Enhanced biogas recovery by applying post-digestion in large-scale centralized biogas plants

2006 ◽  
Vol 54 (2) ◽  
pp. 237-244 ◽  
Author(s):  
I. Angelidaki ◽  
A. Heinfelt ◽  
L. Ellegaard
Keyword(s):  
Particulate Matter ◽  
Large Scale ◽  
Biogas Production ◽  
Stable Process ◽  
Particulate Material ◽  
Limiting Factor ◽  
Biogas Plants ◽  
Temperature Levels ◽  
Rate Limiting ◽  
Digestion Step

The main objective of this study was to investigate the degradation efficiency of centralized biogas plants and provide guidance for the design of more efficient digester and post-digestion systems. These centralized biogas plants in Denmark digest manure together with organic waste from the food industry to generate biogas, which is used for electricity and thermal energy. A total of 20 such plants are currently active in Denmark, most of which were included in the investigation. From the plants, samples were obtained from various steps of the process. Samples were analysed and the residual biogas potential determined by batch post-digestion at various temperature levels. Results were correlated with plant characteristics and production statistics in order to judge the efficiency of various digestion concepts. A simplified model based on a two-step biogas production process was developed and experimental data were used to determine kinetic constants. Experimental results and analysis combined with model simulations showed that the residual biogas potential in the main digestion step effluent is originating mainly from undegraded particulate matter in the biomass. For thermophilic plants 93% of the residual biogas potential was originating from particulate matter and 88% for the mesophilic biogas plants. This indicates that the residual biogas potential is mainly due to insufficient retention time in the main digestion step for hydrolysis of particulate material and that the hydrolysis step is the methane yield limiting factor, while conversion of soluble material such as VFA is the rate limiting factor critical for achieving a stable process.

Assessment of the state of the art of technologies for the processing of digestate residue from anaerobic digesters

2013 ◽  
Vol 67 (9) ◽  
pp. 1984-1993 ◽  
Author(s):  
W. Fuchs ◽  
B. Drosg
Keyword(s):  
Anaerobic Digestion ◽  
Large Scale ◽  
State Of The Art ◽  
Biogas Production ◽  
The State ◽  
Anaerobic Digesters ◽  
Adequate Treatment ◽  
Biogas Plants ◽  
Treatment Technologies ◽  
Digestate Processing

Anaerobic digestion is widely used as an important source of renewable energy. With the increasing number and capacity of biogas plants also, adequate treatment technologies for whole digestate – the residue from anaerobic digestion – are gaining attention. In this study the state of the art of digestate processing is analysed, and currently used treatment schemes and the various technological processes involved are evaluated. The study combines data and experiences from existing large-scale digestate processing facilities in Austria, Germany, Switzerland and Italy, as well as know-how from technology providers and relevant research projects. However, the field of digestate processing is still quite new and little detailed information about the performance of different technologies at industrial scale is available. Digestate processing is gaining importance since digestate utilisation can become an important bottleneck when increasing biogas production. In addition, the production of renewable fertiliser from digestate is increasingly of interest to replace fossil fertilisers. This study is the first profound attempt to establish an assessment of the state-of-the-art technologies in use.

scholarly journals Technologies, challenges and perspectives of biogas production within an agricultural context. The case of China and Africa

2021 ◽  
Author(s):  
Rufis Fregue Tiegam Tagne ◽  
Xiaobin Dong ◽  
Solomon G. Anagho ◽  
Serena Kaiser ◽  
Sergio Ulgiati
Keyword(s):  
Renewable Resources ◽  
Large Scale ◽  
Fossil Fuels ◽  
Biogas Production ◽  
Low Cost ◽  
African Countries ◽  
Waste Production ◽  
Effective Technology ◽  
Biogas Plants ◽  
Biochemical Mechanisms

AbstractThe use of fossil fuels in modern economies has been a success because of the low cost of fossil resources. However, the depletion of fossil reserves, the increase in waste production and global warming concerns have led to increased research on the production of biofuels from renewable resources. Waste production is steadily increasing in quantity and constantly changing in quality, creating enormous risks for the environment and, consequently, for the health of the population. This situation is much more worrying in developing countries, in particular because of the considerable delay in the field of the conversion and recovery of biomaterials, due to their difficulty in approaching the problem in a way that fits their context. The composition of such wastes and residues, rich in organic matter, allows their conversion via biochemical mechanisms, thus constituting an effective solution to address the environmental problems of their disposal. Anaerobic digestion remains a valuable and effective technology for transforming these biomaterials into biogas. The present review focuses on technologies, challenges and areas of application of biogas, especially in China and some African countries, in order to promote the large-scale use of biogas for electricity generation and biofuels. Results point out that China is more used to this technology, while African countries still rely on traditional and less advanced technologies, thus hampering the potential derived from the large availability of biomaterials. Both realities, however, share similar backgrounds about the dimension of the biogas plants and their non-commercial purposes, even if China is recently shifting toward the adoption of a different model. These considerations are used in the article to open an interesting new scenario of political alternatives which may provide a way out from poverty and economic dependence, within the framework of a wider circularity.

scholarly journals Conversion of Post-Socialist Agricultural Premises as a Chance for Renewable Energy Production. Photovoltaics or Biogas Plants?

Energies ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 7164
Author(s):  
Josef Navrátil ◽  
Stanislav Martinát ◽  
Tomáš Krejčí ◽  
Petr Klusáček ◽  
Richard J. Hewitt
Keyword(s):  
Renewable Energy ◽  
Power Plants ◽  
Large Scale ◽  
Planning Process ◽  
Biogas Production ◽  
The Public ◽  
Photovoltaic Power ◽  
Biogas Plants ◽  
Agricultural Areas ◽  
Locally Grown

We aim to contribute to in-depth comprehension of the factors and preferences behind the reuses of large-scale underused or abandoned former collective farms from the 1950s–1980s for biogas plants and solar photovoltaic power plants. As a case study, three regions in the southern part of the Czech Republic have been selected. Our findings signal that the residents’ attitudes towards the mentioned energy sources are rather negative. Similarly, farmers’ interest in photovoltaic power plants is low. More interest has been detected in the case of biogas production; this is especially true for large agricultural companies and farmers, who own underused or abandoned premises. Biogas plants are frequently located in agricultural areas with warmer or just slightly colder climates as a consequence of the potential to process locally grown maize. On the other hand, photovoltaic power plants are found on more fertile plains with high levels of insolation, but, surprisingly, also in mountain regions which typically have low emissions. Both renewable energy solutions were found to be problematic as there is strong opposition to both types of installations among local inhabitants. This indicates the need for “soft” forms of planning. Stakeholder engagement and inclusive participation in all phases of the planning process are essential requirements for arriving at the best possible outcomes for the new renewable energy solutions and their acceptance by the public.

Biogas Production Using Anaerobic Digestion of Industrial Waste

2016 ◽  
Vol 832 ◽  
pp. 55-62
Author(s):  
Ján Gaduš ◽  
Tomáš Giertl ◽  
Viera Kažimírová
Keyword(s):  
Anaerobic Digestion ◽  
Industrial Waste ◽  
Large Scale ◽  
Biogas Production ◽  
Biogas Plant ◽  
Parallel Operation ◽  
Paper Production ◽  
Biochemical Conversion ◽  
Mixed Biomass ◽  
Economic Balance

In the paper experiments and theory of biogas production using industrial waste from paper production as a co-substrate are described. The main aim of the experiments was to evaluate the sensitivity and applicability of the biochemical conversion using the anaerobic digestion of the mixed biomass in the pilot fermentor (5 m3), where the mesophillic temperature was maintained. It was in parallel operation with a large scale fermentor (100 m3). The research was carried out at the biogas plant in Kolíňany, which is a demonstration facility of the Slovak University of Agriculture in Nitra. The experiments proved that the waste arising from the paper production can be used in case of its appropriate dosing as an input substrate for biogas production, and thus it can improve the economic balance of the biogas plant.

scholarly journals The Dynamics of Subunit Rotation in a Eukaryotic Ribosome

Biophysica ◽  
2021 ◽  
Vol 1 (2) ◽  
pp. 204-221
Author(s):  
Frederico Campos Freitas ◽  
Gabriele Fuchs ◽  
Ronaldo Junio de Oliveira ◽  
Paul Charles Whitford
Keyword(s):  
Free Energy ◽  
Large Scale ◽  
Small Subunit ◽  
Free Energy Barrier ◽  
Temperature Dependent ◽  
Molecular Flexibility ◽  
Subunit Rotation ◽  
Biological Kinetics ◽  
Rate Limiting ◽  
Reversible Rotation

Protein synthesis by the ribosome is coordinated by an intricate series of large-scale conformational rearrangements. Structural studies can provide information about long-lived states, however biological kinetics are controlled by the intervening free-energy barriers. While there has been progress describing the energy landscapes of bacterial ribosomes, very little is known about the energetics of large-scale rearrangements in eukaryotic systems. To address this topic, we constructed an all-atom model with simplified energetics and performed simulations of subunit rotation in the yeast ribosome. In these simulations, the small subunit (SSU; ∼1 MDa) undergoes spontaneous and reversible rotation events (∼8∘). By enabling the simulation of this rearrangement under equilibrium conditions, these calculations provide initial insights into the molecular factors that control dynamics in eukaryotic ribosomes. Through this, we are able to identify specific inter-subunit interactions that have a pronounced influence on the rate-limiting free-energy barrier. We also show that, as a result of changes in molecular flexibility, the thermodynamic balance between the rotated and unrotated states is temperature-dependent. This effect may be interpreted in terms of differential molecular flexibility within the rotated and unrotated states. Together, these calculations provide a foundation, upon which the field may begin to dissect the energetics of these complex molecular machines.

scholarly journals Spatial and Temporal Characteristics of Environmental Air Quality and Its Relationship with Seasonal Climatic Conditions in Eastern China during 2015–2018

2021 ◽  
Vol 18 (9) ◽  
pp. 4524
Author(s):  
Zhiyuan Wang ◽  
Xiaoyi Shi ◽  
Chunhua Pan ◽  
Sisi Wang
Keyword(s):  
Particulate Matter ◽  
Air Quality ◽  
Air Pollutants ◽  
Large Scale ◽  
Asian Summer Monsoon ◽  
Eastern China ◽  
Climatic Conditions ◽  
Uniform Structure ◽  
Concentration Limit ◽  
Environmental Air

Exploring the relationship between environmental air quality (EAQ) and climatic conditions on a large scale can help better understand the main distribution characteristics and the mechanisms of EAQ in China, which is significant for the implementation of policies of joint prevention and control of regional air pollution. In this study, we used the concentrations of six conventional air pollutants, i.e., carbon monoxide (CO), sulfur dioxide (SO2), nitrogen dioxide (NO2), fine particulate matter (PM2.5), coarse particulate matter (PM10), and ozone (O3), derived from about 1300 monitoring sites in eastern China (EC) from January 2015 to December 2018. Exploiting the grading concentration limit (GB3095-2012) of various pollutants in China, we also calculated the monthly average air quality index (AQI) in EC. The results show that, generally, the EAQ has improved in all seasons in EC from 2015 to 2018. In particular, the concentrations of conventional air pollutants, such as CO, SO2, and NO2, have been decreasing year by year. However, the concentrations of particulate matter, such as PM2.5 and PM10, have changed little, and the O3 concentration increased from 2015 to 2018. Empirical mode decomposition (EOF) was used to analyze the major patterns of AQI in EC. The first mode (EOF1) was characterized by a uniform structure in AQI over EC. These phenomena are due to the precipitation variability associated with the East Asian summer monsoon (EASM), referred to as the “summer–winter” pattern. The second EOF mode (EOF2) showed that the AQI over EC is a north–south dipole pattern, which is bound by the Qinling Mountains and Huaihe River (about 35° N). The EOF2 is mainly caused by seasonal variations of the mixed concentration of PM2.5 and O3. Associated with EOF2, the Mongolia–Siberian High influences the AQI variation over northern EC by dominating the low-level winds (10 m and 850 hPa) in autumn and winter, and precipitation affects the AQI variation over southern EC in spring and summer.

scholarly journals Indicative Marker Microbiome Structures Deduced from the Taxonomic Inventory of 67 Full-Scale Anaerobic Digesters of 49 Agricultural Biogas Plants

2021 ◽  
Vol 9 (7) ◽  
pp. 1457
Author(s):  
Julia Hassa ◽  
Johanna Klang ◽  
Dirk Benndorf ◽  
Marcel Pohl ◽  
Benedikt Hülsemann ◽  
...  
Keyword(s):  
Stable Process ◽  
Process Condition ◽  
Full Scale ◽  
Process Models ◽  
Process Efficiency ◽  
Process Conditions ◽  
Rrna Gene ◽  
General Process ◽  
Specific Distribution ◽  
Biogas Plants

There are almost 9500 biogas plants in Germany, which are predominantly operated with energy crops and residues from livestock husbandry over the last two decades. In the future, biogas plants must be enabled to use a much broader range of input materials in a flexible and demand-oriented manner. Hence, the microbial communities will be exposed to frequently varying process conditions, while an overall stable process must be ensured. To accompany this transition, there is the need to better understand how biogas microbiomes respond to management measures and how these responses affect the process efficiency. Therefore, 67 microbiomes originating from 49 agricultural, full-scale biogas plants were taxonomically investigated by 16S rRNA gene amplicon sequencing. These microbiomes were separated into three distinct clusters and one group of outliers, which are characterized by a specific distribution of 253 indicative taxa and their relative abundances. These indicative taxa seem to be adapted to specific process conditions which result from a different biogas plant operation. Based on these results, it seems to be possible to deduce/assess the general process condition of a biogas digester based solely on the microbiome structure, in particular on the distribution of specific indicative taxa, and without knowing the corresponding operational and chemical process parameters. Perspectively, this could allow the development of detection systems and advanced process models considering the microbial diversity.

scholarly journals Tyrosinase Nanoparticles: Understanding the Melanogenesis Pathway by Isolating the Products of Tyrosinase Enzymatic Reaction

2021 ◽  
Vol 22 (2) ◽  
pp. 734
Author(s):  
Paul K. Varghese ◽  
Mones Abu-Asab ◽  
Emilios K. Dimitriadis ◽  
Monika B. Dolinska ◽  
George P. Morcos ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Large Scale ◽  
Magnetic Beads ◽  
Enzymatic Reaction ◽  
Oculocutaneous Albinism ◽  
Transmission Electron ◽  
Hill Kinetics ◽  
Rate Limiting ◽  
Human Tyrosinase

Human Tyrosinase (Tyr) is the rate-limiting enzyme of the melanogenesis pathway. Tyr catalyzes the oxidation of the substrate L-DOPA into dopachrome and melanin. Currently, the characterization of dopachrome-related products is difficult due to the absence of a simple way to partition dopachrome from protein fraction. Here, we immobilize catalytically pure recombinant human Tyr domain (residues 19–469) containing 6xHis tag to Ni-loaded magnetic beads (MB). Transmission electron microscopy revealed Tyr-MB were within limits of 168.2 ± 24.4 nm while the dark-brown melanin images showed single and polymerized melanin with a diameter of 121.4 ± 18.1 nm. Using Hill kinetics, we show that Tyr-MB has a catalytic activity similar to that of intact Tyr. The diphenol oxidase reactions of L-DOPA show an increase of dopachrome formation with the number of MB and with temperature. At 50 °C, Tyr-MB shows some residual catalytic activity suggesting that the immobilized Tyr has increased protein stability. In contrast, under 37 °C, the dopachrome product, which is isolated from Tyr-MB particles, shows that dopachrome has an orange-brown color that is different from the color of the mixture of L-DOPA, Tyr, and dopachrome. In the future, Tyr-MB could be used for large-scale productions of dopachrome and melanin-related products and finding a treatment for oculocutaneous albinism-inherited diseases.

Current State of (Dis)Integration: Public Health and Fusion Centers

2020 ◽  
Vol 17 (2) ◽  
Author(s):  
Cody Minks ◽  
Anke Richter
Keyword(s):  
Public Health ◽  
Law Enforcement ◽  
Information Sharing ◽  
Homeland Security ◽  
Large Scale ◽  
Ad Hoc ◽  
Limiting Factor ◽  
Fusion Centers ◽  
Public Health Emergencies ◽  
Public Health Information

AbstractObjectiveResponding to large-scale public health emergencies relies heavily on planning and collaboration between law enforcement and public health officials. This study examines the current level of information sharing and integration between these domains by measuring the inclusion of public health in the law enforcement functions of fusion centers.MethodsSurvey of all fusion centers, with a 29.9% response rate.ResultsOnly one of the 23 responding fusion centers had true public health inclusion, a decrease from research conducted in 2007. Information sharing is primarily limited to information flowing out of the fusion center, with little public health information coming in. Most of the collaboration is done on a personal, informal, ad-hoc basis. There remains a large misunderstanding of roles, capabilities, and regulations by all parties (fusion centers and public health). The majority of the parties appear to be willing to work together, but there but there is no forward momentum to make these desires a reality. Funding and staffing issues seem to be the limiting factor for integration.ConclusionThese problems need to be urgently addressed to increase public health preparedness and enable a decisive and beneficial response to public health emergencies involving a homeland security response.

scholarly journals Empirical Validation of a Biogas Plant Simulation Model and Analysis of Biogas Upgrading Potentials

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2424
Author(s):  
Jan Martin Zepter ◽  
Jan Engelhardt ◽  
Tatiana Gabderakhmanova ◽  
Mattia Marinelli
Keyword(s):  
Simulation Model ◽  
Biogas Production ◽  
Biogas Plant ◽  
Raw Material ◽  
Biogas Upgrading ◽  
Integrated Energy Systems ◽  
First Order Kinetics ◽  
Biogas Plants ◽  
Plant Simulation ◽  
Kinetics Of

Biogas plants may support the transformation towards renewable-based and integrated energy systems by providing dispatchable co-generation as well as opportunities for biogas upgrading or power-to-X conversion. In this paper, a simulation model that comprises the main dynamics of the internal processes of a biogas plant is developed. Based on first-order kinetics of the anaerobic digestion process, the biogas production of an input feeding schedule of raw material can be estimated. The output of the plant in terms of electrical and thermal energy is validated against empirical data from a 3-MW biogas plant on the Danish island of Bornholm. The results show that the model provides an accurate representation of the processes within a biogas plant. The paper further provides insights on the functioning of the biogas plant on Bornholm as well as discusses upgrading potentials of biogas to biomethane at the plant from an energy perspective.

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