Development of highly microporous activated carbon from the alcoholic beverage industry organic by-products

This work has the aim to employ the agave bagasse, a waste from Tequila and Mescal industries, to obtain a product of high commercial value such as activated carbon. The activated carbon production methodology was based on a chemical activation, by using ZnCl₂ and H₃PO₄ as activating agent and agave bagasse as a natural source of carbon. The activation temperature (150-450 °C), activation time (0-60 min) and weight ratio of activating agent to precursor (0.2-4) were studied. The produced carbon materials were characterized by scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and nitrogen physisorption at −196 °C. In addition, the activating agent recovery was evaluated. We were able to obtain highly microporous activated carbons with micropore volumes between 0.24 and 1.20 cm³/g and a surface area within 300 and 2139 m²/g. These results demonstrated the feasibility to treat the industrial wastes of the Tequila and Mescal industries, being this wastes an excellent precursor to produce highly microporous activated carbons that can be processed at low activation temperatures in short times, with the possibility of recycling the activating agent.     

Structural Analysis of Pyrolysis Products From Pyrolysis of Hazelnut (Corylus Avellana L.) Bagasse

Fixed-bed pyrolysis biooils of hazelnut (Corylus Avellana L.) bagasse have been identified for their structures. The condensed biooils were analyzed for their properties as fuels and compared with petroleum-derived products. The biooil was analyzed by Fourier Transform infrared spectroscopy (FTIR) and ¹H-NMR spectra. The biooils were fractionated into pentane solubles and insolubles. Pentane solubles were then solvent fractionated into pentane, toluene and methanol subfractions by fractionated column chromatograpy. The aliphatic subfractions of the biooils were then analyzed by capillary column gas-liquid chromatography (GC). In addition, the physical properties, higher heating value and elemental analysis of the biooil were determined. The empirical formula of biooil that has a heating value of 34.57 MJ/kg was established as CH_1.45O_0.33N_0.127. Chromatographic and spectroscopic studies on the biooil showed that the oil obtained from hazelnut bagasse could be used as a renewable fuel and chemical feedstock.     

Distribution of Anionic Groups in TMP Suspensions

Abstract

The distribution of anionic groups in fibres, fines, the colloidal fraction, and the dissolved fraction of thermomechanical pulp (TMP) suspensions was determined. The influence of extraction, alkaline treatment, and peroxide bleaching of spruce TMP were also studied.

Spruce TMP was extracted with hexane, treated with alkali, or bleached with peroxide. Suspensions were made at pH 5.5 or 8, and fractionated into long fibres, large fines, small fines, a colloidal fraction, and a dissolved fraction. The surface and total charge of the fractions were determined separately by polyelectrolyte titration. To determine the origin of the charges, the contents of fatty acids, resin acids, and acidic units in polysaccharides in the different fractions were determined by gas chromatography.

Extraction of TMP with hexane prior to fractionation increased the measured total and surface charge of the fibres. The removal of wood resin probably uncovered some anionic groups on the fibre surface, or improved the penetration of the polymers into the pores of the fibres. The total charge, determined with polybrene titration, of the fines and the colloidal fraction was lower when the resin had been removed, while the surface charge, determined with poly-DADMAC, was not greatly affected.

Alkaline treatment of the TMP increased both the total charge and the surface charge of the fibres and fines, mainly because of demethylation of pectins. Alkaline treatment also increased the total and surface charge of the dissolved substances, due to the release of pectic acids into the water phase. Alkaline peroxide bleaching further increased the total and surface charge of fibres and dissolved substances, most likely due to oxidation of lignin. The total charge and the surface charge of the colloidal substances, consisting mainly of wood resin, were only slightly affected by alkaline treatment and peroxide bleaching.

The anionic charge in TMP suspensions originated mainly from free uronic acids in the xylans, arabinogalactans, and pectic acids. The contribution from the fatty and resin acids was substantial only for the colloidal fraction.     

浅析江联公司对甘蔗渣锅炉的开发设计

文章介绍了28t/h、40t/h燃蔗渣锅炉的设计思路、结构特点、汽水流程特点、冷热风管道系统,锅炉验收成功也标志着江联公司的设计制造技术及IS09001质量管理水平达到了较高的国际水准.     

基于甘蔗渣的生物降解材料研究(Ⅰ)甘蔗渣的液化反应和聚醚酯多元醇的制备

通过对甘蔗渣液化反应的研究。以探索一种甘蔗渣新的利用方法。在以硫酸为催化剂的条件下讨论了液化试剂，液固比及反应温度等因素对甘蔗渣液化反应的影响。结果表明，甘蔗渣在PEG#400中的液化率可达到96%，而且其中的木质素全部被液化，所得液化物为聚醚酯多元醇，羟值为280mgKOH/g-380mgKOH/g，能满足中强度硬质聚氨酯泡沫的要求。     

Biogas generation from bagasse-based paper mills by anaerobic digestion

Bagasse-based paper mills in developing countries do not have sophisticated waste water treatment technology to combat water pollution released by these mills. This paper presents an overview of bagasse handling and sources of waste generation, the seriousness of pollution discharge, and treatment options available to tackle the waste water derived from bagasse-based paper mills. Extensive laboratory treatability studies indicate that anaerobic digestion for biogas generation is a viable method for handling bagasse-based paper mill wastes. The waste water was treated at an organic loading of 0.8 kg BOD m^?3 day^?1 and 1.6 kg COD m^?3 day^?1 and a detention time of 10 days, achieving 90% reduction in BOD and COD without supplementation of any nutrients. With a yield coefficient of 0.5, the average quantity of cells produced per day was calculated to be 1.683 kg day^?1 or 0.25 kg cells produced kg^?1 BOD removed. Intermittent checking on excess alkalinity in the anerobic system is necessary for achieving maximum treatment efficiency.     

Dilute mixed-acid pretreatment of sugarcane bagasse for ethanol production

Integral utilisation of bagasse is a high priority for the diversification of the sugarcane industry. The application of a biorefinery philosophy to bagasse utilisation requires its fractionation into its main components: cellulose, hemicelluloses and lignin. The first stage in that process is the pretreatment, in which a considerable part of hemicelluloses is solubilised, and cellulose is activated towards enzymatic hydrolysis. In this work, a pretreatment method using a mixture of sulfuric and acetic acid is investigated. Two different solid-to-liquid ratios (1.5:10 and 1:10) were used in the pretreatment. Both conditions efficiently hydrolysed the hemicelluloses giving removals above 90%. The extractive components were also effectively solubilised, and lignin was only slightly affected. Cellulose degradation was below 15%, which corresponded to the low crystallinity fraction. The analysis of the morphology of pretreated bagasse confirmed the results obtained in the chemical characterization.     

水蒸气氛围下甘蔗渣热解气化条件的研究

在试验条件下，考察反应温度、升温速率、物料颗粒大小等因素对蔗渣在水蒸气中的热解气化特性的影响。试验结果表明，热解终温越高，物料粒径越小，越有利于产生高质量的热解气。热解终温是热解气化过程主要的决定因素，在先到达热解终温，再通入水蒸气的操作条件下，升温速率的改变对气化效果的影响并不突出。试验在最佳条件(采用粉末物料，在1000℃下进行热解)下，可以得到高热值(10MJ／m^3)合成气和较高的产气率(1．7m^3／kg)。     

A study on the recovery of xylitol by batch adsorption and crystallization from fermented sugarcane bagasse hydrolysate

Xylitol was recovered from fermented sugarcane bagasse hemicellulosic hydrolysate by adsorption and crystallization procedures. Silica gel adsorption was employed to purify the broth containing xylitol. In this step, different mixtures of the solvents ethyl acetate, ethanol and acetone were used as eluent, and different proportions of fermented broth volume incorporated per gram of silica gel (V_b/M_sg, varying from 1.0 to 2.0 cm³ g^?1) were used to pack the column employed as stationary phase bed. The xylitol purification efficiency varied for each mixture of solvent, and for each V_b/M_sg ratio used. The purified broth was submitted to different crystallization procedures (cooling, concentration and supplementation with commercial xylitol) aiming to recover xylitol crystals. The best result (60% crystallization yield and 33% total recovery of xylitol from fermented broth) was obtained when the column was packed with a V_b/M_sg ratio of 2 cm³ g^?1, and the broth was purified with a mixture of ethyl acetate and ethanol, concentrated 6.5‐fold, and supplemented with commercial xylitol to force the precipitation. Copyright © 2006 Society of Chemical Industry     

光催化漂白硫酸盐蔗渣浆及漂后浆的红外光谱分析

对5种光敏剂用于硫酸盐蔗渣浆漂白进行研究,发现在同一条件下,曙红和玫瑰红光催化漂白硫酸盐蔗渣浆效果较好,在漂白过程中共轭羰基(-C=O)发生了较多断裂。EO进行光催化漂白较加AO、LF、RB和MB4种光敏剂有利于紫丁香基型木素的降解。并且在加各种光敏剂进行光催化漂白过程中,纤维素主链的特征吸收峰都发生了一定程度的下降,而加曙红、玫瑰红和亚甲蓝时吸收峰下降较大。