Two-phase anaerobic treatment of cane-molasses alcohol stillage

1997 ◽  
Vol 36 (6-7) ◽  
pp. 441-448 ◽  
Author(s):  
B. G. Yeoh
Keyword(s):  
Single Phase ◽  
Anaerobic Treatment ◽  
Methane Yield ◽  
Phase System ◽  
Treatment Efficiency ◽  
Two Phase ◽  
Kinetic Evaluation ◽  
Cane Molasses ◽  
Loading Rates ◽  
Phase Process

Anaerobic treatment of cane-molasses alcohol stillage was studied in a thermophilic two-phase system comprising two bioreactors for the acidogenic and methanogenic phases respectively in comparison with the single-phase process. The experiments were conducted with HRT ranging from 36.0 to 9.0 days for single-phase and from 32.7 to 5.6 days for two-phase, corresponding to organic loading rates of 3.452 to 14.487 and 4.646 to 20.022 kgCODm−3day−1 respectively. The treatment efficiency was essentially maintained at BOD5 and COD removal of over 85% and 65% respectively in the two-phase process even with higher substrate loading. The acidogenic phase provided satisfactory conversion of initial COD to VFA averaging 15.6% in the degree of acidification. The methanogenic culture pH of both systems was maintained in a range of 7.4 to 7.8 through self regulation. The methane content of the biogas generated from the two-phase process was significantly higher by about 17% than that from the single-phase process, both decreasing with increasing substrate loading and shorter HRT. The mean overall methane yield was found to be 0.168 m3CH4(STP)kg−1 CODadded or 0.292 m3CH4(STP)kg−1 VSadded from two-phase methanogenesis, compared to 0.055 m3CH4(STP)kg−1CODadded or 0.082 m3CH4(STP)kg−1VSadded from single-phase fermentation. However, methane yield in the two-phase process was enhanced only at COD loading rates higher than 2.9 kgm−3day−1 or VS loading rates higher than 1.8 kgm−3day−1. The ultimate methane yield was evaluated graphically to be 0.216 m3CH4(STP)kg−1CODadded, or 0.401 m3CH4(STP)kg−1 VSadded. This indicated a methane yield efficiency of 73-78% for the two-phase anaerobic digestion of cane-molasses alcohol stillage, which was composed of 24.2% and 28.2% of non-biodegradable COD and VS respectively. Kinetic evaluation of the experimental data provided θm (minumum SRT) and K (kinetic constant) values as 6.6 days and 0.166 respectively based on COD, or 7.0 days and 0.160 respectively based on VS. Application of the two-phase anaerobic process on full scale at an industrial treatment plant for alcohol stillage showed mean treatment efficiency in terms of BOD5 and COD reduction of 84.3% and 63.2% respectively at an average loading rate of 5.1 kgCODm−3day−1, which was in good agreement with the bench-scale studies, considering the great variation in the raw wastewater characteristics typical of an industrial operation.

Single Phase and Two Phase Anaerobic Stabilization in Fluidized Bed Reactors

1983 ◽  
Vol 15 (8-9) ◽  
pp. 333-344 ◽  
Author(s):  
P M Sutton ◽  
A Li
Keyword(s):  
Fluidized Bed ◽  
Process Design ◽  
Pilot Plant ◽  
Single Phase ◽  
Fluidized Bed Reactors ◽  
Phase System ◽  
Two Phase ◽  
Effluent Quality ◽  
Loading Rates ◽  
Scale Design

Pilot plant studies were completed in order to derive information for process design of single and two phase anaerobic fluidized bed systems. A better effluent quality was obtained from the two phase system than from the single phase system at comparable or higher organic loading rates. A full-scale design example is presented to illustrate the implications of the pilot plant results.

Treatment of textile dyes in two-phase and single-phase anaerobic bio-treatment systems

2008 ◽  
Vol 57 (6) ◽  
pp. 863-868 ◽  
Author(s):  
D. Bhattacharyya ◽  
K. S. Singh
Keyword(s):  
Single Phase ◽  
Granular Sludge ◽  
Anaerobic Treatment ◽  
Upflow Anaerobic Sludge Blanket ◽  
Anaerobic Sludge ◽  
Phase System ◽  
Two Phase ◽  
Anaerobic Reactors ◽  
Anaerobic Sludge Blanket

This research integrates two different concepts of anaerobic biotechnology- two-phase anaerobic treatment and anaerobic granular sludge bed technology, in treatment of colored wastewaters from textile industries. Four anaerobic reactors based on upflow anaerobic sludge blanket (UASB) technology were used as acid reactors and an expanded granular sludge bed (EGSB) reactor was used as a methane reactor. A conventional single-phase anaerobic reactor, working on EGSB technology was run in parallel to compare the performances of the two systems. Reactors were operated at different hydraulic retention times. The results from the study, which span over a period of 400 days, indicated that the two-phase system produces a higher quality of effluent in terms of color, COD and suspended solids than single-phase anaerobic treatment when operated under similar conditions. Alkalinity requirement of two-phase system was also observed to be lower than that of single-phase system which is important regarding design consideration.

On the Problem of “Two-Phase” Activated Sludge

1991 ◽  
Vol 24 (7) ◽  
pp. 59-64 ◽  
Author(s):  
R. W. Szetela
Keyword(s):  
Activated Sludge ◽  
Single Phase ◽  
Phase System ◽  
Two Phase ◽  
Wastewater Treatment Process ◽  
Sludge Stabilization ◽  
Technological Advantage ◽  
In Series ◽  
State Models ◽  
Activated Sludge Systems

Steady-state models are presented to describe the wastewater treatment process in two activated sludge systems. One of these makes use of a single complete-mix reactor; the other one involves two complete-mix reactors arranged in series. The in-series system is equivalent to what is known as the “two-phase” activated sludge, a concept which is now being launched throughout Poland in conjunction with the PROMLECZ technology under implementation. Analysis of the mathematical models has revealed the following: (1) treatment efficiency, excess sludge production, energy consumption, and the degree of sludge stabilization are identical in the two systems; (2) there exists a technological equivalence of “two-phase” sludge with “single-phase” sludge; (3) the “two-phase” system has no technological advantage over the “single-phase” system.

The Temperature-Phased Anaerobic Biofilter Process

1994 ◽  
Vol 29 (9) ◽  
pp. 213-223 ◽  
Author(s):  
Sandra K. Kaiser ◽  
Richard R. Dague
Keyword(s):  
System Performance ◽  
Anaerobic Treatment ◽  
Size Ratio ◽  
High Rate ◽  
Phase System ◽  
Optimum Size ◽  
Treatment Technology ◽  
Two Phase ◽  
In Series ◽  
Two Temperature

The “temperature-phased anaerobic biofilter” or TPAB process (U.S. Patent pending), is a new high-rate anaerobic treatment system that includes a thermophilic (56°C) biofilter connected in series with a mesophilic (35°C) biofilter providing for two-temperature, two-phase treatment. Three TPAB systems of different thermophilic:mesophilic reactor size ratios were operated at system HRTs of 24 hrs, 36 hrs, and 48 hrs to characterize performance and to determine if an optimum size ratio exists between the thermophilic and mesophilic phases. The three TPAB systems achieved SCOD reductions in excess of 97% and TCOD reductions in excess of 90% for a synthetic milk substrate over a range of system COD loadings from 2 g COD/L/day to 16 g COD/L/day. There was little difference in performance between the three TPAB systems based on COD reduction and methane production. The 1:7 ratio of thermophilic:mesophilic phase TPAB system performed as well as the 1:3 and 1:1 size ratio TPAB systems. In applications of the process, a relatively small thermophilic first-phase can be used without sacrificing overall two-phase system performance. The TPAB process is a promising new anaerobic treatment technology with the ability to achieve higher efficiencies of organic removals than is generally possible for single-stage anaerobic filter systems operated at equivalent HRTs and organic loadings.

Prediction of Two-Phase Pressure Drop and Density Distribution From Mixing Length Theory

1963 ◽  
Vol 85 (2) ◽  
pp. 137-150 ◽  
Author(s):  
S. Levy
Keyword(s):  
Single Phase ◽  
Continuous Medium ◽  
Phase System ◽  
Mixing Length ◽  
Test Results ◽  
Two Phase ◽  
Pressure Drops ◽  
Mixing Length Theory ◽  
Phase Pressure ◽  
Good Agreement

Single-phase turbulent mixing length methods are used to predict two-phase flow. Two-phase density and velocity distributions and two-phase pressure drops are derived by treating the two-phase system as a continuous medium where the turbulent exchanges of momentum and density are equal. Good agreement is obtained between test results and analytical predictions.

Experimental Investigation of Evacuated Tube Solar Collector with Annular Heat Exchanger

2014 ◽  
Vol 592-594 ◽  
pp. 2355-2359
Author(s):  
Narasimhe Gowda ◽  
B. Putta Bore Gowda ◽  
R. Chandrashekar ◽  
G. Ugrasen ◽  
R. Keshavamurthy
Keyword(s):  
Closed System ◽  
Single Phase ◽  
Working Fluid ◽  
Maintenance Cost ◽  
Phase System ◽  
Two Phase ◽  
Solar Water ◽  
Water Heaters ◽  
Solar Water Heaters ◽  
Evacuated Tube

Now-a-days evacuated tubes solar water heaters are increasingly use in South India because of good thermal efficiency and high water temperature could be achievable as compared to flat plate solar collectors. Low manufacturing and maintenance cost also attract people to go for evacuated tube solar water heaters. This paper reports experimental results of two types of evacuated tube solar water heaters. To evaluate the performance of evacuated tube solar water heater, single-phase forced system and two-phase closed forced systems were considered. In two-phase closed system sunflower oil was used as working fluid to heat water. Throughout the study two-phase closed system shows better performance compared to single-phase open collector system and their efficiency almost 10 to 12% higher. But, because of high initial cost of two-phase system, the pay back periods of both collector systems is almost same. In two phased closed system higher temperature of water could be achieved, which is very useful to operate advanced system.

scholarly journals Production strategy influence on the economic viability of a family fish farm in Pará state, Amazon, Brazil

2021 ◽  
Vol 9 (1) ◽  
pp. 540-549
Author(s):  
Marcos Ferreira Brabo ◽  
Gerfeson Almeida da Silva ◽  
Daniel Abreu Vasconcelos Campelo ◽  
Galileu Crovatto Veras ◽  
Andréia Santana Bezerra ◽  
...  
Keyword(s):  
Single Phase ◽  
Net Present Value ◽  
Cost Benefit ◽  
Phase System ◽  
Operational Cost ◽  
Internal Rate Of Return ◽  
Two Phase ◽  
Cost Benefit Ratio ◽  
The Cost ◽  
Capital Return

The objective of this study was to analyze the influence of the adoption of single-phase and two-phase system on the economic feasibility of tambaqui (Colossoma macropomum) family production in the Tracuateua municipality, Pará state. The operational cost methodology and economic efficiency indicators were adopted to compare these rearing systems. The annual production was 4,200 kg and 5,826 kg. The operational costs were R$ 26,169.00 and R$ 34,365.00, the total operational cost was R$ 27,505 and R$ 35,701.00, and the total operational cost per kg was R$ 6.55 and R$ 6.13 for single-phase and two-phase systems, respectively. Regarding the indicators, the net present value was R$ 24,180.70, the internal rate of return was 24%, the cost-benefit ratio was 1.19, and the capital return period was four years in the single-phase system. In the two-phase period, the net present value was R$ 48,582.06, the internal rate of return was 29%, the cost-benefit ratio was 1.25, and the capital return period was 3.6 years. Despite the demand for greater investment, the two-phase system proved to be more profitable than the single-phase system, promoting even a reduction in unit production cost.

Treatment of Oily Cafeteria Wastewater by Single-Phase and Two-Phase Anaerobic Filter

1990 ◽  
Vol 22 (3-4) ◽  
pp. 299-306 ◽  
Author(s):  
Keisuke Hanaki ◽  
Tomonori Matsuo ◽  
Katsuo Kumazaki
Keyword(s):  
Single Phase ◽  
Material Balance ◽  
Phase System ◽  
Two Phase ◽  
Term Operation ◽  
Effluent Quality ◽  
Anaerobic Filter ◽  
Phase Systems ◽  
Better Than

Cafeteria wastewater containing about 30% of lipid on COD basis was treated at 20°C by laboratory-scale anaerobic filter in single-phase system and two-phase systems. Stable COD removal (about 80%) was achieved in spite of large fluctuation in influent COD concentration (normal range of 1,300 - 2,500 mg−l) both in the single-phase system (hydraulic retention time (HRT) longer than 1.3 d) and in the two-phase system (HRT longer than 3.3 d). The single-phase system gave better effluent quality than the two-phase system because the former entrapped suspended solids better than the latter. However, material balance revealed that methane conversion from removed COD was higher in the two-phase system than the single-phase system. The single-phase system perhaps removed lipids by entrapment with filter media without biodegradation, and this might cause clogging problems in long-term operation. The two-phase system is recommended since it degrades lipids better than the single-phase system.

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