Archive for 3 月, 2012

Phase behavior and decomposition of lignin in hot-compressed water

星期六, 24 3 月, 2012

  Lignin (20%), cellulose (50%) and hemicellulose (25%) are three major constituents of typical lignocellulosic biomass like wood and grass. Among them, lignin is a phenolic biopolymer, which is the most thermal-stable and the most difficult to be degraded by normal biological or thermal methods. Additionallly, it is the industrial waste of cellulosic ethanol and paper making, which makes its recycle very significant. Adschiri group in TohokuUniversityfound that 99% of lignin degraded into phenolic oil in high temperature water-phenol (400 oC). The phenolic oil would not repolymerize to solid even after 2 h reaction. However, we did not know if these reactions were homogeneous reactions, as well as the actual reaction pathways. Professor Zhen Fang in biomass group of XTBG (Xishuangbanna Tropical Botanical Garden), CAS (http://brg.groups.xtbg.ac.cn/) collaborated withTohokuUniversity andSaskatchewanUniversity. They found that lignin was totally dissolved in hot-compressed water-phenol mixture, which greatly promoted the hydrolysis of lignin into phenolic oil. The addition of phenol prevented the repolymerization of formed phenolic oil. Afterwards, the author elucidated the homogeneous/heterogeneous pathway and mechanism of lignin degrading in hot-compressed water. According to the proposed pathway, lignin can totally be degraded into phenolic oil, which can be further processed into bioplastic, chemicals and biofuel. The related paper was published in the international journal “Bioresource Technology”. (更多…)

Fast dissolution and hydrolysis of wood

星期六, 24 3 月, 2012

  Biomass is renewable and rich, and mainly in the form of lignocelluloses. Its annual production is equivalent to ten times of the global energy consumption. Lignin (20%), cellulose (50%) and hemicellulose (25%) are three major constituents of a typical lignocellulosic biomass (e.g., wood and grass), all of which could be hydrolyzed. The production of biofuels based on edible food was unacceptable in developing countries, especially populous countries such asChina. Therefore, it is needed to develop novel bio-refinery based on lignocellulosic biomass for biofuels. (更多…)

Progress on the production of biodiesel from Jatropha oil

星期六, 24 3 月, 2012

  In July 2010, biomass group (http://brg.groups.xtbg.ac.cn/) in Xishuangbanna Tropical Botanical Garden (XTBG), CAS reported their new progress on continuous production of biodiesel from Jatropha oil. Jatropha curcas L., as the most promising plant for biodiesel production, receives much attention at both home and abroad. Jatropha oil has a high content of free fatty acids, which results in the low conversion rate and unstable biodiesel when it is directly catalyzed to biodiesel. Professor Zhen Fang developed a new two-step process to prepare biodiesel from Jatropha oil based on numerous experiments. The new process used ultrasonic radiation to transfer energy directly to the substrate molecules, then induced and enhanced the violent vibration of molecules, which resulted in remarkable faster reaction rate, shorter reaction time and reduce energy consumption as compared with other synthesis technologies. Related achievements were published in the international journal “Energy Conversion and Management”. Two patents were filed with one already authorized. (更多…)

Noncatalytic fast hydrolysis of wood

星期六, 24 3 月, 2012

  Without any pretreatment (energy-saving) and catalyst (environment-friendly), 99% of wood could be dissolved and hydrolyzed in hot compressed water within several seconds (quickly). Wood particles were rapidly dissolved firstly upon fast heated, and then hydrolyzed into sugars in the hot compressed water. Professor Zhen Fang (http://brg.groups.xtbg.ac.cn/) proposed and built up a controllable reactor for hydrolyzing wood continuously, which could convert wood to sugars quickly and continuously. This made industrialized production of wood hydrolysis possible. (更多…)

A new method for producing dye and nano-particles from wood

星期六, 24 3 月, 2012

  Wood is mainly composed of lignin (20%), cellulose (50%) and hemicellulose (25%). These components can be catalytic hydrolyzed into their corresponding monomers by conventional enzymes or liquid acids. Among them, cellulose and hemicellulose are hydrolyzed into sugars, such as glucose. Recently, Professor Zhen Fang (http://brg.groups.xtbg.ac.cn/) found that wood could be quickly dissolved and hydrolyzed to sugars in high temperature water within several seconds. Then, the sugars were degraded into compounds with different colors, which would be subsequently converted into nano-particles through polymerization and carbonization at high temperature. By quenching the ongoing reaction solutions at different temperature and different time, various dyes and carbon nano-particles were obtained. These dyes could be used in food, painting, printing and textile industries, while carbon nano-particles could be applied to prepare explosives, composite materials, fertilizers, catalyst carriers, adsorbing materials, etc. In this study, the pathways and mechanism of glucose decomposition in high-pressure hot water under homogeneous condition were proposed. Based on the research, special products could be expected and obtained under certain conditions. (更多…)