基于CSTR和UASB工艺的沼气工程实例分析

随着沼气技术的日渐成熟,各相关工艺不断发展完善,其中CSTR和UASB因其具备工艺简单,施工管理方便和运行效果好等优点而得以广泛运用。该文通过分析若干典型CSTR和UASB沼气工程,将二者特性进行对比,笔者认为CSTR具有独特的搅拌处理工艺。该工艺①可处理浓度较高的废液(TS 8%～12%);②发酵均匀产气率高;③处理量大,产沼气量多;④反应器结构简单,便于启动运行和管理。目前国外沼气工程技术先进的国家仍采用该工艺。与CSTR相比UASB工艺具有①占地面积小,前期投资成本低;②有机负荷高,处理高浓度有机废水的效果显著;③水力停留时间短,大量活性污泥聚集底部,发酵效果显著。基于这两种工艺的不同特性建议各地在兴建沼气工程时,应结合当地实情灵活运用,在引进先进技术的同时鼓励自主技术创新,使用适宜我国国情的高效沼气工程技术。

Analysis on Biogas Engineering Based on the Processes of CSTR and UASB

As the techniques of biogas fermentation developed rapidly,relevant processes boomed accordingly.Among these,CSTR and UASB were the most widely used in the biogas engineering due to the advantages of simpleness,convenience and efficiency.In this paper,several typical biogas engineerings based on the processes of CSTR and UASB were analyzed and compared with each other.As concluded by the author,CSTR has unique stirring process,which can treat high-concentration fermentation materials(TS 8%-12%),and produce the gas largely and uniformly;it also has simple structure,which is easy to be started and managed.It is now used in most advanced countries.Compared with CSTR,UASB occupies little area and needs little investment,it is good to process high-concentration organic wastewater,its retention time is short,most of active sludge concentrates at the bottom,the fermentation effect is remarkable.Based on the features of two processes,they should be flexibly used given local conditions.With the introduction of advanced technology,we should also innovate our own high-efficient biogas engineering technique especially for our country.