at 800°C. It is found that the tar was broken up completely, which increased the hydrogen content sharply in the pyrolysis gas. The test data shows that the heat value of cotton stalk improves better than that of the corn stalk after pyrolysis, so it is more suitable for cotton stalk than corn stalk to improve the value in use by means of low temperature pyrolysis technology.

The pyrolysis simulation of five biomass species by hemi-cellulose, cellulose and lignin based on thermogravimetric curves

The thermal behavior of five biomass species was investigated using a thermogravimetric analyzer (TGA). The investigation showed that the hemi-cellulose in fruit vegetable biomass differed from that in wood biomass. The cellulose in different materials except Chinese cabbage presented coincident properties while different lignin varied greatly because of various monomers. The thermogravimetric curve overlap ratio was applied to evaluate the simulation of biomass by hemi-cellulose, cellulose and lignin. The results indicated that biomass pyrolysis characteristics could be well simulated by its components and the results from the overlap ratio were compared with the content derived from chemical separation. The temperature was programmed to divide each phase of biomass pyrolysis to investigate further components ratio in biomass mass loss process. The results suggested that fruit vegetable biomass contained more hemi-cellulose and less lignin than wood biomass, and poplar wood contained the largest amount of cellulose.

Effect of high CO2 concentration on char formation through mineral reaction during biomass pyrolysis

O2/CO2 combustion has attracted considerable attention as a promising technology for CO2 capture. Using biomass for fuel is considered carbon neutral, and O2/CO2 biomass combustion can mitigate the deleterious environmental effect of greenhouse. In this study, the effect of CO2, the main component gas in O2/CO2 combustion, on the pyrolysis characteristics of biomass is investigated. Cellulose, lignin, and metal-depleted lignin pyrolysis experiments were performed using a thermobalance. Information on the surface chemistry of the chars was obtained by Fourier transform infrared (FTIR) spectroscopy to investigate changes in the surface chemistry during pyrolysis under different surrounding gasses. When the temperature increased to 1073K at heating rate of 1Ks−1, the char yield of lignin in the presence of CO2 increased by about 10% compared with that under Ar. However, for cellulose and metal-depleted lignin, no significant difference appeared between pyrolysis under CO2 and that under Ar. FT-IR showed that a strong peak corresponding to carbonate ions appeared in the char derived from lignin under CO2. Therefore, salts such as Na2CO3 or K2CO3 formed during the lignin pyrolysis under CO2. At around 1650–1770cm−1, a significant difference appeared in the FTIR spectra of chars formed under CO2 and those formed under Ar. C=O groups not associated with an aromatic ring were found only in chars formed under CO2. It was suggested that these salts affected the char formation reaction, in that the char formed during lignin pyrolysis under CO2 had unique chemical bands that did not appear in the lignin-derived char prepared under Ar.

Bio-oil production by pyrolysis of biomass using hot blast furnace slag

Abstract In this paper, a new concept of a heat recovery system from blast furnace (BF) slag was proposed, which would generate bio-oil and combustible gas, and a direct contacting continuous operational pyrolysis reactor was designed to evaluate the feasibility. In addition, the influences of temperature and particle size of BF slag on pyrolysis characteristics of biomass were discussed. The results showed that bio-oil production by pyrolysis of biomass using waste heat from hot BF slag was reliable. In order to achieve a high bio-oil yield, moderate temperature, smaller BF slag particles and biomass particles were required. At temperature of 650 °C, BF slag with particle sizes below 2 mm and biomass particle sizes below 0.075 mm were used as test samples, the maximum bio-oil yield reached 57.3%.

Influence of the interaction of components on the pyrolysis behavior of biomass

There has been much interest in the utilization of biomass-derived fuels as substitutes for fossil fuels in meeting renewable energy requirements to reduce CO 2 emissions. In this study, the pyrolysis characteristics of biomass have been investigated using both a thermogravimetric analyzer coupled with a Fourier-transform infrared spectrometer (TG-FTIR) and an experimental pyrolyzer. Experiments have been conducted with the three major components of biomass, i.e. hemicellulose, cellulose, and lignin, and with four mixed biomass samples comprising different proportions of these. Product distributions in terms of char, bio-oil, and permanent gas are given, and the compositions of the bio-oil and gaseous products have been analysed by gas chromatography–mass spectrometry (GC–MS) and gas chromatography (GC). The TG results show that the thermal decomposition of levoglucosan is extended over a wider temperature range according to the interaction of hemicellulose or lignin upon the pyrolysis of cellulose; the formation of 2-furfural and acetic acid is enhanced by the presence of cellulose and lignin in the range 350–500 °C; and the amount of phenol, 2,6-dimethoxy is enhanced by the integrated influence of cellulose and hemicellulose. The components do not act independently during pyrolysis; the experimental results have shown that the interaction of cellulose and hemicellulose strongly promotes the formation of 2, 5-diethoxytetrahydrofuran and inhibits the formation of altrose and levoglucosan, while the presence of cellulose enhances the formation of hemicellulose-derived acetic acid and 2-furfural. Pyrolysis characteristics of biomass cannot be predicted through its composition in the main components.

升温速率对生物质与煤共热解特性影响的试验研究<br>Experiment for Heating Rate on Pyrolysis Characteristics of Biomass-coal Mixture

采用热重分析法，在不同升温速率下，对生物质、煤以及生物质与煤的混合物进行热解试验，分析了升温速率对热解过程的影响，研究了生物质与煤热解特性的差异以及他们共热解时生物质对煤热解过程的影响。试验结果表明，随着升温速率的升高，热重曲线向温度高侧移动，生物质与煤的热解特性差异很大，并且在生物质与煤混合热解时，总体热解特性分阶段呈现生物质与煤的热解特性。 The pyrolysis experiment on biomass, coal and biomass-coal mixture with various heating rates were carried out and analyzed by thermo-gravimetric analysis method. The effects of heating rates on the process of pyrolysis characteristics of biomass, coal and biomass-coal mixture were obtained and analyzed. The experiment results showed that the thermo-gravimetric curves move to the high-side of temperature while heating rate increases, there is a large different characteristic between biomass and coal, and the pyrolysis characteristic of biomass-coal mixture occur separately the characteristics of biomass or coal at different stages.

3-12 動力学因子分布に基づくバイオマス熱分解特性の評価((3)ガス化3,Session 3 バイオマス等)

3-12 動力学因子分布に基づくバイオマス熱分解特性の評価((3)ガス化3,Session 3 バイオマス等)

97/00499 Pyrolysis characteristics of biomass and biomass components

Biomass pyrolysis studies were conducted using both a thermogravimetric analyser and a packed-bed pyrolyser. Each kind of biomass has a characteristic pyrolysis behaviour which is explained based on its individual component characteristics. Studies on isolated biomass components as well as synthetic biomass show that the interactions among the components are not of as much significance as the composition of the biomass. Direct summative correlations based on biomass component pyrolysis adequately explain both the pyrolysis characteristics and product distribution of biomass. It is inferred that there is no detectable interaction among the components during pyrolysis in either the thermogravimetric analyser or the packed-bed pyrolyser. However, ash present in biomass seems to have a strong influence on both the pyrolysis characteristics and the product distribution.

96/05117 Pyrolysis characteristics of biomass and biomass components

96/05117 Pyrolysis characteristics of biomass and biomass components