Pyrolysis of sorghum bagasse biomass into bio-char and bio-oil products

The transformation of renewable biomass into valuable products as alternatives to fossil fuels is essential for sustainable energy in sustainable society. This work systematically investigates the pyrolysis of sorghum bagasse biomass into bio-char and bio-oil products and studies the effect of temperature (623–823 K) on the conversion of sorghum bagasse and products yields. The physicochemical properties of bio-char were thoroughly studied using powder X-ray diffraction, elemental analysis (CHNSO), scanning electronic microscope, calorific value (CV), and Fourier transform infrared (FTIR) spectroscopy techniques. Also, gas chromatography–mass spectrometry (GC–MS), CV, and FTIR were used to understand the properties of bio-oil. The results obtained indicate that an increase in the pyrolysis temperature from 623 to 823 K leads to a decrease in the bio-char yield from 42.55 to 30.38%. On the other hand, the maximum bio-oil yield of 15.94% was obtained at 723 K. The bio-char obtained at 673 and 773 K was found by FTIR analysis to be composed of a highly ordered aromatic carbon structure. The calorific value of bio-oil, which contains a greater amount of acidic compounds, was found to be 6740 kcal/kg. The GC–MS analyses revealed the presence of octadecenoic acid, p-cresol, 2,6-dimethoxy phenol, 4-ethyl 2-methoxy phenol, phenol, o-guaiacol, and octadecanoic acid in the bio-oil obtained from the pyrolysis of sorghum bagasse biomass. The present study provides useful information for understanding the quality of bio-oil and bio-char obtained from high biomass sorghum bagasse.     

Utilization of camellia oleifera shell for production of valuable products by pyrolysis

Camellia oleifera shell is used as the feedstock to prepare the valuable products by pyrolysis using microwave heating at 400-800 °C. The yield of pyrolysis product is influenced by pyrolysis temperature, which indicates that high pyrolysis temperature promotes to generate bio-gas and restrains the production of biochar. However, pyrolysis temperature little influences the yield of bio-oil. The main compound of bio-oil is phenols, hydrocarbons, ketones, aldehydes and furans, respectively. While, bio-oil produced at 600 °C has as high as 78 % of phenols, which has potential application in chemical industries. The pyrolysis temperature has significantly influenced the composition and heating value of bio-gas. The maximum heating value of bio-gas is 12.44 MJ/Nm³, which is achieved at 600 °C. The physiochemical properties of biochar are also influenced by pyrolysis temperature. Biochar could be used as an adsorbent to adsorb Ag⁺ from aqueous solution, which is formed the value-added ABiochar composite by reduction. The adsorption and reduction process of Ag⁺ are investigated. While, ABiochar composite can be used as the catalyst for methylene blue degradation. ABiochar composite can be also used in the lithium ion battery cathode material for energy storage.     

Aromatics and phenols from catalytic pyrolysis of Douglas fir pellets in microwave with ZSM-5 as a catalyst

Microwave assisted catalytic pyrolysis was investigated to convert Douglas fir pellets to bio-oils by a ZSM-5 zeolite catalyst. A central composite experimental design (CCD) was used to optimize the catalytic pyrolysis process. The effects of reaction time, temperature and catalyst to biomass ratio on the bio-oil, syngas, and biochar yields were determined. GC/MS analysis results showed that the bio-oil contained a series of important and useful chemical compounds. Phenols, guaiacols, and aromatic hydrocarbons were the most abundant compounds which were about 50–82% in bio-oil depending on the pyrolysis conditions. Comparison between the bio-oils from microwave pyrolysis with and without catalyst showed that the catalyst increased the content of aromatic hydrocarbons and phenols. A reaction pathway was proposed for microwave assisted catalyst pyrolysis of Douglas fir pellets.     

Production of fungicidal oil and activated carbon from pistachio shell

The main objective of this study was to evaluate the feasibility of pistachio shell as a biomass feedstock for the production of fungicidal oil and a precursor for the production of activated carbon by physical activation. For this purpose, pistachio shell was pyrolyzed in a fixed bed reactor at the different temperatures (300-600 °C). The pyrolysis products were identified as gas, bio-oil, aqueous solution and char. The product distribution from pyrolysis process did not significantly change when the pyrolysis temperature was above 300 °C. The pyrolysis gas product had low calorific value since it contained the high proportion of carbon oxides. Because of their high oxygen content, the bio-oils were found not to be used as a fuel. Thus, the bio-oil was tested again four different types of fungi (pathogenetic, wood decaying and saprophyting). It was shown fungicidal activity again all tested fungi at the concentration of 10-50 mg ml⁻¹. The pyrolysis char was evaluated as a precursor for the production of activated carbon. The surface area and micropore volume of the activated carbon produced from the char by CO₂ activation at 900 °C were found to be 708 m² g⁻¹ and 0.280 cm³ g⁻¹, respectively.     

Thermal self-sustainability of biochar production by pyrolysis

The pyrolysis of several agricultural and biofuel production residues (grape residues, sugarcane residues, dried distiller's grain, palm oil residues, apple pomace and forestry residue) has been carried out in a pilot bubbling fluidized bed pyrolyzer operating under a range of temperature from 300 to 600 °C and two vapor residence times (2 and 5 s), with the aim of determining their pyrolysis behavior including products yields and heat balance. The composition of the product gases was determined, from which their heating value was calculated. The liquid bio-oil was recovered with cyclonic condensers. The thermal sustainability of the pyrolysis process was estimated by considering the energy contribution of the product gases and of the liquid bio-oil in relation to the pyrolysis heat requirements. The most promising biomass feedstocks for the sustainable production of biochar were indentified. Furthermore, this study presented the char yield in relation to the excess heat that could be obtained by combusting the gas and bio-oil coproducts of biochar production, as functions of pyrolysis temperature and vapor residence time.     

Simulation of the fast pyrolysis of Tunisian biomass feedstocks for bio-fuel production

An optimized model is developed for the production of bio-fuels from biomass using a SuperPro Designer tool. Four types of Tunisian biomass feedstocks including date palm rachis, olive stones, vine stems and almond shells were selected for the fast pyrolysis process simulation. Simulation tests were performed at different temperatures ranging from 450 to 650 °C, and residence times ranging from 0.1 to 10 s and the products yield were determined. The obtained results indicate that a temperature of 575 °C and 0.25 s vapor residence time are the optimum parameters to maximize the bio-oil yield. Comparison between the different feedstocks indicates that a higher bio-oil fraction was obtained from the date palm rachis and vine stem. However, the difference between the samples is not significant and further investigations on the bio-oil properties are requested to select the suitable biomass for bio-oil production in Tunisia.     

Scale-up of microwave heating process for the production of bio-oil from sewage sludge

A pilot-scale microwave heating apparatus was constructed for the production of bio-oil from sewage sludge, and the effects of important microwave processing parameters and chemical additives on the quality and yield of bio-oils were investigated. It was found that bio-oil was mainly formed at the pyrolysis temperature range of 200–400 °C. A higher heating rate (faster pyrolysis) not only increased the yield of bio-oil, but also improved the quality of bio-oil according to the elemental composition and calorific values. The maximum bio-oil yield was 30.4% of organic fraction, obtained from the pyrolysis of original sewage sludge at microwave radiation power of 8.8 kW and final pyrolysis temperature of 500 °C. All of five simple additives (KOH, H₂SO₄, H₃BO₃, ZnCl₂, and FeSO₄) reduced the bio-oil yield, but the composition and property of bio-oil varied with the additive types greatly. KOH, H₂SO₄, H₃BO₃ and FeSO₄ were found to improve the quality of bio-oils remarkably according to the calorific value, density, viscosity and carbon content of bio-oils, but ZnCl₂ treatment went against that. GC–MS analysis of the bio-oils showed that, alkali treatment promoted the formation of alkanes and monoaromatics, while acid treatment favored the formation of heterocyclics, ketones, alcohols and nitriles. Compared with sulfate slat FeSO₄, chloride salt ZnCl₂ was a better catalyst for selective catalytic pyrolysis of sewage sludge. The addition of ZnCl₂ only promoted the formation reactions of a few kinds of nitriles and ketones remarkably. It is technologically feasible to produce bio-oil form microwave-induced pyrolysis of sewage sludge by optimizing pyrolysis conditions and selecting appropriate additives.     

Pyrolysis of pine needles: effects of process parameters on products yield and analysis of products

Pyrolysis of pine needles was carried out in a semi-batch reactor. The effects of pyrolysis parameters such as temperature (350–650 °C), heating rate (10 and 50 °C min^?1), nitrogen flow rate (50–200 cm³ min^?1) and biomass particle size (0.25–1.7 mm) were examined on products yield. Maximum bio-oil yield of 43.76% was obtained at pyrolysis temperature of 550 °C with a heating rate of 50 °C min^?1, nitrogen flow rate of 100 cm³ min^?1 for biomass particle size of 0.6 < d _p < 1 mm. The characterization of pyrolysis products (bio-oil, bio-char) has been made through different instrumental methods like Fourier transform infrared spectroscopy, gas chromatography–mass spectrometry, nuclear magnetic resonance spectroscopy (¹H NMR), X-ray powder diffraction, field emission scanning electron microscope and Brunauer–Emmett–Teller surface area analysis. The empirical formula of the bio-oil and bio-char was found as CH_1.47O_0.36N_0.005 and CH_0.56O_0.28N_0.013 with heating value of 26.25 and 25.50 MJ kg^?1, respectively. Results show that bio-oil can be potentially valuable as a renewable fuel after upgrading and can be used as a feedstock for valuable chemicals production. The properties of bio-char reveal that it can be used as solid fuels, as a cheap adsorbent and as a feedstock for activated carbon production.     

Influence of feed characteristics on the microwave-assisted pyrolysis used to produce syngas from biomass wastes

A series of biomass wastes (sewage sludges, coffee hulls and glycerol) were subjected to pyrolysis experiments under conventional and microwave heating. The influence of the initial characteristics of the raw materials upon syngas production was studied. Glycerol yielded the highest concentration of syngas, but the lowest H₂/CO ratio, whereas sewage sludges produced the lowest syngas production with the highest H₂/CO molar ratio. Coffee hull displayed intermediate values for both parameters. Microwave heating produced greater gas yields with elevated syngas content than conventional pyrolysis. Moreover, microwave pyrolysis always achieved the desired effect with temperature increase upon the pyrolysis products, whatever biomass material was employed. This could be due to the hot spot phenomenon, which only occurs under microwave heating. In addition, a comparison of the energy consumption of the traditional and microwave-assisted pyrolysis is also presented. Results point at microwave system as less time and energy consuming in comparison to conventional system.     

离子液体作用下微波辐照生物质快速热解制备生物质油(英文)

以离子液体1-丁基-3-甲基咪唑氯([Bmim]Cl)和1-丁基-3甲基咪唑四氟化硼([Bmim]BF4)为催化剂,在微波加热作用下,研究了稻草和锯屑的热解。微波加热20 min,稻草和锯屑的生物油产率分别为38%和34%。考察了微波加热时间、微波功率和离子液体用量对生物质油产率的影响。当以相同的离子液体为催化剂时,稻草微波热解得到的生物质油产率大于锯屑的。生物油成分主要有糠醛、醋酸和1-羟基-2-丁酮等,其含量主要取决于生物质原料和加入的离子液体的类型。     

Effect of different temperatures on the properties of pyrolysis products of Parthenium hysterophorus

This research encompasses the use of noxious weed Parthenium hysterophorus as feedstock for pyrolysis carried out at varying temperatures of 300, 450 and 600°C. Temperature significantly affected the yield and properties of the pyrolysis products including char, syngas and bio-oil. Biochar yield decreased from 61% to 37% from 300 °C to 600 °C, whereas yield of gas and oil increased with increasing temperature. The pyrolysis products were physico-chemically characterized. In biochar, pH, conductivity, fixed carbon, ash content, bulk density and specific surface area of the biochar increased whereas cation exchange capacity, calorific value, volatile matter, hydrogen, nitrogen and oxygen content decreased with increasing temperature. Thermogravimetric analysis showed that the biochar prepared at higher temperature was more stable. Gas Chromatography-Mass Spectrometry analysis of biochar indicated the presence of alkanes, alkenes, nitriles, fatty acids, esters, amides and aromatic compounds. Number of compounds decreased with increasing temperature, but aromatic compounds increased with increasing temperature. Scanning electron micrographs of biochar prepared at different temperatures indicated micropore formation at lower temperature while increase in the size of pores and disorganization of vessels occurred at increasing temperature. The chemical composition was found to be richer at lower pyrolysis temperature. GC–MS analysis of the bio-oil indicated the presence of phenols, ketones, acids, alkanes, alkenes, nitrogenated compounds, heterocyclics and benzene derivatives.     

生物油储存稳定性实验研究

对松木和玉米芯快速热解制取的生物油进行储存稳定性实验,经过储存老化后的生物油黏度增大,水分含量和固体颗粒物含量增加,pH值、热值、密度无明显变化。通过GC-MS对储存前后生物油中主要组分进行定量分析表明,生物油经过储存后,羟基丙酮、乙酸、糠醛等主要组分的含量明显下降,而2-甲氧基苯酚、4-甲基-2-甲氧基-苯酚、4-甲基-苯酚的含量有所上升。核磁共振的碳谱分析表明,经过储存后生物油中甲氧基碳和双氧-烷基碳的含量降低,而芳基碳和不饱和碳的含量增大,生物油的芳香度有所提高。     

Production of Low-carbon Light Olefins from Catalytic Cracking of Crude Bio-oil

Low-carbon light olefins are the basic feedstocks for the petrochemical industry. Catalytic cracking of crude bio-oil and its model compounds (including methanol, ethanol, acetic acid, acetone, and phenol) to light olefins were performed by using the La/HZSM-5 catalyst. The highest olefins yield from crude bio-oil reached 0.19 kg/(kg crude bio-oil). The reaction conditions including temperature, weight hourly space velocity, and addition of La into the HZSM-5 zeolite can be used to control both olefins yield and selectivity. Moderate adjusting the acidity with a suitable ratio between the strong acid and weak acid sites through adding La to the zeolite effectively enhanced the olefins selectivity and improved the catalyst stability. The production of light olefins from crude bio-oil is closely associated with the chemical composition and hydrogen to carbon effective ratios of feedstock. The comparison between the catalytic cracking and pyrolysis of bio-oil was studied. The mechanism of the bio-oil conversion to light olefins was also discussed.     

Co-pyrolysis of macroalgae and lignocellulosic biomass

Synergistic effect of co-pyrolysis of macroalgae [Enteromorpha prolifera (EP)] and lignocellulosic biomass [rice husk (RH)] in a fixed bed reactor for maximum and enhanced biofuels yield has been investigated. The main and interaction effects of three effective co-pyrolysis parameters (pyrolysis temperature, feedstock blending ratio, and heating rate) were also modeled and simulated to determine the yield rates of bio-oil and bio-char, respectively. Optimization studies were, then, performed to predict the optimal conditions for maximum yields using the central composite circumscribed experimental design in Design Expert^® software 8.0.6. Analysis of variance was carried out to determine whether the fit of the multiple regressions is significant for the second-order model. Normal pyrolysis oils from EP, RH, and co-pyrolysis oils obtained from different feedstock blending ratios were examined using the gas chromatography-mass spectrometry to identify their compositions. Some vital properties of oils and bio-chars such as the heating value, water content, elemental compositions, and specific gravity were also determined, which unveiled that synergistic effect exists between EP and RH during co-pyrolysis, and this led to increase in products’ yields and improved co-pyrolysis products’ quality.

     

微拟球藻脂肪热解及对全组分制备生物油的影响

以酸水解法从微拟球藻中提取的粗脂肪为原料,在管式裂解炉中考察不同热解温度下脂肪单组分的热解规律及对微拟球藻全组分各相产率及生物油性能的影响。利用热重分析仪分别考察粗脂肪及全组分的热失重特性,并求出相应的动力学参数。结果表明,脂肪热解能够提高全组分热解有机相产率并改善油品性能。随着温度的升高,粗脂肪与全组分热解后的有机相产率及油品性能的变化趋势相同,且生物油性能均在600℃时达到最佳。经热解,粗脂肪中含氧化合物含量降低,脂肪烃含量显著增加。对比全组分热解,粗脂肪热解后的油品脱氧率及氢、碳元素比例更高,因而增加全组分中脂肪的含量能够促进油品性能的进一步提高。对粗脂肪及全组分的热重数据进行计算,发现两者均满足二级化学反应机理,粗脂肪、全组分的活化能与指前因子分别为64.34 k J/mol与2.94×105min-1,48.13 k J/mol与2.96×103min-1。     

微拟球藻热解及其催化热解制备生物油研究

在氮气气氛下对微拟球藻直接热解及其在H-ZSM-5上的催化热解实验进行了研究。在573K～773K考察了热解温度对热解油产物分布的影响。与木质纤维素生物质的热解相比,微拟球藻的热解不仅温度更低,而且油的收率更高。催化剂H-ZSM-5在热解中起到了脱极性官能团和芳构化的作用,使得热解油中的芳香族化合物含量增多,极性化合物含量减少。与木质纤维素生物质相比,微拟球藻热解获得的油热值更高,适合进一步加工为燃油。     

温度对稻草流化床快速热解液相产物影响的研究

研究了温度对稻草流化床快速热解中热解油产率的影响,利用GC/MS、FT-IR考察了不同热解温度(300℃~600℃)及冷凝温度(22℃、-4.4℃)下,稻草经过热解所获得的热解油组成。结果表明,稻草在400℃热解温度下可获得最高热解油产率43.1%;冷凝温度对热解油的品质有较大影响,降低冷凝温度能够增加热解油中有机物的含量,热解油中的水分含量随之降低,同时热解油的热值也随之得到提高。     

Bio-oil production by flash pyrolysis of sugarcane residues and post treatments of the aqueous phase

The pyrolysis of three sugarcane residues (internal bagasse, external and whole plant) has been carried out in a pilot bubbling fluidized bed pyrolyzer operating under a range of temperature from 300 °C to 600 °C and two vapor residence time (2 and 5 s), with the aim of determining their pyrolysis behavior including products yields and heat balance. The composition of the product gases was determined, from which their heating value was calculated. The liquid bio-oil was recovered with cyclonic condensers and separated into two phases, an aqueous phase and an organic phase. The energy content of the organic phase was determined in comparison with common fossil fuels. Activated carbon adsorption and distillation at 110 °C were used to treat the aqueous phase, with the aim of recovering valuable hydrocarbons and purifying the aqueous phase for wastewater disposal. Furthermore, the thermal sustainability of the pyrolysis process was estimated by considering the energy contribution of the product gases and of the liquid bio-oil in relation to the pyrolysis heat requirements. The optimum pyrolysis temperatures were identified in terms of maximizing the liquid yield, maximizing the energy from the product bio-oil, and maximizing the net energy from the product bio-oil after ensuring a self-sustainable process by utilizing the product gases and part of bio-oil as heat sources.     

酸洗预处理对纤维素热裂解的影响研究

为获得液体产量的最大化和提高产物中糖类的质量分数，采用盐酸（3%、5%、7%）、磷酸（7%）和硫酸（7%）对纤维素进行酸洗预处理。不同酸洗预处理下纤维素的微观结构和聚合度变化表明，酸处理损坏了纤维素的物理结构，并使聚合度大幅度降低。在“┣”形石英玻璃反应器的快速热裂解试验装置上进行了不同酸处理前后的纤维素热裂解试验，发现酸浸泡处理后，生物油产率下降，相应的气体和焦炭产率提高，并且随着酸浓度的提高，该趋势逐渐增强。与盐酸和磷酸相比，硫酸对生物油的生成具有更强的抑制作用，这表明，酸对纤维素交联和脱水反应的催化效果。通过GC-MS色质联机分析技术对生物油成分进行分析，发现酸的存在并没有改变生物油成分的种类，但使化合物之间的相对质量分数发生了变化。左旋葡聚糖的质量分数随稀酸溶液浓度的增加呈下降趋势，原因是残留在物料中的微量酸以催化脱水和交联反应的方式，对其生成起抑制作用。     

Bio-oil from Jackfruit Peel Waste

Fossil fuels such as petroleum, charcoal, and natural gas sources are the main energy sources at present, but considering their natural limitation in availability and the fact that they are not renewable, there exists a growing need of developing bio-fuel production. Biomass has received considerable attention as a sustainable feedstock that can replace diminishing fossil fuels for the production of energy, especially for the transportation sector. JackfruitwasteisabundantinIndonesiamake itpotentiallyas one of thegreenrefineryfeedstockforthe manufacture ofbio-fuel.As intermediate of bio-fuel,jackfruitpeelsisprocessed intobio-oil. Pyrolysis, a thermochemical conversion process under oxygen-absent condition is an attractive way to convert biomass into bio- oil.In this study, the pyrolysis experiments were carried out ina fixed-bedreactor at a range of temperature of400-600 °C, heating rate range between 10-50 °C/min, and a range of nitrogen flow between 2-4litre/min. The aims of this work were to explore the effects of pyrolysis conditions and to identify the optimum condition for obtaining the highest bio-oil yield.The effect of nitrogen flow rate and heating rate on the yield of bio-oil were insignificant. The most important parameter in the bio-oil production was the temperature of the pyrolysis process.The yield of bio-oil initially increased with temperature (up to 550 °C) then further increase of temperature resulting in the decreased of bio-oil yield. Results showed that the highest bio-oil yield (52.6%)wasobtainedat 550 °C with nitrogen flow rate of 4L/min and heating rate of 50 °C/min. The thermal degradation of jackfruit peel was also studied using thermogravimetric analysis (TGA). Gas chromatography (GC-MS) was used to identify the organic fraction of bio-oil. The water content in the bio-oil product was determined by volumetric Karl-Fischer titration. The physicochemical properties of bio-oil produced from pyrolysis of jackfruit peels such as gross calorific value, pH, kinematic viscosity, density, sulfur content, ash content, pour point and flash point were determined and compared to ASTM standard of bio-oil (ASTM 7544).