Co-Digestion of Kitchen Waste with Grass and Leaves after Hyperthermophilic Pretreatment for Methane and Hydrogen Production

The study investigated co-digestion batch experiments using kitchen waste (KW) and garden waste (GW) collected from individual households. Grass and leaves were first subjected to a 3-day hyperthermophilic pretreatment at 70 °C and 80 °C and then co-digested with kitchen waste at 35 °C and 55 °C. The hyperthermophilic pretreatment resulted in the solubilization of organic material with the release of fatty acids, whereas the biogas yield was negligible. In the second stage, the greatest methane yield of 387 NmL/gVS was achieved for the mono-digestion of leaves, whereas the co-digestion of grass with 50% KW gave the highest hydrogen production of 88 NmL/gVS. Considering the overall process performance, the best operating conditions were established using a 3-day hyperthermophilic pretreatment at 70 °C, followed by co-digestion at 55 °C in the second stage for the mixture of 25% garden waste with 75% KW.

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Upgrading of a co-digestion plant by implementation of a hydrolysis stage

Waste Management & Research ◽

10.1177/0734242x11423954 ◽

2011 ◽

Vol 29 (11) ◽

pp. 1145-1152 ◽

Cited By ~ 7

Author(s):

Andreas Blank ◽

Erhard Hoffmann

Keyword(s):

Retention Time ◽

Thermal Hydrolysis ◽

Batch Experiments ◽

Kitchen Waste ◽

Primary Sludge ◽

Biogas Yield ◽

Bench Scale ◽

Second Stage ◽

Hydrolysis Temperature ◽

Pre Treatment

An existing co-digestion plant needed to be rehabilitated after a 20 year operational period. This was planned to be done in sequence by halving the digester volume for a period of 1.5 years. The aim of the present study was to improve the performance of the halved co-digestion capacity by implementing an upstream thermal hydrolysis reactor or an ultrasonic pre-treatment of the substrates. The results of the ultrasonic bench-scale batch experiments showed that an ultrasonic pre-treatment of the co-substrates ‘municipal bio-waste suspension and excess activated sludge led to disintegration efficiencies of up to 51%. However, treating kitchen-waste and primary sludge in the same manner was not promising as the disintegration yields were rather low. The results of the hydrolysis bench-scale batch experiments showed that the optimal boundary conditions for the hydrolysis reactor were a hydrolysis temperature of about 42 °C at a retention time of 24 h. The results of the continuous two-stage experiments showed that it was possible to reduce the retention time in the second stage to about 24% and to increase the biogas yield to about 12.8 %, and the methane yield to about 28% as a result of the implementation of the hydrolysis reactor in the existing system. After the rehabilitation of the existing digesters it was possible to raise the daily substrate input to the two existing digesters from 312 to 495 m3 day−1 with an upstream hydrolysis reactor volume of only 474 m3.

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Effect of hyperthermophilic pretreatment on methane and hydrogen production from garden waste under mesophilic and thermophilic conditions

Bioresource Technology ◽

10.1016/j.biortech.2021.125264 ◽

2021 ◽

pp. 125264

Author(s):

Przemysław Liczbiński ◽

Sebastian Borowski

Keyword(s):

Hydrogen Production ◽

Thermophilic Conditions ◽

Garden Waste

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Evaluation of Maturity and Odor Emissions in the Process of Combined Composting of Kitchen Waste and Garden Waste

Applied Sciences ◽

10.3390/app11125500 ◽

2021 ◽

Vol 11 (12) ◽

pp. 5500

Author(s):

Bangxi Zhang ◽

Feifei Fan ◽

Chao Guo ◽

Mingji Yu ◽

Mingcan Zhao ◽

...

Keyword(s):

Municipal Solid Waste ◽

Solid Waste ◽

Kitchen Waste ◽

Odor Emissions ◽

Maturity Effect ◽

Better Than ◽

Garden Waste

With the development of urbanization, kitchen waste and garden waste have become an important part of municipal solid waste (MSW), which is in urgent need of resource treatment. This study investigated the impacts of garden waste as auxiliary materials on maturity and odor emissions (NH3 and H2S) during kitchen waste composting. The result showed that the combined composting product of kitchen waste and garden waste achieved the maturity effect, and the co-composting effect was better than that of separate composting of kitchen waste. Meanwhile, compared with the separate composting treatment of kitchen waste, the co-composting treatment of kitchen waste and garden waste can effectively reduce the cumulative emissions of H2S by more than 85%, and effectively reduce the cumulative emissions of NH3 by more than 75%. This study provides a technical reference for the green fertilizer utilization of kitchen waste and garden waste.

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Process performance = membrane properties + operating conditions

Journal of Membrane Science ◽

10.1016/s0376-7388(03)00221-7 ◽

2003 ◽

Vol 220 (1-2) ◽

pp. 1-3 ◽

Cited By ~ 111

Author(s):

J.G. Wijmans

Keyword(s):

Operating Conditions ◽

Membrane Properties ◽

Process Performance

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Hydrogen Production via Catalytic Autothermal Reforming of Desulfurized Jet-A Fuel

Volume 1: Biofuels, Hydrogen, Syngas, and Alternate Fuels; CHP and Hybrid Power and Energy Systems; Concentrating Solar Power; Energy Storage; Environmental, Economic, and Policy Considerations of Advanced Energy Systems; Geothermal, Ocean, and Emerging Energy Technologies; Photovoltaics; Posters; Solar Chemistry; Sustainable Building Energy Systems; Sustainable Infrastructure and Transportation; Thermodynamic Analysis of Energy Systems; Wind Energy Systems and Technologies ◽

10.1115/es2016-59095 ◽

2016 ◽

Author(s):

Shuyang Zhang ◽

Xiaoxin Wang ◽

Peiwen Li

Keyword(s):

Energy Efficiency ◽

Hydrogen Production ◽

Hydrogen Storage ◽

Coke Formation ◽

Autothermal Reforming ◽

Operating Conditions ◽

Hydrogen Yield ◽

Fuel Conversion ◽

Optimal Operating ◽

Reaction Equilibrium

On-board hydrogen production via catalytic autothermal reforming is beneficial to vehicles using fuel cells because it eliminates the challenges of hydrogen storage. As the primary fuel for both civilian and military air flight application, Jet-A fuel (after desulfurization) was reformed for making hydrogen-rich fuels in this study using an in-house-made Rh/NiO/K-La-Ce-Al-OX ATR catalyst under various operating conditions. Based on the preliminary thermodynamic analysis of reaction equilibrium, important parameters such as ratios of H2O/C and O2/C were selected, in the range of 1.1–2.5 and 0.5–1.0, respectively. The optimal operating conditions were experimentally obtained at the reactor’s temperature of 696.2 °C, which gave H2O/C = 2.5 and O2/C = 0.5, and the obtained fuel conversion percentage, hydrogen yield (can be large than 1 from definition), and energy efficiency were 88.66%, 143.84%, and 64.74%, respectively. In addition, a discussion of the concentration variation of CO and CO2 at different H2O/C, as well as the analysis of fuel conversion profile, leads to the finding of effective approaches for suppression of coke formation.

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Diagnosis and Monitoring of Volatile Fatty Acids Production from Raw Cheese Whey by Multiscale Time-Series Analysis

Applied Sciences ◽

10.3390/app11135803 ◽

2021 ◽

Vol 11 (13) ◽

pp. 5803

Author(s):

Antonio Lara-Musule ◽

Ervin Alvarez-Sanchez ◽

Gloria Trejo-Aguilar ◽

Laura Acosta-Dominguez ◽

Hector Puebla ◽

...

Keyword(s):

Fatty Acids ◽

Time Series ◽

Time Series Analysis ◽

Multiscale Analysis ◽

Volatile Fatty Acids ◽

Cheese Whey ◽

Anaerobic Treatment ◽

Operating Conditions ◽

Series Analysis ◽

Key Variables

Anaerobic treatment is a viable alternative for the treatment of agro-industrial waste. Anaerobic digestion reduces organic load and produces volatile fatty acids (VFA), which are precursors of value-added products such as methane-rich biogas, biohydrogen, and biopolymers. Nowadays, there are no low-cost diagnosis and monitoring systems that analyze the dynamic behavior of key variables in real time, representing a significant limitation for its practical implementation. In this work, the feasibility of using the multiscale analysis to diagnose and monitor the key variables in VFA production by anaerobic treatment of raw cheese whey is presented. First, experiments were carried out to evaluate the performance of the proposed methodology under different operating conditions. Then, experimental pH time series were analyzed using rescaled range (R/S) techniques. Time-series analysis shows that the anaerobic VFA production exhibits a multiscale behavior, identifying three characteristic regions (i.e., three values of Hurst exponent). In addition, the dynamic Hurst exponents show satisfactory correlations with the chemical oxygen demand (COD) consumption and VFA production. The multiscale analysis of pH time series is easy to implement and inexpensive. Hence, it could be used as a diagnosis and indirect monitoring system of key variables in the anaerobic treatment of raw cheese whey.

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