DESIGN OF DOMESTIC SCALE BIO-DIGESTER ASSEMBLY, EXPERIMENTATION FOR BIOGAS PRODUCTION AND COMPARISON OF RESULTS WITH CONVENTIONAL DIGESTER

2015 ◽  
Vol 75 (11) ◽  
Author(s):  
Susmita Mishra ◽  
Srinivas Tenneti ◽  
Suman Mishra

The work explored various digesters that are currently under implementation, explored their pros and cons and designed a digestion gas collection mechanism suitable for small scale applications. Internal mixing being uneconomical in the domestic and individual scale, it is not being practiced which has to be compensated with large hydraulic retention time to prevent sludge accumulation and scum formation. This in turn reduces the plant capacity for gas production. Our design configuration incorporates automatic and controlled pressure swing mechanisms incorporated by the gas production which acts as the driving force for slurry circulation in the digester and promotes gas recovery as well as improve digestion efficiency. The configuration was run  in 20 l and 50 L scales  and observed for the physical constraints encountered during  operation, recorded for change in digestion parameters with changes in substrate and organic loading rates and also recorded the gas production which was compared with the results in the literature as well as conventionally operated domestic  scale digesters.  

2021 ◽  
Author(s):  
Qin He ◽  
Teresa Reid ◽  
Guofang Zheng

Abstract Increased production in natural gas from shale reservoirs has sparked concern that greenhouse gas emissions have also been on the rise. As a result, large- and small-scale operators and service companies are enthusiastically supporting a push toward "net carbon zero emissions". Carbon capture utilization and storage (CCUS) is playing an impactful role in companies’ goals to reach net zero. CO2 sequestration is the process of capturing and storing CO2 emissions from industrial and energy-related sources. Most CO2 sequestration are recommended to locate in saline aquifer, coalbed zone and depleted reservoirs, while CO2 sequestration in shale reservoir could become another good option to minimize the environmental footprint and enhance the gas production. Similar as CO2 sequestration into coalbed methane reservoir, the fluid flow mechanism in shale also includes desorption, diffusion and Darcy's law. In this paper, the effects of CO2 sequestration on shale reservoirs will be discussed from a technical and economical viewpoint. A reservoir simulation was used to evaluate the quantity of CO2 that can be stored in shale, the effects of CO2 mitigation when injected into shale, and any significant opportunities for CO2 enhanced shale gas recovery. Lastly, an economic analysis was performed to evaluate the economic efficiency of such projects in shales.


Energies ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2540
Author(s):  
Abiodun O. Jegede ◽  
Grietje Zeeman ◽  
Harry Bruning

This study examines the effect of mixing on the performance of anaerobic digestion of cow manure in Chinese dome digesters (CDDs) at ambient temperatures (27–32 °C) in comparison with impeller mixed digesters (STRs) and unmixed digesters (UMDs) at the laboratory scale. The CDD is a type of household digester used in rural and pre-urban areas of developing countries for cooking. They are mixed by hydraulic variation during gas production and gas use. Six digesters (two of each type) were operated at two different influent total solids (TS) concentration, at a hydraulic retention time (HRT) of 30 days for 319 days. The STRs were mixed at 55 rpm, 10 min/hour; the unmixed digesters were not mixed, and the Chinese dome digesters were mixed once a day releasing the stored biogas under pressure. The reactors exhibited different specific biogas production and treatment efficiencies at steady state conditions. The STR 1 exhibited the highest methane (CH4) production and treatment efficiency (volatile solid (VS) reduction), followed by STR 2. The CDDs performed better (10% more methane) than the UMDs, but less (approx. 8%) compared to STRs. The mixing regime via hydraulic variation in the CDD was limited despite a higher volumetric biogas rate and therefore requires optimization.


2015 ◽  
Vol 10 (1) ◽  
pp. 133-142 ◽  
Author(s):  
H.-B. Ding ◽  
M. Doyle ◽  
A. Erdogan ◽  
R. Wikramanayake ◽  
P. Gallagher

This paper presents two types of dissolved air flotation application together with biosorption (the ‘Captivator® system’) as primary treatments. In the first instance, the Captivator® system is the sole primary treatment for a new plant installation and helps to gain 65% more biogas while requiring only 44% of aeration for COD oxidation, compared to a conventional process with a primary clarifier. In the second application, the Captivator® system is used to enhance the existing primary treatment for plant capacity expansion. With digested anaerobic sludge recycled as an additional adsorbent, the Captivator® system in the second application increases the biogas yield by 52% and only generates 59% excess sludge. Overall, the Captivator® system would help WWTPs to approach energy neutrality by diverting more organics for biogas production and reducing the energy requirements for aeration. In addition, it would help to reduce the installation footprint for primary treatment and save considerable capital cost by eliminating the sludge thickening process.


2021 ◽  
Author(s):  
Mohamed El Sgher ◽  
Kashy Aminian ◽  
Ameri Samuel

Abstract The objective of this study was to investigate the impact of the hydraulic fracturing treatment design, including cluster spacing and fracturing fluid volume on the hydraulic fracture properties and consequently, the productivity of a horizontal Marcellus Shale well with multi-stage fractures. The availability of a significant amount of advanced technical information from the Marcellus Shale Energy and Environment Laboratory (MSEEL) provided an opportunity to perform an integrated analysis to gain valuable insight into optimizing fracturing treatment and the gas recovery from Marcellus shale. The available technical information from a horizontal well at MSEEL includes well logs, image logs (both vertical and lateral), diagnostic fracture injection test (DFIT), fracturing treatment data, microseismic recording during the fracturing treatment, production logging data, and production data. The analysis of core data, image logs, and DFIT provided the necessary data for accurate prediction of the hydraulic fracture properties and confirmed the presence and distribution of natural fractures (fissures) in the formation. Furthermore, the results of the microseismic interpretation were utilized to adjust the stress conditions in the adjacent layers. The predicted hydraulic fracture properties were then imported into a reservoir simulation model, developed based on the Marcellus Shale properties, to predict the production performance of the well. Marcellus Shale properties, including porosity, permeability, adsorption characteristics, were obtained from the measurements on the core plugs and the well log data. The Quanta Geo borehole image log from the lateral section of the well was utilized to estimate the fissure distribution s in the shale. The measured and published data were utilized to develop the geomechnical factors to account for the hydraulic fracture conductivity and the formation (matrix and fissure) permeability impairments caused by the reservoir pressure depletion during the production. Stress shadowing and the geomechanical factors were found to play major roles in production performance. Their inclusion in the reservoir model provided a close agreement with the actual production performance of the well. The impact of stress shadowing is significant for Marcellus shale because of the low in-situ stress contrast between the pay zone and the adjacent zones. Stress shadowing appears to have a significant impact on hydraulic fracture properties and as result on the production during the early stages. The geomechanical factors, caused by the net stress changes have a more significant impact on the production during later stages. The cumulative gas production was found to increase as the cluster spacing was decreased (larger number of clusters). At the same time, the stress shadowing caused by the closer cluster spacing resulted in a lower fracture conductivity which in turn diminished the increase in gas production. However, the total fracture volume has more of an impact than the fracture conductivity on gas recovery. The analysis provided valuable insight for optimizing the cluster spacing and the gas recovery from Marcellus shale.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Kulvinder Kaur ◽  
Pawan Kumar

PurposeThe rise in the use of Internet technologies and social media has shifted the marketing practices from offline to online. This study aims to determine the pros and cons of social media marketing in the beauty and wellness industry.Design/methodology/approachIn-depth interviews were conducted with the owners and marketing executives of beauty and wellness centers to understand the use of popular social media platforms in this industry and their pros and cons.FindingsThe researchers identified eight merits and seven demerits of social media in the beauty and wellness industry. Every respondent is happy and satisfied with social media use, particularly Instagram and Facebook. Irrespective of the demerits, they have shown the intention to increase its usage in the future. The merits override demerits; thus, social media is a blessing for this industry from the owners' perspective.Research limitations/implicationsThe research is exploratory and is confined to just one industry. Research implication is that the visual nature of social media makes it a powerful tool for the promotion of the beauty and wellness industry.Practical implicationsThe study's findings will be beneficial for small-scale businesses as it will push them to take advantage of this low-cost marketing tool.Social implicationsSocial media marketing is helpful for communication and marketing purposes for society.Originality/valueThe beauty and wellness industry remained unfocused by researchers because it is highly unorganized, fragmented and not regulated, yet has huge growth potential. This research will provide a closer look at this industry as well as social media marketing.


2015 ◽  
Vol 137 (5) ◽  
Author(s):  
Kyung Sung Kim ◽  
Moo-Hyun Kim ◽  
Jong-Chun Park

For oil/gas production/processing platforms, multiple liquid layers can exist and their respective sloshing motions can also affect operational effectiveness or platform performance. To numerically simulate those problems, a new multiliquid moving particle simulation (MPS) method is developed. In particular, to better simulate the relevant physics, robust self-buoyancy model, interface searching model, and surface-tension model are developed. The developed multiliquid MPS method is validated by comparisons against experiment in which three-liquid-sloshing experiment and the corresponding linear potential theory are given. The validated multiliquid MPS program is subsequently coupled with a vessel-motion program in time domain to investigate their dynamic-coupling effects. In case of multiple liquid layers, there exists a variety of sloshing natural frequencies for respective interfaces, so the relevant physics can be much more complicated compared with the single-liquid-tank case. The simulation program can also reproduce the detailed small-scale interface phenomenon called Kelvin–Helmholtz instability. The numerical simulations also show that properly designed liquid cargo tank can also function as a beneficial antirolling device.


2000 ◽  
Vol 41 (3) ◽  
pp. 195-202 ◽  
Author(s):  
H. Kübler ◽  
K. Hoppenheidt ◽  
P. Hirsch ◽  
A. Kottmair ◽  
R. Nimmrichter ◽  
...  

Operational results of a co-digestion facility were assessed over a period of 18 months. The organic fraction of municipal solid waste (OFMSW) contains a considerable amount of contaminants and grit (up to 6% w/w). A BTA-Pulper efficiently treated the different waste streams and converted a high amount of volatile solids (VS) into the digester feedstock. The seasonal fluctuations of the waste composition significantly influenced the biogas production. The impact of this seasonally variant degradability of VS had to be considered by evaluating the operation results. The waste streams investigated did not show any negative impact on digester performance. The hydraulic retention time (HRT) in the digester considerably affected the VS-reduction. Despite a considerable decrease of VS-degradation a reduction of HRT from 14 to 8 days slightly improves the gas production rate (GPR). An activated sludge system efficiently reduced the pollution of the effluent.The nutrient content of the anaerobic compostwas favourable and the content of pollutants was low. The facility produced surplus electrical power up to 290 MJ/t. An overall energy balance shows that the facility substitutes primary energy.


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