scholarly journals GASEOUS FUEL OBTAINING VIA FERMENTATION OF ORGANIC LANDFILL WASTE

2021 ◽  
pp. 36-48
Author(s):  
Vira Hovorukha ◽  
Olesia Havryliuk ◽  
Galyna Gladka ◽  
Bida Iryna ◽  
Yanina Danko ◽  
...  

Fossil carbon-containing fuel is currently one of the most common in industry and economy. The rapid depletion of reserves of this fuel makes it necessary to search for the alternative one. Landfills are a place where methane is spontaneously synthesized due to the decay of organic waste. Controlled and regulated fermentation of the landfill organics can provide biomethane as well as environmental bioremediation. The aim of the work was to study the patterns of methane fermentation of multi component organic waste and optimize the process to increase the efficiency of biomethane synthesis and waste decomposition. Colorimetric and potentiometric methods were used for pH and Eh measurement. Volumetric and chromatographic methods were applied to control volume and composition of synthesized gas. Fermentation parameters were calculated with the use of mathematical and statistical ones. The achievement of high efficiency of methane fermentation of organic waste due to the process regulation was shown. The modeling of unregulated fermentation of organic waste in landfills showed low efficiency of the process. It took 69 days. Weight of waste decreased only 5 times. Hydrogen yield was 5 L/kg of waste. Methane was not synthesized. The regular mass transfer, regulation of the process and waste grinding showed the greatest efficiency. Weight of waste decreased 20 times during only 14 days. Hydrogen yield was 27 L/kg, methane yield was 12 L/kg of waste. Thus, the absence of regulation caused long term decay of waste. The high efficiency is achieved due to regulation of the fermentation process. The results will serve as a basis for the development of industrial biotechnology for the utilization of organic waste to reduce the volume of existing landfills and produce methane energy. This will further allow bioremediation of contaminated areas, obtaining an alternative to fossil fuel biomethane.

2020 ◽  
pp. 5-14
Author(s):  
Olesia Havryliuk ◽  
Vira Hovorukha ◽  
Galina Gladka ◽  
Oleksandr Tashyrev

The environmental pollution by copper and the increasing amount of environmentally hazardous organic waste destroy natural ecosystems and have negative and even lethal effect on living organisms. The chemical techniques of metal containing waste detoxification are expensive and hazardous being the advanced problem today. The aim was to justify theoretically and confirm experimentally the possibility of toxic Cu2+ removal by hydrogen producing microbiome (HPM) via dark hydrogen fermentation of solid multicomponent food waste (MFW). Colorimetric and potentiometric methods were used for pH and redox potential measurement. Volumetric and chromatographic methods were applied to control volume and composition of synthesized gas. Fermentation parameters were calculated with the use of mathematical and statistical ones. The high effectiveness of solid waste destruction and Cu2+ removal was shown by spore forming HPM. The MFW were fastly and effectively digested by the microbiome at the absence of Cu2+. The weight of MFW was 90 times decreased (Kd = 90). The maximum concentration of H2 was 35% and biohydrogen yield was 76 L/kg of MFW counting on absolutely dry weight (ADW). The fermentation process was inhibited by Cu2+ in the form of citrate complex. The biohydrogen yield and efficiency of waste destruction were decreased on 41% (45 L/kg of waste) and 37% (Kd = 57) consequently after addition of 50 ppm Cu2+ to the culture liquid of the bioreactor during the beginning of final phase (50 hours) of MFW fermentation. The effect of complete inhibition of H2 synthesis was obtained in the case of adding 100 ppm Cu2+ to the culture liquid sampled from bioreactor during the final phase (80 hours) of fermentation. Nonetheless, the Cu2+ was bioremoved by HPM with high efficiency up to 99.0 % and 99.5% after 5 hours and 30 hours of fermentation where initially the concentrations of Cu2+ were consequently 50 and 100 ppm. The synthesis of gas was not significantly restored after the addition of Cu2+ in both variants of the experiment. Obtained patterns will be used as a basis for the development of novel universal biotechnologies of metal-containing sewage purification with simultaneous destruction of MFW.


2020 ◽  
Vol 14 (1) ◽  
pp. 174-186
Author(s):  
Vira Hovorukha ◽  
Oleksandr Tashyrev ◽  
Olesia Havryliuk ◽  
Larysa Iastremska

Background: Multicomponent organic waste is a significant environment hazard. Natural mechanisms can no longer ensure the processing of increasing volumes of such waste. The accumulation of multicomponent organic waste to environment pollution with toxic gases and leachate. Therefore, there is an urgent need to develop cost-effective technologies for the rapid treatment of huge volumes of toxic waste. Moreover, multicomponent organic waste can be used as the substrate for the production of green energy - biohydrogen. Objective: To scale up the technology of biohydrogen production from multicomponent organic waste in experimental-industrial anaerobic batch reactor and to establish fermentation parameters of its operation. Methods: An experimental-industrial anaerobic batch reactor was designed and the method of thermodynamic prognosis was applied to determine the most effective microbial pathway for hydrogen synthesis. The efficiency of the fermentation was evaluated by the pH and redox potential (Eh, mV) of culture medium, the concentration and volume of synthesized gas. Results: The experimental-industrial anaerobic batch reactor with a volume of 240 L was successfully applied to scale up the process of obtaining hydrogen via fermentation of organics. The duration of the technological cycle (T) was 1.5-4 days. The coefficient of waste destruction (Kd) that is the ratio between the initial and final weight of waste was high and ranged from 86 to 140. Hydrogen yield was 45-90 L/kg of dry weight of waste. The maximum concentration of hydrogen (H2max) was 50-58%. Conclusion: The developed approach and scaling of the biotechnology is promising for industrial application for effective hydrogen production via dark fermentation of multicomponent organic waste. Its industrial application might help to solve the problem of toxic multicomponent organic waste destruction and simultaneously to produce green energy H2.


Genetics ◽  
1975 ◽  
Vol 80 (4) ◽  
pp. 667-678
Author(s):  
Mary Lee S Ledbetter ◽  
Rollin D Hotchkiss

ABSTRACT A sulfonamide-resistant mutant of pneumococcus, sulr-c, displays a genetic instability, regularly segregating to wild type. DNA extracts of derivatives of the strain possess transforming activities for both the mutant and wild-type alleles, establishing that the strain is a partial diploid. The linkage of sulr-c to strr-61, a stable chromosomal marker, was established, thus defining a chromosomal locus for sulr-c. DNA isolated from sulr-c cells transforms two mutant recipient strains at the same low efficiency as it does a wild-type recipient, although the mutant property of these strains makes them capable of integrating classical "low-efficiency" donor markers equally as efficiently as "high efficiency" markers. Hence sulr-c must have a different basis for its low efficiency than do classical low efficiency point mutations. We suggest that the DNA in the region of the sulr-c mutation has a structural abnormality which leads both to its frequent segregation during growth and its difficulty in efficiently mediating genetic transformation.


Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 788
Author(s):  
Jinlin Mei ◽  
Aijun Duan ◽  
Xilong Wang

The traditional hydrothermal method to prepare zeolite will inevitably use a large amount of water as a solvent, which will lead to higher autogenous pressure, low efficiency, and wastewater pollution. The solvent-free method can be used to synthesize various types of zeolites by mechanical mixing, grinding, and heating of solid raw materials, which exhibits the apparent advantages of high yield, low pollution, and high efficiency. This review mainly introduces the development process of solvent-free synthesis, preparation of hierarchical zeolite, morphology control, synthesis mechanism and applications of solvent-free methods. It can be believed that solvent-free methods will become a research focus and have enormous industrial application potential.


Author(s):  
Zhaozhi Wang ◽  
Edwin R Galea ◽  
Angus Grandison ◽  
John Ewer ◽  
Fuchen Jia

Abstract Background An issue of concern to the travelling public is the possibility of in-flight transmission of COVID-19 during long- and short-haul flights. The aviation industry maintains that the probability of contracting the illness is small based on reported cases, modelling and data from aerosol dispersion experiments conducted on-board aircraft. Methods Using experimentally derived aerosol dispersion data for a B777–200 aircraft and a modified version of the Wells-Riley equation we estimate inflight infection probability for a range of scenarios involving quanta generation rate and face mask efficiency. Quanta generation rates were selected based on COVID-19 events reported in the literature while mask efficiency was determined from the aerosol dispersion experiments. Results The MID-AFT cabin exhibits the highest infection probability. The calculated maximum individual infection probability (without masks) for a 2-hour flight in this section varies from 4.5% for the ‘Mild Scenario’ to 60.2% for the ‘Severe Scenario’ although the corresponding average infection probability varies from 0.1% to 2.5%. For a 12-hour flight, the corresponding maximum individual infection probability varies from 24.1% to 99.6% and the average infection probability varies from 0.8% to 10.8%. If all passengers wear face masks throughout the 12-hour flight, the average infection probability can be reduced by approximately 73%/32% for high/low efficiency masks. If face masks are worn by all passengers except during a one-hour meal service, the average infection probability is increased by 59%/8% compared to the situation where the mask is not removed. Conclusions This analysis has demonstrated that while there is a significant reduction in aerosol concentration due to the nature of the cabin ventilation and filtration system, this does not necessarily mean that there is a low probability or risk of in-flight infection. However, mask wearing, particularly high-efficiency ones, significantly reduces this risk.


2010 ◽  
Vol 2010 ◽  
pp. 1-15 ◽  
Author(s):  
Abdul-Majeed Azad ◽  
Desikan Sundararajan

Clean power source utilizing vast logistic fuel reserves (jet fuels, diesel, and coal) would be the main driver in the 21st century for high efficiency. Fuel processors are required to convert these fuels into hydrogen-rich reformate for extended periods in the presence of sulfur, and deliver hydrogen with little or no sulfur to the fuel cell stack. However, the jet and other logistic fuels are invariably sulfur-laden. Sulfur poisons and deactivates the reforming catalyst and therefore, to facilitate continuous uninterrupted operation of logistic fuel processors, robust sulfur-tolerant catalysts ought to be developed. New noble metal-supported ceria-based sulfur-tolerant nanocatalysts were developed and thoroughly characterized. In this paper, the performance of single metal-supported catalysts in the steam-reforming of kerosene, with 260 ppm sulfur is highlighted. It was found that ruthenium-based formulation provided an excellent balance between hydrogen production and stability towards sulfur, while palladium-based catalyst exhibited rapid and steady deactivation due to the highest propensity to sulfur poisoning. The rhodium supported system was found to be most attractive in terms of high hydrogen yield and long-term stability. A mechanistic correlation between the role of the nature of the precious metal and the support for generating clean desulfurized -rich reformate is discussed.


2015 ◽  
Vol 2015 ◽  
pp. 1-16 ◽  
Author(s):  
Burhan Khurshid ◽  
Roohie Naaz Mir

Generalized parallel counters (GPCs) are used in constructing high speed compressor trees. Prior work has focused on utilizing the fast carry chain and mapping the logic onto Look-Up Tables (LUTs). This mapping is not optimal in the sense that the LUT fabric is not fully utilized. This results in low efficiency GPCs. In this work, we present a heuristic that efficiently maps the GPC logic onto the LUT fabric. We have used our heuristic on various GPCs and have achieved an improvement in efficiency ranging from 33% to 100% in most of the cases. Experimental results using Xilinx 5th-, 6th-, and 7th-generation FPGAs and Stratix IV and V devices from Altera show a considerable reduction in resources utilization and dynamic power dissipation, for almost the same critical path delay. We have also implemented GPC-based FIR filters on 7th-generation Xilinx FPGAs using our proposed heuristic and compared their performance against conventional implementations. Implementations based on our heuristic show improved performance. Comparisons are also made against filters based on integrated DSP blocks and inherent IP cores from Xilinx. The results show that the proposed heuristic provides performance that is comparable to the structures based on these specialized resources.


2014 ◽  
Vol 889-890 ◽  
pp. 1262-1265
Author(s):  
Chun Fang Shi

Printing system of college educational administration has been managed by artificial, which result in low efficiency and high human cost. So we build a system by docking the software and hardware system of background database based on IC card to realize self-service printing for teachers and students of college, which provide a high-efficiency, convenient and humanized service mode, and enhane the economical sense of teachers and students for creating a green campus.


2020 ◽  
Author(s):  
Ankit Patel ◽  
Kenneth B Christopher

Renal replacement therapy (RRT) can be used to support patient’s kidney function in cases of acute kidney injury (AKI). However, timing, modality, and dosing of RRT continue to remain in question. Recent studies have begun to provide data to help guide clinicians on when to initiate RRT, what form of RRT to use ranging from continuous venovenous hemofiltration (VVH) to intermittent hemodialysis, and the impact of high versus low-intensity dosing. Additionally, the risks associated with temporary vascular access with regard to thrombosis and infection, the impact of high efficiency and flux versus low efficiency and flux membranes, and options for anticoagulation in RRT for AKI are also discussed. This review contains 75 references.  Key words: acute kidney injury, chronic kidney disease, continuous venovenous hemofiltration, continuous venovenous hemodialysis, renal replacement therapy, venovenous hemofiltration, 


Energies ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 534
Author(s):  
Laura Felício ◽  
Sofia T. Henriques ◽  
André Serrenho ◽  
Tiago Domingos ◽  
Tânia Sousa

We use the societal exergy analysis to identify periods and factors controlling efficiency dilution and carbon deepening of electricity in Portugal from 1900 to 2014. Besides estimating the carbon intensity of electricity production, we propose a new indicator, the carbon intensity of electricity use, which quantifies CO2/kWh of electricity derived useful exergy. Results show final to useful efficiency dilution until World War I (50% to 30%) due to a decrease in share of the high-efficiency transport sector and from mid-1940s to 1960 and mid-1990s onwards (58% to 47% and 47% to 40%) due to an increase in share of the low efficiency commercial and residential sector. Decarbonization from 1900 to mid-1960s, with carbon intensities of electricity production and use dropping respectively from 12.8 to 0.2 and from 33.6 to 0.4 kg CO2/kWh due to an increase in thermoelectricity efficiencies and an increase in share of hydro. Then, a period of carbon deepening until 1990 with carbon intensities tripling due to a shift in shares from hydro to thermoelectricity and more recently a period of decarbonization with carbon intensities decreasing to 0.35 and 0.9 kg CO2/kWh, due to the increase in renewable electricity despite a dilution in final to useful efficiency.


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