Yield Of Pyrolysis Products Research Articles

Influence of the heat loss intensity on the characteristics of the filtration combustion of solid organic fuels

The effect of lateral heat loss on the characteristics of the filtration combustion of solid organic fuels is studied experimentally and theoretically. The results show that, for an reaction trailing, an increase in the heat loss intensity leads to a marked reduction in the combustion temperature and an increase in the temperature at which fuel pyrolysis is complete, with the yield of liquid pyrolysis products remaining practically unchanged. For a reaction leading, an increase in the heat transfer coefficient causes a reduction in the combustion temperature and the yield of liquid pyrolysis products.

Pyrolytic Processing of Cellulose-Containing Wastes from Food Industry Plants

A possible thermal process for disposal of wastes from the brewing and sugar industries was studied. Information on the yields of secondary pyrolysis products (pyrogas, pyroliquid, solid residue) as a function of changes in the processing parameters was obtained. Pyrogas consisting of H2, CO, CO2, CH4, and saturated and unsaturated C2–C5 fractions had a heat of combustion of 1.79 and 1.65 MJ/m3 for spent grain and sugar-beet pulp, respectively. A universal unit allowing any type of waste with various quantities of added hydrocarbon waste to be processed was developed.

Effect of operating parameters on production of bio-oil from fast pyrolysis of maize stalk in bubbling fluidized bed reactor

AbstractThe yield and composition of pyrolysis products depend on the characteristics of feed stock and process operating parameters. Effect of particle size, reaction temperature and carrier gas flow rate on the yield of bio-oil from fast pyrolysis of Pakistani maize stalk was investigated. Pyrolysis experiments were performed at temperature range of 360-540°C, feed particle size of 1-2 mm and carrier gas fl ow rate of 7.0-13.0 m3/h (0.61.1 m/s superficial velocity). Bio-oil yield increased with the increase of temperature followed by a decreasing trend. The maximum yield of bio-oil obtained was 42 wt% at a temperature of 490°C with the particle size of around 1.0 mm and carrier gas flow rate of 11.0 m3/h (0.9 m/s superficial velocity). High temperatures resulted in the higher ratios of char and non-condensable gas.

Co-pyrolysis of sugarcane bagasse and low-density polyethylene: Influence of plastic on pyrolysis product yield

The aim of this study was to investigate the effect on plastic during co-pyrolysis with biomass. Pyrolysis of sugarcane bagasse (SCB), low density polyethylene (LDPE), and their mixtures of different ratios was carried out in a semi-batch reactor with varying temperatures ranging from 350 to 600°C at a heating rate of 20±1°C/min. The maximum liquid product yields for the pyrolysis of SCB and LDPE obtained were 47.15% and 74.40%, respectively, whereas the maximum liquid product yield for SCB/LDPE co-pyrolysis was 52.75% at 500°C with 1:1 blend ratio. A significant improvement of the calorific value has been observed for the co-pyrolytic oil in comparison with SCB pyrolytic oil. The results of GC–MS and FTIR analysis confirmed the interaction between SCB and LDPE during co-pyrolysis, which resulted into a decreasing amount of oxygenated compounds, phenol and acidic compounds, makes the co-pyrolysis process more favorable for the production of high calorific value fuel.

Coupled reactor and particle model of biomass drying and pyrolysis in a bubbling fluidized bed reactor

A comprehensive single particle model of biomass drying and pyrolysis is coupled with an ideal reactor model of a bubbling fluidized bed with nitrogen as the fluidizing gas. To predict biomass pyrolysis products yield and composition under steady-state operation, a two-step biomass pyrolysis kinetic mechanism is adopted with primary pyrolysis described by two different reaction kinetic schemes: (a) Three parallel first-order reactions producing primary pyrolysis products (non-condensable gas, tar/bio-oil and char), and (b) a detailed solid state kinetics mechanism based on multiple reactions of lignin, cellulose, and hemicellulose contents of two specific types of biomass (poplar and lodgepole pine). Secondary pyrolysis is modeled by two parallel reactions describing homogeneous thermal cracking of tar to non-condensable gas and char. In addition to the yields of pyrolysis products often modeled as lumped species, this model addresses an existing gap of knowledge in predicting the proportions of major compounds in the pyrolysis gas based on a few simplifying assumptions and CHO elemental balances. This predictive model is a useful tool to relate biomass pyrolysis products yield and composition to process operating parameters such as biomass ultimate analysis, reactor temperature, gas residence time, mean solids residence time inside the reactor, as well as biomass particle size and moisture content. Model predictions for the two kinetic schemes are in good agreement with available experimental data from the literature.

Influence of temperature and residence time in the pyrolysis of woody biomass waste in a continuous screw reactor

The aim of this paper is to study the influence of temperature and residence time in the quality of the charcoal obtained in the pyrolysis of biomass waste, in order to be used as a reducing agent in metallurgical applications. Woody biomass waste (pinus pinaster) coming from forest activities carried out in the north of Spain has been pyrolyzed in a laboratory scale screw continuous reactor connected to a second reactor where the pyrolysis vapors have been thermally treated to promote further cracking, with the aim of diminishing tars and improving the composition of the gas phase.Both the peak temperature and the exposition time at peak temperature have an impact in the pyrolysis fractions yields and composition, however it is at 1173 K where the bigger changes occur both in pyrolysis products yield and composition. In all cases the solids obtained (charcoal) fulfill the requirements to perform as metallurgical reducers. The higher the peak temperature the greater the charcoal quality but the lower the pyrolysis solid yield since secondary pyrolysis reactions consume charcoal. The pyrolysis gases obtained are valuable products rich in CO (22–35 vol%) and hydrogen (35–50 vol%); on the contrary, the pyrolysis liquids obtained are mainly worthless products composed of water and some aromatic compounds (e.g. naphthalene, fluorene & antrhacene).

The effect of added minerals on the pyrolysis products derived from a vitrinite-rich demineralised South African coal

A better understanding of the behaviour of the inorganic matter present in coal will assist in more cost-effective operations and more consistency in product yield and composition during thermal processing. In this study, the effect of specific major coal minerals on pyrolysis product yield and composition was determined. 5wt% calcite, dolomite, kaolinite, pyrite, or quartz was added to an acid washed South African medium rank C bituminous coal fraction and pyrolysed using a modified Fischer Assay procedure, using stainless steel retorts, and temperatures of 520°C, 750°C and 900°C. It was found that mineral activity decreased in the order calcite/dolomite ≫ pyrite > kaolinite ⋙ quartz. Calcite and dolomite addition led to a highly significant decrease in tar yield, and tar producers should note this finding as the presence of these minerals in the coal feedstock could have a considerable effect on the tar yield and composition at their operations. Detailed characterization of the measured pyrolysis products provided valuable insight and data for the development of a pyrolysis yield and compositional model based on mineral addition.

Influence of process conditions on product yield of waste tyre pyrolysis- A review

Waste tyres have become a grave concern as their accumulation is aggregating every year. Not only the size of waste tyre has to be reduced, but also some useful energy has to be recovered out of it as the world badly requires energy from alternate sources. Pyrolysis is one such method to extract energy potential products from waste tyres. It is extensively used to generate carbon black (solid product), tyre-oil (liquid product) and syngas (gas product) from waste tyres. In that connection, this article discusses the effect of various parameters on the product composition of pyrolysis of waste tyres. The current usage of pyrolysis products and their typical characteristics are also discussed in this critique. Of late, extraction of high value added products, such as activated carbon from carbon black, and limonene from tyre-oil is gaining attention. The article also throws some light on the application and generation routes of activated carbon and limonene from waste tyres.

Flash pyrolysis of palmyra palm (Borassus flabellifer) using an electrically heated fluidized bed reactor

ABSTRACTAgriculture residues such as palmyra fruit bunch are one of the biomass categories that can be utilized for conversion to bio-oil by using pyrolysis process. Flash pyrolysis experiments have been conducted in the electrically heated fluidized bed reactor to determine the effect of pyrolysis temperature, particle size, and sweep gas flow rate on the pyrolysis product yield. In this study the maximum oil yield of 48.2% was achieved at a temperature of 500°C, particle size of 1 mm, and at a sweep gas flow rate of 2 m3/h. The results show that the effects of pyrolysis temperature and particle size on pyrolysis yields are more significant than that of sweep gas flow rate. Bio-oil was identified as a biofuel candidate and it was further upgraded for better-quality biofuel. Various physical and elemental analyses were performed for bio-oil and the same characteristics study was also carried out for biofuel.

Effect of torrefaction pretreatment and catalytic pyrolysis on the pyrolysis poly-generation of pine wood

Torrefaction of pine wood was performed in a tube furnace at three temperatures (220, 250, and 280°C) for 30min. Then catalytic pyrolysis of raw and torrefied pine wood was performed using HZSM-5 catalyst in a fixed-bed pyrolysis reactor at 550°C for 15min. Torrefaction pretreatment and catalytic pyrolysis have an very important effect on the yield, property, and energy distribution of pyrolysis products. The results showed that the yield of biochar rapidly increased, while that of bio-oil decreased with increasing torrefaction temperature. The oxy-compound content of bio-oil, such as acids and aldehydes, sharply decreased. However, the aromatic hydrocarbon content not only increased but also further promoted by HZSM-5 catalyst. With highest mass yields and energy yields, biochar was also the very important product of pyrolysis. The oxygen content in biomass was mainly removed in the form of CO2 and H2O, leading to increasing CO2 content in non-condensable gas.

Microwave pyrolysis of oily sludge with activated carbon

ABSTRACTThe aim of this study is to explore catalytic microwave pyrolysis of crude oil storage tank sludge for fuels using granular activated carbon (GAC) as a catalyst. The effect of GAC loading on the yield of pyrolysis products was also investigated. Heating rate of oily sludge and yield of microwave pyrolysis products such as oil and fuel gas was found to depend on the ratio of GAC to oily sludge. The optimal GAC loading was found to be 10%, while much smaller and larger feed sizes adversely influenced production. During oily sludge pyrolysis, a maximum oil yield of 77.5% was achieved. Pyrolytic oils with high concentrations of diesel oil and gasoline (about 70 wt% in the pyrolytic oil) were obtained. The leaching of heavy metals, such as Cr, As and Pb, was also suppressed in the solid residue after pyrolysis. This technique provides advantages such as harmless treatment of oily sludge and substantial reduction in the consumption of energy, time and cost.

Catalytic effect of tin oxide nanoparticles on cellulose pyrolysis

In this study, SnO2 nanoparticles were synthesized via hydrothermal method and used as a catalyst for cellulose (model biomass) pyrolysis. Effect of catalyst on the yields of pyrolysis products was discussed in details. Optimum catalyst to biomass ratio was found as %5 (w/w). The pyrolytic oil (tar) was characterized by Gas chromatography–Mass spectrometry (GC–MS) while the gaseous products were characterized with micro Gas Chromatography (μGC) to understand the catalytic ability of SnO2 nanoparticles. The results indicate that gaseous product yields significantly increase while the char yield decreases. Although the tar yields don’t change significantly in the uncatalysed runs, the product distribution in tar decreases in the presence of catalyst.

Combination of Light Bio-oil Washing and Torrefaction Pretreatment of Rice Husk: Its Effects on Physicochemical Characteristics and Fast Pyrolysis Behavior

A combination of light bio-oil washing and torrefaction pretreatment of rice husk samples was proposed in this study, to investigate the impact on physicochemical characteristics and fast pyrolysis behavior. The results indicated that pretreatment removed a significant percentage of metallic species and significantly improved the fuel characteristics of rice husk samples. Fourier transform infrared spectroscopy (FTIR) analysis indicated that some organic groups decomposed by dehydration and decarboxylation reactions during the process of torrefaction pretreatment. The results of fast pyrolysis indicated that the yield and quality of pyrolysis products significantly changed with combined light bio-oil washing and torrefaction pretreatment. Pretreatment resulted in a significant increase of pH and higher heating values (HHVs) along with a reduction of the water content. Meanwhile, it can be obtained from gas chromatography/mass spectrometry (GC/MS) analysis of bio-oil that pretreatment enhanced selective py...

Production high yields of aromatic hydrocarbons through catalytic fast pyrolysis of torrefied wood and polystyrene

Catalytic fast pyrolysis of torrefied wood has been shown to improve the yields of aromatic hydrocarbons in the bio-oil. In this study, Py-GC/MS was employed on torrefied wood (TW), polystyrene (PS) and torrefied wood/polystyrene (TW/PS) with and without zeolite catalyst (HZSM-5) to produce a wide range of aromatic hydrocarbons. The effects of pyrolysis temperature, presence of polystyrene and catalyst on the yields and nature of aromatic hydrocarbons were investigated. Experimental results showed that the chemical composition of TW pyrolysis products was significantly different than that produced from TW/PS and TW/PS/catalyst. Presence of PS significantly reduced the yield of oxygenated phenolic compounds and produced more aromatic hydrocarbons compared to TW. More than twenty aromatic hydrocarbons were introduced during the co-pyrolysis of TW/PS and TW/PS/catalyst due to the presence of PS. The highest yields of aromatic hydrocarbons in co-pyrolysis samples were obtained at 600°C, but higher temperatures slightly decreased the yield of most hydrocarbons. The major aromatic hydrocarbons were found to have high influence on the yields of pyrolysis products are: Styrene; α-methylstyrene; 2-phenyl-1,2,3,4-tetrahydronaphthalene; diphenylpropane and diphenylbutane derivatives. Most of aromatic hydrocarbons identified in this study were proposed to be formed through free radical reaction mechanism.

Yields of pyrolysis products from refuse-derived fuel

ABSTRACTPyrolysis yields and gas characteristics must be studied to control pollution caused by waste-energy recycling and to develop a refuse-derived fuel technology. In this study, refuse-derived fuel pyrolysis experiments were performed in a high-temperature tube furnace. The effects of the final pyrolysis temperature, material mixture ratio, and pyrolysis rate on the yields of pyrolysis products, including gas, tar, and semi-coke, were studied. The volume fractions of the pyrolysis gas components (H2, CO, CH4, and CO2) of the samples were also detected. Results showed that with increased final temperature, the tar and gas yields increased but the semi-coke yield decreased. The volume fractions of the components had the following trends: H2 increased, CO initially decreased and then increased, CH4 initially increased and then decreased, and CO2 decreased. With decreased biomass, the tar yield decreased and then increased, whereas the semi-coke and gas yields increased and then decreased. Compared with slow pyrolysis, fast pyrolysis decreased the tar yield by 9.13%, increased the gas yield by 7.45%, increased the CO and CH4 volume fractions, and decreased the CO2 volume fraction.

Production of phenol-rich bio-oil during catalytic fixed-bed and microwave pyrolysis of palm kernel shell

Catalytic fixed-bed and microwave pyrolysis of palm kernel shell using activated carbon (AC) and lignite char (LC) as catalysts and microwave receptors are investigated. The effects of process parameters including temperature and biomass:catalyst ratio on the yield and composition of pyrolysis products were studied. The addition of catalyst increased the bio-oil yield, but decreased the selectivity of phenol in fixed-bed. Catalytic microwave pyrolysis of PKS significantly enhanced the selectivity of phenol production. The highest concentration of phenol in bio-oil of 64.58 %(area) and total phenolics concentration of 71.24 %(area) were obtained at 500°C using AC. Fourier transform infrared spectroscopy (FTIR) results indicated that concentration of OH, CH, CO and CO functional groups in char samples decreased after pyrolysis. Scanning electron microscopy (SEM) analysis clearly indicated the development of liquid phase in biomass particles during microwave pyrolysis, and the mechanism is also discussed.

Evaluation of influence of two different catalysts on the pyrolysis of laurel (Laurus nobilis L.) extraction residues

ABSTRACTLaurel extraction residues with zeolite and alumina catalysts were pyrolyzed in a fixed-bed reactor with a constant heating rate of 10°C min–1. The final pyrolysis temperature and sweep gas flow rate were kept constant at 500°C and 100 ml min–1 in all of the experiments, respectively. The influence of catalysts and their ratio (10, 20, 30, 40, and 50% w/w) on the pyrolysis conversion and product yields were investigated in detail. The physicochemical properties of the catalytic bio-oil were determined and compared to those of non-catalytic bio-oil. The catalytic bio-oils were examined using some spectroscopic and chromatographic techniques.

Co-pyrolysis of waste newspaper with high-density polyethylene: Synergistic effect and oil characterization

Biomass from waste newspaper (WP) was first co-pyrolyzed with high-density polyethylene (HDPE) in order to enhance the oil yield and its fuel properties. The synergistic effects during co-pyrolysis were investigated in terms of entire pyrolysis process, products yield and properties of liquid products (aqueous phase and oil phase) using thermogravimetric analysis coupled with infrared spectroscopy (TG-FTIR), physical properties analysis, elemental analysis, Fourier transform infrared spectroscopy (FT-IR), and gas chromatography/mass spectrometry (GC/MS). The results showed that synergistic effect occurred at 400–500°C resulting in an obviously increase in oil phase by 31.59% as compared to theoretical data. Positive synergistic effects on fuel properties of co-pyrolysis oil were observed, especially demonstrating dramatically decrease in viscosity and total acid number by 75.96% and 216.04% in comparison to theoretical data. WP pyrolyzed alone gives mainly oxygenated compounds in its derived oil, while HDPE give hydrocarbons. No cross reaction products appeared in co-pyrolysis oil, implying that the synergistic effects were determined by altering its compounds content rather than generating cross reaction products. Unfortunately, aqueous phase and oil phase exhibit similar composition.

Organic oxygen transformation during pyrolysis of Baiyinhua lignite

Fast pyrolysis of a lignite containing a high content of oxygen was investigated to understand the effects of pyrolysis temperature and gas resident time on the yields of pyrolysis products and the distributions of organic oxygen species (OOSs). OOSs in the lignite contain carboxyl, carbonyl, hydroxyl and ether by the results of XPS and FTIR analyses. The tar yield reached the maximum of 15.3% at 500°C and a gas resident time of 2.5s. CO2 was found to be the predominant oxygenous gas at 600°C, and the significant release of CO2 at temperatures lower than 400°C should be related to the high carboxyl content in the lignite. The CO yield increased significantly with the raising temperature and reached 46.4mL/g (daf) at 700°C. The O yield in water was lower than 20% during pyrolysis at 200°C, and sharply increased to 30.6% at 700°C because of thermal cracking of volatiles. Above 400°C, the OOSs are mainly released as pyrolysis water and gas. The OOSs detected in the tar include phenols, ketones, ethers, alcohols, and dibenzofuran and its substitute, among which phenols (phenol, cresol, and xylenol) are the main components with yield up to 27.1% (based on tar) at 500°C and gas residence time of 10s. The possible oxygen transformation routes for BYHL pyrolysis are also discussed in this work. Such an approach may lead to the development of efficient lignite upgrading technology.

Fast pyrolysis of glucose‐based carbohydrates with added NaCl part 2: Validation and evaluation of the mechanistic model

A mechanistic model considering the significant catalytic effects of Na+ on fast pyrolysis of glucose‐based carbohydrates was developed in Part 1 of this study. A computational framework based on continuous distribution kinetics and mass action kinetics was constructed to solve the mechanistic model. Agreement between model yields of various pyrolysis products with experimental data from fast pyrolysis of glucose‐based carbohydrates dosed with NaCl ranging from 0–0.34 mmol/g at 500 °C validated the model and demonstrated the robustness and extendibility of the mechanistic model. The model was able to capture the yields of major and minor products as well as their trends across NaCl concentrations. Modeling results showed that Na+ accelerated the rate of decomposition and reduced the time for complete thermoconversion of carbohydrates. The sharp reduction in the yield of levoglucosan (LVG) from fast pyrolysis of cellulose in the presence of NaCl was mainly caused by reduced decomposition of cellulose chains via end‐chain initiation and depropagation due to Na+ favoring competing dehydration reactions. Analysis of the contributions of reaction pathways showed that the decomposition of LVG made a minor contribution to its yield reduction and contributed less than 0.5% to the final yield of glycolaldehyde from fast pyrolysis of glucose‐based carbohydrates in the presence of NaCl. © 2015 American Institute of Chemical Engineers AIChE J, 62: 778–791, 2016