Anaerobic Fermentation Characteristics of Corn Straw Pretreated by Steam Explosion

2012 ◽  
Vol 512-515 ◽  
pp. 334-337 ◽  
Author(s):  
Gui Zhuan Xu ◽  
Shuai Yao Fan ◽  
Bai Liang Zhang ◽  
Jie Bo Liu

The anaerobic fermentation characteristics of green and dried corn straw pretreated by steam explosion method were investigated. The steam pressure and retention time were 1.0Mpa and 90s, TS of fermentation liquid were 2% and 4%. It was shown that the fermentation cycle of green straw is shorter than that of the dried one by 4-7 days, the gas productivity of green straw is 220 mL/gVS, which is higher than that of dried one (153 mL/gVS) while TS is 2%, but there is no significant difference between the green and dried corn straw while TS is 4%, the average methane content in biogas produced from green straw is slightly less than that of the dried one.

2011 ◽  
Vol 183-185 ◽  
pp. 1975-1978 ◽  
Author(s):  
Xu Tao Wang ◽  
Hua Zhen Cai ◽  
Li Sha Liu

Using the steam exploded pretreatment technology to process the corn stalk, and then the pretreated corn stalk were used the materials of anaerobic fermentation under the temperature 35°C. Experimental results show that: the biogas production per unit of pretreated corn stalk increased 16.8 % ~ 63.2% than the unexploded corn stalk. The gas production can up to the peak (484.3ml / g dry steam exploded straw) under the condition (retained time 90s, pressure 3.0Mpa). The longer the retained time is the earlier the gas production peak occurs under the same steam pressure and the peak range become wider. The main gas production area is the former 20d, the production amount to about 80% of total production, while the gas production of untreated straw fermentation in is only 60% of total production under medium temperature.


2013 ◽  
Vol 295-298 ◽  
pp. 1735-1739
Author(s):  
Fu Bin Yin ◽  
Zi Fu Li ◽  
Shuang Hou ◽  
Xiao Feng Bai ◽  
Ting Ting Wang

The main objectives of this research were to determine the effect of leachate refluence on biogas production for dry mesophilic co-fermentation of chicken manure and corn straw. The biogas production, the ratio of biogas production, methane content and pH were analyzed. The results showed that the leachate refluence has a significant impact on biogas production of dry co-fermentation. The cumulative biogas yield of the once in 48h has an increase by 10% and 5% for no reflux and once in 24h, respectively. The leachate refluence has little influence on the methane content, but it has good effect to keep pH in the optimum rang.


2011 ◽  
Vol 64 (4) ◽  
pp. 967-973
Author(s):  
S. Koyunluoglu-Aynur ◽  
R. Riffat ◽  
S. Murthy

The objective of the present work was to evaluate the effect of hydraulic retention time (HRT) on hydrolysis and acidogenesis for the pretreatment processes: acid phase digestion (APD) and autothermal thermophilic aerobic digestion (ATAD) using blended municipal sludge. The effect of the different pretreatment steps on mesophilic anaerobic digestion (MAD) was evaluated in terms of methane yield, keeping the operating conditions of the MAD the same for all systems. Best operating conditions for both APD and ATAD were observed for 2.5 d HRT with high total volatile fatty acids (tVFA), and the highest methane yield observed for MAD. No significant difference was observed between the two processes in terms of overall volatile solids (VS) reduction with same total HRT. The autothermal process produced heat of 14,300 J/g VS removed from hydrolytic and acetogenic reactions without compromising overall methane yields when the HRT was 2.5 d or lower and the total O2 used was 0.10 m3 O2/g VS added or lower. However, the process needs the input of oxygen and engineering analysis should balance these differences when considering the relative merits of the two pretreatment processes. This is the first study of its kind directly comparing these two viable pretreatment processes with the same sludge.


2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Xiao-Shuang Shi ◽  
Jian-Jun Dong ◽  
Jun-Hong Yu ◽  
Hua Yin ◽  
Shu-Min Hu ◽  
...  

Three semicontinuous continuous stirred-tank reactors (CSTR) operating at mesophilic conditions (35°C) were used to investigate the effect of hydraulic retention time (HRT) on anaerobic digestion of wheat straw. The results showed that the average biogas production with HRT of 20, 40, and 60 days was 46.8, 79.9, and 89.1 mL/g total solid as well as 55.2, 94.3, and 105.2 mL/g volatile solids, respectively. The methane content with HRT of 20 days, from 14.2% to 28.5%, was the lowest among the three reactors. The pH values with HRT of 40 and 60 days were in the acceptable range compared to that with HRT of 20 days. The propionate was dominant in the reactor with HRT of 20 days, inhibiting the activities of methanogens and causing the lower methane content in biogas. The degradation of cellulose, hemicellulose, and crystalline cellulose based on XRD was also strongly influenced by HRTs.


2010 ◽  
Vol 113-116 ◽  
pp. 450-458 ◽  
Author(s):  
Yong Zhi Chi ◽  
Yu You Li ◽  
Min Ji ◽  
Hong Qiang ◽  
Heng Wei Deng ◽  
...  

This paper presents an experimental study over 204 days on anaerobic degradation of thickened waste activated sludge (TWAS) from a municipal wastewater treatment plant (WWTP). The experiments were conducted under thermophilic (55°C) and mesophilic (35°C) condition, respectively, by using the semi-continuous flow completely mixed reactors. The influent total solids (TS), hydraulic retention time (HRT) and chemical oxygen demand (COD) loading levels were around 4%, 30 days and 1.67 kg-CODCr•m-3•d-1 , respectively. During the opration period, the thermophilic anaerobic digestion process (TADP) and the mesophilic anaerobic digestion process (MADP) were stable and well-functioned without ammonia inhibition. Particulate organic matters reduction of TADP was superior to that of MADP. This result implies that TADP has higher sludge reduction efficiency than MADP. According to the simulated chemical formula of TWAS, C5.85H9.75O3.96N, and the stoichiometric equation, the methane content and the ammonia yield in the anaerobic process could be calculated, which were consistent with the experimental results. The methane yield of TADP was a little higher than that of MADP. The statistical mean values of methane content for TADP and MADP were 60.97% and 62.38%, respectively.According to paired t-test, there was a significant difference in methane content between TADP and MADP(α=0.01, n=62). Compared with the mesophilic digested sludge, the dewaterability of thermophilic digested sludge was lower.


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