Advanced Materials Research Vols. 512-515

Abstract: The Poyang Lake Eco-Economics Zone includes 38 counties where 25 relatively poor counties are close to the lake. The country has been helping those rural areas and enhancing farmers’ living standard for many years, however, due to the historical, geographical, climatic reasons, farmers’ living standards do not have significant improvement so far. In addition to government subsidy, another way to enhance farmers’ income is to encourage of bioenergy production in a form of biochar/pyrolysis. Biochar/pyrolysis is a feasible method to produce clean and renewable energy along with substantial environmental and economic benefits such as increase in farmer’s revenue. However, there are also difficulties in its application due to transportation, feedstock collection, and storage. However, there need further investigation to quantify the gains and losses of pyrolysis/biochar technology.

Abstract: This research is to produce biogas by using cassava waste cake as a feed stock in a two-stage anaerobic digestion system. The system was designed and built as a pilot-scale plant consisting of mixing tank, a fermented acid tank, two methanogenic tanks and a storage tank connecting in series. Feed stocks were mixed in the mixing tank and then fed into the fermented acid tank. The feeding was a batch feeding with a hydraulic retention time of 12 days. The system was operated to determine the biogas production rate and the net energy production. The temperature of the fermented tanks were set at 35°C during the testing period. The pH value was initially set at 8. The organic loading rate was at 0.417 g COD/ L-day. The results showed that the system can produce biogas at a rate of 140 L/day in average. The net energy production was found to be 48.52 W-h/day.

Abstract: A Pichia pastoris cell-surface display system was constructed using a Flo1p anchor system containing N-terminal flocculation functional domain (874 residues, FS), derived from Saccharomyces cerevisiae. The lipase from Rhizopus oryzae with a pro sequence (ProROL) and green fluorescent protein (GFP) gene were successfully cloned and genetically fused to the anchor system with their C-terminus free. Fluorescence microscope was used to detect the GFP displayed on the recombinant P. pastoris cell surface. The results showed that the yeast surface display system using Flo1p as the anchor protein was successfully constructed, and the activity of ProROL displayed on KM71H reached to 217.15 U/g, much higher than 61.30 U/g reported by Matsumoto. Besides, the yeast surface display system could effectively shorten the fermentation time compared with traditional fermentation.

Abstract: The development of biomass energy industry carries a great significance to alleviating the shortage of fossil energy supply, to optimizing energy structure, safeguarding national energy security, and establishing stable energy supply system. In this paper, the writer introduces basic situation and characteristics of biomass energy, then current situation of biomass energy utilization in our country is summarized, and the development prospect and significance of biomass energy are analyzed at last.

Abstract: To clarify the degradation mechanism of arabinose in a subcritical water system, the degradation process kinetics of arabinose and furfural in a subcritical water system was studied for temperatures from 210 to 250°C and under pressure of 10Mpa. The activation energy and frequency factor for the degradation of each substrate were estimated from the temperature dependence of the rate constant. The molar yield of a arabinose to furfural was ca. 0.3 at any temperature, Acidic compounds were also formed from the arabinose in proportion to the amount of consumed substrates. The formation of acidic compounds resulted in a rapid decrease in pH.

Abstract: The paper is about the summing-up of production and research of biomass briquettes (hereinafter referred to as BDMF) that mainly rely on crop stalks. Core technology and policy Issues from productive practice are mainly introduced. The paper exposes the characteristics of BDMF of China and foreign countries’, and the differences between them; at last, suggestions on development of Chinese BDMF in the future.

Abstract: This thesis does thermal gravimetric analysis（TGA）studies on Chinese fir sawdust biomass by integrated thermal analyzer under vacuum conditions. Through the analysis on lostmass curve at different heating rate of 10, 15, 20 and 30°C/min, we found the process of Chinese fir sawdust vacuum pyrolysis can be mainly divided into three stages: evaporation of free water and combined water desorption, rapid lostmass of pyrolysis and slow decomposition of residues. The lostmass major temperature range is between 250 ~ 450°C, the peak temperature is between 365 ~ 400°C. When the pyrolysis temperature is 500°C, vacuum pyrolysis reaction of Chinese fir sawdust has basically completed. As the heating rate rises, the lostmass curve is moving to the right, the peak temperature is shifting to higher temperature, and the temperature range of thermal decomposition reaction widens significantly. According to experimental datas, we tried to obtain the vacuum pyrolysis dynamic parameters of Chinese fir sawdust, and the results are that the apparent activation energy of vacuum pyrolysis reaction of Chinese fir sawdust biomass is 128.34kJ/mol, with the pre-exponential factor being 6.42×109 and reaction order being 1.08, similar to first order reaction.

Abstract: Corn straw from steam-explosion treatment process was treated with different organic solvents to reduce the inhibition for the sequent enzymatic hydrolysis and fermentation. The detoxified substrates (100 g DW/L) were hydrolyzed with a blend of Novozym 188 (15 IU/g cellulose), Celluclast CP cellulase (15 FPU/g cellulose) and lignase (15 IU/g hemicellulose). The reducing sugar was bio-converted to ethanol with separated hydrolysis and fermentation processes using Pachysolen tannophilus P-01. The reducing sugar yield varied from 34.8 to 89.7% depending on the detoxification solvents and modes. The highest ethanol yield (96.1% of theoretical value) was obtained with the combined extraction of ether and acetone.

Abstract: The effect of particle size on the water-soluble substances and microscopic structure of sorghum straw powder were investigated. Sorghum straw powder with four particle size (300 ~ 450μm, 125 ~ 150μm, 97 ~ 105μm, 330 ~ 420nm ) were studied for analysing changes of water-soluble substances and microscopic structure. The results showed that with the particle size decreasing the pH value of water-soluble substances decreased, the concentration of reducing sugar in water increased firstly then began to decrease when it reached to a certain value, the crystallinity of sorghum straw powder decreased, and the degree of polymerization of sorghum straw was lowered ,respectively.

Abstract: In order to explore the forming rules of ethyl levulinate from glucose in ethanol, several reaction parameters including the initial glucose concentration (10~30 g/L), sulfuric acid concentration (0.1~2 wt%), temperature (170~200 °C) and water addition were investigate, respectively. In addition, effect of the acid concentration on ethanol conversion was also studied. The results show that lower initial glucose concentration is helpful to improve the ethyl levulinate yield, and higher acid concentration can improve the conversion of glucose to ethyl levulinate, which also can improve the condensation of the ethanol. However, higher temperature is unfavorable for the increase of ethyl levulinate yield, and the ethyl levulinate decreased significantly with the increase of water addition.