scholarly journals Improving biogas yields using an innovative concept for conversion of the fiber fraction of manure

2012 ◽  
Vol 66 (8) ◽  
pp. 1751-1758 ◽  
Author(s):  
Rajib Biswas ◽  
B. K. Ahring ◽  
H. Uellendahl
Keyword(s):  
Treatment Time ◽  
Methane Yield ◽  
Process Conditions ◽  
Batch Experiments ◽  
Biogas Yield ◽  
Fiber Fraction ◽  
Biogas Plants ◽  
Biogas Reactor ◽  
Innovative Concept ◽  
Wet Explosion

The potential of a new concept to enable economically feasible operation of manure-based biogas plants was investigated at laboratory scale. Wet explosion (WEx) was applied to the residual manure fibers separated after the anaerobic digestion process for enhancing the biogas yield before reintroducing the fiber fraction into the biogas reactor. The increase in methane yield of the digested manure fibers was investigated by applying the WEx treatment under five different process conditions. The WEx treatment at 180 °C and a treatment time of 10 min without addition of oxygen was found to be optimal, resulting in 136% increase in methane yield compared with the untreated digested manure fibers in batch experiments. In a continuous mesophilic reactor process the addition of WEx-treated digested fibers in co-digestion with filtered manure did not show any signs of process inhibition, and the overall methane yield was on average 75% higher than in a control reactor with addition of non-treated digested fibers.

scholarly journals Biomethane Potential Test: Influence of Inoculum and the Digestion System

2020 ◽  
Vol 10 (7) ◽  
pp. 2589 ◽  
Author(s):  
Benedikt Hülsemann ◽  
Lijun Zhou ◽  
Wolfgang Merkle ◽  
Juli Hassa ◽  
Joachim Müller ◽  
...  
Keyword(s):  
Laboratory Tests ◽  
Methane Yield ◽  
Biochemical Methane Potential ◽  
Measurement Variability ◽  
Biogas Yield ◽  
Yield Test ◽  
Biogas Plants ◽  
Methane Potential ◽  
Bmp Test

High precision of measurement of methane potential is important for the economic operation of biogas plants in the future. The biochemical methane potential (BMP) test based on the VDI 4630 protocol is the state-of-the-art method to determine the methane potential in Germany. The coefficient of variation (CV) of methane yield was >10% in several previous inter-laboratory tests. The aim of this work was to investigate the effects of inoculum and the digestion system on the measurement variability. Methane yield and methane percentage of five substrates were investigated in a Hohenheim biogas yield test (D-HBT) by using five inocula, which were used several times in inter- laboratory tests. The same substrates and inocula were also tested in other digestion systems. To control the quality of the inocula, the effect of adding trace elements (TE) and the microbial community was investigated. Adding TE had no influence for the selected, well- supplied inocula and the community composition depended on the source of the inocula. The CV of the specific methane yield was <4.8% by using different inocula in one D-HBT (D-HBT1) and <12.8% by using different digestion systems compared to D-HBT1. Incubation time between 7 and 14 days resulted in a deviation in CV of <4.8%.

scholarly journals Optimization of the Alkaline Pretreatment of Rice Straw for Enhanced Methane Yield

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Zilin Song ◽  
Gaihe Yang ◽  
Xinhui Han ◽  
Yongzhong Feng ◽  
Guangxin Ren
Keyword(s):  
Rice Straw ◽  
Treatment Time ◽  
Interactive Effects ◽  
Methane Yield ◽  
Optimal Conditions ◽  
Biogas Yield ◽  
Digestion Process ◽  
Lime Pretreatment ◽  
Experimental Parameters ◽  
Pretreatment Time

The lime pretreatment process for rice straw was optimized to enhance the biodegradation performance and increase biogas yield. The optimization was implemented using response surface methodology (RSM) and Box-Behnken experimental design. The effects of biodegradation, as well as the interactive effects of Ca(OH)2concentration, pretreatment time, and inoculum amount on biogas improvement, were investigated. Rice straw compounds, such as lignin, cellulose, and hemicellulose, were significantly degraded with increasing Ca(OH)2concentration. The optimal conditions for the use of pretreated rice straw in anaerobic digestion were 9.81% Ca(OH)2(w/w TS), 5.89 d treatment time, and 45.12% inoculum content, which resulted in a methane yield of 225.3 mL/g VS. A determination coefficient (R2) of 96% was obtained, indicating that the model used to predict the anabolic digestion process shows a favorable fit with the experimental parameters.

Study on the Chemical Modification Process of Jute Fiber

TAPPI Journal ◽  
2010 ◽  
Vol 9 (2) ◽  
pp. 23-29 ◽  
Author(s):  
Wei-ming Wang ◽  
Zai-sheng Cai ◽  
Jian-yong Yu
Keyword(s):  
Sodium Hydroxide ◽  
Sodium Silicate ◽  
Treatment Time ◽  
Jute Fiber ◽  
Process Conditions ◽  
Silicate Concentration ◽  
Sodium Hydroxide Concentration ◽  
Liquor Ratio ◽  
Degumming Process ◽  
Selection Of

Degumming of pre-chlorite treated jute fiber was studied in this paper. The effects of sodium hydroxide concentration, treatment time, temperature, sodium silicate concentration, fiber-to-liquor ratio, penetrating agent TF-107B concentration, and degumming agent TF-125A concentration were the process conditions examined. With respect to gum decomposition, fineness and mechanical properties, sodium hydroxide concentration, sodium silicate concentration, and treatment time were found to be the most important parameters. An orthogonal L9(34) experiment designed to optimize the conditions for degumming resulted in the selection of the following procedure: sodium hydroxide of 12g/L, sodium silicate of 3g/L, TF-107B of 2g/L, TF-125A of 2g/L, treatment time of 105 min, temperature of 100°C and fiber to liquor ratio of 1:20. The effect of the above degumming process on the removal of impurities was also examined and the results showed that degumming was an effective method for removing impurities, especially hemicellulose.

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.

Surface Treatment of the Glass Fibers in Low Pressure Microvave Plasma

1983 ◽  
Vol 30 ◽  
Author(s):  
Ryszard Parosa
Keyword(s):  
Microwave Power ◽  
Industrial Application ◽  
Treatment Time ◽  
Plasma Reactor ◽  
Glass Fibers ◽  
Process Conditions ◽  
Plasma Region ◽  
Optimal Process ◽  
Driving System ◽  
Air Plasmas

ABSTRACTIn the method described here, oxygen and air plasmas were generated at pressure of 1 – 10 Torr in quartz tube placed inside various kinds of microwave cavieties. Cavieties were supplied by 10 to 500 W of microwave power / f=2.45 GHz /. Processed fiber was fastly moved across the plasma region by special driving system. Experimentally the optimal process conditions, i.e. treatment time and gas pressure, were found. Moreover, a special construction of a “long” plasma reactor for industrial application of the process was worked out.

scholarly journals Evaluation of Biogas Collection from Reed Canary Grass, Depending on Nitrogen Fertilisation Levels

2012 ◽  
Vol 33 (4) ◽  
pp. 697-701 ◽  
Author(s):  
Anna Kacprzak ◽  
Mariusz Matyka ◽  
Liliana Krzystek ◽  
Stanisław Ledakowicz
Keyword(s):  
Energy Production ◽  
Fossil Fuels ◽  
New Technologies ◽  
Renewable Energy Sources ◽  
Weather Conditions ◽  
Reed Canary Grass ◽  
Nitrogen Fertilisation ◽  
Biogas Yield ◽  
Biogas Plants ◽  
Canary Grass

The world in 21st century is facing the problem of growing energy consumption while the supply of fossil fuels is being reduced. This resulted in the development of research into the use of renewable energy sources and development of new technologies for energy production. In Polish conditions the development of agricultural biogas plants finds its legitimacy in the document developed by the Ministry titled "Trends in agricultural biogas plants in Poland in 2010-2020”. The purpose of this study was to investigate the influence of the weather conditions and the degree of nitrogen fertilisation on yield of reed canary grass (Phalaris Arundinacea L.) and to determine their susceptibility to anaerobic digestion, and usefulness of the production of biogas. Carried out experiments showed that increasing nitrogen fertilisation (from 40 to 120 kg N/ha) linearly increased canary grass green biomass yield from 32 to 46.3 t/ha. However, the highest biogas yield 126 m3/ha was obtained when 80 kg N/ha was applied.

Optimization of Agar Preparation Based on Transparency

2021 ◽  
Vol 1033 ◽  
pp. 103-108
Author(s):  
Ying Cai ◽  
Zhan Xia Wu ◽  
Zhao Yu Zhang ◽  
Zhang Hu
Keyword(s):  
Activated Carbon ◽  
Treatment Time ◽  
Orthogonal Experiment ◽  
Economic Benefits ◽  
Experimental Results ◽  
Practical Significance ◽  
Process Conditions ◽  
Processing Temperature ◽  
Experimental Conditions ◽  
Filtration Method

To meet the requirement for high transparency of agar gel used in tissue culture, bacteriological applications, and high-quality cosmetics and food, this study on improving the transparency of agar products was carried out by using activated carbon for decolorization and perlite for aiding filtration. The results showed that the pre-coating filtration method was better than that of the mixed slurry filtration, so an orthogonal experiment optimization was conducted using the pre-coating filtration method based on the single factor experimental results. The experimental results showed that the optimal process conditions based on the transparency index were: concentration of agar of 1.30%, activated carbon dosage of 0.80%, processing temperature of 95 °C, and treatment time of 20 min. Agar products with gel transparency of 58.93% and blue-ray whiteness value of 93.82 could be obtained under these experimental conditions. The order of the factors influencing the decolorization ratio of agar was as follows: activated carbon dosage > concentration of agar > processing temperature > treatment time. The experimental results provided effective procession methods for the production enterprises based on transparency and increased economic benefits, and it was of practical significance.

Anaerobic digestion of sludge differing in inorganic solids content: performance comparison and the effect of inorganic suspended solids content on degradation

2016 ◽  
Vol 74 (9) ◽  
pp. 2152-2161 ◽  
Author(s):  
Nina Duan ◽  
Xiaohu Dai ◽  
Bin Dong ◽  
Lingling Dai
Keyword(s):  
Anaerobic Digestion ◽  
Suspended Solids ◽  
Degradation Process ◽  
Performance Comparison ◽  
Batch Experiments ◽  
Biogas Yield ◽  
Stirred Tank Reactors ◽  
Volatile Fatty Acid Concentration ◽  
Substrate Conversion ◽  
Solids Content

High inorganic suspended solids (ISS) content of sludge in many areas (especially with combined sewage systems) results in low VS/TS (volatile solids, VS; total solids, TS) levels and raises concerns about its effect on anaerobic digestion. The performances of sludge anaerobic digestion with different feeding VS/TS levels as well as the effect of ISS content on the anaerobic degradation process were investigated in completely stirred tank reactors by semi-continuous and batch experiments. In semi-continuous experiment with sludge at VS/TS of 61.4%, 45.0, 30.0% and 15.0%, biogas yield, VS reduction and methane content decreased logarithmically with the feeding VS/TS decreasing; slightly higher volatile fatty acid concentration was observed at VS/TS 15%. Results of the batch experiments suggested that acetogenesis and methanogenesis are obviously affected by high ISS addition, while hydrolysis is less affected. The retardment of substrate conversion rate is probably attributed to decreased mass transfer efficiency at high ISS content.

scholarly journals Monitoring N : P Ratio and Cd, Cu, Pb, and Zn Contents in Different Types of Anaerobic Digestates: A Six-Year Study Case

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Christina-Luise Roß ◽  
Kerstin Nielsen ◽  
Jorita Krieger ◽  
Marieke Hoffmann ◽  
Karen Sensel-Gunke ◽  
...  
Keyword(s):  
Stable Process ◽  
Zinc Content ◽  
Pig Manure ◽  
Process Conditions ◽  
Pig Slurry ◽  
Large Variability ◽  
Lead And Zinc ◽  
German Legislation ◽  
Biogas Plants

Depending on the quality of the input substrates, process parameters, and postfermentation treatments, digestates may contain a broad spectrum of potentially toxic elements. We suspected that these contents may vary on a broad scale even under seemingly stable process conditions at the biogas plant. Digestates from four biogas plants were therefore continuously analyzed for their contents of phosphorus, nitrogen, cadmium, copper, lead, and zinc over a period of six years. The input substrates varied between the plants (e.g., cattle and pig slurry and rye and maize silage), but were the same for each plant over the whole period. The N : P ratio of the digestates ranged from 2 to 24, with the digestate coming from cofermentation of pig slurry and energy crops (“DG Pig”) having the widest range of N : P ratio over the years. Heavy metal loads of all digestates and during all evaluations did not exceed the limits set by European or German legislation, but as previously expected, showed a large variability especially if cattle or pig manure were used as substrates. Copper content of Cattle slurry before digestion was 897.7 mg kg−1 DM in one case, and zinc content of DG Pig reached 590.2 mg kg−1 DM also once during the investigation. As a result, we strongly recommend to monitor especially phosphorus, copper, and zinc contents in digestates very closely and in short intervals.

scholarly journals Production efficiency of Poland farm-scale biogas plants: A case study

2020 ◽  
Vol 154 ◽  
pp. 02002 ◽  
Author(s):  
Krzysztof Pilarski ◽  
Agnieszka A. Pilarska
Keyword(s):  
Production Efficiency ◽  
Laboratory Scale ◽  
Methane Yield ◽  
Correction Coefficient ◽  
Batch Reactors ◽  
Pig Slurry ◽  
Maize Silage ◽  
Biogas Plants ◽  
Beet Pulp ◽  
Analysis Of Results

This paper provides the analysis of results of biogas and methane yield for: maize silage (MS), pig slurry (PS), waste potatoes (WP) and sugar beet pulp (SB). The results show that maize silage is the most energy substrate (among the samples tested), providing a cumulative methane yield from 595 to 631 m-3 Mg VS (VS – volatile solids). The study was carried out in a laboratory scale using anaerobic batch reactors, at controlled (mesophilic) temperature and pH conditions. This paper is Part I of a report of an experiment carried out, in the laboratory scale and in the commercial scale (in parallel) The purpose of the experiment was to verify differences in biomethane yields of the same materials in the two scales. Moreover, this paper is an introduction to a presentation of the method to determine the biochemical methane potential correction coefficient (BMPCC), the details of which will be explained in Part II.

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