Methods of Radical Regeneration of Spent Solvent Containing TBP and Diluent

2001 ◽  
Author(s):  
Boris Ya. Zilberman ◽  
Mikhail N. Makarychev-Mikhailov ◽  
Vladimir F. Saprykin ◽  
Stanislav V. Sakulin ◽  
Yury N. Dulepov ◽  
...  
Keyword(s):  
Atmospheric Pressure ◽  
Boiling Point ◽  
Continuous Flow ◽  
Tributyl Phosphate ◽  
Vacuum Distillation ◽  
Superheated Steam ◽  
Single Stage ◽  
Saturated Steam ◽  
Two Stage ◽  
Stage Process

Abstract Methods of steam-supported distillation of spent solvent containing 30% tributyl phosphate (TBP) in various diluents have been developed. Single-stage and two-stage processes were tested. Single-stage distillation can be realized either with the use of superheated steam under vacuum or with saturated steam at atmospheric pressure, ensuring transportation of all the solvent to distillate, independently of the used diluent. Two-stage process allows separating TBP and diluent, both of them being purified, when the diluent boiling temperature is 50–70°C below TBP boiling point. At the first stage of the process, pure diluent is obtained through distillation at atmospheric pressure with the use of saturated steam. Then TBP is distilled off from wet bottoms of the first stage by continuous-flow vacuum distillation at the circulating bottoms.

scholarly journals The determination of the specific heat of superheated steam by throttling and other experiments

1905 ◽  
Vol 76 (509) ◽  
pp. 185-205 ◽  
Keyword(s):  
Specific Heat ◽  
Atmospheric Pressure ◽  
Superheated Steam ◽  
Electrical Energy ◽  
Total Heat ◽  
Saturated Steam ◽  
External Work

In October, 1898, the author commenced experiments, having for their object the determination of the specific heat of superheated steam. At first an attempt was made to obtain this end by measuring the rise in temperature produced in a known quantity of steam by supplying a definite amount of heat in the form of electrical energy, but the experimental difficulties experienced in satisfactorily preventing radiation, in maintaining the rate of flow of steam uniform and in securing a steam supply sufficiently homogeneous and constant as to temperature, proved so great that the attempt on these lines was given up for a time, but returned to later. Then another method was adopted, that of allowing dry saturated steam to expand without doing external work, and observing the resulting change in temperature. This method had been used in preliminary experiments on this subject by Professor Ewing and Mr. Dunkerley, who found that the specific heat of superheated steam at atmospheric pressure, as deduced by this method from Regnault’s values of the "total heat,” was not a constant, as had been previously supposed, but increased with temperature.

Comparison of Various Alternative Refrigerants for Vapour Compression Refrigeration Systems

2011 ◽  
Author(s):  
Ahmet Selim Dalkilic¸ ◽  
Somchai Wongwises
Keyword(s):  
Heat Exchanger ◽  
Single Stage ◽  
Refrigeration System ◽  
Performance Study ◽  
Alternative Refrigerants ◽  
Two Stage ◽  
Stage Process ◽  
Cascade Refrigeration System ◽  
Cascade Refrigeration ◽  
Vapour Compression

Single-stage vapour compression refrigeration system was compared with an actual vapour compression cycle, single-stage process with internal heat exchanger, and a two-stage process with economiser using the refrigerants of HCFC-22, CFC-502 and their alternatives such as HFC-134a, HFC-32, HFC-152a, HFC-404A, HFC-407C, HFC-507, HFC-410A. A theoretical performance study on a cascade refrigeration system was performed using two refrigeration cycles connected through the heat exchanger in the middle working as the evaporator for the high pressurized cycle and condenser for the low pressurized cycle. Other performance study was performed using a two-stage cascade refrigeration system having low and high pressure compressors connected through the mixing chamber in the middle. The condensation temperatures were between 30 and 50 °C, evaporation temperatures were between −50 °C and 5 °C and heat exchanger and economiser temperatures were kept as constant for the comparisons. Some of the alternative refrigerants’ coefficients of performance values are found to be higher than their base traditional pure refrigerants. The effects of the main parameters of performance analysis such as refrigerant type, degree of subcooling, and superheating on the performance coefficient, refrigerant charge rate and volumetric refrigeration capacity are investigated for various operating conditions as case studies.

scholarly journals Influence of the dispersion method of modified layered silicate on the structure and properties of mixed composites based on polyamide and functionalized polyolefin

2020 ◽  
Vol 65 (2) ◽  
pp. 177-184
Author(s):  
S. S. Pesetskii ◽  
Yu. M. Krivoguz ◽  
S. P. Bogdanovich
Keyword(s):  
Impact Resistance ◽  
Layered Silicate ◽  
Polyamide 6 ◽  
Single Stage ◽  
Test Method ◽  
Structure And Properties ◽  
Twin Screw Extrusion ◽  
Two Stage ◽  
Twin Screw ◽  
Stage Process

The dependences of the structure and properties of polyamide 6 (PA6) with a functionalized polyolefin (FPO) mixtures on the dispersing method of organically modified clay Cloisite 30В (Cl30В) were studied. The concentration of Cl30B organoclay in PA6/fPO mixtures was constant and amounted to 3.0 wt.%, and the content of fPO varied from 10 to 50 wt.%. Compounding of the mixtures was carried out in the melt using a twin-screw extrusion reactor-mixer. Organoclay was introduced into the composition of the mixtures in two ways: simultaneously with all polymer components (one-stage process) and from the previously obtained Cl30B concentrate into fPO (two-stage process). It is established that the introduction of Cl30B organoclay into the composition of the PA6/fPO mixture using the two-stage technology makes it possible to obtain nanocomposites with increased yield strengths (5–6 %), tensile strength (9–15 %), and elongation at break (1.2–4 times) compared with nanocomposites prepared according to a single-stage technology. At the same time, nanocomposites obtained by a single-stage technology in which PA6 forms a dispersion medium, regardless of the type of incision and the test method, have higher impact resistance (up to 1.2 times) than materials prepared by the two-stage method. This is explained by differences in the degree of dispersion of the nanofiller and the level of interphase interactions between the polymer components and nanoparticles, as a result of which the crystallinity of the components in the mixtures changes, as well as the complex of their rheological and mechanical characteristics. It was also shown that Cl30B organoclay additives, irrespective to the method of its introduction, increase the thermal stability of PA 6/fPO mixtures in comparison with the initial PA6. The results can be used in the development of real technical nanocomposites with improved properties based on PA6 and fPO.

Coiled Flow Inverter Mediated Synthesis of Activated Carbon Fibers-Supported Ni Nanoparticles

2022 ◽  
Author(s):  
Amol Pophali ◽  
Rakshit Kajala ◽  
Haider Ali ◽  
Nishith Verma ◽  
K. D. P. Nigam
Keyword(s):  
Activated Carbon ◽  
Carbon Fibers ◽  
Continuous Flow ◽  
Single Stage ◽  
Activated Carbon Fibers ◽  
Ni Nanoparticles ◽  
Stage Process ◽  
First Time ◽  
Supported Ni

NNi nanoparticles-dispersed activated carbon fibers (Ni/ACFs) were synthesized for the first time via a continuous flow single-stage process using coiled flow inverter (CFI) at ~30 oC. The process involved impregnation...

scholarly journals Two-Stage Anaerobic Co-digestion of Landfill Leachate and Starch Wastes Using Anaerobic Biofilm Reactor for Methane Production

2019 ◽  
Vol 15 (1) ◽  
pp. 53-70
Author(s):  
◽  
Ulfa Triovanta ◽  
Ridho Rinaldi
Keyword(s):  
Landfill Leachate ◽  
Methane Production ◽  
Loading Rate ◽  
Biofilm Reactor ◽  
Single Stage ◽  
Organic Loading Rate ◽  
Volatile Solid ◽  
Two Stage ◽  
Stage Process ◽  
Bod Removal

Abstract The study aims to evaluate two-stage anaerobic co-digestion of leachate and starch waste using anaerobic biofilm bioreactor to enhance methane production. The anaerobic digestion process was operated under the mesophilic condition at 35 ± 1 °C. Hydraulic retention time (HRT) applied to the acidogenesis and methanogenesis reactors were 5 and 25 days, respectively. The organic loading rate (OLR) used in the process of acidogenesis was 2.91 gram volatile solid /L.day, while methanogenesis was 0.58 gram volatile solid (VS) per liter per day. Results showed that two-stage process using biofilm was an effective method for operating anaerobic co-digestion of starch waste and landfill leachate in which the system produced higher methane yield at 125.11 mL methane (CH4) per gram volatile solid (VS) added (mL.CH4/g.VS.added) in comparison to the single-stage process (20.57 mL CH4/g.VS.added) and two-stage process (77.60 mL CH4/g.VS.added) without using biofilm. Two-stage process using biofilm also effectively reduced organic matters in the culture in which the system reached 61% BOD removal in comparison to the single-stage process and two-stage process without biofilm that only had 27.6 and 39.3% BOD removal, respectively. This study suggested that the two-stage process using biofilm would be the preferred technique for treating starch waste and landfill leachate.

Two-stage anaerobic digestion process for complete inactivation of enteric bacterial pathogens in human night soil

2004 ◽  
Vol 50 (6) ◽  
pp. 103-108 ◽  
Author(s):  
D.P. Kunte ◽  
T.Y. Yeole ◽  
D.R. Ranade
Keyword(s):  
Anaerobic Digestion ◽  
Bacterial Pathogens ◽  
Single Stage ◽  
Shigella Dysenteriae ◽  
Pathogen Inactivation ◽  
Two Stage ◽  
Anaerobic Digestion Process ◽  
Digestion Process ◽  
Complete Inactivation ◽  
Stage Process

Anaerobic digestion offers a good alternative for human waste treatment. However, the fate of enteric bacterial pathogens present in human night soil (HNS) remains a major concern for hygienic safety of the process. A two-stage anaerobic digestion process, consisting of separate acidogenic and methanogenic digesters, was designed and its efficacy in the inactivation of Salmonella typhi was compared to a single-stage digestion process. In a single-stage digestion, complete pathogen inactivation was achieved only in the digesters with high levels of volatile fatty acids (VFA ≅18,000 mg/l) and acidic pH (≅6.0). These digesters, however, showed drastic reduction in methane yield. In the two-stage digestion process, S. typhi was completely inactivated in the acidogenic digester and the methanogenic digester was free from the pathogen even after receiving a daily dose of the pathogen. The process also achieved complete inactivation of other enteric pathogens, viz., Shigella dysenteriae and Vibrio cholerae. The two-stage process was efficient in biogas generation from HNS. Thus, the two-stage process ensures complete hygienic safety in anaerobic digestion of human night soil.

scholarly journals Towards sustainable hydrogenation of 5-(hydroxymethyl)furfural: a two-stage continuous process in aqueous media over RANEY® catalysts

RSC Advances ◽  
2017 ◽  
Vol 7 (50) ◽  
pp. 31401-31407 ◽  
Author(s):  
Sérgio Lima ◽  
David Chadwick ◽  
Klaus Hellgardt
Keyword(s):  
Continuous Flow ◽  
Continuous Process ◽  
Aqueous Media ◽  
Two Stage ◽  
Hydroxymethyl Furfural ◽  
Stage Process

Two-stage process for DHMTHF production from HMF through continuous-flow.

scholarly journals Characterization and anaerobic digestion of highly concentrated Mexican wine by-products and effluents

2020 ◽  
Vol 81 (1) ◽  
pp. 190-198 ◽  
Author(s):  
M. Vital-Jacome ◽  
M. Cazares-Granillo ◽  
J. Carrillo-Reyes ◽  
G. Buitron
Keyword(s):  
Anaerobic Digestion ◽  
Oxygen Demand ◽  
Anaerobic Treatment ◽  
Single Stage ◽  
Organic Load ◽  
Organic Loading Rate ◽  
Two Stage ◽  
Wine Production ◽  
Stage Process ◽  
By Products

Abstract Wine production has increased in recent years, especially in developing countries such as Mexico. This increase is followed by an increase of winery effluents that must be treated to avoid environmental risks. However, little information is available about the characteristics of these effluents and the possible treatments. This paper aimed to characterize the effluents and by-products generated by the Mexican winery industry and to evaluate the performance and stability of the anaerobic treatment using a single-stage and a two-stage process. Results showed that the winery effluents had a high content of biodegradable organic matter, with chemical oxygen demand (COD) values ranging from 221 to 436 g COD/L. The single-stage anaerobic process was able to treat an organic loading rate of 9.6 kg COD/(m3 d); however, it was unstable and highly dependent on the addition of bicarbonate alkalinity (0.31 g NaHCO3/g COD removed). The two-stage process was more stable working at a higher organic load (12.1 kg COD/(m3 d)) and was less dependent on the addition of bicarbonate (0.17 g NaHCO3/g COD removed). The results highlight the potential of the winery effluents to produce methane through anaerobic digestion in a two-stage process, making wine production more sustainable.

scholarly journals Assessment of Single- vs. Two-Stage Process for the Anaerobic Digestion of Liquid Cow Manure and Cheese Whey

Energies ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5423
Author(s):  
Margarita Andreas Dareioti ◽  
Aikaterini Ioannis Vavouraki ◽  
Konstantina Tsigkou ◽  
Michael Kornaros
Keyword(s):  
Anaerobic Digestion ◽  
Production Rate ◽  
Methane Production ◽  
Cheese Whey ◽  
Biogas Production ◽  
Single Stage ◽  
Cow Manure ◽  
Two Stage ◽  
Methane Production Rate ◽  
Stage Process

The growing interest in processes that involve biomass conversion to renewable energy, such as anaerobic digestion, has stimulated research in this field in order to assess the optimum conditions for biogas production from abundant feedstocks, like agro-industrial wastes. Anaerobic digestion is an attractive process for the decomposition of organic wastes via a complex microbial consortium and subsequent conversion of metabolic intermediates to hydrogen and methane. The present study focused on the exploitation of liquid cow manure (LCM) and cheese whey (CW) as noneasily and easily biodegradable sources, respectively, using continuous stirred-tank reactors for biogas production, and a comparison was presented between single- and two-stage anaerobic digestion systems. No significant differences were found concerning LCM treatment, in a two-stage system compared to a single one, concluding that LCM can be treated by implementing a single-stage process, as a recalcitrant substrate, with the greatest methane production rate of 0.67 L CH4/(LR·d) at an HRT of 16 d. On the other hand, using the easily biodegradable CW as a monosubstrate, the two-stage process was considered a better treatment system compared to a single one. During the single-stage process, operational problems were observed due to the limited buffering capacity of CW. However, the two-stage anaerobic digestion of CW produced a stable methane production rate of 0.68 L CH4/(LR·d) or 13.7 L CH4/Lfeed, while the total COD was removed by 76%.

Two-stage anaerobic digestion harnesses more energy from the co-digestion of end-of-life dairy products with agro-industrial waste compared to the single-stage process

2020 ◽  
Vol 153 ◽  
pp. 107404 ◽  
Author(s):  
Myrsini Sakarika ◽  
Konstantinos Stavropoulos ◽  
Alexandros Kopsahelis ◽  
Eleni Koutra ◽  
Constantina Zafiri ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
End Of Life ◽  
Dairy Products ◽  
Industrial Waste ◽  
Single Stage ◽  
Two Stage ◽  
Stage Process
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