Bio-oil production from pyrolysis of waste sawdust with catalyst ZSM-5

Journal of Material Cycles and Waste Management - Slow pyrolysis is characterized by a low heating rate and high reaction time. The products are bio-char, bio-oil and bio-gas. In bio-oil, there are...     

Quality improvement of pyrolysis oil from waste rubber by adding sawdust

This work was aimed at improving the pyrolysis oil quality of waste rubber by adding larch sawdust. Using a 1 kg/h stainless pyrolysis reactor, the contents of sawdust in rubber were gradually increased from 0%, 50%, 100% and 200% (wt%) during the pyrolysis process. Using a thermo-gravimetric (TG) analyzer coupled with Fourier transform infrared (FTIR) analysis of evolving products (TG–FTIR), the weight loss characteristics of the heat under different mixtures of sawdust/rubber were observed. Using the pyrolysis–gas chromatography (GC)–mass spectrometry (Py–GC/MS), the vapors from the pyrolysis processes were collected and the compositions of the vapors were examined. During the pyrolysis process, the recovery of the pyrolysis gas and its composition were measured in-situ at a reaction temperature of 450 °C and a retaining time of 1.2 s. The results indicated that the efficiency of pyrolysis was increased and the residual carbon was reduced as the percentage of sawdust increased. The adding of sawdust significantly improved the pyrolysis oil quality by reducing the polycyclic aromatic hydrocarbons (PAHs) and nitrogen and sulfur compounds contents, resulting in an improvement in the combustion efficiency of the pyrolysis oil.     

The pyrolysis of sawdust and polyethylene in TG and U-shape tube reactor

The co-pyrolysis of sawdust and polyethylene was carried out in a TG-DTG system and a U-shape tube reactor. This research was focused on the interaction between sawdust and polyethylene during the pyrolysis process. The results showed that the interaction between the sawdust particles and polyethylene particles could be ignored during the devolatile process, but there was interaction among the volatile components in the co-pyrolysis process.     

Catalytic pyrolysis of Eupatorium adenophorum by sodium salt

Journal of Material Cycles and Waste Management - Eupatorium adenophorum (EA) has been spread widely in China and its increasing number has posed potential threats and damages to the ecosystem and...     

Influence of pine wood shavings on the pyrolysis of poultry litter

Poultry litter from broilers and turkeys are a mixture of manure, feathers, feed and wood shavings, thus pyrolysis oils produced from this material are influenced by the individual components. In order to determine the influence of wood shavings that are used as bedding material, we investigated the pyrolysis of pine wood shavings and poultry manure. Because manure from layer chickens are usually not contaminated with wood shavings, we made mixtures of layer manure and pine wood shavings in the following manure to wood ratios, 100:0, 75:25, 50:50, 25:75, and 0:100 w/w and pyrolyzed them in a fluidized bed reactor at 450 °C. The total liquid yield ranged from 43.3 to 62.7 wt.%. The layer manure oil had a HHV of 29.7 MJ/kg and pH of 5.89 compared to pine wood oil which had HHV of 25.6 MJ/kg and pH of 3.04. The addition of wood shavings to manure clearly influenced the physical properties of the oil, resulting in a decrease in pH and HHV and an increase in density. The oils had relatively high nitrogen content ranging from 1.36 to 5.88 wt.%. The ash (<0.07 wt.%) and sulfur (<0.28 wt.%) contents were very low. FTIR, ¹³C NMR and ¹H NMR spectrometric analysis of the oils showed that manure oil was rich in hydrocarbons and nitrogenous compounds such as primary, secondary amides, aromatic amines and N-heterocyclic. The properties of the oils were strongly influenced by the amount of wood in the mixture.     

Catalytic pyrolysis of car tire waste using expanded perlite

In this study, the non-catalytic and catalytic pyrolysis experiments were conducted on the sample of tire waste using expanded perlite as an additive material to determine especially the effect of temperature and catalyst-to-tire ratio on the products yields and the compositions and qualities of pyrolytic oils (NCPO and CPO). Non-catalytic studies, which were carried out under the certain conditions (a nitrogen flow of 100 mL/min and a heating rate of 10 °C/min), showed that the highest yield of pyrolytic oil (NCPO) was 60.02 wt.% at 425 °C. Then, the catalytic pyrolysis studies were carried out at catalyst-to-tire ratio range of 0.05-0.25 and the highest catalytic pyrolytic oil (CPO) yield was 65.11 wt.% at the ratio of 0.10 with the yield increase of 8.48 wt.% compared with the non-catalytic pyrolysis. Lastly, the pyrolytic oils were characterized with applying a various techniques such as elemental analyses and various chromatographic and spectroscopic techniques (GC-MS, ¹H NMR, FT-IR, etc.). The characterization results revealed that the pyrolytic oils which were complex mixtures of C₅-C₁₅ organic compounds (predominantly aromatic compounds) and also the CPO compared to the NCPO was more similar to conventional fuels in view of the certain fuel properties.     

几种金属氧化物催化臭氧氧化降解p-CBA

选择Al₂O₃,TiO₂,MnO₂,Fe₃O₄ 4种金属氧化物对溶液中的对氯苯甲酸（p-CBA）进行催化臭氧氧化降解。催化剂的表征结果显示：TiO₂具有最大的比表面积,为93.84 m²/g,Al₂O₃的比表面积最低,仅为10.28 m²/g;MnO₂和Fe₃O₄表面含有大量强酸性位,故其等电点较低,分别为1.45和1.82。4种催化剂对p-CBA的吸附能力与其比表面积相关,而催化臭氧氧化活性高低却与其等电点的高低顺序一致。Al₂O₃具有最高的等电点（6.92）,也表现出相对较强的催化臭氧氧化活性。在臭氧通量6 mg/min、p-CBA初始质量浓度40 mg/L、Al₂O₃投加量0.5 g/L、反应时间40 min的条件下,p-CBA去除率达到58.6%,远高于单独臭氧化和吸附过程的去除率。     

A comparative study on valuable products: bio-oil,biochar, non-condensable gases from pyrolysis of agricultural residues

Journal of Material Cycles and Waste Management - In this study, pyrolysis of agricultural residues, such as rice straw (RS), wheat straw (WS), and sugarcane bagasse (SB), was performed in a...     

泥磷液相催化氧化氮氧化物

采用磷化工行业的固体废物泥磷液相催化氧化氮氧化物。实验结果表明,该方法是可行且有效的。随着温度的升高,泥磷吸收液的脱硝效率提高,当温度达到泥磷熔点时脱硝效率最佳。泥磷吸收液的脱硝效率随固液比的增大而有所下降,而随着NO体积分数和气体流量的增大,泥磷吸收液的脱硝效率呈先升后降的趋势。各因素对脱硝率的影响大小顺序为：气体流量>反应温度>固液比>NO体积分数。在反应温度60 ℃、固液比1∶4、NO体积分数0.03%、气体流量0.3 L/min的最佳工艺条件下,反应160 min的平均脱硝率可达97.38%。     

Characterization of bio-oil and biochar obtained by pyrolysis at high temperatures from the lignocellulosic biomass of the henequen plant

Journal of Material Cycles and Waste Management - In this work, the trunk and flower stalk of henequen were characterized and subjected to pyrolysis at high temperatures. The chemical composition...     

Mass balance and characterization of bio-oil from sludge pyrolysis generated in the treatment of effluent from the biodiesel industry

Journal of Material Cycles and Waste Management - The present work produced bio-oil from the pyrolysis of sludge from the biodiesel processing industry in a fixed bed reactor, aiming at industrial...     

Catalytic upgrading of higher 1-alkenes from polyethylene thermal cracking by modified Wacker oxidation

The economic success of feedstock recycling procedures for plastic wastes is increasingly demanding the conversion of the starting residue into more valuable chemicals. Thermal cracking of polyethylenes leads to the preparation of equimolar mixtures of n-paraffins and 1-alkenes within the C₂–C₁₀₀ range. These 1-olefins can be catalytically upgraded by selective oxidation processes to more valuable products (e.g., ketones and fatty acids) with different uses such as polar waxes, cetane improvers, varnishes, and printer inks. The results obtained on oxidation in a modified Wacker system of a model 1-olefin (1-dodecene) as well as of a distillate cut (C₁₀–C₂₅) of the product from the thermal cracking of urban polyethylene waste are described.     

Effect of C/N on composting of pig manure with sawdust

The aim of this composting trial was to evaluate the effect of C/N on the composting process of pig manure with the purpose of reducing the amount of sawdust normally used as co-composting materials. Two aerobic static piles were prepared consisting of pig manure mixed with sawdust at an initial C/N of 30 (pile A) and 15 (pile B), respectively. Pile B containing larger amount of pig manure showed a slower rise in temperature, lower maximum temperature, and shorter thermophilic phase than pile A. It also resulted in higher pH and electrical conductivity (EC) values, and even higher contents of soluble NH4-N and volatile solids throughout the composting period. Chemical and biological parameters including dissolved organic carbon (DOC) (4932 mg kg(-1)), soluble NH4-N (371 mg kg(-1)), C/Nsolid (18.3), C/Naquoeus (5.8) and seed germination index (GI) (66.5%) indicated that pile A achieved maturity after 49 days of composting. After 63 days of composting, pile B contained 5352 and 912 mg kg(-1) of DOC and soluble NH4-N content, respectively, which was much higher than the criterion of 5% and 400 mg kg(-1), indicating its immature nature. Pile B showed a relatively low GI value of 46%, which may be due to its high indigenous EC value as a result of larger amount of pig manure. Therefore, co-composting of pig manure with sawdust at a low initial C/N would require a composting longer than 63 days, and, the high salinity due to the large amount of pig manure would pose a potential inhibition on plant growth.     

Bio-oil production by fast pyrolysis of cellulose/polyethylene mixtures in the presence of metal chloride

Cellulose/polyethylene mixture (3:1 w/w) and Tetra Pak wastes with and without metal chloride (ZnCl₂, AlCl₃, CuCl₂, FeCl₃) addition were subjected to a fast pyrolysis process at 350–500 °C and heating rate 100 °C/s to evaluate the possibility of liquid product formation with a high yield. The addition of zinc, aluminum, iron and copper chlorides has influenced the range of samples decomposition as well as the chemical composition of resulting pyrolytic oils. It was found that formation of levoglucosan, the main product of cellulose thermal decomposition, and phenol and its derivatives decreased in a presence of metal chlorides. Non-catalytic fast pyrolysis of polyethylene leads to the formation of solid long chain hydrocarbons, whereas the addition of metal chlorides promotes the formation of more liquid hydrocarbons.     

石化废水生化处理工艺优化及提标改造

针对已建炼化污水处理装置提质达标的需求,采用旋流强化工艺对缺氧-好氧（A/O）池进行改造,生化出水TN由（32.8±8.9）mg/L降至（25.6±5.7） mg/L,TN平均去除率提高了约10百分点,且出水TN达标率达到100%,出水水质稳定达到GB 31570—2015《石油炼制行业污染物排放标准》的TN排放限值要求。旋流强化工艺技术先进,便于实施,适用于石化行业污水处理装置的改造升级,具有广泛的应用前景。     

粉煤灰基层状金属氧化物对水中活性红X-3B的吸附

以粉煤灰(FA)为原料,采用共沉淀法制备了层状双金属氢氧化物(LDH)和层状金属氧化物(LMO,也称LDO),并采用XRD和BET技术进行了表征。比较了FA、LDH、LMO对活性红X-3B染料(X-3B)的吸附效果;考察了LMO吸附X-3B的影响因素,并探讨了吸附机理。XRD表征结果表明,LMO在吸附X-3B后重新恢复LDH层状结构。BET表征结果表明,LMO的比表面积大于LDH。吸附实验结果表明,3种吸附剂对X-3B吸附效果的优劣顺序为:LMOLDHFA;在初始X-3B质量浓度为50 mg/L、LMO投加量为2.0 g/L、吸附温度为25℃、吸附pH为7、吸附时间为30 min的条件下,X-3B去除率可达98.1%;LMO对X-3B的吸附符合Langmuir等温吸附方程,饱和吸附量为129.53 mg/g,且吸附过程可用准二级动力学方程描述。     

Vacuum pyrolysis of waste tires with basic additives

Granules of waste tires were pyrolyzed under vacuum (3.5-10kPa) conditions, and the effects of temperature and basic additives (Na(2)CO(3), NaOH) on the properties of pyrolysis were thoroughly investigated. It was obvious that with or without basic additives, pyrolysis oil yield increased gradually to a maximum and subsequently decreased with a temperature increase from 450 degrees C to 600 degrees C, irrespective of the addition of basic additives to the reactor. The addition of NaOH facilitated pyrolysis dramatically, as a maximal pyrolysis oil yield of about 48wt% was achieved at 550 degrees C without the addition of basic additives, while a maximal pyrolysis oil yield of about 50wt% was achieved at 480 degrees C by adding 3wt% (w/w, powder/waste tire granules) of NaOH powder. The composition analysis of pyrolytic naphtha (i.b.p. (initial boiling point) approximately 205 degrees C) distilled from pyrolysis oil showed that more dl-limonene was obtained with basic additives and the maximal content of dl-limonene in pyrolysis oil was 12.39wt%, which is a valuable and widely-used fine chemical. However, no improvement in pyrolysis was observed with Na(2)CO(3) addition. Pyrolysis gas was mainly composed of H(2), CO, CH(4), CO(2), C(2)H(4) and C(2)H(6). Pyrolytic char had a surface area comparable to commercial carbon black, but its proportion of ash (above 11.5wt%) was much higher.