Evaluation of methane yield using acidogenic effluent of NaOH pretreated corn stover in anaerobic digestion

Lignocellulosic by-products from agricultural crops represent an important raw material for anaerobic digestion and clean renewable, which is a key component of the circular economy. Lignocellulose is recalcitrant to biodegradation and pretreatments are required to increase methane yield during anaerobic digestion. In this work, the efficacy of different physicochemical pretreatments was compared using corn stover biomass as substrate. Anaerobic digestion of untreated and pretreated corn stover was performed in batch mode at mesophilic temperature (38°C) and organic matter solubilization of pretreated substrates was also investigated. The highest organic matter solubilization occurred in autoclave pretreatment (soluble chemical oxygen demand = 5630 ± 42 mg O2 L−1). However, the highest methane yield was obtained using alkaline pretreatment (367 ± 35 mL CH4 g−1 VSadded). Alkaline pretreatment increased methane yield by 43.3% compared to untreated control (256 ± 15 mL CH4 g−1 VSadded). Two mathematical models (i.e. first-order kinetics and transfer function) were utilized to fit the experimental data with the aim of assessing anaerobic biodegradation and to obtain the kinetic constants in all cases studied. Both models adequately fit the experimental results. The kinetic constant, k, of the first-order model increased by 92.8% when stover was pretreated with sulphuric acid compared with control. The transfer function model revealed that the maximum methane production rate, Rm, was obtained for the sulphuric acid treatment, which was 63.5% higher compared to control.

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Impact of Fe3O4 Nanoparticles on Solid-state Anaerobic Digestion Performance in Calcium-pretreated Corn stover Co-digested with Dairy manure

10.13031/aim.202000140 ◽

2020 ◽

Author(s):

A. A. Ajayi-Banji ◽

S. Rahman

Keyword(s):

Anaerobic Digestion ◽

Solid State ◽

Corn Stover ◽

Fe3o4 Nanoparticles ◽

Dairy Manure ◽

Pretreated Corn Stover

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Enhancing methane production from the invasive macroalga Rugulopteryx okamurae through anaerobic co-digestion with olive mill solid waste: process performance and kinetic analysis

Journal of Applied Phycology ◽

10.1007/s10811-021-02548-3 ◽

2021 ◽

Author(s):

D. de la Lama-Calvente ◽

M. J. Fernández-Rodríguez ◽

J. Llanos ◽

J. M. Mancilla-Leytón ◽

R. Borja

Keyword(s):

Anaerobic Digestion ◽

Solid Waste ◽

Methane Production ◽

Methane Yield ◽

Specific Rate ◽

Order Kinetic ◽

Two Phase ◽

First Order ◽

Olive Mill Solid Waste ◽

Olive Mill

AbstractThe biomass valorisation of the invasive brown alga Rugulopteryx okamurae (Dictyotales, Phaeophyceae) is key to curbing the expansion of this invasive macroalga which is generating tonnes of biomass on southern Spain beaches. As a feasible alternative for the biomass management, anaerobic co-digestion is proposed in this study. Although the anaerobic digestion of macroalgae barely produced 177 mL of CH4 g−1 VS, the co-digestion with a C-rich substrate, such as the olive mill solid waste (OMSW, the main waste derived from the two-phase olive oil manufacturing process), improved the anaerobic digestion process. The mixture improved not only the methane yield, but also its biodegradability. The highest biodegradability was found in the mixture 1 R. okamurae—1 OMSW, which improved the biodegradability of the macroalgae by 12.9% and 38.1% for the OMSW. The highest methane yield was observed for the mixture 1 R. okamurae—3 OMSW, improving the methane production of macroalgae alone by 157% and the OMSW methane production by 8.6%. Two mathematical models were used to fit the experimental data of methane production time with the aim of assessing the processes and obtaining the kinetic constants of the anaerobic co-digestion of different combination of R. okamurae and OMSW and both substrates independently. First-order kinetic and the transference function models allowed for appropriately fitting the experimental results of methane production with digestion time. The specific rate constant, k (first-order model) for the mixture 1 R. okamurae- 1.5 OMSW, was 5.1 and 1.3 times higher than that obtained for the mono-digestion of single OMSW and the macroalga, respectively. In the same way, the transference function model revealed that the maximum methane production rate (Rmax) was also found for the mixture 1 R. okamurae—1.5 OMSW (30.4 mL CH4 g−1 VS day−1), which was 1.6 and 2.2 times higher than the corresponding to the mono-digestions of the single OMSW and sole R. okamurae (18.9 and 13.6 mL CH4 g−1 VS day−1), respectively.

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Co-Digestion of Rice Straw with Cow Manure in an Innovative Temperature Phased Anaerobic Digestion Technology: Performance Evaluation and Trace Elements

Energies ◽

10.3390/en14092561 ◽

2021 ◽

Vol 14 (9) ◽

pp. 2561

Author(s):

Furqan Muhayodin ◽

Albrecht Fritze ◽

Oliver Christopher Larsen ◽

Marcel Spahr ◽

Vera Susanne Rotter

Keyword(s):

Trace Elements ◽

Anaerobic Digestion ◽

Greenhouse Gas ◽

Rice Straw ◽

Methane Yield ◽

Methane Formation ◽

Cow Manure ◽

Volatile Solids ◽

Mass Fractions ◽

Cu And Zn

Rice straw is an agricultural residue produced in abundant quantities. Open burning and plowing back the straw to the fields are common practices for its disposal. In-situ incorporation and burning cause emissions of greenhouse gas and particulate matter. Additionally, the energy potential of rice straw is lost. Anaerobic digestion is a technology that can be potentially used to utilize the surplus rice straw, provide renewable energy, circulate nutrients available in the digestate, and reduce greenhouse gas emissions from rice paddies. An innovative temperature phased anaerobic digestion technology was developed and carried out in a continuous circulating mode of mesophilic and hyperthermophilic conditions in a loop digester (F1). The performance of the newly developed digester was compared with the reference digester (F2) working at mesophilic conditions. Co-digestion of rice straw was carried out with cow manure to optimize the carbon to nitrogen ratio and to provide the essential trace elements required by microorganisms in the biochemistry of methane formation. F1 produced a higher specific methane yield (189 ± 37 L/kg volatile solids) from rice straw compared to F2 (148 ± 36 L/kg volatile solids). Anaerobic digestion efficiency was about 90 ± 20% in F1 and 70 ± 20% in F2. Mass fractions of Fe, Ni, Co, Mo, Cu, and Zn were analyzed over time. The mass fractions of Co, Mo, Cu, and Zn were stable in both digesters. While mass fractions of Fe and Ni were reduced at the end of the digestion period. However, no direct relationship between specific methane yield and reduced mass fraction of Fe and Ni was found. Co-digestion of rice straw with cow manure seems to be a good approach to provide trace elements except for Se.

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High-efficient cellulosic butanol production from deep eutectic solvent pretreated corn stover without detoxification

Industrial Crops and Products ◽

10.1016/j.indcrop.2021.113258 ◽

2021 ◽

Vol 162 ◽

pp. 113258

Author(s):

Xiaoqing Lin ◽

Yao Liu ◽

Xiaojie Zheng ◽

Nasib Qureshi

Keyword(s):

Corn Stover ◽

Deep Eutectic Solvent ◽

Butanol Production ◽

Pretreated Corn Stover ◽

High Efficient

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Sugarcane Bagasse as a Co-Substrate with Oil-Refinery Biological Sludge for Biogas Production Using Batch Mesophilic Anaerobic Co-Digestion Technology: Effect of Carbon/Nitrogen Ratio

Water ◽

10.3390/w13050590 ◽

2021 ◽

Vol 13 (5) ◽

pp. 590

Author(s):

Aiban Abdulhakim Saeed Ghaleb ◽

Shamsul Rahman Mohamed Kutty ◽

Gasim Hayder Ahmed Salih ◽

Ahmad Hussaini Jagaba ◽

Azmatullah Noor ◽

...

Keyword(s):

Anaerobic Digestion ◽

Sugarcane Bagasse ◽

Organic Waste ◽

Wastewater Treatment Plants ◽

Biogas Production ◽

Raw Materials ◽

Oil Refinery ◽

Methane Yield ◽

Oil Refineries ◽

Biological Sludge

Man-made organic waste leads to the rapid proliferation of pollution around the globe. Effective bio-waste management can help to reduce the adverse effects of organic waste while contributing to the circular economy at the same time. The toxic oily-biological sludge generated from oil refineries’ wastewater treatment plants is a potential source for biogas energy recovery via anaerobic digestion. However, the oily-biological sludge’s carbon/nitrogen (C/N) ratio is lower than the ideal 20–30 ratio required by anaerobic digestion technology for biogas production. Sugarcane bagasse can be digested as a high C/N co-substrate while the oily-biological sludge acts as a substrate and inoculum to improve biogas production. In this study, the best C/N with co-substrate volatile solids (VS)/inoculum VS ratios for the co-digestion process of mixtures were determined empirically through batch experiments at temperatures of 35–37 °C, pH (6–8) and 60 rpm mixing. The raw materials were pre-treated mechanically and thermo-chemically to further enhance the digestibility. The best condition for the sugarcane bagasse delignification process was 1% (w/v) sodium hydroxide, 1:10 solid-liquid ratio, at 100 °C, and 150 rpm for 1 h. The results from a 33-day batch anaerobic digestion experiment indicate that the production of biogas and methane yield were concurrent with the increasing C/N and co-substrate VS/inoculum VS ratios. The total biogas yields from C/N 20.0 with co-substrate VS/inoculum VS 0.06 and C/N 30.0 with co-substrate VS/inoculum VS 0.18 ratios were 2777.0 and 9268.0 mL, respectively, including a methane yield of 980.0 and 3009.3 mL, respectively. The biogas and methane yield from C/N 30.0 were higher than the biogas and methane yields from C/N 20.0 by 70.04 and 67.44%, respectively. The highest biogas and methane yields corresponded with the highest C/N with co-substrate VS/inoculum VS ratios (30.0 and 0.18), being 200.6 mL/g VSremoved and 65.1 mL CH4/g VSremoved, respectively.

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