Effect of H3PO4 Pretreatment on Biogas Production of Rice Straw during Anaerobic Digestion

2014 ◽  
Vol 953-954 ◽  
pp. 216-219
Author(s):  
Ben Lin Dai ◽  
An Feng Zhu ◽  
Fei Hu Mu ◽  
Ning Xu ◽  
Zhen Wu

To improve the gas production ability, relatively low cost H3PO4was chosen as the pretreating agent in this study. Rice straws were pretreated by four different weight percentages (2%, 4%, 6% and 8%) of H3PO4retting for seven days in an biochemical incubator at (25±1) °C, and the effects with different conditions of H3PO4pretreatment on anaerobic digestion of rice straws for variation of components and anaerobic digestion performance (under temperature of (35±1) °C) were studied. The results showed that the peak value of biogas production was attained on the 1stday for using 6% H3PO4pretreatment on rice straw, which is 2284 mL. The test daily methane content of different pretreatment conditions mainly ranges from 3.8% to 43.1%, with the highest recorded at the 12thday of the 2% H3PO4- treated rice straw. The cumulative biogas production of 6% H3PO4pretreatment was the highest, about 16 474 mL.

2014 ◽  
Vol 587-589 ◽  
pp. 208-211 ◽  
Author(s):  
Ben Lin Dai ◽  
An Feng Zhu ◽  
Fei Hu Mu ◽  
Ning Xu ◽  
Zhen Wu

The chemical pretreatment of rice straw was achieved via the liquid-state dissolution of CaCO3. Pretreatment effects on the biodegradability and subsequent anaerobic production of methane were investigated. The results showed that the peak value of biogas production was attained of 4% CaCO3 pretreatment on the 20th day, which is 1 589 mL. The test daily methane content of different pretreatment conditions mainly ranges from 3.4% to 47.4%. The cumulative biogas production of 6% CaCO3 pretreatment was the highest, about 19 917 mL.


2014 ◽  
Vol 587-589 ◽  
pp. 856-859
Author(s):  
Ben Lin Dai ◽  
An Feng Zhu ◽  
Fei Hu Mu ◽  
Ning Xu ◽  
Zhen Wu

The anaerobic fermentation characteristic of rice straw pretreated by HCl was studied. The results showed that the test pH values of different pretreatment conditions mainly range from 5.09 to 7.52. The peak value of biogas production was attained of 2% HCl pretreatment on the 20th day, which is 1 180 mL. The test daily methane content of different pretreatment conditions mainly ranges from 3.2% to 58.1%. However, the cumulative biogas production by using HCl pretreatment of rice straw during anaerobic fermentation is poor.


2014 ◽  
Vol 953-954 ◽  
pp. 220-223
Author(s):  
Ben Lin Dai ◽  
An Feng Zhu ◽  
Fei Hu Mu ◽  
Ning Xu ◽  
Zhen Wu

To discuss the effect of NaOH pretreatment technology for biogas production and methane (CH4) content enhancement during the anaerobic digestion of rice straw waste, a self-designed laboratory-scale continuous anaerobic biogas digester was used in this study. Anaerobic biogas slurry, NaOH pretreatment and anaerobic digestion were evaluated for biogas production from rice straw. The results showed that the peak value of biogas production was attained on the 16th day by using 6% NaOH pretreatment on rice straw. However, the highest CH4 content was 60.8% on the 24th day for the 4% NaOH-treated rice straw. The cumulative biogas production of 6% NaOH pretreatment was the highest, about 18 720 mL, which was followed by 8% NaOH (15 057 mL), 4% NaOH (12 103 mL), and 2% NaOH (10 754 mL).


2014 ◽  
Vol 587-589 ◽  
pp. 896-899 ◽  
Author(s):  
Ben Lin Dai ◽  
An Feng Zhu ◽  
Fei Hu Mu ◽  
Ning Xu ◽  
Zhen Wu

To discuss the internal effect of urea (CO(NH2)2) pretreatment on anaerobic digestion biogas production of rice straw waste, a self-designed laboratory-scale continuous anaerobic biogas digester was used in this study. Anaerobic biogas slurry, urea pretreatment and anaerobic digestion were evaluated for biogas production from rice straw. The results showed that the peak value of biogas production was attained on the 17th day by using 6% urea pretreatment on rice straw. However, the highest CH4 content was 49.8% on the 15th day for the 8% urea-treated rice straw. The cumulative biogas production of 6% urea pretreatment was the highest, about 16 540 mL, which was followed by 2% urea (12 283 mL), 8% urea (9 883 mL), and 4% urea (5 668 mL).


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Karol Postawa ◽  
Jerzy Szczygieł ◽  
Marek Kułażyński

Abstract Background Increasing the efficiency of the biogas production process is possible by modifying the technological installations of the biogas plant. In this study, specific solutions based on a mathematical model that lead to favorable results were proposed. Three configurations were considered: classical anaerobic digestion (AD) and its two modifications, two-phase AD (TPAD) and autogenerative high-pressure digestion (AHPD). The model has been validated based on measurements from a biogas plant located in Poland. Afterward, the TPAD and AHPD concepts were numerically tested for the same volume and feeding conditions. Results The TPAD system increased the overall biogas production from 9.06 to 9.59%, depending on the feedstock composition, while the content of methane was slightly lower in the whole production chain. On the other hand, the AHPD provided the best purity of the produced fuel, in which a methane content value of 82.13% was reached. At the same time, the overpressure leads to a decrease of around 7.5% in the volumetric production efficiency. The study indicated that the dilution of maize silage with pig manure, instead of water, can have significant benefits in the selected configurations. The content of pig slurry strengthens the impact of the selected process modifications—in the first case, by increasing the production efficiency, and in the second, by improving the methane content in the biogas. Conclusions The proposed mathematical model of the AD process proved to be a valuable tool for the description and design of biogas plant. The analysis shows that the overall impact of the presented process modifications is mutually opposite. The feedstock composition has a moderate and unsteady impact on the production profile, in the tested modifications. The dilution with pig manure, instead of water, leads to a slightly better efficiency in the classical configuration. For the TPAD process, the trend is very similar, but the AHPD biogas plant indicates a reverse tendency. Overall, the recommendation from this article is to use the AHPD concept if the composition of the biogas is the most important. In the case in which the performance is the most important factor, it is favorable to use the TPAD configuration.


Energies ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2392 ◽  
Author(s):  
Marcin Dębowski ◽  
Marcin Zieliński ◽  
Marta Kisielewska ◽  
Joanna Kazimierowicz

The aim of this study was the performance evaluation of anaerobic digestion of dairy wastewater in a multi-section horizontal flow reactor (HFAR) equipped with microwave and ultrasonic generators to stimulate biochemical processes. The effects of increasing organic loading rate (OLR) ranging from 1.0 g chemical oxygen demand (COD)/L·d to 4.0 g COD/L·d on treatment performance, biogas production, and percentage of methane yield were determined. The highest organic compounds removals (about 85% as COD and total organic carbon—TOC) were obtained at OLR of 1.0–2.0 g COD/L·d. The highest biogas yield of 0.33 ± 0.03 L/g COD removed and methane content in biogas of 68.1 ± 5.8% were recorded at OLR of 1.0 g COD/L·d, while at OLR of 2.0 g COD/L·d it was 0.31 ± 0.02 L/COD removed and 66.3 ± 5.7%, respectively. Increasing of the OLR led to a reduction in biogas productivity as well as a decrease in methane content in biogas. The best technological effects were recorded in series with an operating mode of ultrasonic generators of 2 min work/28 min break. More intensive sonication reduced the efficiency of anaerobic digestion of dairy wastewater as well as biogas production. A low nutrient removal efficiency was observed in all tested series of the experiment, which ranged from 2.04 ± 0.38 to 4.59 ± 0.68% for phosphorus and from 9.67 ± 3.36 to 20.36 ± 0.32% for nitrogen. The effects obtained in the study (referring to the efficiency of wastewater treatment, biogas production, as well as to the results of economic analysis) proved that the HFAR can be competitive to existing industrial technologies for food wastewater treatment.


2019 ◽  
Vol 293 ◽  
pp. 122066 ◽  
Author(s):  
Yang Liu ◽  
Junnan Fang ◽  
Xinyu Tong ◽  
ChenChen Huan ◽  
Gaosheng Ji ◽  
...  

2018 ◽  
Vol 64 (No. 3) ◽  
pp. 128-135 ◽  
Author(s):  
Radmard Seyed Abbas ◽  
Alizadeh Hossein Haji Agha ◽  
Seifi Rahman

The effects of thermal (autoclave and microwave irradiation (MW)) and thermo-chemical (autoclave and microwave irradiation – assisted NaOH 5N) pretreatments on the chemical oxygen demand (COD) solubilisation, biogas and methane production of anaerobic digestion kitchen waste (KW) were investigated in this study. The modified Gompertz equation was fitted to accurately assess and compare the biogas and methane production from KW under the different pretreatment conditions and to attain representative simulations and predictions. In present study, COD solubilisation was demonstrated as an effective effect of pretreatment. Thermo-chemical pretreatments could improve biogas and methane production yields from KW. A comprehensive evaluation indicated that the thermo-chemical pretreatments (microwave irradiation and autoclave- assisted NaOH 5N, respectively) provided the best conditions to increase biogas and methane production from KW. The most effective enhancement of biogas and methane production (68.37 and 36.92 l, respectively) was observed from MW pretreated KW along with NaOH 5N, with the shortest lag phase of 1.79  day, the max. rate of 2.38 l·day<sup>–1</sup> and ultimate biogas production of 69.8 l as the modified Gompertz equation predicted.


Author(s):  
Fei Wang ◽  
Mengfu Pei ◽  
Ling Qiu ◽  
Yiqing Yao ◽  
Congguang Zhang ◽  
...  

Poultry manure is the main source of agricultural and rural non-point source pollution, and its effective disposal through anaerobic digestion (AD) is of great significance; meanwhile, the high nitrogen content of chicken manure makes it a typical feedstock for anaerobic digestion. The performance of chicken-manure-based AD at gradient organic loading rates (OLRs) in a continuous stirred tank reactor (CSTR) was investigated herein. The whole AD process was divided into five stages according to different OLRs, and it lasted for 150 days. The results showed that the biogas yield increased with increasing OLR, which was based on the volatile solids (VS), before reaching up to 11.5 g VS/(L·d), while the methane content was kept relatively stable and maintained at approximately 60%. However, when the VS was further increased to 11.5 g VS/(L·d), the total ammonia nitrogen (TAN), pH, and alkalinity (CaCO3) rose to 2560 mg·L−1, 8.2, and 15,000 mg·L−1, respectively, while the volumetric biogas production rate (VBPR), methane content, and VS removal efficiency decreased to 0.30 L·(L·d)−1, 45%, and 40%, respectively. Therefore, the AD performance immediately deteriorated and ammonia inhibition occurred. Further analysis demonstrated that the microbial biomass yield and concentrations dropped dramatically in this period. These results indicated that the AD stayed steady when the OLR was lower than 11.5 g VS/(L·d); this also provides valuable information for improving the efficiency and stability of AD of a nitrogen-rich substrate.


Author(s):  
Shuaixing Xue ◽  
Ling Qiu ◽  
Xiaohui Guo ◽  
Yiqing Yao

Abstract To accelerate the degradation of substrate, 50% liquid digestate recirculation (LDR) was used in the anaerobic digestion (AD) of corn straw. The effects of recirculation on the enzyme activities and biogas production were investigated by comparing with control reactor (ReactorCK). During the AD process, the fermentation system with 50% LDR was more stable. The average biogas and methane production in ReactorLDR were 7,891 mL·d−1 and 347 mL CH4·g−1 VSadded·d−1 respectively. The total volatile fatty acids (TVFAs) concentration in the two reactors both increased at first and then decreased with time. The LDR made the VFAs accumulation significant, especially propionic acid accumulation in 4 ∼ 16 days. The maximum peak value of cellulase, xylanase, dehydrogenase and coenzyme F420 activities in ReactorLDR were 0.51 mg·g−1·h−1, 0.29 mg·g−1·h−1, 4.88 mL·g−1·h−1 and 6.69 μmol·L−1, respectively, which were higher than that in ReactorCK. With or without recirculation, the concentration of TVFAs was positively correlated with cellulase, xylanase and dehydrogenase activities, while was negatively correlated with coenzyme F420 activity. Besides, a very significant correlation existed between hydrolase and dehydrogenase activities and daily biogas production in ReactorCK. And the peaks of cellulase, xylanase and dehydrogenase activities appeared ahead of the peak of daily biogas production with the LDR.


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