scholarly journals Production of Purified Methane and Bio-Fertilizers by Anaerobic Digestion of Food Waste

2019 ◽  
Vol 8 (3) ◽  
pp. 31-33
Keyword(s):  
Anaerobic Digestion ◽  
Large Scale ◽  
Energy Resource ◽  
Gas Production ◽  
Organic Substances ◽  
Biochemical Process ◽  
Filtration Process ◽  
Gas System ◽  
Power Application ◽  
Electricity Transport

Anaerobic digestion is a biochemical process in which the organic substances are digested by microorganisms to methane (biogas) and carbon dioxide in the absence of oxygen. This process is spontaneous but the control on large scale requires good knowledge. The search for appropriate models of this entire system of bio gas production with filtration process by benefitting the society, improving world’s economy, and protecting the environment at the same time making biogas as a sustainable energy resource is covered. The aim of this paper is filtration of raw bio gas and methane production in all economic aspects. For this, a low costbio gas system by separating the other gases from methane, called chemical scrubbing was developed. Purified methane obtained can be used in various fields as domestic and industrial (cooking, electricity, transport and other power application).

Gasification as an optimum alternative for the sludge management

2011 ◽  
Vol 6 (4) ◽  
Author(s):  
C. Peregrina ◽  
J. M. Audic ◽  
P. Dauthuille
Keyword(s):  
Power Generation ◽  
Anaerobic Digestion ◽  
Sewage Sludge ◽  
Combined Heat And Power ◽  
Gas Production ◽  
Waste Reduction ◽  
Fluidised Bed ◽  
Sludge Management ◽  
Gas Cleaning ◽  
Cleaning System

Assimilate sludge to a fuel is not new. Sludge incineration and Combined Heat and Power (CHP) engines powered with sludge-derived anaerobic digestion gas (ADG) are operations widely used. However, they have a room of improvement to reach simultaneously a positive net power generation and a significant level of waste reduction and stabilization. Gasification has been used in other realms for the conversion of any negative-value carbon-based materials, that would otherwise be disposed as waste, to a gaseous product with a usable heating value for power generation . In fact, the produced gas, the so-called synthetic gas (or syngas), could be suitable for combined heat and power motors. Within this framework gasification could be seen as an optimum alternative for the sludge management that would allow the highest waste reduction yield (similar to incineration) with a high power generation. Although gasification remains a promising route for sewage sludge valorisation, campaigns of measurements show that is not a simple operation and there are still several technical issues to resolve before that gasification was considered to be fully applied in the sludge management. Fluidised bed was chosen by certain technology developers because it is an easy and well known process for solid combustion, and very suitable for non-conventional fuels. However, our tests showed a poor reliable process for gasification of sludge giving a low quality gas production with a significant amount of tars to be treated. The cleaning system that was proposed shows a very limited removal performance and difficulties to be operated. Within the sizes of more common WWTP, an alternative solution to the fluidised bed reactor would be the downdraft bed gasifier that was also audited. Most relevant data of this audit suggest that the technology is more adapted to the idea of sludge gasification presented in the beginning of this paper where a maximum waste reduction is achieved with a great electricity generation thanks to the use of a “good” quality syngas in a CHP engine. Audit show also that there is still some work to do in order to push sludge gasification to a more industrial stage. Regardless what solution would be preferred, the resulting gasification system would involve a more complex scenario compared to Anaerobic Digestion and Incineration, characterised by a thermal dryer and gasifier with a complete gas cleaning system. At the end, economics, reliability and mass and energy yields should be carefully analysed in order to set the place that gasification would play in the forthcoming processing of sewage sludge.

A Mathematical Model for the Anaerobic Digestion Process Applied to a Mixture of Night Soil and Septic Tank Sludge

1986 ◽  
Vol 18 (7-8) ◽  
pp. 239-248 ◽  
Author(s):  
Sung Ryong Ha ◽  
Dwang Ho Lee ◽  
Sang Eun Lee
Keyword(s):  
Mathematical Model ◽  
Anaerobic Digestion ◽  
Biomass Concentration ◽  
Gas Production ◽  
Septic Tank ◽  
Volatile Acid ◽  
Hydraulic Residence Time ◽  
Anaerobic Digestion Process ◽  
Digestion Process ◽  
Proposed Model

Laboratory scale experiments were conducted to develop a mathematical model for the anaerobic digestion of a mixture of night soil and septic tank sludge. The optimum mixing ratio by volume between night soil and septic tank sludge was found to be 7:3. Due to the high solids content in the influent waste, mixed-liquor volatile suspended solids (MLVSS) was not considered to be a proper parameter for biomass concentration, therefore, the active biomass concentration was estimated based on deoxyribonucleic acid (DNA) concentration in the reactor. The weight ratio between acidogenic bacteria and methanogenic bacteria in the mixed culture of a well-operated anaerobic digester was approximately 3:2. The proposed model indicates that the amount of volatile acid produced and the gas production rate can be expressed as a function of hydraulic residence time (HRT). The kinetic constants of the two phases of the anaerobic digestion process were determined, and a computer was used to simulate results using the proposed model for the various operating parameters, such as BOD5 and volatile acid concentrations in effluent, biomass concentrations and gas production rates. These were consistent with the experimental data.

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 Improving the Anaerobic Digestion of Swine Manure through an Optimized Ammonia Treatment: Process Performance, Digestate and Techno-Economic Aspects

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 787
Author(s):  
Anna Lymperatou ◽  
Niels B. Rasmussen ◽  
Hariklia N. Gavala ◽  
Ioannis V. Skiadas
Keyword(s):  
Anaerobic Digestion ◽  
Large Scale ◽  
Treatment Process ◽  
Aqueous Ammonia ◽  
Swine Manure ◽  
Batch Experiments ◽  
Ammonia Treatment ◽  
Aqueous Ammonia Soaking ◽  
High Ammonia ◽  
Reduction Efficiency

Swine manure mono-digestion results in relatively low methane productivity due to the low degradation rate of its solid fraction (manure fibers), and due to the high ammonia and water content. The aqueous ammonia soaking (AAS) pretreatment of manure fibers has been proposed for overcoming these limitations. In this study, continuous anaerobic digestion (AD) of manure mixed with optimally AAS-treated manure fibers was compared to the AD of manure mixed with untreated manure fibers. Due to lab-scale pumping restrictions, the ratio of AAS-optimally treated manure fibers to manure was only 1/3 on a total solids (TS) basis. However, the biogas productivity and methane yield were improved by 17% and 38%, respectively, also confirming the predictions from a simplified 1st order hydrolysis model based on batch experiments. Furthermore, an improved reduction efficiency of major organic components was observed for the digester processing AAS-treated manure fibers compared to the non-treated one (e.g., 42% increased reduction for cellulose fraction). A preliminary techno-economic analysis of the proposed process showed that mixing raw manure with AAS manure fibers in large-scale digesters could result in a 72% increase of revenue compared to the AD of manure mixed with untreated fibers and 135% increase compared to that of solely manure.

Geomechanical Response Induced by Multiphase (Gas/Water) Flow in the Mallik Hydrate Reservoir of Canada

SPE Journal ◽  
2021 ◽  
pp. 1-18
Author(s):  
Yingli Xia ◽  
Tianfu Xu ◽  
Yilong Yuan ◽  
Xin Xin ◽  
Huixing Zhu
Keyword(s):  
Shear Stress ◽  
Shear Failure ◽  
Energy Resource ◽  
Gas Production ◽  
Production Performance ◽  
Reservoir Model ◽  
Hydrate Reservoir ◽  
Maximum Subsidence ◽  
Permeability Anisotropy

Summary Natural gas hydrate (NGH) is regarded as an important alternative future energy resource. In recent years, a few short-term production tests have been successfully conducted with both permafrost and marine sediments. However, long-term hydrate production performance and the potential geomechanical problems are not very clear. According to the available geological data at the Mallik site, a more realistic hydrate reservoir model that considers the heterogeneity of porosity, permeability, and hydrate saturation was developed and validated by reproducing the field depressurization test. The coupled multiphase and heat flow and geomechanical response induced by depressurization were fully investigated for long-term gas production from the validated hydrate reservoir model. The results indicate that long-term gas production through depressurization from a vertically heterogeneous hydrate reservoir is technically feasible, but the production efficiency is generally modest, with the low average gas production rate of 4.93 × 103 ST m3/d (ST represents the standard conditions) over a 1-year period. The hydrate dissociation region is significantly affected by the reservoir heterogeneity and reveals a heterogeneous dissociation front in the reservoir. The depressurization production results in significant increase of shear stress and vertical compaction in the hydrate reservoir. The response of shear stress indicates that the potential region of sand migration is mainly in the sand-dominant layer during gas production from the hydraulically heterogeneous hydrate reservoir (e.g., sand layers interbedded with clay layers). The maximum subsidence is approximately 78 mm and occurred at the 72nd day, whereas the final subsidence is slowly dropped to 63 mm after 1-year of depressurization production. The vertical subsidence is greatly dependent on the elastic properties and the permeability anisotropy. In particular, the maximum subsidence increased by approximately 81% when the ratio of permeability anisotropy was set at 5:1. Furthermore, the potential shear failure in the hydrate reservoir is strongly correlated to the in-situ stress state. For the normal fault stress regime, the greater the initial horizontal stress is, the less likely the hydrate reservoir is to undergo shear failure during depressurization production.

Biological nutrient removal wastewater treatments and sewage sludge anaerobic mesophilic digestion performances

2002 ◽  
Vol 46 (10) ◽  
pp. 199-208 ◽  
Author(s):  
D. Bolzonella ◽  
L. Innocenti ◽  
F. Cecchi
Keyword(s):  
Anaerobic Digestion ◽  
Sewage Sludge ◽  
Economic Assessment ◽  
Gas Production ◽  
Anaerobic Digester ◽  
Biological Nutrient Removal ◽  
Energetic Balance ◽  
Mesophilic Digestion ◽  
The Difference ◽  
Energy Balances

The paper deals with the performances of the mesophilic anaerobic digestion treatment of sewage sludge from a full scale BNR process without primary settling (nominally 300,000 PE). A relation between the activated sludge observed yields, Yobs, and the anaerobic digester performance was preliminarily found: for values of Yobs of 0.25 kgVSS/kgCOD the anaerobic digester specific gas production showed the best performances (0.22 m3/kgVSfed). This has to be confirmed with wider future studies. It was also shown the level of sludge pre-thickening to be reached for the self-sustaining warming of the digester also in wintertime. According to the energetic balance and to a comparison with an aerobic stabilisation process, it was pointed out as when a co-generation unit for heat and energy production was introduced about 3.4 kWh/PE y of energy were produced in the anaerobic digestion process. On the other hand, 4.3 kWh/PE y were spent if an aerobic stabilisation process was applied. The economic assessment, carried out on the basis of the energy balances, showed that the anaerobic digestion is always economically advantageous if compared to aerobic stabilisation processes, also for small WWTPs. According to the energetic evaluations an environmental balance was assessed, in terms of CO2 emissions. The difference between anaerobic and aerobic processes was about 5.3 kgCO2/PE y in favour of anaerobic processes application.

Anaerobic Digestion of Piggery Wastes

1992 ◽  
Vol 25 (1) ◽  
pp. 9-16 ◽  
Author(s):  
A. D. Andreadakis
Keyword(s):  
Anaerobic Digestion ◽  
Anaerobic Degradation ◽  
Gas Production ◽  
Feasible Method

Anaerobic digestion can be an attractive and economically feasible method for the treatment of piggery wastes, provided that maximization of gas production and efficient subsequent utilization can be attained. Expedience from anaerobic digestion of domestic sludges can not be directly transferred to the design of digestion treating piggery wastes, due to the particular characteristics of the latter. The sequential anaerobic degradation of these wastes favours the adoption of short retention times for maximum gas production while at the same time satisfactory stabilization can be obtained.

Access and Logistics Challenges in Mountain Terrain Pipeline Projects

2014 ◽  
Author(s):  
Mark McDougall ◽  
Ken Williamson
Keyword(s):  
Construction Projects ◽  
Large Scale ◽  
Oil And Gas ◽  
Large Diameter ◽  
Gas Production ◽  
Additional Time ◽  
Oil And Gas Production ◽  
Road Design ◽  
Regulatory Constraints ◽  
The Right

Oil and gas production in Canada’s west has led to the need for a significant increase in pipeline capacity to reach export markets. Current proposals from major oil and gas transportation companies include numerous large diameter pipelines across the Rocky Mountains to port locations on the coast of British Columbia (BC), Canada. The large scale of these projects and the rugged terrain they cross lead to numerous challenges not typically faced with conventional cross-country pipelines across the plains. The logistics and access challenges faced by these mountain pipeline projects require significant pre-planning and assessment, to determine the timing, cost, regulatory and environmental impacts. The logistics of pipeline construction projects mainly encompasses the transportation of pipe and pipeline materials, construction equipment and supplies, and personnel from point of manufacture or point of supply to the right-of-way (ROW) or construction area. These logistics movement revolve around the available types of access routes and seasonal constraints. Pipeline contractors and logistics companies have vast experience in moving this type of large equipment, however regulatory constraints and environmental restrictions in some locations will lead to significant pre-planning, permitting and additional time and cost for material movement. In addition, seasonal constraints limit available transportation windows. The types of access vary greatly in mountain pipeline projects. In BC, the majority of off-highway roads and bridges were originally constructed for the forestry industry, which transports logs downhill whereas the pipeline industry transports large equipment and pipeline materials in both directions and specifically hauls pipe uphill. The capacity, current state and location of these off-highway roads must be assessed very early in the process to determine viability and/or potential options for construction access. Regulatory requirements, environmental restrictions, season of use restrictions and road design must all be considered when examining the use of or upgrade of existing access roads and bridges. These same restrictions are even more critical to the construction of new access roads and bridges. The logistics and access challenges facing the construction of large diameter mountain pipelines in Western Canada can be managed with proper and timely planning. The cost of the logistics and access required for construction of these proposed pipeline projects will typically be greater than for traditional pipelines, but the key constraint is the considerable time requirement to construct the required new access and pre-position the appropriate material to meet the construction schedule. The entire project team, including design engineers, construction and logistics planners, and material suppliers must be involved in the planning stages to ensure a cohesive strategy and schedule. This paper will present the typical challenges faced in access and logistics for large diameter mountain pipelines, and a process for developing a comprehensive plan for their execution.

scholarly journals An Assessment of Different Integration Strategies of Hydrothermal Carbonisation and Anaerobic Digestion of Water Hyacinth

Energies ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5983
Author(s):  
Aaron E. Brown ◽  
Jessica M. M. Adams ◽  
Oliver R. Grasham ◽  
Miller Alonso Camargo-Valero ◽  
Andrew B. Ross
Keyword(s):  
Anaerobic Digestion ◽  
Water Hyacinth ◽  
Large Scale ◽  
Aquatic Macrophyte ◽  
Integration Strategy ◽  
Bioenergy Generation ◽  
Global Presence ◽  
Freshwater Bodies ◽  
Hydrothermal Carbonisation ◽  
Integration Strategies

Water hyacinth (WH) is an invasive aquatic macrophyte that dominates freshwater bodies across the world. However, due to its rapid growth rate and wide-spread global presence, WH could offer great potential as a biomass feedstock, including for bioenergy generation. This study compares different integration strategies of hydrothermal carbonisation (HTC) and anaerobic digestion (AD) using WH, across a range of temperatures. These include (i) hydrochar combustion and process water digestion, (ii) hydrochar digestion, (iii) slurry digestion. HTC reactions were conducted at 150 °C, 200 °C, and 250 °C. Separation of hydrochars for combustion and process waters for digestion offers the most energetically-feasible valorisation route. However, hydrochars produced from WH display slagging and fouling tendencies; limiting their use in large-scale combustion. AD of WH slurry produced at 150 °C appears to be energetically-feasible and has the potential to also be a viable integration strategy between HTC and AD, using WH.

Prospects for Large-Scale Solar Thermal Electricity Generation From the Libyan Desert: Technical Feasibility

2009 ◽  
Author(s):  
Y. Aldali ◽  
D. Henderson ◽  
T. Muneer
Keyword(s):  
Large Scale ◽  
Potable Water ◽  
Energy Resource ◽  
Clearness Index ◽  
Technical Feasibility ◽  
Latitude Range ◽  
Thermal Energy Conversion ◽  
Rain Fall ◽  
Libyan Desert ◽  
Electrical Generation

The Great Sahara desert covers the entire range of Libyan longitude 11° 44′ to 23° 58′ E and a latitude range of 24° 17′ through to 30° 31′N, thus covering an area of 1,750,000 sq km and 88% of this land is desert. The authors have measured hourly solar radiation at Kufra oasis (24° 17′N, 23° 15′E) within the Libyan Desert and found it to be a most reliable and consistent energy resource — the rain fall averages a few mm every 30 years. With no cloud cover throughout the year, the measured noon clearness-index often exceeding 0.84 and availability of large volumes of potable water from underground aquifers, large-scale electrical generation warrants a serious feasibility study. This article presents the technical feasibility for Cylindrical Parabolic Concentrator (CPC) thermal energy conversion.

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