scholarly journals Purification and Compression of Biogas: A Research Experience

1970 ◽  
Vol 7 (1) ◽  
pp. 90-98 ◽  
Author(s):  
Tri Ratna Bajracharya ◽  
Alok Dhungana ◽  
Nirajan Thapaliya ◽  
Gogan Hamal

Biogas is widely used in villages of Nepal for cooking and lighting. But its commercial use has never been realized due to difficulties in its storage and transportation. Solution identified to the problem is to increase the energy density of the gas through removal of incombustible and corrosive gas and consequent compression which was experimented on a lab-scale model. This paper presents all the results of removal of CO2 gas from biogas using different chemicals and relative purity with raw gas. Further, compression of biogas and was carried out by methane refrigerant compressor and bottled into normal LPG cylinder. Compression of biogas was carried out under near Isothermal and Adiabatic conditions up to 11bar absolute pressure. The energy efficiency of compression was determined to be 98.71% and if the gas used for generation of electricity using a generator with an efficiency of 30%, the net energy efficiency turned out to be 95.72%. Later, a boiling test was conducted whereby the combustibility of the compressed biogas from the cylinder in normal biogas-stove was tested to validate its use in cooking, the results of which are included.Key words: Purification of Biogas, Compression of Biogas, Chemical purification, Energy efficiency, Combustion test.Journal of the Institute of Engineering, Vol. 7, No. 1, July 2009,  pp. 90-98doi: 10.3126/jie.v7i1.2066

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Shahryar Habibi

Purpose The purpose of this study is to design a zero-energy home, which is known to be capable of balancing its own energy production and consumption close to zero. Development of low-energy homes and zero-net energy houses (ZEHs) is vital to move toward energy efficiency and sustainability in the built environment. To achieve zero or low energy targets in homes, it is essential to use the design process that minimizes the need for active mechanical systems. Design/methodology/approach The methodology discussed in this paper consists of an interfacing building information modeling (BIM) tool and a simulation software to determine the potential influence of phase change materials on designing zero-net energy homes. Findings BIM plays a key role in advancing methods for architects and designers to communicate through a common software platform, analyze energy performance through all stages of the design and construction process and make decisions for improving energy efficiency in the built environment. Originality/value This paper reviews the literature relevant to the role of BIM in helping energy simulation for the performance of residential homes to more advanced levels and in modeling the integrated design process of ZEHs.


2018 ◽  
Vol 35 (1) ◽  
pp. 57-75 ◽  
Author(s):  
Jennifer K. Sansom ◽  
Beverly D. Ulrich

Due to increased metabolic demands during walking, ∼50% of children with myelomeningocele transition to wheelchair use during adolescence/early adulthood. The purpose of our pilot study involving children with myelomeningocele was to determine: (a) energy expenditure needs during acute use of common assistive devices and (b) if walking poles are a feasible assistive device. Oxygen uptake was recorded for eight (5–12 years old) children in four conditions: independent, walker, crutches, and poles. Acute pole use did not significantly differ from independent walking net energy consumption or cost. Participants consumed more energy while walking with the walker than independently. Our pilot results suggest that (a) acute use of common assistive devices while walking increases energy consumption and cost versus independent and (b) poles are feasible assistive devices, resulting in slightly increased energy requirements. Poles may have provided “just enough” support with minimal change in energy requirements for our participants and, with practice, may enable children with myelomeningocele to remain community ambulators.


Author(s):  
Thomas J. Breen ◽  
Ed J. Walsh ◽  
Jeff Punch ◽  
Amip J. Shah ◽  
Niru Kumari ◽  
...  

As the energy footprint of data centers continues to increase, models that allow for “what-if” simulations of different data center design and management paradigms will be important. Prior work by the authors has described a multi-scale energy efficiency model that allows for evaluating the coefficient of performance of the data center ensemble (COPGrand), and demonstrated the utility of such a model for purposes of choosing operational set-points and evaluating design trade-offs. However, experimental validation of these models poses a challenge because of the complexity involved with tailoring such a model for implementation to legacy data centers, with shared infrastructure and limited control over IT workload. Further, test facilities with dummy heat loads or artificial racks in lieu of IT equipment generally have limited utility in validating end-to-end models owing to the inability of such loads to mimic phenomena such as fan scalability, etc. In this work, we describe the experimental analysis conducted in a special test chamber and data center facility. The chamber, focusing on system level effects, is loaded with an actual IT rack, and a compressor delivers chilled air to the chamber at a preset temperature. By varying the load in the IT rack as well as the air delivery parameters — such as flow rate, supply temperature, etc. — a setup which simulates the system level of a data center is created. Experimental tests within a live data center facility are also conducted where the operating conditions of the cooling infrastructure are monitored — such as fluid temperatures, flow rates, etc. — and can be analyzed to determine effects such as air flow recirculation, heat exchanger performance, etc. Using the experimental data a multi-scale model configuration emulating the data center can be defined. We compare the results from such experimental analysis to a multi-scale energy efficiency model of the data center, and discuss the accuracies as well as inaccuracies within such a model. Difficulties encountered in the experimental work are discussed. The paper concludes by discussing areas for improvement in such modeling and experimental evaluation. Further validation of the complete multi-scale data center energy model is planned.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Nguyen-Van-Hung ◽  
Bjoern Ole Sander ◽  
James Quilty ◽  
Carlito Balingbing ◽  
Angeli Grace Castalone ◽  
...  

AbstractThe research provided scientific evidences for improved rice straw management. Rice cultivation with in-field burning of rice straw is the worst option with the lowest energy efficiency and highest air pollution emission. This article comprises a comparative assessment of energy efficiency and the environmental footprint of rice production using four different rice straw management scenarios, namely, straw retained, straw burned, partial straw removal, and complete straw removal. Paddy yield, grain quality, and energy balance were assessed for two seasons while greenhouse gas emissions (GHGE) were measured weekly starting from land preparation through to the cropping and fallow period. Despite the added energy requirements in straw collection and transport, the use of collected rice straw for mushroom production can increase the net energy obtained from rice production systems by 10–15% compared to burning straw in the field. Partial and complete removal of rice straw reduces GHGE by 30% and 40% compared to complete straw retention, respectively.


2019 ◽  
Vol 98 (11) ◽  
pp. 5746-5758 ◽  
Author(s):  
S Barzegar ◽  
S-B Wu ◽  
J Noblet ◽  
M Choct ◽  
R A Swick

2019 ◽  
Vol 98 (6) ◽  
pp. 2701
Author(s):  
Shu-Biao Wu ◽  
Robert A. Swick ◽  
Jean Noblet ◽  
Nicholas Rodgers ◽  
David Cadogan ◽  
...  

2021 ◽  
Vol 67 (No. 3) ◽  
pp. 137-146
Author(s):  
Gerhard Moitzi ◽  
Reinhard W. Neugschwandtner ◽  
Hans-Peter Kaul ◽  
Helmut Wagentristl

Sustainable cropping systems require efficient usage of fossil energy. This study performed on a long-term field experiment in the Pannonian Basis investigated the energy efficiency of four tillage systems (mouldboard plough (MP), deep conservation tillage (CT<sub>d</sub>), shallow conservation tillage (CT<sub>s</sub>) and no-tillage (NT)) for sugar beet and soybean production, taking fuel consumption, total energy input (made up of both direct and indirect inputs), crop yield, energy output, net-energy output, energy intensity and energy use efficiency into account. The input rates of fertiliser, chemical plant protection, and seeds were set constant across years; whereas measured values of fuel consumption were used for all tillage treatments. NT required a considerably lower energy input than MP and CT<sub>d</sub> as no fuel is needed for tillage and just slightly more fuel for additional spraying of glyphosate. Anyhow, the energy efficiency parameters did not differ between tillage treatments, as theses parameters were mainly determined by energy output, which was considerably higher than the energy input. However, year effects on the energy efficiency were observed for both crops. Nitrogen fertilisation and diesel fuel consumption were identified as the most energy-intensive inputs. Consequently, the energy input for sugar beet was higher than that for soybean, which was identified as a low-input crop. But sugar beet attained a more than 4 times higher net-energy output, a 2.5 times higher energy use efficiency, and an energy intensity for yield production of less than 3 times those of soybean.  


2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 175-176
Author(s):  
Zhikai Zeng ◽  
YaKuan Huang ◽  
Liqiang Zhu ◽  
Zhiyuan Chen ◽  
Z J Yuan ◽  
...  

Abstract This study evaluated the effects of dietary net energy concentrations on feeding behavior and growth performance of growing-finishing pigs monitored using a feed intake recording equipment (FIRE). Two hundred and sixteen (48.8 ± 5.6 kg) gilts were blocked by bodyweight and assigned randomly to 1 of 3 dietary treatments, which included low (2,350 kcal/kg), medium (2,450 kcal/kg), and high (2,550 kcal/kg) dietary NE levels. Pigs were housed in 18 pens for 68 d in four phases with 12 pigs and one FIRE station per pen. Bodyweight, feed consumption, and the amount of time and visit at the station of individual pigs were monitored every day by using FIRE. Pigs fed low NE diet spent more time (min) at the station during the first two weeks and visited the station more times with fewer amounts of time (min) per visit after two weeks compared with pigs fed medium and high levels of NE diets (P &lt; 0.05). The speed (g/min) and amount (g/visit) of feed intake were lower (P &lt; 0.05) during phase 3 and the overall period in low NE diet compared with pigs fed medium NE diet. Pigs fed medium NE diet tended to have a greater (P = 0.066) average daily feed intake at phase 4 than pigs fed low NE diet. Increasing NE levels linearly improved (P &lt; 0.05) average daily gain, feed conversion ratio, and final BW during phase 3 and the overall period. However, the overall energy efficiency (Mcal NE/ kg gain) was linearly decreased with increasing NE levels. In conclusion, decreasing dietary NE to 2350 Mcal/kg resulted in more visits to feeders with slow ingestion speed compared with pigs fed diets with 2450 or 2550 Mcal/kg NE. Increasing dietary NE levels linearly improved daily gain and feed conversion ratio, but linearly decreased energy efficiency.


1998 ◽  
Vol 78 (4) ◽  
pp. 553-563 ◽  
Author(s):  
R. P. Zentner ◽  
B. G. McConkey ◽  
M. A. Stumborg ◽  
C. A. Campbell ◽  
F. Selles

There is growing interest in the potential for improving nonrenewable energy use efficiency of traditional agricultural production activities in the Canadian prairies. This study, which was conducted on three soil textures in the Brown soil zone of southwestern Saskatchewan, examined the energy performance of conventional tillage (CT), minimum tillage (MT), and no-tillage (NT) management practices for spring wheat grown in fallow-wheat (F–W) and continuous wheat (Cont W) rotations over a 12-yr period (1982–1993). Metabolizable energy output increased with cropping intensity on a silt loam at Swift Current and on a clay at Stewart Valley (average of 16 751 MJ ha–1 for F–W and 24 110 MJ ha−1 for Cont W), but not on a sandy loam at Cantuar (average 14 828 MJ ha−1) where soil water-holding capacity was limited. Further, because grain yield was rarely significantly influenced by tillage method, the latter had little influence on the overall output of metabolizable energy. Total input of nonrenewable energy per unit of rotation also increased with cropping intensity (average 2585 MJ ha−1 for F–W and 5274 MJ ha−1 for Cont W). This was primarily because of the higher rates of N fertilizer that were required with stubble cropping. We found little or no net energy savings with NT management; the F–W (MT) system tended to have the lowest overall nonrenewable energy requirement at all test sites. Although the use of conservation tillage practices provided significant energy savings in fuel and machinery, particularly for F–W systems, these were largely offset by increases in the energy input for herbicides, and higher rates of N fertilizer that were required for NT managed areas. Consequently, net energy produced (energy output minus energy input) had similar patterns as metabolizable energy output. In contrast, when efficiency was expressed as ratios of energy output to energy input, or quantity of wheat produced per unit of energy input, the values were higher for F–W (average 6.2 and 456 kg GJ−1, respectively) than for Cont W systems (average 3.8 and 278 kg GJ−1, respectively). These measures of energy efficiency also tended to be higher for CT and MT than for NT management on the medium- and fine-textured soils, but on the coarse-textured soil, tillage had no influence on the energy efficiency of the cropping systems. We concluded that the potential for achieving energy savings by adopting conservation tillage management for monoculture wheat rotations is low in this semiarid region. This was because of the lack of consistent yield advantages with MT and NT, and due to the few tillage operations that are traditionally used to control weeds on summerfllow areas and to prepare the seedbed with CT management. Key words: Wheat, minimum tillage, no-tillage, nonrenewable energy, energy output/input, energy efficiency


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