Search results for "Biogas"
showing 10 items of 156 documents
Co-digestion of energy crops and industrial confectionery by-products with cow manure: batch-scale and farm-scale evaluation.
2002
The possible co-digestion of energy crops and industrial confectionery by-products with cow manure was evaluated firstly, through long-term batch experiments and secondly, in a farm-scale digester. In batch assays, digestion with mesophilically digested cow manure as inoculum resulted in specific methane yields (m3 kg−1 VSadded waste) of 0.35 for grass hay (particle size <1.0 cm); 0.26 for oats (0.5 cm) and 0.21 for clover (2.0 cm) harvested at vegetative stage and 0.14 (2.0 cm) for clover harvested at flowering stage. Specific methane yields (m3 kg−1 VSadded waste) for confectionery by-products were 0.37 for chocolate, 0.39 for black candy and 0.32 for confectionery raw material. Ou…
Methane potential of sterilized solid slaughterhouse wastes.
2012
Abstract The aim of the current study was to determine chemical composition and methane potential of Category 2 and 3 solid slaughterhouse wastes rendering products (SSHWRP) viz. melt, decanter sludge, meat and bone meal (MBM), technical fat and flotation sludge from wastewater treatment. Chemical analyses showed that SSHWRP were high in protein and lipids with total solids (TS) content of 96–99%. Methane yields of the SSHWRP were between 390 and 978 m3 CH4/t volatile solids (VS)added. Based on batch experiments, anaerobic digestion of SSHWRP from the dry rendering process could recover 4.6 times more primary energy than the energy required for the rendering process. Estonia has technologic…
A life cycle assessment of tri-generation from biomass waste: The experience of the “agro-combined” of Thibar
2020
Abstract The paper presents a life cycle assessment of energy produced by biogas obtained by biomass waste and fuelled in a tri-generation pilot plant located in Tunisia. The results, referred to 1 MJ of exergy, showed that the plant construction causes 76% of primary energy consumption and gives a contribution higher than 90% on resource depletion and ionizing radiation, and of 50% on ozone depletion. Operation causes 66% of the impact on human toxicity—cancer effects and more than 90% of the other impacts, except for ecotoxicity of freshwater mainly caused during the end of life. The study is one of the first applications of environmental analysis to tri-generation from waste in developin…
Anaerobic digestion of grass silage in batch leach bed processes for methane production.
2007
Abstract Anaerobic digestion of grass silage in batch leach bed reactors, with and without a second stage upflow anaerobic sludge blanket (UASB) reactor, was evaluated. Sixty six percent of the methane potential in grass was obtained within the 55 days solids retention time in the leach bed–UASB process without pH adjustment, whereas in the one-stage leach bed process 20% of the methane potential in grass was extracted. In two-stage operation, adjustment of the pH of influent to the leach bed reactor to 6 with HCl led to inhibition of both hydrolysis/acidogenesis and methanogenesis. In the leach bed–UASB process 39% of the carbohydrates and 58% of the acid soluble lignin were solubilised wi…
GIS-data related route optimization, hierarchical clustering, location optimization, and kernel density methods are useful for promoting distributed …
2019
Currently, geographic information system (GIS) models are popular for studying location-allocation-related questions concerning bioenergy plants. The aim of this study was to develop a model to investigate optimal locations for two different types of bioenergy plants, for farm and centralized biogas plants, and for wood terminals in rural areas based on minimizing transportation distances. The optimal locations of biogas plants were determined using location optimization tools in R software, and the optimal locations of wood terminals were determined using kernel density tools in ArcGIS. The present case study showed that the utilized GIS tools are useful for bioenergy-related decision-maki…
Estimation of biogas produced by the landfill of Palermo, applying a Gaussian model
2008
Abstract In this work, a procedure is suggested to assess the rate of biogas emitted by the Bellolampo landfill (Palermo, Italy), starting from the data acquired by two of the stations for monitoring meteorological parameters and polluting gases. The data used refer to the period November 2005–July 2006. The methane concentration, measured in the CEP suburb of Palermo, has been analysed together with the meteorological data collected by the station situated inside the landfill area. In the present study, the methane has been chosen as a tracer of the atmospheric pollutants produced by the dump. The data used for assessing the biogas emission refer to night time periods characterized by weak…
Experimental study of the anaerobic urban wastewater treatment in a submerged hollow-fibre membrane bioreactor at pilot scale
2011
The aim of this study was to assess the effect of several operational variables on both biological and separation process performance in a submerged anaerobic membrane bioreactor pilot plant that treats urban wastewater. The pilot plant is equipped with two industrial hollow-fibre ultrafiltration membrane modules (PURON¿ Koch Membrane Systems, 30m 2 of filtration surface each). It was operated under mesophilic conditions (at 33°C), 70days of SRT, and variable HRT ranging from 20 to 6h. The effects of the influent COD/SO 4-S ratio (ranging from 2 to 12) and the MLTS concentration (ranging from 6 to 22gL -1) were also analysed. The main performance results were about 87% of COD removal, efflu…
Gas-lift anaerobic dynamic membrane bioreactors for high strength synthetic wastewater treatment: Effect of biogas sparging velocity and HRT on treat…
2016
Abstract A laboratory scale external anaerobic dynamic membrane bioreactor (AnDMBR) treating high strength wastewater (influent COD ≈ 20 g/L) was operated to assess the effect of biogas sparging velocity (GSV) and hydraulic retention time (HRT) on removal efficiency and dynamic membrane (DM) filtration characteristics. An increase in GSV resulted in a decrease in DM filtration resistance. DM or cake layer was identified as the main contributor to the total filtration resistance. The external AnDMBR achieved over 99% COD removal efficiency irrespective of the GSV. The results showed that the DM formation process proceeded until a stable cake layer was reached. Reducing of HRT resulted in an …
Biomethane production from maize and liquid cow manure – Effect of share of maize, post-methanation potential and digestate characteristics
2013
Abstract This study investigates the co-digestion of liquid cow manure and maize with different share of maize in continuously stirred tank reactors (CSTRs). The objective was to determine the methane yield of reactor and the post-methanation potential of the digestate from different reactor trials. The highest specific methane yield (259 Nl CH 4 /kg volatile solids (VSs)) was obtained when the share of maize in the feedstock was 40% (VS) and the second highest specific methane yield was when the proportion of maize was 60% (VS) (234 Nl CH 4 /kg VS). The post-methanation potential of the digestate was determined in batch assays. The minimum value (maize 40%, 75 ± 1 Nl CH 4 /kg VS feed ) occ…
Long-term thermophilic mono-digestion of rendering wastes and co-digestion with potato pulp
2014
In this study, mono-digestion of rendering wastes and co-digestion of rendering wastes with potato pulp were studied for the first time in continuous stirred tank reactor (CSTR) experiments at 55°C. Rendering wastes have high protein and lipid contents and are considered good substrates for methane production. However, accumulation of digestion intermediate products viz., volatile fatty acids (VFAs), long chain fatty acids (LCFAs) and ammonia nitrogen (NH4-N and/or free NH3) can cause process imbalance during the digestion. Mono-digestion of rendering wastes at an organic loading rate (OLR) of 1.5 kg volatile solids (VS)/m(3)d and hydraulic retention time (HRT) of 50 d was unstable and resu…