两种底物厌氧发酵产氢能力的比较

The Comparison of Hydrogen Production Capacity with Two Substrates in the Anaerobic Fermentation

以糖蜜废水和人工稀释的赤糖水为发酵底物,采用连续流搅拌槽式反应器(Continuous Stirred Tank Reactor,CSTR)作为反应装置,对两种底物厌氧发酵产氢稳定性进行了探讨。结果表明:当水力停留时间(HRT)为6.2h、温度控制在(35±1)℃、维持反应器内底物浓度负荷为3000CODmg/L时,以糖蜜和赤糖废水为底物,其最大产氢量分别为0.65L/d和1.95L/d。其液相末端组分的比例也发生了较大的变化,在发酵前28d主要以乙酸和丙酸为主,当底物由糖蜜变为赤糖时,丙酸和丁酸的比例明显下降,其比例从底物改变前的25.7%和15.4%下降到底物改变后的11.8%和9.47%,发酵类型由混合酸发酵转变为稳定的乙醇型发酵。

Abstract： The experiment took a continuous stirred tank reactor as a reacting device, which based on molasses wastewater and brown sugar wastewater as the fermentation substrate. We studied the hydrogen production capacity with the two difterent substrates under the anaerobic fermentation. The resuits showed that the maximum values of hydrogen production were 0.65L/d （molasses as the substrate） and 1.951rid （brown sugar as tFle substrate）, respectively, with the retention time （HRT） of 6.2h, temperature of （35±1）℃and the reactor substrate concentration of 3000 mgCOD/l.. At the same time, the liq- uid end components were changed in a large scope. During the first 28 days, acetic acid and propionic acid were the main components, when molasses was replaced by brown sugar as the substrate, the percentages of propionic acid and butyrate acid decreased significantly from 25.7%, 15.4% to 11.8%, 9.47%, respectively. The fermentation type was transformed from the mixed-acid-type fermentation to ethanol-type fermentation.