Advanced Materials Research Vols. 724-725

Abstract: Willow is an abundant plant in many countries all over the world. It has an extremely rapid growing rate, and it can be considered as a sustainable raw material wood resource. In this study, H₃PO₄ of catalyzed willow pyrolysis was investigated by means of CP-GC-MS. Moreover pyrolysis products such as furfural, levoglucosenone,levoglucosan and phenolic compounds was ananlyzed. The results indicate that H₃PO₄ shows increased selectivity towards sugar and furan compounds at the expense of acetic acid and phenolic compounds. The biomass treatment with H₃PO₄ enhances dehydration and decarbonylation of levoglucosan resulting in more furfural and levoglucosenone, promoting the lignin to form carbon rather than phenolic compounds. and inhibit acetic acid formation.. The content of the major sugar compounds reached 50% in the prensence of catalyst. The content of the major furan compounds enhanced, mainly furfural.

Abstract: Biodiesel is a renewable, biodegradable, and nontoxic fuel. At present, biodiesel is primarily produced in batch reactors in which the required energy is provided by heating accompanied by mechanical mixing. Alternatively, ultrasonic processing is an effective way to attain required mixing while providing the necessary activation energy. Biodiesel was synthesized by soybean oil using ultrasonication and alkali-acid catalysis method. Its structure was characterized by gas chromatograph, and the effects of various factors on transesterification rate were studied. The results show that a biodiesel yield in excess of 98% can be achieved in 30 min, methanol/oil molar ratio of 6:1, alkali-acid catalysis includes 0.5% of NaOH and 0.5% of solid super acid.

Abstract: In this paper, the sweet sorghum straw by alkali pretreatment has been fermented to alcohol with synchronized hydrolysis and fermentation technology. According to the quadratic orthogonal rotating of four factors combination experimental design, the test studied the relationship between the nutrient additive amount about (NH₄)₂SO₄, KH₂PO4, MgSO₄·7H₂O, CaCl₂ and alcohol yield, meanwhile this fermentation 1conditions were optimized. By analysis, these factors impacted alcohol yield and the mathematical equations has been established about four factors on the yield of alcohol. The results showed that a significant regression equation was obtained. The optimum conditions for alcohol yield are obtained, (NH₄)₂SO₄ 0.09 percent, KH₂PO₄ 0.1 percent, MgSO₄·7H₂O 0.414 percent, CaCl₂ 0.385 percent, at this time alcohol yield is 13.07 percent (by weight).

Abstract: Biogas production efficiencies from sole aquatic vegetables waste and plus with straw were investigated in this research. The results as flowns:The biogas production of 3375 ml with 62% CH₄ content was achieved when the ratio of the aquatic vegetables waste to the straw was 15:35 (g/g), which is much higher than the control using aquatic vegetables waste or straw as sole raw fermentation material to the extent of 15.85%-37.72%. And the volatile solids (VS) and total solids (TS) drastically change also be coincided with the biogas production. Which pyruvic acid, the acetic acid and citric acid content lower than that of control (the aquatic vegetables waste, the aquatic vegetables waste and the straw at ratio of 25:25 (g/g), the straw) 27.32%-44.35%, 37.77%-57.52%, 30.78%-46.52% respectely. The results implied that with certain proportions, aquatic vegetables waste can promote the biogas generated form straw fermentation.

Abstract: We conducts a systematic study on the biological sources of the sediment organic matter through the analysis of the organic carbon and nitrogen content in the sediments of Poyang Lake, the n-alkanes as biomarker and the characteristics of the compound-specific isotope of n-alkanes. It is found that the C/N ratio of organic matter is less than 10 in Poyang Lake and that the organic matter mainly originates from lacustrine aquatic organism. The short-chain hydrocarbon takes absolute advantage in the n-alkanes. The value of C₂₁^-/C₂₂⁺ is greater than 1, which shows that the biomass of bacteria and algae is greater than the sum of the aquatic submerged plants and terrigenous organisms biomass. The value of (nC₁₅+nC₁₇)/(nC₂₃+nC₂₅) of n-alkanes is greater than 2, which reveals that bacteria and algae have an absolute predominance in aquatic organism. The high carbon n-alkanes come from terrigenous plants and their compound-specific carbon isotope demonstrates that C₃ plant is the main biological source.

Abstract: This study was carried out to investigate the suitable technique for increasing the stalk sugar content of two sweet sorghum cultivars (salt-tolerant cultivar Jitianza 2 and salt-sensitive cultivar Lvneng 1) in saline soils of Yellow River Delta. Stalk sugar content of sweet sorghum in saline soil was significantly increased using the following integrated cultivation technique: (1) increasing organic fertilizer level; (2) applying optimum phosphorus and potassium fertilizer; (3) surface fertilizer application; (4) cultivating salt-tolerant sweet sorghum cultivars; (5) planting with plastic mulching; (6) planting in the early of the optimum seedling time (sowing as early as possible); (7) removing tillers during seedling stage; (8) cutting spike by half-strength before flowering. Jitianza 2 had higher stalk Brix than Lvneng 1 under the same cultivation condition. Therefore, planting salt-tolerant sweet sorghum cultivars in saline soil combined with these integrated cultivation techniques can get higher stalk sugar content in Yellow River Delta of China, which was beneficial for energy alcohol production from sweet sorghum.

Abstract: Hybrid Pennisetum (Pennisetum americanum × P. purpureum) is a popular bioenergy grass that could also serve as forage for livestock production. In a pot experiment, salinity inhibited hybrid Pennisetum growth, photosynthesis, soluble sugar content, and NR activity; decreased K⁺ content; and increased Na⁺ content. These adverse effects of soil salinity were reduced, however, by applications of NO₃^--N up to 5 mmol·L^-1; higher applications of NO₃^--N increased soil salinity problems. These findings will be useful for the production of hybrid Pennisetum as a biofuel on saline land.

Abstract: A model was prepared for the preparation of biochar from the biomass of mushroom residue at different carbonization temperature (350 °C,450 °Cand 550 °C) for adsorption characteristics of ammonium nitrogen in water through different ammonium nitrogen concentration, reaction time, pH and temperature. The investigation result showed that the adsorptive amount of these three biochar substances increased quickly with the initial concentration (0-2 h) and the adsorption equilibrium was reached after 4 hours. The adsorptive amount of these three biochars increased with the rise of pH from 5 to 9. Different temperature preparation of biochar on ammonium nitrogen adsorption increases with the rise of temperature. Different temperature preparation of biochar on ammonium nitrogen adsorption amount is in the order of 550 °Cbiochar > 450 °Cbiochar > 350 °Cbiochar.

Abstract: Direct drive permanent magnet synchronous generator have the advantages of direct drive, simple structure, high efficiency and so on, in which make it become one of mainstream models within MW wind turbine presently. Making the direct drive permanent magnet wind power generation system as the main research object, based on the principle of the operating characteristics of direct drive permanent magnet synchronous wind generator ( DDPMG ), establish mathematical model of the whole system including wind velocity, wind turbine, direct drive permanent magnet synchronous generator and machine side converter, Appling the method of stator flux orientation to make the study of vector control strategy, to build the simulation model of direct drive permanent magnet synchronous generator system with Matlab and simulate when wind speed changes by step, the results validate the reasonableness of the model and the correctness and feasibility of the control strategy.

Abstract: Due to the fluctuations and intermittency of wind power, large-scale wind farms integration will cause adverse impact on the safety and stability of the system,such as harmonic pollution, bad power quality, system stability destruction.On the basis of multiple constraints, including hydropower’s and thermal power’s operating characteristics, determination of reserve capacity considering wind power forecasting bias, climbing speed constraints, and maximum output constraints, this paper proposed a control strategy of joint coordination of wind, hydropower and thermal power, which suppressed the fluctuations of wind power effectively. At last, the article give a simulation to verify the feasibility of the control strategy to stabilize system frequency.