Porsgrunn, Norway
Porsgrunn, Norway

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Han J.,Tel Tek | Han J.,Telemark University College | Jin J.,Telemark University College | Eimer D.A.,Tel Tek | And 3 more authors.
Journal of Chemical and Engineering Data | Year: 2012

Densities in liquid solutions of monoethanolamine (MEA) and water have been measured at temperatures from (298.15 to 423.15) K. The mass fraction of MEA ranged from 0.3 to 1.0. Excess volumes were correlated by a Redlich-Kister equation. The model uses a third-order Redlich-Kister equation and a linear relationship with the temperature. Densities of CO 2 loaded aqueous MEA solutions were measured at temperatures from (298.15 to 413.15) K. The mass fraction of MEA was 0.3, 0.4, 0.5, and 0.6. Molar volumes of CO 2 loaded aqueous MEA solutions were correlated by the equations from the literature. Polynomial equations are in turn used to correlate the parameters with the temperature. Surface tensions of aqueous MEA solutions were measured at temperatures from (303.15 to 333.15) K. The mass fraction of MEA ranged from 0 to 1.0. The experimental surface tension data were correlated with temperature and mole fraction, respectively. © 2012 American Chemical Society.

Wang T.,Telemark University College | Hovland J.,Tel Tek | Jens K.J.,Telemark University College
Journal of Environmental Sciences (China) | Year: 2015

Amine scrubbing is the most developed technology for carbon dioxide (CO2) capture. Degradation of amine solvents due to the presence of high levels of oxygen and other impurities in flue gas causes increasing costs and deterioration in long term performance, and therefore purification of the solvents is needed to overcome these problems. This review presents the reclaiming of amine solvents used for post combustion CO2 capture (PCC). Thermal reclaiming, ion exchange, and electrodialysis, although principally developed for sour gas sweetening, have also been tested for CO2 capture from flue gas. The three technologies all have their strengths and weaknesses, and further development is needed to reduce energy usage and costs. An expected future trend for amine reclamation is to focus on process integration of the current reclaiming technologies into the PCC process in order to drive down costs. © 2014 The Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences.

Ying J.,Tel Tek | Ying J.,Telemark University College | Eimer D.A.,Tel Tek | Eimer D.A.,Telemark University College
Industrial and Engineering Chemistry Research | Year: 2012

The molecular diffusivities of nitrous oxide (N2O) with aqueous monoethanolamine (MEA) solutions up to 12 M were studied over a temperature range from 298.15 to 333.15 K under atmospheric pressure using a laminar liquid jet absorber. The diffusivities of CO2 in aqueous MEA solutions were calculated by the "N2O analogy" method. A simple and effective thermal control technique was used to control the temperatures of gas and liquid in the laminar liquid jet absorber. The rates of absorption were determined by measuring the flow of gas needed to replace the gas absorbed. The results showed that the diffusivities of both N2O and CO2 into aqueous MEA solution decrease with the increase of the concentration of MEA, and increase with an increase of the temperature of the solution. The relationship between the diffusivity and the viscosity of the solution roughly agrees with the modified Stokes-Einstein equation, but an exponent mathematical model was employed to simulate the diffusivity data and shows a better agreement between data and model for the diffusivity of N2O and CO2 in the monoethanolamine + water system. © 2012 American Chemical Society.

Viumdal H.,Tel Tek | Viumdal H.,Telemark University College | Mylvaganam S.,Telemark University College
Ultrasonics | Year: 2014

Buffer rods (BR) as waveguides in ultrasonic time domain reflectometry (TDR) can somewhat extend the range of industrial applications of ultrasonics. Level, temperature and flow measurements involving elevated temperatures, corrosive fluids and generally harsh environments are some of the applications in which conventional ultrasonic transducers cannot be used directly in contact with the media. In such cases, BRs with some design modifications can make ultrasonic TDR measurements possible with limited success. This paper deals with TDR in conjunction with distance measurements in extremely hot fluids, using conventional ultrasonic transducers in combination with BRs. When using BRs in the ultrasonic measurement systems in extreme temperatures, problems associated with size and the material of the buffer, have to be addressed. The resonant frequency of the transducer and the relative size of the transducer with respect to the diameter of BR are also important parameters influencing the signal to noise ratio (SNR) of the signal processing system used in the ultrasonic TDR. This paper gives an overview of design aspects related to the BRs with special emphasis on tapers and cladding used on BRs. As protective cladding, zirconium oxide-yttrium oxide composite was used, with its proven thermal stability in withstanding temperatures in rocket and jet engines up to 1650 C. In general a BR should guide the signals through to the medium and from and back to the transducer without excessive attenuation and at the same time not exacerbate the noise in the measurement system. The SNR is the decisive performance indicator to consider in the design of BR based ultrasonic TDR, along with appropriate transducer, with suitable size and operating frequency. This work presents and analyses results from extensive experiments related to fine-tuning both geometry of and signals in cladded/uncladded BRs used in high temperature ultrasonic TDR with focus on overall performance based on measured values of SNR. © 2013 Elsevier B.V. All rights reserved.

Chladek J.,Tel Tek | Enstad G.G.,Tel Tek | Enstad G.G.,Telemark University College | Melaaen M.C.,Telemark University College
Powder Technology | Year: 2011

The effect of the fluidization air flow rate and the transport air velocity on the solids mass flow rate and the pressure drop along the transport pipe was investigated in a vertical air-lift. The use of two different materials, glass (150 μm) and zirconium oxide (260 μm) particles (Geldart's B class), enabled to estimate the effect of particle properties on the air-lift performance. Different levels of the solids mass flow rate were obtained by varying the fluidization air flow rate while keeping the transport air velocity constant. The solids loading ratio varied between 2 and 16 for both types of particles. The pressure drop was non-linearly related to the solids mass flow rate at most of the transport air velocities tested. State diagrams presenting the relationship between the transport air velocity, the solids mass flow rate, and the pipeline pressure drop were constructed to characterize the flow pattern and to compare the behavior of the glass and zirconium oxide particles. Owing to the larger size and higher density, the zirconium oxide particles displayed higher pressure drop values than the glass beads and the minimum pressure drop shifted towards higher transport air velocities. The velocity at the transition between dilute and dense phase conveying was approximately in the range of 7 to 10. m/s for glass beads and 10 to 12. m/s for zirconium oxide, at the solids mass flow rates tested. The flow patterns could be also effectively characterized from the analysis of the pressure drop fluctuations at different transport air velocities. © 2010 Elsevier B.V.

Ying J.,Tel Tek | Ying J.,Telemark University College | Eimer D.A.,Tel Tek | Eimer D.A.,Telemark University College
Industrial and Engineering Chemistry Research | Year: 2013

The gas-liquid reaction rate was determined with a stirred cell from the fall in pressure and the reaction rate constant was determined by two data treatment methods, viz. a "differential" and an "integral" method. The liquid-side mass transfer coefficient without chemical reaction in the stirred cell reactor was determined via the pressure drop method. The kinetics of the reaction of carbon dioxide with aqueous monoethanolamine (MEA) solutions over a wide concentration range from 0.5 to 12 M at a temperature range from 298.15 to 323.15 K were studied using a stirred cell absorber with a plane gas-liquid interface. Low CO2 partial pressure (3-4 kPa) was employed to satisfy the criterion for a pseudo-first-order reaction. Very low inert gas pressures of N2 and solution vapor were kept, and the stirrer was sped up to reduce the gas-phase resistance. The results showed that the investigated reactions took place in the pseudo-first-order fast reaction regime. The reaction rate constant obtained for MEA with CO2 at 298.15 K agrees with literature. The reaction activation energy (Ea) of aqueous MEA + CO2 is 44.89 kJ mol-1, and the pre-exponential factor value is 4.14 × 1011. The enhanced mass transfer coefficient in the liquid phase, kLE, initially increases with the concentration of MEA solutions but decreases when the molarity of MEA is higher than 8 M. © 2013 American Chemical Society.

Ihunegbo F.N.,Telemark University College | Ratnayake C.,Tel Tek | Halstensen M.,Telemark University College
Powder Technology | Year: 2013

An emerging process analytical technology (PAT) technique, acoustic chemometrics, was applied for monitoring of heated fluidised bed drying process. The feasibility of quantitative on-line monitoring of the drying progress and end-point determination of silica gel dried in a heated fluidised bed was investigated. Silica gel was used owing to its high water adsorption property and stability to heat. Acoustic signals were acquired using four accelerometers mounted at different locations on the wall of the fluidised bed. The accelerometer located close to the base was the best based results from this study. Prediction models validated with independent acoustic data (test set validation) were developed using partial least square regression, PLS-R. Some data pre-preprocessing techniques were applied to improve the developed prediction model. The final prediction results were satisfactory for monitoring of the drying progress and end point determination. The prediction results based on the independent data indicated a slope=0.97, correlation coefficient, R2=0.99 and the root mean square error of prediction was 1.71 water %, within the range 0-35.69 water % of sampled reference. It was concluded that the results from this feasibility study show that acoustic chemometrics is a viable on-line technique for monitoring the drying progress and for determining the end-point during drying of particulate matter. This on-line monitoring technique for the drying process developed in this study can be applied in many relevant industries in order to improve the overall economics of material drying by optimising fluidised bed drying technology using this decisive end-point determination approach. © 2013 Elsevier B.V.

Ellingsen L.A.-W.,Norwegian University of Science and Technology | Majeau-Bettez G.,Norwegian University of Science and Technology | Singh B.,Norwegian University of Science and Technology | Srivastava A.K.,Tel Tek | And 2 more authors.
Journal of Industrial Ecology | Year: 2014

Summary: Electric vehicles (EVs) have no tailpipe emissions, but the production of their batteries leads to environmental burdens. In order to avoid problem shifting, a life cycle perspective should be applied in the environmental assessment of traction batteries. The aim of this study was to provide a transparent inventory for a lithium-ion nickel-cobalt-manganese traction battery based on primary data and to report its cradle-to-gate impacts. The study was carried out as a process-based attributional life cycle assessment. The environmental impacts were analyzed using midpoint indicators. The global warming potential of the 26.6 kilowatt-hour (kWh), 253-kilogram battery pack was found to be 4.6 tonnes of carbon dioxide equivalents. Regardless of impact category, the production impacts of the battery were caused mainly by the production chains of battery cell manufacture, positive electrode paste, and negative current collector. The robustness of the study was tested through sensitivity analysis, and results were compared with preceding studies. Sensitivity analysis indicated that the most effective approach to reducing climate change emissions would be to produce the battery cells with electricity from a cleaner energy mix. On a per-kWh basis, cradle-to-gate greenhouse gas emissions of the battery were within the range of those reported in preceding studies. Contribution and structural path analysis allowed for identification of the most impact-intensive processes and value chains. This article provides an inventory based mainly on primary data, which can easily be adapted to subsequent EV studies, and offers an improved understanding of environmental burdens pertaining to lithium-ion traction batteries. © 2013 by Yale University.

Botheju D.,Telemark University College | Lf Y.,Telemark University College | Hovland J.,Tel Tek | Haugen H.A.,Tel Tek | Bakke R.,Telemark University College
Energy Procedia | Year: 2011

The wastes generation by amine degradation is an important issue to be addressed when considering CCS schemes. Biological treatment of amine wastes can be a strategy with reasonable economy and environmental sustainability. Both the aerobic and anaerobic wastewater treatment techniques can be used for amine wastes treatment, providing culture adaptation and maintaining suitable operating conditions. Aerobic treatment can, generally, provide higher biodegradation rates while anaerobic processes can be much more energy efficient. A combination of aerobic and anaerobic treatment is promising. Addition of a supplementary organic feed may facilitate the anaerobic digestion of amine wastes and this opens the possibility of using common industrial or municipal waste digesters for amine wastes treatment. © 2011 Published by Elsevier Ltd.

Meyer J.,Institute for Energy Technology of Norway | Mastin J.,Institute for Energy Technology of Norway | Bjornebole T.-K.,CMR Prototech | Ryberg T.,CMR Prototech | Eldrup N.,Tel Tek
Energy Procedia | Year: 2011

The objective of this study has been to evaluate the technical and economical feasibility of the novel hybrid Zero Emission Gas power concept (ZEG), featuring production of electrical power from natural gas with integrated CO2 capture, via a close integration of the Sorption Enhanced Steam Methane Reforming process (SE-SMR) with a high temperature Solid Oxide Fuel Cell (SOFC). Technical design, process simulations and the preparation of detailed equipment lists have been carried out to calculate capital expenditure (CAPEX) and operation expenditure (OPEX) of the process. A cost analysis has been carried out for different price scenarios involving natural gas and electrical power prices, as well as CO2-quota cost and CO2 sales value. The ZEG concept has been compared with a more conventional pre-combustion technology alternative as a reference case (REF), involving the coupling of auto-thermal reforming, water gas shift, amine CO2 capture technology and a combined cycle. The results of this study show that the ZEG-case technology is likely to be profitable with relatively high net present values (NPV) in most of the price scenarios chosen, while the REF-case technology, using more conventional pre-combustion available technologies, shows negative NPV-values for all scenarios. Even with no income for the CO2 captured and a quite moderate natural gas price of 19 EUR/MWh, the ZEG-case shows profitability for an electric power price of 50 EUR/MWh or higher. The promising and encouraging results of this study show the potential of the two technologies and of their close integration towards future zero emission power plants on a medium to long term perspective. © 2011 Published by Elsevier Ltd.

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