不同预处理和发酵条件对浒苔沼气产率的影响

摘要

为了有效利用绿潮海藻资源,该文开展了浒苔厌氧发酵产沼气潜力及其特性的试验研究.探讨了浒苔不同预处理、发酵温度和料液浓度对产气量和所产沼气的甲烷体积分数的影响.结果表明,粉碎粒度对浒苔厌氧发酵沼气产率有一定影响,相同条件(发酵温度为35℃和料液总固体(TS)质量分数为3％)下,粗粒(1.50 mm)比细粒(0.15 mm)的单位质量挥发性固体(VS)产气率高,分别为327.1和458.5 mL/g;发酵温度对浒苔厌氧发酵产沼气产率的影响是,随着温度的提高沼气产率先增加而后降低,当粉碎粒度为1.5 mm的浒苔在发酵料液TS质量分数为3％条件下,分别在25℃、35℃和55℃温度下发酵时,35℃的料液单位质量VS产气率比25℃和45℃分别高31.3％和7.5％；随着料液TS质量分数的提高,沼气产率先增加而后降低,利用粒度为1.50 mm的浒苔制备TS质量分数分别为3％、6％和10％的料液在35℃温度发酵时,TS质量分数为6％的料液产气率最高,达到465.2mL/g,所产沼气的甲烷体积分数比3％的料液高5.3％,且与10％的料液相当.因此在浒苔粉碎粒度为1.50 mm,料液TS质量分数为6％以及温度为35℃的发酵条件下,对提高浒苔产气量、甲烷体积分数和发酵系统稳定性比较有利.该研究可为浒苔厌氧发酵产沼气技术和设备研发以及其他大型海藻产沼气技术的研究提供参考.%For enhancing utilization of green tide algae, biogas production and characteristics of Enteromorpha prolifera were experimentally studied. Biogas yield and volumetric proportion of methane were evaluated under different pretreatment and anaerobic fermentation conditions. When mass proportion of total solid (TS) was 3% and fermentation temperature was 35 ℃, the biogas yield per unit mass of volatile solid (VS) were 327.1 mL/g and 458.5 mL/g from Enteromorpha prolifera with particle size of 0.15 mm and 1.50 mm, respectively, and the corresponding volumetric proportion of methane were 64.5% and 66.1%, Comparatively, with alkali pretreated Enteromorpha prolifera of 1.50 mm, the biogas yield per unit mass of VS and volumetric proportion of methane were 340.5 mL/g and 69.4%, respectively. With Enteromorpha prolifera of 1.50 mm and TS mass proportion of 3%, the biogas yield per unit mass of VS at 35 ℃ increased by 31.3% and 7.5% than that of 25 ℃ and 55℃ respectively, the corresponding volumetric proportion of methane increased by 10.0% than that of 25℃ and was close to that of 55℃, For Enteromorpha prolifera of 1.50 mm and fermentation at 35℃, the biogas yield per unit mass of VS was the highest when TS mass proportion was kept at 6%, the corresponding volumetric proportion of methane increased by 5.3% than that 3% and was nearly equal to that of 10%. It was accordingly' that higher biogas yield, volumetric proportion of methane and system stability could obtain from Enteromorpha prolifera with grinding particle of 1.50 mm, TS mass proportion of 6% and fermentation temperature of 35℃. The results can provide a reference for further studies on biogas production of Enteromorpha prolifera and other macro algae.