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The Coats-Redfern method was used to analyze the kinetic characteristics of biomass catalytic pyrolysis, indicating that it can be described by multi-step reactions, rather than as a simple first-order reaction. Friedman model-free calculations were used to describe the starting reaction types and the corresponding initial kinetic parameters. Finally, nonlinear regression of biomass catalytic pyrolysis showed that the reaction mechanism of the whole process could be kinetically characterized by three successive reactions: a one-dimensional diffusion reaction, followed by an apparent first-order reaction, and then by a two-dimensional diffusion reaction. The kinetic parameters and equations were also calculated.

• Ca/ZSM-5 performs well in boosting the reaction of furfural (C5) with acetone (C3). • The formation of CaO over the catalyst was critical to the catalyst activity. • High yields of C8 (38%) and C13 (60%) are achieved under optimized conditions. • The reaction is first-order dependence on the concentration of each reactant. • The reaction of C8-OH (intermediates) with C5 is essential in the reaction system. In this paper the aldol condensation of furfural (C5) with acetone (C3) over Ca/ZSM-5 was studied with lower dosages of water and acetone as compared to previous studies. It was observed that the formation of CaO over the catalyst is critical to catalyst activity and that the reaction may not occur without water. Although higher quantity of water was favorable for the formation of 4-(2-Furyl)-3-buten-2-one (C8), it was inhibitive for the formation of 1,5-bis-(2-furanyl)-1,4-pentadien-3-one (C13). Highest yields of C8 (38.4 mol%) and C13 (60.2 mol%) were obtained with C3-to-C5 mole ratio of 0.8:1, and water content of 29.7 wt%. The deactivated catalyst was further regenerated by re-loading CaO. An intrinsic kinetic model was established whereby the reaction was first-order dependent on the concentration of each reactant. The formation of 4-(2-furyl)-4‑hydroxy‑butan-2-one (C8-OH), and the C8-OH-to-C8 dehydration were essential steps. The reaction of C8-OH with C5 owned the highest activation energy (41.9 kJ/mol), this step was more sensitive to reaction temperature than those of other steps. [ABSTRACT FROM AUTHOR]

Bio-oil, a complex mixture of organics, can be a source for automobile fuel and for chemicals, it is advantageous to separate the complex mixture to simplified fractions for further treatments. Herein, wood-tar fractionation by column chromatographic separating method by eluting solvents of cyclohexane (or petroleum ether[PE])-dichloromethane-methanol with adsorbent of acidic Al2O3was investigated. It was found that alkoxyl-monophenols were more concentrated in the cyclohexane or PE fraction. In the dichloromethane fraction, alkyl-monophenols were abundant, and particularly the content of 1-(4-hydroxy-3-methoxyphenyl)-2-propanone after eluted by PE was distinctly higher. The diphenols of 1,2-benzenediol and 4-methyl-1,2-benzenediol in the methanol fraction were particularly in high contents. [ABSTRACT FROM AUTHOR]

Abstract: The catalytic gasification of char from co-pyrolysis of coal and wheat straw was studied. Alkali metal salts, especially potassium salts, are considered as effective catalysts for carbon gasification by steam and CO2, while too expensive for industry application. The herbaceous type of biomass, which has a high content of potassium, may be used as an inexpensive source of catalyst by co-processing with coal. The reactivity of chars from co-pyrolysis of coal and straw was experimentally examined. The chars were prepared in a spout-entrained reactor with different ratios of coal to straw. The gasification characteristics of chars were measured by thermogravimetric analysis (TGA). The co-pyrolysis chars revealed higher gasification reactivity than that of char from coal, especially at high level of carbon conversion. The influence of the alkali in the char and the pyrolysis temperature on the reactivity of co-pyrolysis char was investigated. The experimental results show that the co-pyrolysis char prepared at 750 °C have the highest alkali concentration and reactivity. [Copyright &y& Elsevier]

The lignin-rich biomass materials can widely be obtained from the resources of black liquor and lignocellulose fermentation residue. The reutilization of the waste lignin-rich biomass material relates to environment, energy, and materials, and thus worth for investigation with great enthusiasm. In this paper, the pyrolysis of corn straw fermentation residue (CSFR) under catalysis of three zeolites of HSAPO-34, HZSM-5, and NaY zeolite were investigated via the instrument of Py-GC/MS. The results showed that the main pyrolytic products were alkoxy phenols, alkoxy aromatics, 2,3-dihydro-benzofuran, alkyl phenols, and alkyl aromatics. Additionally, some acids, long-chain hydrocarbons, and saccharides were also identified. Comparatively alkyl aromatics could be more generated under the catalysis of HZSM-5, while NaY zeolite promoted the formation of phenol more distinctly. HSAPO-34 exerted a weakest influence to all product components with close similarities to the non-catalytic curves. The different catalytic behaviors of the three zeolites could be attributed to their different acidities and textural structures. [ABSTRACT FROM AUTHOR]

Abstract: Biomass can be converted to liquid product for fuels and for chemicals by hydrothermal treatment. A method for further treatment of the liquid product much depends on the composition determination, and therefore analysis of the liquid product is important. The much water makes the analysis difficult, while much pretreatment will make the analysis complicated and bring more error sources. Herein hydrothermal treatment of cellulose was carried out, and the liquid product was directly analyzed by GC/MS. The major components were identified as some small acids, ketones, some five ring oxygen-containing compounds, and small amounts of some phenol derivatives. Specially, the content of the major component of levulinic acid in two reaction systems are compared, and the effect of the water solvent on the levulinic acid content is discussed. Phenol in the product is specially analyzed by MS/MS mode for assurance, and the result confirms the existence of phenol in the liquid product by hydrothermal treatment of cellulose. [Copyright &y& Elsevier]

Abstract: Acetol, as one of the components in biomass pyrolysis liquid, is a high value added compound for medicine synthesis. Benefit may be obtained if acetol can be extracted from the pyrolysis liquid, while the instability of acetol makes the concentrating difficult. In this paper, the concentrating of acetol from wood vinegar is preliminarily investigated, and the conditions of distillation, solvent extraction, and Na2CO3 effect on the concentrating result are discussed. Herein the content of acetol can be concentrated from below 4% in the raw wood vinegar to above 60%, and the number of main components reduce from over 20 to 5, while the yield of acetol is still rather low. It was found that in the organic solution distillation process, acetol can be easily concentrated from 1% to above 40%, while a further distillation of the concentrated acetol system was rather hard. The conversion of acetol in the distillation process was probably an important cause to the low yield of acetol, and a lower distillation temperature was advantageous for the concentrating of acetol. [Copyright &y& Elsevier]

The ash fusion characteristics are important parameters for thermochemical utilization of biomass. In this research, a method for measuring the fusion characteristics of biomass ash by Thermo-mechanical Analyzer, TMA, is described. The typical TMA shrinking ratio curve can be divided into two stages, which are closely related to ash melting behaviors. Several characteristics temperatures based on the TMA curves are used to assess the ash fusion characteristics. A new characteristics temperature, T m , is proposed to represent the severe melting temperature of biomass ash. The fusion characteristics of six types of biomass ash have been measured by TMA. Compared with standard ash fusibility temperatures (AFT) test, TMA is more suitable for measuring the fusion characteristics of biomass ash. The glassy molten areas of the ash samples are sticky and mainly consist of K-Ca-silicates. [ABSTRACT FROM AUTHOR]

Abstract: Coal bio-oil slurries (CBSs) were prepared by blending coal with bio-oil from the fast pyrolysis, and their apparent viscosities were measured by a rotary viscometer. The influences of coal rank, solid concentration, particle size distribution and temperature on the apparent viscosity and rheological properties of slurries were investigated. Additionally, the grey relational analysis was employed to determine the order of importance of factors affecting the apparent viscosity for different rank coals. Results show that, the CBS exhibits non-Newtonian fluid behavior and can be described by Herschel–Bulkley equation. The main factors for different rank coals affecting apparent viscosity of CBS are inherent moisture and carboxyl groups. The maximum solid concentration of CBS can reach 45–47 wt. % for Shenmu bituminous coal. Appropriate solid particle size distribution and preparation temperature can provide satisfied slurries with low viscosity. [Copyright &y& Elsevier]

Gasification is a promising technology to dispose antibiotic mycelial dreg (AMD) which is a typical pharmaceutical hazardous bio-waste. However, the gasification of AMD is rarely studied. Since char gasification is the key step in the gasification process, the present work focused on the steam gasification of char. The influence of inorganic elements inside AMD char (mainly P, K and Ca) on the char gasification reactivity is investigated. Particularly, the effect of P on char gasification reactivity was deeply studied, and the co-effect of P, K and Ca on char gasification reactivity was firstly studied and explained. The obtained results suggested that P can deactivate the catalytic function of K and Ca on char gasification by forming K-phosphates and Ca-phosphates. The existence form of P can affect its inhibitory effect on K and Ca, and the pyrophosphate P had a stronger inhibiting effect than orthophosphate P. The deactivation of P on K is related to the ratio of K to P, and the bigger the ratio of K to P the less the deactivation of P on K. The existence of Ca can effectively eliminate the deactivation of P on K by reacting with P to form more stable Ca 3 (PO 4) 2. • Samples gasification reactivity difference mainly come from inorganic difference. • The effect of P on char gasification reactivity was deeply studied. • P can deactivate the catalytic function of K and Ca on char gasification. • The deactivation of P relates to the existence form of P and the ratio of P to K. • The existence of Ca can effectively eliminate the deactivation of P on K. [ABSTRACT FROM AUTHOR]