scholarly journals Effect of ultrasonic pre-treatment on biogas yield and specific energy in anaerobic digestion of fruit and vegetable wholesale market wastes

2017 ◽  
Vol 27 (6) ◽  
pp. 259-264 ◽  
Author(s):  
Reyhaneh Zeynali ◽  
Mehdi Khojastehpour ◽  
Mohammadali Ebrahimi-Nik
2018 ◽  
Vol 65 ◽  
pp. 05025 ◽  
Author(s):  
Sagor Kumar Pramanik ◽  
Fatihah Binti Suja ◽  
Biplob Kumar Pramanik ◽  
Shahrom Bindi Md Zain

Solid organic wastes create potential risks to environmental pollution and human health due to the uncontrolled discharge of huge quantities of hazardous wastes from numerous sources. Now-a-days, anaerobic digestion (AD) is considered as a verified and effective alternative compared to other techniques for treating solid organic waste. The paper reviewed the biological process and parameters involved in the AD along with the factors could enhance the AD process. Hydrolysis is considered as a rate-limiting phase in the complex AD process. The performance and stability of AD process is highly influenced by various operating parameters like temperature, pH, carbon and nitrogen ratio, retention time, and organic loading rate. Different pre-treatment (e.g. mechanical, chemical and biological) could enhance the AD process and the biogas yield. Co-digestion can also be used to provide suitable nutrient balance inside the digester. Challenges of the anaerobic digestion for biogas production are also discussed.


2009 ◽  
Vol 60 (6) ◽  
pp. 1525-1532 ◽  
Author(s):  
S. Pérez-Elvira ◽  
M. Fdz-Polanco ◽  
F. I. Plaza ◽  
G. Garralón ◽  
F. Fdz-Polanco

Prior research indicates that ultrasounds can be used in batch reactors as pre-treatment before anaerobic digestion, but the specific energy required at laboratory-scale is too high. This work evaluates both the continuous ultrasound device performance (efficiency and solubilisation) and the operation of anaerobic digesters continuously fed with sonicated sludge, and presents energy balance considerations. The results of sludge solubilisation after the sonication treatment indicate that, applying identical specific energy, it is better to increase the power than the residence time. Working with secondary sludge, batch biodegradability tests show that by applying 30 kWh/m3 of sludge, it is possible to increase biogas production by 42%. Data from continuous pilot-scale anaerobic reactors (V=100 L) indicate that operating with a conventional HRT = 20 d, a reactor fed with pre-treated sludge increases the volatile solids removal and the biogas production by 25 and 37% respectively. Operating with HRT = 15 d, the removal efficiency is similar to the obtained with a reactor fed with non-hydrolysed sludge at HTR = 20 d, although the specific biogas productivity per volume of reactor is higher for the pretreated sludge. Regarding the energy balance, although for laboratory-scale devices it is negative, full-scale suppliers state a net generation of 3–10 kW per kW of energy used.


2014 ◽  
Vol 21 (3) ◽  
pp. 447-464 ◽  
Author(s):  
Jolanta Bohdziewicz ◽  
Mariusz Kuglarz ◽  
Klaudiusz Grűbel

Abstract The article presents the results of determining the most appropriate conditions of microwave sludge pre-treatment (500-1200 W), prior to its anaerobic digestion in a continuous mode. The assessment of the pre-treatment conditions (microwave power, sludge temperature after pre-treatment) was based on: the release of organic (COD, protein) and inorganic (NH4+, PO43-) substances into liquid, the quantity of methane produced, sludge higienisation and the susceptibility of the pre-treated sludge to dewatering. The power of the microwaves applied did not play significant role on the pre-treatment effectiveness. Taking into account the fact that sludge pre-treatment by microwave irradiation requires the delivery of energy, the pre-treatment by microwaves of higher power (1200 W) and resulting in sludge temperature of 70°C was recommended for further experiments. Sludge pre-treatment by means of microwave irradiation as a pre-treatment step influenced the effectiveness of the subsequent anaerobic digestion, conducted in continuous conditions, in a positive way. The largest amount of biogas was obtained for HRT in the range of 15-20 days. As compared to the sludge which did not undergo pre-treatment, daily biogas production and biogas yield increased by 18-41% and 13-35% respectively. The combination of microwave pre-treatment and mesophilic anaerobic digestion ensured the elimination of pathogens (Salmonella spp., Escherichia coli).


Processes ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 492 ◽  
Author(s):  
Burcu Gunes ◽  
Maxime Carrié ◽  
Khaled Benyounis ◽  
Joseph Stokes ◽  
Paul Davis ◽  
...  

Whiskey distillery waste streams consisting of pot ale (liquid residue) and spent grain (solid residue) are high strength organic wastes and suitable feedstock for anaerobic digestion (AD) from both economic and environmental stand points. Anaerobic digestion of pot ale and pot ale/spent grain mixtures (with mixing ratios of 1:1, 1:3, and 1:5 by wet weight) was performed after implementation of a novel hybrid pre-treatment (combined chemical and mechanical) in order to modify lignocellulosic structure and ultimately enhance digestion yield. Lignin, hemicellulose, and cellulose fractions were determined before and after chemical pre-treatment. Effects of different inoculum rates (10–30–50% on wet basis) and beating times (0–7.5–15 min) on anaerobic digestion of pot ale alone and of pot ale/spent grain mixtures were investigated in lab scale batch mode with a major focus of optimising biogas yield by using response surface methodology (RSM) in Design Expert Software. The highest biogas yields of 629 ± 8.5 mL/g vs. (51.3% CH4) and 360 ± 10 mL/g vs. (55.0 ± 0.4) with anaerobic digestion of pot ale alone and spent grain mix after 1M NaOH and 7.5 min beating pre-treatments with 50% inoculum ratio respectively. The optimum digestion conditions to maximise the biogas quality and quantity were predicted as 10 and 13 min beating times and 32 and 38 °C digestion temperatures for anaerobic digestion of pot ale alone and spent grain mix respectively.


2016 ◽  
Vol 36 (01) ◽  
pp. 79
Author(s):  
Darwin Darwin ◽  
Yusmanizar Yusmanizar ◽  
Muhammad Ilham ◽  
Afrizal Fazil ◽  
Satria Purwanto ◽  
...  

Thermal pre-treatment was given on corn stover in the purpose of breaking the lignin content; thus, it may help anaerobic microorganisms to convert polymer including cellulose and hemicelluloses into biogas. This study aimed to investigate the effects of thermal pre-treatment on corn stover in anaerobic digestion process related to the production of biogas as well as digestion process efficiency. This research was carried out by utilizing batch reactors where the temperature was maintained at mesophilic conditions above room temperature (33 ± 2 oC). Based on the result, it was known that thermal pre-treatment given on the corn stover may enhance anaerobic digestion process for biogas production at the first 10 days. This condition reduced the time of lag phase during anaerobic digestion. The biogas production of corn stover given thermal pre-treatment was slow at 26 days where their average total production were 12,412.5 mL,12,310 mL at 15 and 25 minutes thermal pre-treatment, respectively while biogas production of non pre-treated corn stover was 12,557 mL. The highest daily biogas production was accomplished by corn stover that was given thermal pre-treatment at 25 minutes (915 mL). Corn stover given with 15 minutes thermal pre-treatment also generated higher daily biogas production at day 9 (772.5 mL) compared with corn stover that was not pre-treated (405 mL). This research also revealed that corn stover given thermal pre-treatment reached higher biogas yield compared with non pre-treated corn stover where their biogas yield were 670.39, 690.65 mL/g volatile solids added at 15 and 25 minutes thermal pre- treatment respectively, and 456.37 mL/g volatile solids added of non pre-treated corn stover.Keywords: Thermal pre-treatment, corn stover, anaerobic digestion, biogas ABSTRAKThermal pre-treatment diberikan pada limbah tanaman jagung dengan tujuan untuk memecahkan kandungan lignin yang terdapat pada limbah tanaman jagung sehingga memudahkan mikroorganisme anaerobik untuk mengkonversi polimer yang berupa selulosa dan hemiselulosa menjadi biogas. Tujuan dari penelitian ini adalah untuk melakukan kajian mengenai penerapan thermal pre-treatment pada limbah tanaman jagung terhadap proses anaerobik digesi yang meliputi efisiensi proses digesi dan produksi biogas yang dihasilkan. Penelitian ini dilakukan dengan menggunakan reaktor tipe batch yang suhunya dipertahankan pada kondisi mesophilic atau di atas rata-rata suhu kamar (33 ± 2 oC). Hasil penelitian diperoleh bahwa thermal pre-treatment yang diberikan pada limbah tanaman jagung mampu mempercepat proses produksi biogas pada 10 hari pertama sehingga dapat mengurangi lag-phase pada proses anaerobik digesi. Limbah tanaman jagung yang diberikan thermal pre-treatment mengalami perlambatan produksi biogas pada hari ke 26 dengan rata-rata total produksi 12.412,5 mL untuk limbah tanaman jagung yang diberikan thermal pre- treatment selama 15 menit, dan 12.310 mL untuk limbah tanaman jagung yang diberikan thermal pre-treatment selama 25 menit, sedangkan limbah tanaman jagung yang tidak diberikan pre-treatment menghasilkan produksi biogas sebesar 12.557 mL pada hari ke 26. Produksi biogas harian tertinggi terjadi pada substrat yang diberikan thermal pre-treatment 25 menit, dengan produksi biogas tertinggi pada hari ke 9 dengan rata-rata produksi sebesar 915 mL. Substrat yang diberikan thermal pre-treatment 15 menit juga memproduksi biogas jauh lebih tinggi (772,5 mL) pada hari ke 9 jika dibandingkan dengan substrat tanpa diberikan pre-treatment yang hanya memproduksi biogas sebesar 405 mL. Data hasil penelitian menunjukkan bahwa limbah tanaman jagung yang diberikan thermal pre-treatment memperoleh biogas yield lebih tinggi dari pada yang tidak diberikan pre-treatment dimana 670,39 mL/g volatile solids untuk thermal pre- treatment 15 menit, 690,65 mL/g volatile solids untuk thermal pre-treatment 25 menit dan 456,37 mL/g volatile solids untuk limbah tanaman jagung yang tidak diberikan pre-treatment.Kata kunci: Thermal pre-treatment, limbah tanaman jagung, anaerobik digesi, biogas


2021 ◽  
Author(s):  
Venkateshkumar R ◽  
Shanmugam S ◽  
Veerappan AR

Abstract Cow dung is generally used as the feedstock material for the anaerobic digestion to produce biogas. A selection of alternate biomass material is needed to reduce the consumption or to eliminate the use of cow dung. Recently, cottonseed hull has been considered as the primary substrate to produce biogas. In this paper, the effect of biogas production on anaerobic co-digestion of cow dung with pre-treated cottonseed hull using different concentrations of sulfuric acid, hydrochloric acid, hydrogen peroxide, and acetic acid is investigated. Sodium hydroxide and calcium hydroxide are used at different concentrations for pre-treatment of cottonseed hull. The enhancement of biogas production from the batch reactors at mesophilic temperature (35 ± 2 ℃) is observed for mono- and co-digestion of cow dung with treated cottonseed hull. Maximum biogas yield is achieved for the treated cottonseed hull at 6% sodium hydroxide during mono digestion and at 6% calcium hydroxide during co-digestion.


2012 ◽  
Vol 66 (11) ◽  
pp. 2284-2290 ◽  
Author(s):  
Lise Appels ◽  
Sofie Houtmeyers ◽  
Floriaan Van Mechelen ◽  
Jan Degrève ◽  
Jan Van Impe ◽  
...  

In this work, the influence of an ultrasonic pre-treatment on anaerobic digestion of waste activated sludge is studied. Attention is paid to the solubilisation of the main organic (proteins, carbohydrates) and inorganic (heavy metals) sludge components during ultrasonic treatment and the influence of the dry solids content (DS) on the degree of solubilisation. The second part of the paper focuses on the relationship between the applied specific energy of the ultrasonic treatment and methane production. In general, a higher specific energy and a higher DS content are beneficial for the release of organic matter, resulting in an increased methane production. The efficiency of the subsequent anaerobic digestion is similar for both sludge types (2.1 and 3.2% DS). However, at lower DS contents (2.1%), the methane production increase was more significant.


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