In this paper,the raw materials of hybrid Pennisetum were pretreated in different conditions of high voltage pulsed electric field(HPEF)to improve its material utilization ratios and biogas production rates of anaerob...In this paper,the raw materials of hybrid Pennisetum were pretreated in different conditions of high voltage pulsed electric field(HPEF)to improve its material utilization ratios and biogas production rates of anaerobic fermentation.Then,anaerobic digestion experiments were conducted within 32 days at moderate temperature(35℃)with TS mass fraction(6%),inoculation rate(20%)and initial pH(7.0).It is indicated that compared with the control group,9 groups of hybrid Pennisetum pretreated by HPEF are obviously superior in gas production efficiency of anaerobic fermentation,and higher in cumulative gas production,peak daily gas production and maximum methane concentration;that the most remarkable stimulation occurs in the HPEF condition of 15 kV/120 Hz/60 min,in that situation,the cumulative gas production in the fermentation period of 32 days is up to 9587 mL,26.95%higher than that of the control group,the peak daily gas production increases and the range of peak period extends.It is demonstrated that the optimal HPEF pretreatment time is 60 min and three HPEF parameters have a better effect on gas production in the order of voltage>time>frequency;and that the effect degree of treatment parameters on peak daily gas production is voltage,frequency and time in turn.It is concluded that HPEF can improve material utilization ratio and gas production rate of hybrid Pennisetum by anaerobic fermentation and shorten the gas production cycle.By virtue of this physical pretreatment method,the resource of Pennisetum is utilized sufficiently and the classes of energy plants are enlarged effectively.展开更多
[Objective] This study aimed to test the effects of high-intensity pulsed electric field on the amino acid content in Pu’er tea leaves. [Method] The amino acid contents of fermented and unfermented the leaves of larg...[Objective] This study aimed to test the effects of high-intensity pulsed electric field on the amino acid content in Pu’er tea leaves. [Method] The amino acid contents of fermented and unfermented the leaves of large-leaf Pu’er tea variety produced in Yunnan Mengku, were measured before and after the treatment with high-intensity pulsed electric field （HPEF）. [Result] The difference of amino acid contents was notable between fermented and unfermented tea leaves produced in the same year. The amino acid content of unfermented tea leaves was larger than that in fermented tea leaves. The amino acid content in tea leaves decreased over time during storage. HPEF treatment under al the conditions improved the amino acid content in tea leaves. [Conclusion] This experiment provides theoretical foundation for the application of HPEF in processing of Pu’er tea leaves.展开更多
为提高杂交狼尾草厌氧发酵的原料利用率及沼气产气率,采用不同条件下的高压脉冲电场(High Voltage Pulsed Electric Field,缩写为HPEF)对杂交狼尾草原料进行预处理,在中温(35℃)、TS质量分数6%、接种率20%、初始pH值为7.0的条件下,进行3...为提高杂交狼尾草厌氧发酵的原料利用率及沼气产气率,采用不同条件下的高压脉冲电场(High Voltage Pulsed Electric Field,缩写为HPEF)对杂交狼尾草原料进行预处理,在中温(35℃)、TS质量分数6%、接种率20%、初始pH值为7.0的条件下,进行32 d厌氧消化试验。结果表明:(1)经HPEF预处理的9组杂交狼尾草厌氧发酵的产气效果均明显优于对照组,其累计产气量都比对照组高,日产气量的峰值及甲烷浓度的最大值也有所增加;(2)促进作用最显著的HPEF条件为15 kV/120 Hz/60min,其在32 d的发酵期间累计产气量达9 587 mL,与对照组相比增幅达26.95%,其日产气量峰值与高峰期范围也有所增加;发现HPEF的最佳处理时间为60 min,HPEF三参数对产气效果均有着较好的影响,影响程度大小排序为电压>时间>频率;(4)各处理参数对日产气量峰值的影响顺序依次为电压、频率、时间。结论认为:HPEF能够有效提高杂交狼尾草厌氧发酵的原料利用率及产气率、缩短产气周期,该物理手段的预处理方法充分实现了狼尾草的资源化利用,有效扩充了能源植物的种类。展开更多
基金Project supported by the National Natural Science Foundation of China(No.61561054)the Biogas Industrialization Technology Engineering Research Center in Universities of Yunnan Province.
文摘In this paper,the raw materials of hybrid Pennisetum were pretreated in different conditions of high voltage pulsed electric field(HPEF)to improve its material utilization ratios and biogas production rates of anaerobic fermentation.Then,anaerobic digestion experiments were conducted within 32 days at moderate temperature(35℃)with TS mass fraction(6%),inoculation rate(20%)and initial pH(7.0).It is indicated that compared with the control group,9 groups of hybrid Pennisetum pretreated by HPEF are obviously superior in gas production efficiency of anaerobic fermentation,and higher in cumulative gas production,peak daily gas production and maximum methane concentration;that the most remarkable stimulation occurs in the HPEF condition of 15 kV/120 Hz/60 min,in that situation,the cumulative gas production in the fermentation period of 32 days is up to 9587 mL,26.95%higher than that of the control group,the peak daily gas production increases and the range of peak period extends.It is demonstrated that the optimal HPEF pretreatment time is 60 min and three HPEF parameters have a better effect on gas production in the order of voltage>time>frequency;and that the effect degree of treatment parameters on peak daily gas production is voltage,frequency and time in turn.It is concluded that HPEF can improve material utilization ratio and gas production rate of hybrid Pennisetum by anaerobic fermentation and shorten the gas production cycle.By virtue of this physical pretreatment method,the resource of Pennisetum is utilized sufficiently and the classes of energy plants are enlarged effectively.
基金Supported by Scientific Research Fund from Department of Education of Yunnan Province(2012Z134C)~~
文摘[Objective] This study aimed to test the effects of high-intensity pulsed electric field on the amino acid content in Pu’er tea leaves. [Method] The amino acid contents of fermented and unfermented the leaves of large-leaf Pu’er tea variety produced in Yunnan Mengku, were measured before and after the treatment with high-intensity pulsed electric field （HPEF）. [Result] The difference of amino acid contents was notable between fermented and unfermented tea leaves produced in the same year. The amino acid content of unfermented tea leaves was larger than that in fermented tea leaves. The amino acid content in tea leaves decreased over time during storage. HPEF treatment under al the conditions improved the amino acid content in tea leaves. [Conclusion] This experiment provides theoretical foundation for the application of HPEF in processing of Pu’er tea leaves.
