scholarly journals Continuous Bioethanol Production Using Uncontrolled Process in a Laboratory Scale of Integrated Aerobic–Anaerobic Baffled Reactor

2019 ◽  
Vol 64 (2) ◽  
pp. 172-178
Author(s):  
Margono Margono ◽  
Mujtahid Kaavessina ◽  
Mior Ahmad Khushairi Mohd Zahari ◽  
Anwaruddin Hisyam

The expensiveness of bioethanol has made it unattractive and uncompetitive for alternative energy sources. Therefore, several ways to reduce the production cost of bioethanol become interesting topics, e.g. increasing its productivity. This research investigated the performance sensitivity of a laboratory scale of integrated aerobic–anaerobic baffled reactor (IAABR) towards the residence time. The ethanol productivity was monitored to know the optimum residence time. The difference residence times were varied between at 19.2 h and 26.7 h by using difference volume of fermenters i.e. 10 and 100 l, respectively. Molasses as a medium was fed into a reactor containing one compartment of aerobic fermentation and three compartments of anaerobic fermentation. Total sugar and bioethanol concentration were measured for each compartment to determine the production yield to sugar consumption and bioethanol productivity. The fermentation process was conducted at 30 °C, medium pH (4-5), and feed sugar concentration of 170 g/l. The results showed that the optimum residence time in this investigation range is 19.2 h. The ethanol productivity was recorded at 4.63 g/l.h and the production yield to sugar was obtained at 46 % (equivalent to 86 % of theoretical yield) with average feeding of molasses at 0.52 l/h.

Author(s):  
Jiamin Li ◽  
Xiaoping Chen ◽  
Jiliang Ma ◽  
Cai Liang

AbstractTraditional methods for measuring the residence time distribution (RTD) of particles in a fluidized bed are complex and time-consuming. To this regard, the present work proposes a new measurement method with remarkable efficiency based on digital image analysis. The dyed tracers are recognized in the images of the samples due to the difference of colors from bed materials. The HSV and the well-known RGB color space were employed to distinguish the tracers. By enhancing the Saturation and the Value in HSV and adjusting the gray range of images, the recognition error is effectively reduced. Then the pixels representing the tracers are distinguished, based on which the concentration of the tracers and RTD are measured. The efficiency, accuracy and repeatability of the method were validated by RTD measurements experiments. The method is also fit for distinguishing the target particles from multi-component systems consisting of particles of different colors.


2007 ◽  
Vol 55 (1-2) ◽  
pp. 121-128 ◽  
Author(s):  
A.K. Karunarathna ◽  
N. Tanaka ◽  
K.B.S.N. Jinadasa

Coconut dust, which is used intensively in horticultural applications, was tested as an external organic additive in a series of laboratory-scale subsurface-flow constructed wetlands planted with Phragmites australis. The systems were fed with a mixture of NO−3-N, NH+4-N, and SRP in tap water to simulate high nutrient loads. In the absence of plants, TN removal efficiency was 66%, and the efficiency increased to >80% in the microcosm wetlands. TN and NO−3 removal efficiencies were marginally increased by coconut-dust treatment in comparison with sand-bed microcosms. Analysis by ANOVA showed that the TN removal from a coconut dust-supplemented sand-bed microcosm was significantly different from a sand-bed microcosm (0.0437 < p<0.05). All the systems showed an equal capacity to treat NH+4 nitrogen under low influent concentration levels. Phosphorus removal efficiencies were >98% in all three systems, and a difference between planted and unplanted systems was not observed. Shoot height and shoot densities of P. australis grown in the coconut dust-supplemented medium were significantly higher than those grown in the sand-bed medium. The difference in P. australis growth in response to the coconut dust addition revealed that the added material has the potential to create favourable conditions for plant growth.


JURNAL ELTEK ◽  
2020 ◽  
Vol 18 (1) ◽  
pp. 57
Author(s):  
Mira Esculenta Martawati

Pembangkit energi alternatif Saat ini semakin meningkat dikarenakan  berkaitan dengan semakin banyaknya kebutuhan pasar akan energi. Ada beberapa pembangkit energi alternatif yang sudah mulai dibangun antara lain pembangkit listrik tenaga angin. Pada umumnya pembangkit listrik tenaga angin didirikan di daerah pesisir pantai atau di daerah yang  miliki yang menghasilkan banyak angin. Dalam membangun pembangkit listrik tenaga angin dibutuhkan banyak perhitungan yang matang supaya didapatkan desain  yang sesederhana mungkin dengan biaya yang seminim mungkin akan tetapi dapat menghasilkan daya yang maksimal, sehingga dapat mengurangi pemborosan energi dan dapat memanfaatkan tenaga angin yang tersedia pada alam sekitarnya semaksimal mungkin dan dapat dimanfaatkan oleh masyarakat sekitar. Pembuatan simulasi turbin angin dapat dilakukan dengan menggunakan simulasi simulink pada matlab. Hasil dari simulasi dan analisa data adalah terdapat perbedaan  pengaruh antara variasi pitch angle dan kecepatan turbin terhadap daya keluaran dan nilai tegangan , karena nilai  p-value < 0,05 dan membuktikan bahwa H0 dinyatakan ditolak. Hasil dari penelitian ini menunjukkan bahwa semakin besar pitch angle maka kecepatan turbin terhadap daya keluaran dan tegangan yang dihasilkan juga akan semakin besar   Alternative energy generation is increasing as it relates to the growing number of energy market needs. There are several alternative energy plants that have begun to be built, such as wind power plants. In general, wind power plants are established in coastal areas or in areas that have produced a lot of wind. In building wind power plants needed a lot of mature calculations so that the design is as simple as possible with a minimal cost possible but can produce maximum power, so as to reduce energy waste and can utilize the wind power available in the surrounding nature as much as possible and can be utilized by the surrounding community. The manufacture of simulation of wind turbine can be done using simulink simulation in MATLAB. The result of the simulation and data analysis is the difference in influence between the variation of pitch angle and the speed of the turbine to the output power and the voltage value, due to the P-value value of < 0.05 and proving that the H0 declared rejected. The result of this study shows that the greater the pitch angle then the turbine speed to the output power and the resulting voltage will also be greater


SINERGI ◽  
2019 ◽  
Vol 24 (1) ◽  
pp. 73 ◽  
Author(s):  
Hamzah Eteruddin ◽  
Atmam Atmam ◽  
David Setiawan ◽  
Yanuar Z. Arief

People can make solar energy alternative energy by employing solar panels to generate electricity. The utilization of solar energy on a solar panel to generate electricity is affected by the weather and the duration of the radiation, and they will affect the solar panel’s temperature. There are various types of solar panels that can be found on the market today, including Mono-Crystalline and Poly-Crystalline. The difference in the material used needs to be observed in terms of temperature changes in the solar module. Our study’s findings showed that a change in the temperature would impact the solar panel’s output voltage, and the solar panel’s output voltage would change when it was connected to the load although the measured temperatures were almost the same.


2019 ◽  
Author(s):  
Qiang Lu ◽  
Gentu Ge ◽  
Qiming Cheng ◽  
Meiling Hou ◽  
shan Yu Jia

Abstract Background We aim to assess the nutritional quality of alfalfa in saline-alkali and the main fermenting microorganisms acting on alfalfa in saline-alkali soils.Results In this study, We tested the nutrient composition and microbial community of Zhongmu No. 3 (salt-tolerant) alfalfa, including the nutritional fermentation quality and microbial diversity analysis of alfalfa before and after ensiling (30 days and 60 days). Then we got closely genus that related to saline-alkali soils.The validity of the microbiological data was confirmed by alpha diversity analysis. From the Microbial network, we obtained the difference of the saline-type mantle type.Conclusions we found that the silage quality of Saline-alkali alfalfa can be ensured by anaerobic fermentation with addition. The LABs that play a major role in the saline alkaline alfalfa silage are Lactobacillus, lactococcus and enterococcus.


Molecules ◽  
2019 ◽  
Vol 24 (16) ◽  
pp. 2915
Author(s):  
Işık Sena Akgün ◽  
Can Erkey

The effects of design and operating parameters on the superficial velocity at the onset of circulatory motion and the residence time of alginate aerogel particles in a laboratory scale Wurster fluidized bed were investigated. Several sets of experiments were conducted by varying Wurster tube diameter, Wurster tube length, batch volume and partition gap height. The superficial velocities for Wurster tube with 10 cm diameter were lower than the tube with 8 cm diameter. Superficial velocities increased with increasing batch volume and partition gap height. Moreover, increasing batch volume and partition gap height led to a decrease in the particle residence time in the Wurster tube. The results showed that there is an upper limit for each parameter in order to obtain a circulatory motion of the particles. It was found that the partition gap height should be 2 cm for proper particle circulation. Maximum batch volume for the tube with 10 cm diameter was found as 500 mL whereas maximum batch volume was 250 mL for the tube with 8 cm diameter. The fluidization behavior of the aerogel particles investigated in this study could be described by the general fluidization diagrams in the literature.


2008 ◽  
Vol 57 (3) ◽  
pp. 353-359 ◽  
Author(s):  
Y. Wang ◽  
K. W. Ong ◽  
M. W. D. Brannock ◽  
G. L. Leslie

Unlike conventional wastewater treatment systems that have a single effluent discharge point, membrane bioreactors (MBR) may have multiple extraction points resulting from the location of the membrane element in the reactor. This leads to multiple residence time distributions for an MBR system. One method to characterise the mixing is based on the concept of residence time distribution (RTD). A set of RTDs were generated using the conservative tracer, lithium chloride, for pilot plant MBRs with capacity up to 300 m3/day. Flat sheet and hollow fibre pilot plant MBR systems were operated in parallel on primary effluent collected at the Bedok Water Reclamation Plant in the republic of Singapore. Analysis of the RTD profiles indicated that membrane geometry did not impact on the kinetic conversion associated with nitrification because both MBRs were in well mixed conditions. However, the energy required to achieve perfect mixing with a hollow fibre module MBR, as defined by the velocity gradient, was lower than that with a flat sheet module MBR. The implication is that energy input associated with reactor mixing will depend on the configuration of the membrane. The difference in energy requirements between flat sheets and hollow fibres is such that careful consideration should be given to membrane selection in larger municipal installations.


Radiocarbon ◽  
2016 ◽  
Vol 58 (3) ◽  
pp. 491-503 ◽  
Author(s):  
Kotaro Nakata ◽  
Takuma Hasegawa ◽  
Teruki Iwatsuki ◽  
Toshihiro Kato

AbstractDissolved inorganic carbon (DIC) in groundwater is used to estimate the residence time based on radiocarbon concentration. DIC is usually extracted by a gas-strip or precipitation (SrCO3 or BaCO3) method. In this study, the gas-strip and precipitation methods of DIC were applied to both artificially prepared NaHCO3 solutions and natural groundwater to estimate the certainty of the two methods for 14C dating. 14C values obtained by the gas-strip method for NaHCO3 solutions with distinct salinity, DIC, and 14C concentrations were close to the theoretically predicted 14C value based on the 14C value of NaHCO3 powder. Conversely, the 14C value obtained by the precipitation method always showed higher values than the predicted values. The difference in 14C value between the gas-strip and precipitation methods was assumed to be caused by the contamination of modern carbon in the NaOH solution used in the precipitation method. The contamination of modern carbon derived from the NaOH solution during precipitation was found to range from less than 1 mg/L to about 1 mg/L. The applicability of the precipitation method for groundwater should be considered carefully according to the DIC, 14C concentration of groundwater, and purpose of the study being conducted.


2016 ◽  
Author(s):  
Logan T. Berner ◽  
Beverly E. Law ◽  
Tara W. Hudiburg

Abstract. Much of the western US is projected to become warmer and drier over the coming century, underscoring the need to understand how climate influences terrestrial ecosystems in this region. We quantified the response of tree net primary productivity (NPP), live biomass (BIO), and mean carbon residence time (CRT = BIO/NPP) to spatial variation in climatic water availability in the western US. We used forest inventory measurements from 1,953 mature stands (≥ 100 years) in Washington, Oregon, and California (WAORCA) along with satellite and climate data sets covering the western US. We summarized forest structure and function in both domains along a 400 cm yr−1 hydrologic gradient, quantified with a climate moisture index based on the difference between precipitation and reference evapotranspiration summed from October-September (i.e., water-year) and then averaged annually from 1985–2014 (CMIwy). Median NPP, BIO, and CRT computed at 10 cm yr−1 intervals along the CMIwy gradient increased monotonically with increasing CMIwy across both WAORCA (rs = 0.93–0.96, p 


2012 ◽  
Vol 1 (1) ◽  
pp. 30-37
Author(s):  
Bambang Trisakti ◽  
Irvan ◽  
Hari Tiarasti ◽  
Irma Suraya

Indonesia has a lot of natural resources which is deficient to fulfill the energy demand of consumers, particularly fuel. Therefore, the government keeps on promoting the search for alternative energy. One of these is hydrogen. Hydrogen is an environmental friendly product that does not produce carbon emissions. In the formation of hydrogen we can use carbohydrate-rich waste as a raw material and by using fermentation process. However, it is still limited research only. So this encourage us to design biohydrogen plant from palm oil mill effluent (POME) with the conditions of thermophilic anaerobic fermentation in order to accomplish the needs of consumers and contribute in developing clean technologies. For the production capacity of 495.1694 tons / year, the total investment required to build a factory of biohydrogen in Indonesia is Rp. 507,190,573,523, - with a total production cost of Rp. 354,636,600,139, -. Parameter feasibility of the production capacity of 495.1694 tons / year is the total product sales of Rp 174,261,989.701, - and net income 180,030,185,327, -. Profit Margin (PM) 41.9% Break Even Point (BEP) 45.24%, Return on Investment (ROI) 35.5%, Pay Out Time (POT) 2.82 years, Return of Network (RON) 59.16%, Internal Rate of Return (IRR) 53.52 %.


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