Showing papers on "Pyrolysis published in 2013"
TL;DR: Results suggest that biochar pyrolized at high temperature may possess a higher carbon sequestration potential when applied to the soil compared to that obtained at low temperature.
719 citations
TL;DR: A review of biochar-N research can be found in this paper, where the authors established emerging trends and gaps in biochar N research, as well as the long-term practical effectiveness of inorganic-N adsorption as a NO3 − leaching mitigation option, requires further study.
Abstract: Interest in biochar stems from its potential agronomic benefits and carbon sequestration ability. Biochar application alters soil nitrogen (N) dynamics. This review establishes emerging trends and gaps in biochar-N research. Biochar adsorption of NO3 − , up to 0.6 mg g −1 biochar, occurs at pyrolysis temperatures >600 °C with amounts adsorbed dependent on feedstock and NO3 − concentration. Biochar NH4 + adsorption depends on feedstock, but no pyrolysis temperature trend is apparent. Long-term practical effectiveness of inorganic-N adsorption, as a NO3 − leaching mitigation option, requires further study. Biochar adsorption of ammonia (NH3) decreases NH3 and NO3 − losses during composting and after manure applications, and offers a mechanism for developing slow release fertilisers. Reductions in NH3 loss vary with N source and biochar characteristics. Manure derived biochars have a role as N fertilizers. Increasing pyrolysis temperatures, during biochar manufacture from manures and biosolids, results in biochars with decreasing hydrolysable organic N and increasing aromatic and heterocyclic structures. The short- and long-term implications of biochar on N immobilisation and mineralization are specific to individual soil-biochar combinations and further systematic studies are required to predict agronomic and N cycling responses. Most nitrous oxide (N2O) studies measuring nitrous
671 citations
TL;DR: The results showed that both feedstock properties and production conditions are important for determining the yield and properties of biochar, but their respective influence changes with the property or set of properties of interest.
657 citations
TL;DR: In this article, a fixed-bed slow pyrolysis from various feedstock biomasses under a range of process conditions was used to produce biochar, which was characterized by proximate analysis, CHN-elemental analysis, pH in solution, bomb calorimetry for higher heating value, N2 adsorption for BET surface area and two biological degradation assays (oxygen demand, carbon mineralization in soil).
Abstract: Biochar was produced by fixed-bed slow pyrolysis from various feedstock biomasses under a range of process conditions. Feedstocks used were pine wood, wheat straw, green waste and dried algae. Process conditions varied were the highest treatment temperature (HTT) and residence time. The produced chars were characterized by proximate analysis, CHN-elemental analysis, pH in solution, bomb calorimetry for higher heating value, N2 adsorption for BET surface area and two biological degradation assays (oxygen demand, carbon mineralization in soil). In proximate analysis, it was found that the fixed carbon content (expressed in wt% of dry and ash-free biochar) in the biochar samples strongly depended on the intensity of the thermal treatment (i.e. higher temperatures and longer residence times in the pyrolysis process). The actual yield in fixed carbon (i.e. the biochar fixed carbon content expressed as wt% of the dry and ash-free original feedstock biomass weight) was practically insensitive to the highest treatment temperature or residence time. The pH in solution, higher heating value and BET surface positively correlated with pyrolysis temperature. Finally, soil incubation tests showed that the addition of biochar to the soil initially marginally reduced the C-mineralization rate compared against the control soil samples, for which a possible explanation could be that the soil microbial community needs to adapt to the new conditions. This effect was more pronounced when adding chars with high fixed carbon content (resulting from more severe thermal treatment), as chars with low fixed carbon content (produced through mild thermal treatment) had a larger amount of volatile, more easily biodegradable, carbon compounds.
635 citations
TL;DR: In this paper, a comprehensive review has been carried out in order to show the effects of the main process conditions (heating rate, temperature, pressure, carrier gas flow rate and type, volatiles residence time and pyrolysis time) on physicochemical properties and distributions of the resulting products (gas, liquid and solid fractions).
Abstract: This review deals with the state-of-the-art of waste tyre pyrolysis for the first time in literature. Pyrolysis has been addressed as an attractive thermochemical process to tackle the waste tyre disposal problem while allowing energy recovery. Pyrolysis enables the separation of carbon black from tyres and the volatile matter released (condensable and non-condensable compounds) has the potential of renewable energy recovery given the significant proportion of natural rubber present in the tyre. Given this waste-to-energy pathway, a comprehensive review has been carried out in order to show the effects of the main process conditions (heating rate, temperature, pressure, carrier gas flow rate and type, volatiles residence time and pyrolysis time) on the physicochemical properties and distributions of the resulting products (gas, liquid and solid fractions). It has also been reviewed the influence of the size and composition of the feedstock. All reported results have been framed regarding the type of reactor as well as the experimental conditions used to avoid contradictions among the large number of publications on the subject. It is shown that the occurrence of secondary reactions is very sensitive to the interaction of the aforementioned variables. Also, the main properties of the pyrolytic products are pointed out. The liquid and gaseous fractions obtained are a valuable fuel source; while the solid fraction (char) has the recovery potential of low- grade carbon black or as carbon adsorbent after applying an activation step. Special attention has been given to the liquid fraction, highlighting its properties as alternative fuel in compression ignition engines.
596 citations
TL;DR: Examples of commercial and semi-commercial scale tyre pyrolysis systems show that small scale batch reactors and continuous rotary kiln reactors have been developed to commercial scale.
535 citations
TL;DR: The results showed that the biochar yield and quality depend principally on the applied temperature where pyrolysis at 600 °C leaves a biochar with higher fixed carbon content and percentage carbon and higher heating value than the original feedstock.
508 citations
TL;DR: In this article, pyrolyzed sludge was used to assess the effect of pyrolysis temperature, residence time and biomass chemical impregnation on the yield of biochar production.
472 citations
TL;DR: In the biochar yield, the influence of the inert and lignin contents was significant, and PKS biochar had dense matrix with few large pores, while the elemental composition and pH of biochars were compared.
464 citations
TL;DR: In this article, the authors investigated the devolatilization kinetics during pyrolysis of three biomass types in a thermogravimetric analyzer (TGA) and derived a one-step multi-component model with three independent parallel reactions for hemicellulose, cellulose and lignin.
437 citations
TL;DR: In this paper, the effectual parameters of the microwave-assisted pyrolysis process and advantages of this technique have been summarized and concluded that microwave assisted technology is an effectual method to reduce the reaction time and increase the quality of value-added products from different kinds of feedstocks.
Abstract: Pyrolysis is a promising bioconversion technique for energy recovery, waste management, and converting biomass into useful energy products which has attracted considerable attention during the past decades. Char/carbonaceous residue, bio-oil, and syngas are the three main products of the pyrolysis process. The pyrolysis technique is one of the major barriers for large-scale commercialization of this method. This study strives to extensively review the recent work on microwave-assisted technology applied to the pyrolysis process as a way of cost reduction. The fundamentals of microwave irradiation and a brief background of pyrolysis are presented. Additionally, biomass resources which can be the raw material for pyrolysis process have been categorized and reviewed in this paper. The effectual parameters of the microwave-assisted pyrolysis process and advantages of this technique have been summarized. It is concluded that microwave-assisted technology is an effectual method to reduce the pyrolysis reaction time and increases the quality of value-added products from different kinds of feedstocks. In addition, this technique can overcome the needs of feedstock shredding and improves the quality of heating as well. Therefore, it can be a suitable method for decreasing the pyrolysis processing cost and a pathway out of poverty for developing countries.
TL;DR: In this paper, a biochar based composite material with AlOOH nano-flakes was fabricated from AlCl 3 pretreated biomass through slow pyrolysis in a N 2 environment at 600°C.
TL;DR: In this paper, the Edinburgh accelerated ageing tool (Edinburgh stability tool) was used to evaluate the long-term stability of biochar in three feedstocks (Pine, Rice husk and Wheat straw) at four temperatures (350, 450, 550 and 650°C).
Abstract: Biochar is the porous, carbonaceous material produced by thermochemical treatment of organic materials in an oxygen-limited environment. In general, most biochar can be considered resistant to chemical and biological decomposition, and therefore suitable for carbon (C) sequestration. However, to assess the C sequestration potential of different types of biochar, a reliable determination of their stability is needed. Several techniques for assessing biochar stability have been proposed, e.g. proximate analysis, oxygen (O): C ratio and hydrogen (H): C ratio; however, none of them are yet widely recognized nor validated for this purpose. Biochar produced from three feedstocks (Pine, Rice husk and Wheat straw) at four temperatures (350, 450, 550 and 650 °C) and two heating rates (5 and 100 °C min−1) was analysed using three methods of stability determination: proximate analysis, ultimate analysis and a new analytical tool developed at the UK Biochar Research Centre known as the Edinburgh accelerated ageing tool (Edinburgh stability tool). As expected, increased pyrolysis temperatures resulted in higher fractions of stable C and total C due to an increased release of volatiles. Data from the Edinburgh stability tool were compared with those obtained by the other methods, i.e. fixed C, volatile matter, O : C and H : C ratios, to investigate potential relationships between them. Results of this comparison showed that there was a strong correlation (R > 0.79) between the stable C determined by the Edinburgh stability tool and fixed C, volatile matter and O : C, however, H : C showed a weaker correlation (R = 0.65). An understanding of the influence of feedstock and production conditions on the long-term stability of biochar is pivotal for its function as a C mitigation measure, as production and use of unstable biochar would result in a relatively rapid return of C into the atmosphere, thus potentially intensifying climate change rather than alleviating it.
TL;DR: In this paper, the authors used a TGA coupled with a mass spectrometer to study pyrolysis of 34 Chinese coals and found that the mass loss registered in TGA during temperature programmed heating is attributed mainly to devolatilization of fragments generated from cleavage of covalent bonds.
TL;DR: The photocatalytic activity for hydrogen evolution from aqueous triethanolamine solution was investigated and the highest activity can be attributed to the pure composition, the higher dye adsorption amount and the lowest defect concentration.
Abstract: Graphitic carbon nitride (g-C3N4) was prepared by pyrolysis of urea at different temperatures (450–650 °C), and characterized by thermogravimetric and differential thermal analysis (TG-DTA), elemental analysis (C/H/N), X-ray diffraction (XRD), UV-vis diffuse reflectance spectra (DRS), Brunauer–Emmett–Teller (BET) analysis, Fourier transform-infrared (FT-IR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and photoluminescence (PL) spectra. The samples prepared at low temperatures (450 and 500 °C) are a mixture of g-C3N4 and impurities, whereas the samples prepared at high temperatures (550, 600 and 650 °C) should be g-C3N4 (polymeric carbon nitride). The polymerization degree of g-C3N4 for the prepared samples increases to a maximum at 600 °C with increasing pyrolysis temperature and then decreases, whereas the defect concentration changes conversely, that is, g-C3N4 prepared at 600 °C has the lowest defect concentration. Using Eosin Y (EY) and the prepared sample as the sensitizer and the matrix, respectively, the photocatalytic activity for hydrogen evolution from aqueous triethanolamine solution was investigated. The g-C3N4 prepared at 600 °C exhibits the highest sensitization activity. Under optimum conditions (1.25 × 10−5 mol L−1 EY and 7.0 wt% Pt), the maximal apparent quantum yield of EY-sensitized g-C3N4 prepared at 600 °C for hydrogen evolution is 18.8%. The highest activity can be attributed to the pure composition, the higher dye adsorption amount and the lowest defect concentration.
TL;DR: Pyrolysis of nitrogen-ligated cobalt(II) acetate supported on commercial carbon transforms typical homogeneous complexes to highly active and selective heterogeneous Co3O4-N@C materials.
Abstract: Novel cobalt-based heterogeneous catalysts have been developed for the direct oxidative esterification of alcohols using molecular oxygen as benign oxidant. Pyrolysis of nitrogen-ligated cobalt(II) acetate supported on commercial carbon transforms typical homogeneous complexes to highly active and selective heterogeneous Co3O4-N@C materials. By applying these catalysts in the presence of oxygen, the cross and self-esterification of alcohols to esters proceeds in good to excellent yields.
TL;DR: In this paper, pyrolysis and combustion of pine sawdust have been investigated by using thermogravimetric analyzer coupled with Fourier transform infrared spectrometry (TG-FTIR) analysis.
TL;DR: The surface characteristics of sludge-derived biochar (SDBC) made from three feedstocks of wastewater sludge under different pyrolysis temperatures were investigated in this paper, which showed that the sludge from Waste Water Treatment Plant (WWTP) with pure domestic wastewater influent and less mixed industrial wastewater produced the highest biochar yield, and these SDBC samples have the highest IEP and the most uniform charge distribution, compared with other sources.
TL;DR: P pH and surface area of biochar increased greatly at pyrolytic temperatures ≥ 500°C, which increased Cd sorption capacity up to 13.24 mgg(-1) and the diffuse-controlled Cd removal was likely due to a surface sorption or a precipitation reaction depending on pH.
TL;DR: In this article, the co-pyrolysis of Indonesian coal and two types of biomass, rice straw and Leucaena leucocepha wood, was studied using a drop tube fixed-bed reactor.
TL;DR: In this paper, the authors compared biochar production conditions to the yield and properties of biochar, particularly its long-term stability, and found that the yield of stable biochar fraction is nearly independent of the temperature.
TL;DR: Most biochars exhibited attractive acid-base interactions that impeded their transport, whereas the biochar with the greatest mobility had repulsive acid- base interaction, and greater retention of the MPs than that of the NPs was in contrast with the XDLVO predictions.
Abstract: Land application of biochar is increasingly being considered for potential agronomic and environmental benefits, e.g., enhancing carbon sequestration, nutrient retention, water holding capacity, and crop productivity; and reducing greenhouse gas emissions and bioavailability of environmental contaminants. However, little is known about the transport of biochar particles in the aqueous environment, which represents a critical knowledge gap because biochar particles can facilitate the transport of adsorbed contaminants. In this study, column experiments were conducted to investigate biochar particle transport and retention in water-saturated quartz sand. Specific factors considered included biochar feedstocks (wheat straw and pine needle), pyrolysis temperature (350 and 550 °C), and particle size (micrometer-particle (MP) and nanoparticle (NP)). Greater mobility was observed for the biochars of lower pyrolysis temperatures and smaller particle sizes. Extended Derjaguin–Landau–Verwey–Overbeek (XDLVO) calcula...
TL;DR: In this article, the pyrolysis behavior of a β-O-4 type oligomeric lignin model compound is studied at a temperature range from 250 °C to 550 °C.
TL;DR: In this article, a thermogravimetric analyzer was used to examine the co-pyrolysis characteristics of fuel blends and five different biomass blending ratios (BBRs) of 100, 75, 50, 25, and 0.1% were taken into consideration.
TL;DR: The high inorganic content (potassium, phosphorous, and nitrogen) of the biochar suggests it may be suitable to provide nutrients for crop production, and the bio-oil and biochar represented 57% and 36% of the energy content of the microalgae remnant feedstock, respectively.
TL;DR: In this paper, a review of the recent developments in lignin pyrolysis chemistry, mechanism, catalysts, and the upgrading of the bio-oil from LPS is presented.
Abstract: Biomass pyrolysis oil has been reported as a potential renewable biofuel precursor. Although several review articles focusing on lignocellulose pyrolysis can be found, the one that particularly focus on lignin pyrolysis is still not available in literature. Lignin is the second most abundant biomass component and the primary renewable aromatic resource in nature. The pyrolysis chemistry and mechanism of lignin are significantly different from pyrolysis of cellulose or entire biomass. Therefore, different from other review articles in the field, this review particularly focuses on the recent developments in lignin pyrolysis chemistry, mechanism, catalysts, and the upgrading of the bio-oil from lignin pyrolysis. Although bio-oil production from pyrolysis of biomass has been proven on commercial scale and is a very promising option for production of renewable chemicals and fuels, there are still several drawbacks that have not been solved. The components of biomass pyrolysis oils are very complicated and related to the properties of bio-oil. In this review article, the details about pyrolysis oil components particularly those from lignin pyrolysis processes will be discussed first. Due to the poor physical and chemical property, the lignin pyrolysis oil has to be upgraded before usage. The most common method of upgrading bio-oil is hydrotreating. Catalysts have been widely used in petroleum industry for pyrolysis bio-oil upgrading. In this review paper, the mechanism of the hydrodeoxygenation reaction between the model compounds and catalysts will be discussed and the effects of the reaction condition will be summarized.
TL;DR: In this article, a biochar was produced from waste rubber-wood-sawdust and the produced biochars were characterized by Brunauer-Emmett-Teller (BET) gas porosimetry, scanning electron microscopy (SEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and Fourier transform infrared spectroscopy (FTIR).
TL;DR: In this article, the effects of water washing on fuel properties, pyrolysis and combustion characteristics, and ash fusibility of biomass fuels are studied via fuel analysis, thermogravimetric analysis and ash fusion temperature measurements.
TL;DR: A critical review of past efforts over the last four decades in oil and liquids production from the pyrolysis of waste tires is provided in this paper, where various operating conditions under which pyrolynsis of scrap tires is carried out are reviewed.
TL;DR: In this paper, the effect of temperature on oil shale pyrolysis and the creation of pore volume during thermal treatment was investigated using three-dimensional X-ray micro tomography (XMT).