Critical operating conditions for enhanced energy-efficient molten salt CO2 capture and electrolytic utilization as durable looping applications

A novel solar process and reactor for thermochemical conversion of biomass to synthesis gas is described. The concept is based on dispersion of biomass particles in a molten inorganic salt medium and, simultaneously, absorbing, storing and transferring solar energy needed to perform pyrolysis reactions in the high-temperature liquid phase. A lab-scale reactor filled with carbonates of potassium and sodium was set up to study the kinetics of fast pyrolysis and the characteristics of transient heat transfer for cellulose particles (few millimeters size) introduced into the molten salt medium. The operating conditions were reaction temperatures of 1073–1188 K and a particle peak-heating rate of 100 K/sec. The assessments performed for a commercial-scale solar reactor demonstrate that pyrolysis of biomass particles dispersed in a molten salt phase could be a feasible option for the continuous, round-the-clock production of syngas, using solar energy only.

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Design and Analysis of High-Efficient Driver Model for LED Luminaires

Light & Engineering ◽

10.33383/2021-012 ◽

2021 ◽

pp. 96-106

Author(s):

Onur Akalp ◽

Harun Ozbay ◽

Serhat Berat Efe

Keyword(s):

Energy Efficient ◽

Supply System ◽

Operating Conditions ◽

Driver Model ◽

Zero Voltage Switching ◽

Proposed Model ◽

High Efficient ◽

Driver Circuit ◽

Low Volume ◽

Zero Voltage

LED luminaires need a driver circuit for working properly. Most of the drivers have disadvantages such as losses during operation. This issue becomes more important while supplying with limited sources such as renewables. To overcome the problem, this study proposes a novel energy efficient driver for LED luminaires based on zero voltage switching (ZVS) single-ended primary inductance converter (SEPIC) technology. Driver and hence luminaires were designed to be fed from photovoltaic (PV) panels. In addition, an adaptive MPPT algorithm was developed to obtain optimum efficiency from supply system. SEPIC approach was preferred for MPPT application due to its advantages such as non-reversing polarity. This feature allows energy efficiency in corporation with ZVS. Proposed model was designed under PSIM platform with all components; PV panels, ZVS, SEPIC, and LED luminaires. A detailed analysis was performed by using system graphs under various operating conditions as different irradiance levels. Results show that proposed model is energy efficient and modular because of its low-volume structure. Therefore the model can lead smaller driver circuits with minimum losses.

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Uncertainty Analysis of Inflow Conditions on an HPT Gas Turbine Nozzle: Effect on Particle Deposition

Volume 2B: Turbomachinery ◽

10.1115/gt2020-15370 ◽

2020 ◽

Author(s):

R. Friso ◽

N. Casari ◽

M. Pinelli ◽

A. Suman ◽

F. Montomoli

Keyword(s):

Gas Turbine ◽

Energy Efficient ◽

Gas Turbines ◽

Particle Deposition ◽

Operating Conditions ◽

Wide Range ◽

And Performance ◽

Gas Turbine Nozzle ◽

The Impact ◽

Inflow Conditions

Abstract Gas turbines (GT) are often forced to operate in harsh environmental conditions. Therefore, the presence of particles in their flow-path is expected. With this regard, deposition is a problem that severely affects gas turbine operation. Components’ lifetime and performance can dramatically vary as a consequence of this phenomenon. Unfortunately, the operating conditions of the machine can vary in a wide range, and they cannot be treated as deterministic. Their stochastic variations greatly affect the forecasting of life and performance of the components. In this work, the main parameters considered affected by the uncertainty are the circumferential hot core location and the turbulence level at the inlet of the domain. A stochastic analysis is used to predict the degradation of a high-pressure-turbine (HPT) nozzle due to particulate ingestion. The GT’s component analyzed as a reference is the HPT nozzle of the Energy-Efficient Engine (E3). The uncertainty quantification technique used is the probabilistic collocation method (PCM). This work shows the impact of the operating conditions uncertainties on the performance and lifetime reduction due to deposition. Sobol indices are used to identify the most important parameter and its contribution to life. The present analysis enables to build confidence intervals on the deposit profile and on the residual creep-life of the vane.

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Energy-Efficient CO2 Capture Using Nonaqueous Absorbents of Secondary Alkanolamines with a 2-Butoxyethanol Cosolvent

ACS Sustainable Chemistry & Engineering ◽

10.1021/acssuschemeng.0c06345 ◽

2020 ◽

Vol 8 (49) ◽

pp. 18071-18082

Author(s):

Tiantian Ping ◽

Yu Dong ◽

Shufeng Shen

Keyword(s):

Co2 Capture ◽

Energy Efficient

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Energy-Efficient Single-Stage Nitrite Shunt Denitrification with Saline Sewage through Concise Dissolved Oxygen (DO) Supply: Process Performance and Microbial Communities

Microorganisms ◽

10.3390/microorganisms8060919 ◽

2020 ◽

Vol 8 (6) ◽

pp. 919 ◽

Cited By ~ 1

Author(s):

Huichuan Zhuang ◽

Zhuoying Wu ◽

Linji Xu ◽

Shao-Yuan Leu ◽

Po-Heng Lee

Keyword(s):

Dissolved Oxygen ◽

Microbial Communities ◽

Energy Efficient ◽

Oxygen Demand ◽

Operating Conditions ◽

Single Stage ◽

Rrna Gene ◽

Unexpected Finding ◽

Sequencing Analysis ◽

Ratio Requirement

Single-stage nitrite shunt denitrification (through nitrite rather than nitrate) with low dissolved oxygen (DO) supply is a better alternative in terms of energy-efficiency, short-footprint, and low C/N-ratio requirement. This study investigates the optimal DO level with temperature effect, with saline sewage at the fixed hydraulic and solids retention times of 8 h and 8 d, respectively. Moreover, 16S rRNA gene sequencing analysis corresponding with total nitrogen (TN) and chemical oxygen demand (COD) removals in each operating condition were performed. Results showed that DO of 0.3 mg/L at 20 °C achieved over 60.7% and over 97.9% of TN and COD removal, respectively, suggesting that such condition achieved effective nitrite-oxidizing bacteria inhibition and efficient denitrification. An unexpected finding was that sulfur-reducing Haematobacter and nitrogen-fixing Geofilum and Shinella were highly abundant with the copredominance of ammonia-oxidizing Comamonas and Nitrosomonas, nitrite-oxidizing Limnohabitans, and denitrifying Simplicispira, Castellaniella, and Nitratireductor. Further, canonical correspondence analysis (CCA) with respect to the operating conditions associated with phenotype prediction via R-based tool Tax4Fun was performed for a preliminary diagnosis of microbial functionality. The effects of DO, temperature, nitrite, and nitrate in various extents toward each predominant microbe were discussed. Collectively, DO is likely pivotal in single-stage nitrite shunt denitrification, as well as microbial communities, for energy-efficient saline sewage treatment.

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