NaOH预处理花生壳厌氧发酵制取沼气的试验研究

为了探索花生壳厌氧发酵制取沼气的产气特性和潜力,利用NaOH在无流动水和常温的条件下,分别用质量分数为2%、4%、6%、8%的NaOH溶液对花生壳进行了碱性化学预处理,在中温（35±1）℃、总固TS质量分数为8%、pH为7.0～7.6条件下,利用自行设计的厌氧发酵实验装置进行批量厌氧消化试验,研究NaOH预处理对花生壳厌氧发酵过程中产气量、pH值和甲烷含量的影响规律。结果表明,4%NaOH预处理下的花生壳的总产气量为28083mL,比不使用NaOH和8%NaOH预处理的总产气量分别高48.91%和35.72%;甲烷含量最高超过60%,且平均甲烷含量高于不处理、2%和8%NaOH预处理;pH初期波动,13d后基本稳定在7.2左右。4%NaOH预处理下的TS产气率、VS产气率以及甲烷含量和不处理以及8%NaOH预处理下的差异性显著（P〈0.05）,和其他两组试验之间的差异不显著（P〉0.05）,表明4%NaOH预处理是较优的工艺条件。

Experiments on Anaerobic Digestion of Peanut Shell for Biogas Production Under NaOH Pretreatment

The effect of NaOH pretreatments on characteristics of the biogas production of peanut shell was studied by experiment.In order to improve the biogas yield and potentiality,NaOH pretreatment of peanut shell without fluid water was performed at normal temperature in different mass fractions of sodium hydroxide solution,which were 2%,4%,6%,8%.Simultaneously,another non-use NaOH pretreatment was performed under distilled water.After the pretreatment,a batch of experiments of peanut shell were conducted in a self-manufactured anaerobic fermentation reactor,under the condition of 8% mass fraction of total solid,（35±1）℃,pH value 7.0～7.6.The experiment was conducted to investigate the effect of sodium hydroxide pretreatment in different mass fractions on gas production,pH values,methane content during the process of anaerobic fermentation of peanut shell.The results showed that,the total gas production of peanut shell under 4% NaOH pretreatment was 28 083 mL,which was 48.91% and 35.72% higher than non-use of NaOH pretreatment and 8% NaOH pretreatment,respectively.In addition,the methane content under 4% NaOH pretreatment reached more than 60%,and the average methane content was higher than non-use NaOH pretreatment,2% and 8%NaOH pretreatments.The pH value fluctuated in initial stage,after anaerobic digestion for 13 days,it stabilized at around 7.2.The differences of TS gas yield,VS gas yield and average methane content were significant between 4%NaOH and non-use NaOH pretreatment,4% and 8% NaOH pretreatment（P0.05）,respectively.By contrast,the differences were not significant between 4% and 2%NaOH pretreatment,4% and 6% NaOH pretreatment（P0.05）,respectively.All the results indicated that 4%NaOH pretreatment was much better.