scholarly journals Activated Carbons as Methanol Adsorbents for a New Cycle “Heat from Cold”

Fibers ◽  
2020 ◽  
Vol 8 (8) ◽  
pp. 51
Author(s):  
Ilya Girnik ◽  
Alexandra Grekova ◽  
Larisa Gordeeva ◽  
Yuri Aristov
Keyword(s):  
Performance Indicator ◽  
Activated Carbons ◽  
Carbon Powder ◽  
Pressure Jump ◽  
Multi Wall Carbon Nanotubes ◽  
Large Pressure ◽  
Useful Power ◽  
Useful Heat ◽  
And Storage ◽  
Fine Carbon

Activated carbons are widely used for sustainable technology of adsorptive transformation and storage of heat. Here, we analyze the applicability of twelve commercial carbons and an innovative carbonaceous composite “LiCl confined to multi-wall carbon nanotubes” (LiCl/MWCNT) for a new cycle “Heat from Cold” (HeCol). It has recently been proposed for amplification of low- temperature ambient heat in cold countries. The analysis is made in terms of the methanol mass exchanged and the useful heat generated per cycle; the latter is the main performance indicator of HeCol cycles. The maximum specific useful heat, reaching 990 and 1750 J/g, can be obtained by using carbon Maxsorb III and the composite, respectively. For these materials, methanol adsorption dynamics under typical HeCol conditions are experimentally studied by the large pressure jump method. Before making this analysis, the fine carbon powder is consolidated by either using a binder or just pressing to obtain larger particles (ca. 2 mm). The methanol desorption from the consolidated samples of Maxsorb III at T = 2 °C is faster than for LiCl/MWCNT, and the maximum (initial) useful power reaches (2.5–4.0) kW/kg sorbent. It is very promising for designing compact HeCol units utilizing the carbon Maxsorb III.

Energy/Exergy Conversion Factors of Low Enthalpy Geothermal Plants

2021 ◽  
Author(s):  
Henning Francke
Keyword(s):  
Performance Indicator ◽  
Energy System ◽  
Heat Pumps ◽  
Electricity Sector ◽  
Not Given ◽  
Geothermal Heat ◽  
Operation Costs ◽  
Integrated Energy System ◽  
Useful Heat ◽  
Selection Of

Abstract A geothermal heat plant is a not only a source of heat, but, in general, also a sink for relevant amounts of electricity, consumed mainly by the pump(s). This electricity demand is usually not given much attention although being decisive for operation costs, but also offering chances for demand side management as a variable consumer. From the perspective of an integrated energy system, geothermal installations basically move energy from the electricity sector into the heat sector, similar to compression heat pumps. The main heat pump performance indicator is the ratio between invested energy and useful heat, the COP. This paper transfers the COP concept to geothermal sites, by defining and determining the quantity for a selection of mostly German geothermal sites.

Incidence of the Presence of Lead on the Elimination of Humic Substances

2016 ◽  
Vol 723 ◽  
pp. 645-649
Author(s):  
Saâdia Guergazi ◽  
Mohamed Mahdi Missaoui
Keyword(s):  
Activated Carbon ◽  
Humic Substances ◽  
Reaction Rate ◽  
Activated Carbons ◽  
Removal Rate ◽  
Granular Activated Carbon ◽  
Maximum Efficiency ◽  
Carbon Powder ◽  
Powder Activated Carbon ◽  
Agitation Time

The main objective of our work is to test the performance of powder activated carbon (PAC) and granular activated carbon (GAC) in the retention of humic substances in the presence of lead. The adsorption tests conducted in synthetic solutions of distilled water. The results showed that, the removal efficiency of humic substances varies with the agitation time was obtained maximum efficiency after 180 minutes for PAC and 300 for the GAC. However, on granular activated carbon (GAC) recorded an improvement in the removal of humic substances in the order of 1.60%. The reaction rate is the same for the activated carbon powder (PAC). By against, for the GAC the removal rate of humic substances in the presence of lead is slower. A comparison between our results with the absorption of humic substances without the presence of lead showed that the elimination of humic substances (10 mg/l) in the presence of lead (5mg/l) on powder activated carbon (1 g/L) is disturbed. The removal efficiencies decrease with the increase on the pH of medium in an interval ranging from 2 to 12.The variation of the mass of lead has recorded an inhibiting role in the adsorption of humic substances for both activated carbons.

scholarly journals Thermodynamic Analysis of Working Fluids for a New “Heat from Cold” Cycle

Entropy ◽  
2020 ◽  
Vol 22 (8) ◽  
pp. 808 ◽  
Author(s):  
Ilya Girnik ◽  
Mikhail Tokarev ◽  
Yuri Aristov
Keyword(s):  
Thermodynamic Analysis ◽  
Chemical Engineering ◽  
Activated Carbons ◽  
Maximum Temperature ◽  
Adsorption Potential ◽  
Working Fluids ◽  
Useful Heat ◽  
Heat Transformation ◽  
Transformation Systems ◽  
Made In

Adsorptive Heat Transformation systems are at the interface between thermal and chemical engineering. Their study and development need a thorough thermodynamic analysis aimed at the smart choice of adsorbent-adsorptive pair and its fitting with a particular heat transformation cycle. This paper addresses such an analysis for a new “Heat from Cold” cycle proposed for amplification of the ambient heat in cold countries. A comparison of four working fluids is made in terms of the useful heat per cycle and the temperature lift. The useful heat increases in the row water > ammonia ≥ methanol > hydrofluorocarbon R32. A threshold mass of exchanged adsorbate, below which the useful heat equals zero, raises in the same sequence. The most promising adsorbents for this cycle are activated carbons Maxsorb III and SRD 1352/2. For all the adsorptives studied, a linear relationship F = A·ΔT is found between the Dubinin adsorption potential and the driving temperature difference ΔT between the two natural thermal baths. It allows the maximum temperature lift during the heat generation stage to be assessed. Thus, a larger ΔT-value promotes the removal of the more strongly bound adsorbate.

DIRECT OXIDATION OF TRYPTOPHAN ON MULTI-WALL CARBON NANOTUBES MODIFIED CARBON ELECTRODE AND ITS APPLICATION TO FUEL CELL

2012 ◽  
Vol 06 ◽  
pp. 115-120
Author(s):  
TOMOKI YABUTANI ◽  
YOSHIO SHODA ◽  
YUJI TANI ◽  
YOHEI YAMADA ◽  
JUNKO MOTONAKA
Keyword(s):  
Carbon Nanotubes ◽  
Amino Acids ◽  
Fuel Cell ◽  
Glassy Carbon ◽  
Cell Voltage ◽  
Carbon Powder ◽  
Carbon Electrode ◽  
Direct Oxidation ◽  
Multi Wall Carbon Nanotubes ◽  
Surface Poisoning

Direct oxidation of tryptophan on multi-wall carbon nanotubes modified glassy carbon electrode was examined. Surface poisoning, which was suppression of oxidative current caused from adsorption of oxidized compounds of amino acids through multiple redox scan, was observed on carbon material electrodes (multi-wall carbon nano tube(CNT), carbon powder(CP), Ketjen Black (KB) and glassy carbon(GC). It was found that CNT showed a highly inhibitory effect on the surface poisoning and high current value in the direct oxidation of tryptophan because of a π-π interaction between CNT and indole ring of tryptophan results from orbital mixing. This CNT modified GC electrode was applied to an anode in a fuel cell used with amino acids as fuel. As a result, the maximum of the power density showed 0.36 mW cm-2 at 2.5 mA cm-2 of the current density and 140 mV of the cell voltage.

Impact of preparation and storage of activated carbon on the high pressure sorption of CO2

2014 ◽  
Vol 62 (1) ◽  
pp. 113-119 ◽  
Author(s):  
M. Lutyński
Keyword(s):  
High Pressure ◽  
Activated Carbon ◽  
Flue Gas ◽  
Coalbed Methane ◽  
Activated Carbons ◽  
Untreated Sample ◽  
Gas Treatment ◽  
Energy And Environment ◽  
Adsorbed Phase ◽  
And Storage

Abstract Adsorption of carbon dioxide on activated carbons has become extremely interesting in the field of energy and environment. Activated carbon is either used as a model to understand sorption processes on coals as a part of research on CO2 geological storage/Enhanced Coalbed Methane or as an adsorbent for processes such as natural gas treatment or CO2 separation from flue gas. The paper presents results of high-pressure CO2 sorption at the temperature of 318K on two similar activated carbons (Filtrasorb 400 and WAZ 0.6-2.4 mm) where one sample of WAZ was not subjected to any pretreatment procedure. Experimental results were fitted with three parameter Langmuir and therefore it was possible to calculate CO2 adsorbed phase densities. The WAZ activated carbon has a slightly lower sorption even though it was pretreated with the same procedure. The untreated sample of WAZ exhibited sorption which was lower over 15%. Calculated adsorbed phase densities differ between the activated carbons and the lowest value was obtained for the untreated WAZ sample (21.0 mol/dm3).

Effect of Modified MIL-53 with Multi-Wall Carbon Nanotubes and Nanofibers on CO2 Adsorption

2014 ◽  
Vol 625 ◽  
pp. 870-873 ◽  
Author(s):  
Sami Ullah ◽  
Azmi Mohamad Shariff ◽  
Mohammad Azmi Bustam ◽  
Ali E.I. Elkhalifah ◽  
Ghulam Murshid ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Carbon Nanotubes ◽  
Research Work ◽  
Bet Surface Area ◽  
Carbon Dioxide Content ◽  
Multi Wall Carbon Nanotubes ◽  
Adsorption Performance ◽  
Adsorption Of Co ◽  
Reduce Carbon Dioxide ◽  
And Storage

There is a growing need of counter assessing the increase of releases greenhouse gases such as carbon dioxide by researching an alternative technology that can help to reduce carbon dioxide content in atmosphere. This research work investigates the potential of MIL-53 as CO2capture and storage candidate by conducting an experiment with different pressure between the synthesised and modified MIL-53. To investigate the effect of the Multi-wall carbon nanotubes (MWCNTs) and carbon nanofibers (CNFs) in MIL-53 towards CO2adsorption performance. The synthesised samples were characterized by Fourier Transform Spectroscopy (FTIR) and Brunauer, Emmett and Teller (BET) techniques. A significant change is observed in the region of the aromatic deformation vibrations due to the different substitution patterns of the aromatic ring. BET surface area for MWCNT@MIL-53 is higher than CNF@MIL-53 and MIL-53. MWCNTs showed the adsorption of CO2uptake is 0.3mmole-1/g at 100Kpa.

Synthesis, CO2 Adsorption Performance of Modified MIL-101 with Multi-Wall Carbon Nanotubes

2016 ◽  
Vol 1133 ◽  
pp. 486-490 ◽  
Author(s):  
Sami Ullah ◽  
Mohamad Azmi Bustam ◽  
Ali E.I. Elkhalifah ◽  
Nadia Riaz ◽  
Girma Gonfa ◽  
...  
Keyword(s):  
Research Work ◽  
X Ray Diffraction ◽  
Separation Processes ◽  
Gas Field ◽  
Multi Wall Carbon Nanotubes ◽  
Adsorption Performance ◽  
Carbon Nano Tubes ◽  
Adsorption Of Co ◽  
High Level ◽  
And Storage

Nearly 40% of the world gas reservoir contains high level of CO2 that stance problems to development. The discovery of natural gas field with CO2 content of as high as 87% in Malaysia poses new challenges in terms of the CO2 separation processes. This research work investigates the potential of MIL(Materials Institute Lavoisier)-101 as CO2 capture and storage candidate by conducting an experiment with different pressure between the synthesised and modified MIL-101 using Multi-wall carbon nano tubes (MWCNTs). To investigate the effect of the MWCNTs in MIL-101 towards CO2 adsorption performance. The synthesized MOFs were characterized using scanning electron microscopy (SEM) for surface morphology, Thermogravimetric analysis (TGA) for thermal stability, X-ray diffraction (XRD) for crystals plane, Brunauer-Emmet-Teller (BET) for surface area and CO2 adsorption performance. The result had showed that the modified MIL-101 enhanced the CO2 adsorption compared to the pure MIL-101. MWCNT@MIL-101 showed the adsorption of CO2 uptake is 0.0029mmole-1/g at 100kPa.

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