scholarly journals CFD Modelling of Biomass Mixing in Anaerobic Digesters of Biogas Plants

2019 ◽  
Vol 23 (3) ◽  
pp. 57-69 ◽  
Author(s):  
Fosca Conti ◽  
Abdessamad Saidi ◽  
Markus Goldbrunner
Keyword(s):  
Fluid Dynamics ◽  
Energy Demand ◽  
Biogas Production ◽  
Electricity Consumption ◽  
Electrical Energy ◽  
Matter Content ◽  
Dry Matter Content ◽  
Cfd Modelling ◽  
Anaerobic Digesters ◽  
Biogas Plants

Abstract Cut in greenhouse gas emissions, increment of energy from renewables and improvement in energy efficiency represent the three key targets for future energy systems. Among the available bioenergy technologies, biogas production via biodegradation and anaerobic digestion is a widely applied approach, not only to produce biofuels but also to manage industrial and domestic organic waste. Within the biogas production, a sufficient mixing of the organic mass is a crucial step to ensure high biogas yields by bacteria and enzymes. Measurements of the electric power consumption of biogas plants revealed that the electrical energy demand of the stirrer system has a high share of the total electricity consumption of a biogas plant. Investigations on real biogas digesters to optimize the mixing process are cost and time intensive. Therefore, laboratory prototypes and computational simulations represent promising alternatives to analyse and improve the efficiency of mixing systems. In this paper, a computational fluid dynamics (CFD) model is presented, which is applied to commercial stirring systems. The case of two propeller stirrers, located in diametrically opposite positions in a tank filled with ca. 1400 m3 of substrate is described in detail. For the simulation, the rheology of the fluid is adapted to a biomass with 12 wt % dry matter content and obeying the non-Newtonian generalized Ostwald-de Waele power law. The developed simulation procedure considers the rotation angle of each propeller and its height. A total of 441 mixing configurations are calculated and evaluated in terms of the technical benefit. The investigation reveals that locations of the rotors far away from the bottom and high rotational angles cause advantageous fluid dynamics.

scholarly journals Determination of mixing quality in biogas plant digesters using tracer tests and computational fluid dynamics

2013 ◽  
Vol 61 (5) ◽  
pp. 1269-1278 ◽  
Author(s):  
Luděk Kamarád ◽  
Stefan Pohn ◽  
Günther Bochmann ◽  
Michael Harasek
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Energy Demand ◽  
Biogas Production ◽  
Tracer Tests ◽  
Full Scale ◽  
Biogas Plant ◽  
Tracer Concentration ◽  
Anaerobic Digesters ◽  
Biogas Plants

The total electricity demand of investigated biogas plants (BGP) makes up 7–8 % of the total electricity produced. Nearly 40 % of this energy is consumed just for mixing in digesters and the energy demand for mixing in some biogas plants can be even higher. Therefore, optimal mixing in anaerobic digesters is a basic condition for efficient plant operation and biogas production. The use of problematic substrates (e.g. grass silage or other fibrous substrates), installation of unsuitable mixing systems or inconvenient mixing intervals may lead to mixing problems. Knowledge about mixing in biogas digesters is still insufficient, so the objective of this study was to fill the information gaps in the literature by determining the minimal retention time of substrates fed into anaerobic digesters and to describe substrate distribution and washing out rates from investigated digesters. Two full-scale biogas plant digesters (2000 m3 and 1500 m3) using different mixing systems and substrates were investigated. To characterize the substrate distribution, lithium hydroxide monohydrate solutions were used for tracer tests at concentrations of 47.1 mg Li+ / kg TS and 46.6 mg Li+ / kg TS in digester. The tracer concentration in the digester effluents was measured during two hydraulic retention times and compared. Although the tracer was detected in the digester effluent at nearly the same time in both cases, the tracer tests showed very different distribution curves. The tracer concentration in effluent B grew much slower than in effluent A and no significant short circuiting streams were detected. Although the data calculated by computational fluid dynamics methods (CFD) showed a very good agreement with the full scale results, full comparison was not possible.

Optimum harvest date of maize for biogas and silage purposes

2009 ◽  
Vol 57 (2) ◽  
pp. 119-125
Author(s):  
G. Hadi
Keyword(s):  
Dry Matter ◽  
Biogas Production ◽  
Weather Conditions ◽  
Vegetation Period ◽  
Dry Mass ◽  
Matter Content ◽  
Harvest Date ◽  
Dry Matter Content ◽  
Dry Matter Yield ◽  
Vegetative Organs

The dry matter and moisture contents of the aboveground vegetative organs and kernels of four maize hybrids were studied in Martonvásár at five harvest dates, with four replications per hybrid. The dry matter yield per hectare of the kernels and other plant organs were investigated in order to obtain data on the optimum date of harvest for the purposes of biogas and silage production.It was found that the dry mass of the aboveground vegetative organs, both individually and in total, did not increase after silking. During the last third of the ripening period, however, a significant reduction in the dry matter content was sometimes observed as a function of the length of the vegetation period. The data suggest that, with the exception of extreme weather conditions or an extremely long vegetation period, the maximum dry matter yield could be expected to range from 22–42%, depending on the vegetation period of the variety. The harvest date should be chosen to give a kernel moisture content of above 35% for biogas production and below 35% for silage production. In this phenophase most varieties mature when the stalks are still green, so it is unlikely that transport costs can be reduced by waiting for the vegetative mass to dry.

scholarly journals POTENSI ENERGI LISTRIK YANG DIHASILKAN DARI EMISI GAS METANA DI TPA SUWUNG PROVINSI BALI

2017 ◽  
Vol 11 (2) ◽  
pp. 132 ◽  
Author(s):  
Putu Dian Paramitha Dewi ◽  
I Wayan Suarna ◽  
I Wayan Budiarsa Suyasa
Keyword(s):  
Dry Matter ◽  
Organic Waste ◽  
Electrical Power ◽  
Value Added ◽  
Electrical Energy ◽  
Methane Emissions ◽  
Matter Content ◽  
Gas Content ◽  
Dry Matter Content ◽  
Methane Gas

Waste is one source of greenhouse gas emissions (GHG) that has methane gas form which caused an early multi-dimensional, massive and complex problems. The rapid increase of garbage volume entering landfill, annually result a high garbage dumps in the Suwung Landfill area. It should have been considered a handing solution for example by converting the methane gas content in the waste into a useful value added product. The objective of this research is determining the amount of electrical energy that can be produced through methane gas emission at Suwung Landfill. The characteristic and composition of waste could give effect to the formation of methane emissions. The research on the composition and characteristic of waste were done by sorting 1 m3 of garbage sample from new garbage entering landfill. Garbage is divided based on the source of DLHK waste, market waste, and private waste. The volume of waste that went to Suwung Landfill in 2016 calculated 1.296.438 m3 which was dominated by organic waste (78,1%). The density of the waste that went into Suwung Landfill, based on the research's results, amounted to 135,09 kg / m3, there fore could be assumed that the weight of waste that went to Suwung Landfill in 2016 was 175.135,81 tons. Based on these data, the number of 136.785,13 tons of waste, which was organic waste, could increase the concentration of greenhouse gases in the atmosphere if this situation does not manage properly. Gravimeter method is using for measures the dry matter content value of waste. From the measurement, the results obtained the waste components that have the highest dry matter content is from rubber and leather garbage (76,52%) while the lowest dry matter is food waste (19,13%). By using calculations based on IPCC 2006, it was found that the amount of methane emissions could be generated by the waste at the Suwung Landfill in 2016, amounted to 3.535,06 tons. Based on the energy equivalence table, the electrical power that is generated from the potential methane emissions at the Suwung Landfill is 6,66 MW. Keywords: waste composition, waste characteristics, methane emissions, ipcc2006, electrical power.

scholarly journals BIOGAS PRODUCTION FROM AMARANTH BIOMASS

2013 ◽  
Vol 10 (2) ◽  
pp. 59-62
Author(s):  
Vladimír Sitkey ◽  
Ján Gaduš ◽  
Ľubomír Kliský ◽  
Alexander Dudák
Keyword(s):  
Dry Matter ◽  
Large Scale ◽  
Biogas Production ◽  
Organic Fertilizer ◽  
Matter Content ◽  
Raw Material ◽  
Dry Matter Content ◽  
Optimum Conditions ◽  
Average Yield ◽  
Amaranthus Spp

Abstract Energy variety of amaranth (Amaranthus spp.) was grown in large-scale trials in order to verify the capability of its cultivation and use as a renewable energy source in a biogas plant. The possibility of biogas production using anaerobic co-fermentation of manure and amaranth silage was verified in the experimental horizontal fermentor of 5 m3 volume, working at mesophilic conditions of 38-40 °C. The goal of the work was also to identify the optimum conditions for growth, harvesting and preservation of amaranth biomass, to optimize biogas production process, and to test the residual slurry from digestion process as a high quality organic fertilizer. The average yield of green amaranth biomass was 51.66 t.ha-1 with dry matter content of 37%. Based on the reached results it can be concluded that amaranth silage, solely or together with another organic materials of agricultural origin, is a suitable raw material for biogas production.

scholarly journals Modelling of Demand Driven Biogas Plants to Cover Residual Load Rises

Proceedings ◽  
2018 ◽  
Vol 2 (22) ◽  
pp. 1385 ◽  
Author(s):  
Lena Peters ◽  
Piotr Biernacki ◽  
Frank Uhlenhut ◽  
Sven Steinigeweg
Keyword(s):  
Reaction Time ◽  
Energy Demand ◽  
Energy Production ◽  
Process Model ◽  
Input Data ◽  
Biogas Production ◽  
Pi Controller ◽  
Feeding Program ◽  
Biogas Plants ◽  
Flexible Operation

In future, systems for energy storage and demand-driven energy production will be essential to cover the residual load rises. A rigorous dynamic process model based on ADM1 was used to analyze the flexible operation of biogas plants for covering the residual load rises. This model was optimized and an operation concept for a demand-driven energy production was worked out. For the input data different substrates were analyzed by batch fermentations and the Weender analysis with van Soest method. The results show that the substrates have got a different biogas production rate and reaction time. Finally, an intelligent feeding algorithm by implementation of a PI controller was developed. It calculates feeding times and quantities of available substrates so that a defined energy demand can be covered by biogas plants. The results demonstrate that a flexible operation of biogas plants with an individual and intelligent feeding program is possible.

scholarly journals Valorization of dietary lemon pomace waste to enhance lucerne silage composition and quality characteristics, and ruminal biogas production and fermentation

2021 ◽  
Author(s):  
Maghsoud Besharati ◽  
Valiollah Palangi ◽  
Zabihollah Nemati ◽  
Rashid Safari ◽  
Abdelfattah Z. M. Salem
Keyword(s):  
Dry Matter ◽  
Volatile Fatty Acids ◽  
Biogas Production ◽  
Bacterial Species ◽  
Gas Production ◽  
Matter Content ◽  
Dry Matter Content ◽  
Production Volume ◽  
Randomized Design

Abstract The purpose of this study was to investigate the effect of adding various levels of waste sour lemon pomace to lucerne on the properties and ruminal gas production of silage. Levels of 0 (Control), 25 (L1), 50 (L2), 75 (L3), and 100 (L4) % lemon pomace were replaced by lucerne for silage preparation and silenced for 60 days. The experiment was conducted in a completely randomized design with three replications (3 silos per treatment). After opening the silos, pH and dry matter were measured immediately, and the dried samples were kept at -20 until further tests. The silage pH decreased with the addition of lemon pomace compared to the control (p < 0.05). Total silage volatile fatty acids and dry matter content increased with adding lemon pomace. The results of gas production also showed that lemon pomace increased the in vitro gas production volume. Adding lemon pomace to lucerne silage due to the high pectin content in these agricultural wastes caused a rapid decrease of silage pH and an acidic environment. It prevented the growth of non-beneficial bacterial species. The obtained data showed that waste sour lemon has a good potential to use as a livestock feedstuff that can be useful in reducing the cost of ruminant production and preventing environmental pollution.

scholarly journals Supplying the energy demand in the chicken meat processing poultry with biogas

2016 ◽  
Vol 36 (1) ◽  
pp. 118-121 ◽  
Author(s):  
Adriano Henrique Ferrarez ◽  
Delly Oliveira Filho ◽  
Adílio Flauzino Lacerda Filho ◽  
José Márcio Costa ◽  
Fabrício Segui Aparisi
Keyword(s):  
Economic Analysis ◽  
Energy Demand ◽  
Energy Use ◽  
Biogas Production ◽  
Poultry Litter ◽  
Electric Energy ◽  
Electrical Energy ◽  
Chicken Meat ◽  
Processing Unit ◽  
Meat Processing

<p>The main use of electrical energy in the chicken meat processing unit is refrigeration. About 70% of the electricity is consumed in the compressors for the refrigeration system. Through this study, the energetic viability of using biogas from poultry litter in supplying the demand for the refrigeration process was found. The meat processing unit studied has the potential to process about a hundred and sixty thousand chickens a day. The potential biogas production from poultry litter is 60,754,298.91 m3.year-1. There will be a surplus of approximately 8,103MWh per month of electric energy generated from biogas. An economic analysis was performed considering a planning horizon of 20 years and the discount rate of 12% per year. The economic analysis was performed considering scenario 1: sale of all electricity generated by the thermoelectric facility, and scenario 2: sale of the surplus electricity generated after complying with the demands of the refrigeration process and all other electrical energy and thermal energy use. Economic indicators obtained for scenarios 1 and 2 were favorable for the project implementation.</p>

scholarly journals Methodology for Analysing Energy Demand in Biogas Production Plants—A Comparative Study of Two Biogas Plants

Energies ◽  
2017 ◽  
Vol 10 (11) ◽  
pp. 1822 ◽  
Author(s):  
Emma Lindkvist ◽  
Maria Johansson ◽  
Jakob Rosenqvist
Keyword(s):  
Comparative Study ◽  
Energy Demand ◽  
Biogas Production ◽  
Biogas Plants

scholarly journals Energy Demand and Supply Forecasting Based on Electricity Consumption Intensity and Production Capacity for Development of Operating Support in Headquarter of Indonesian National Army

2018 ◽  
Vol 73 ◽  
pp. 01004
Author(s):  
Budi Nur Cahyo ◽  
Ahmad Agus Setiawan ◽  
Wahyu Wilopo ◽  
Afrizal Abdi Musyafiq
Keyword(s):  
Energy Demand ◽  
Low Voltage ◽  
Large Population ◽  
Production Capacity ◽  
Electricity Consumption ◽  
Electrical Energy ◽  
The State ◽  
Demand And Supply ◽  
Energy Needs ◽  
Consumption Intensity

Indonesia is one of the major countries composed of many islands; directly adjacent to several neighboring countries; and is also a country with a large population in the world. The security and resilience of the state of threats coming from abroad and within the country would have been anticipated by a government agency namely the Indonesian National Army (TNI). The TNI in performing its duties must be supported by means of supporting facilities for operations at headquarters. Supporting facilities for operations at the TNI Headquarters should have enough energy, especially on the need for electrical energy. The need for electrical energy at the TNI Headquarters is fully supported by the State Electricity Company (PLN). In this research will take into account the needs of Tower A and underground at TNI Headquarters which will be built with low voltage building planning. Analysis using LEAP to estimate demand and energy needs lsitrik at TNI Headquarters in order to experience the energy balance. The end result of this research is to provide recommendations to the TNI ranks regarding the capacity building of the necessary operational facilities at the TNI Headquarters.

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.

Sign in / Sign up

Export Citation Format

Share Document