Demonstration of Power Generation from Fertilizer Solutions via Pressure-Retarded Osmosis

2021 ◽  
Vol 64 (2) ◽  
pp. 495-505
Author(s):  
Pouyan Pourmovahed ◽  
Jonathan Maisonneuve
Keyword(s):  
Power Generation ◽  
Energy Recovery ◽  
High Performance ◽  
Batch Process ◽  
Cellulose Triacetate ◽  
Mechanical Work ◽  
List Type ◽  
Membrane Area ◽  
Food Energy ◽  
Pressure Retarded Osmosis

HighlightsMechanical work can be generated from fertilizer via pressure-retarded osmosis.Laboratory tests show up to 5 Wh of energy recovered per kg of fertilizer.Tradeoffs between energy recovery and power generation are demonstrated.Maintaining power above 5 W m-2 is reasonable given current membrane technology.Abstract. Large amounts of energy are released when concentrated fertilizers are diluted in water. In this study, we demonstrate the use of fertilizer to generate useful mechanical work via pressure-retarded osmosis (PRO). A number of common single solutes and fertilizer blends were analyzed using both experimental and numerical methods. Laboratory test trials showed energy recovery of up to 5 Wh kg-1 of fertilizer and power of up 6 W m-2 of membrane area given commercial cellulose triacetate membranes. A drop in power was demonstrated throughout the fertilizer PRO batch process, and the resulting tradeoffs between energy recovery and power density are discussed. Simulation results suggest that high-performance membranes can be used to maintain elevated power above 5 W m-2 throughout the batch process, while recovering approximately 5 Wh kg-1. The loss of valuable fertilizer via leakage to the feed stream was found to be less than 1% of the initial fertilizer mass, suggesting that this non-ideal dynamic can be reasonably minimized. Implications at the food-energy-water nexus are discussed. Keywords: Fertilizer osmosis, Forward osmosis, Fertilizer energy, Food-energy-water nexus.

scholarly journals Direct Ink Writing of Highly Conductive MXene Frames for Tunable Electromagnetic Interference Shielding and Electromagnetic Wave-Induced Thermochromism

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Xinyu Wu ◽  
Tingxiang Tu ◽  
Yang Dai ◽  
Pingping Tang ◽  
Yu Zhang ◽  
...  
Keyword(s):  
Electromagnetic Wave ◽  
Electromagnetic Interference ◽  
High Performance ◽  
Normal Operation ◽  
List Type ◽  
Emi Shielding ◽  
Electromagnetic Interference Shielding ◽  
Direct Ink Writing ◽  
Aluminum Ions ◽  
Wave Induced

Highlights 3D printing of MXene frames with tunable electromagnetic interference shielding efficiency is demonstrated. Highly conductive MXene frames are reinforced by cross-linking with aluminum ions. Electromagnetic wave is visualized by electromagnetic-thermochromic MXene patterns. Abstract The highly integrated and miniaturized next-generation electronic products call for high-performance electromagnetic interference (EMI) shielding materials to assure the normal operation of their closely assembled components. However, the most current techniques are not adequate for the fabrication of shielding materials with programmable structure and controllable shielding efficiency. Herein, we demonstrate the direct ink writing of robust and highly conductive Ti3C2Tx MXene frames with customizable structures by using MXene/AlOOH inks for tunable EMI shielding and electromagnetic wave-induced thermochromism applications. The as-printed frames are reinforced by immersing in AlCl3/HCl solution to remove the electrically insulating AlOOH nanoparticles, as well as cross-link the MXene sheets and fuse the filament interfaces with aluminum ions. After freeze-drying, the resultant robust and porous MXene frames exhibit tunable EMI shielding efficiencies in the range of 25–80 dB with the highest electrical conductivity of 5323 S m−1. Furthermore, an electromagnetic wave-induced thermochromic MXene pattern is assembled by coating and curing with thermochromic polydimethylsiloxane on a printed MXene pattern, and its color can be changed from blue to red under the high-intensity electromagnetic irradiation. This work demonstrates a direct ink printing of customizable EMI frames and patterns for tuning EMI shielding efficiency and visualizing electromagnetic waves.

Performance evaluation of a supercritical circulating fluidized bed boiler for power generation under flexible operation

2021 ◽  
pp. 095765092199396
Author(s):  
Matteo Bruzzone ◽  
Silvia Ravelli
Keyword(s):  
Power Generation ◽  
Fluidized Bed ◽  
High Performance ◽  
Circulating Fluidized Bed ◽  
Thermal Power ◽  
Rankine Cycle ◽  
Hard Coal ◽  
Cfb Boiler ◽  
Power Cycles ◽  
Commercial Code

It is well known that the Łagisza power plant in Poland is the world’s first supercritical circulating fluidized bed (CFB) boiler, whose commercial operation started on June 2009. It has attracted a great deal of interest and operational data are publicly available, therefore it has been chosen as the object of the present study aimed at assessing load and fuel flexibility of supercritical CFB plants. First, the thermal cycle was modelled, by means of the commercial code Thermoflex®, at nominal and part load conditions for validation purposes. After having verified the validity of the applied modelling and simulation tool, the advantage of having supercritical steam combined with CFB boiler over subcritical steam and pulverized coal (PC) boiler, respectively, was quantified in terms of electric efficiency. As a next step, the designed fuel, i.e. locally mined hard coal, was replaced with biomass: 100% biomass firing was taken into account in the case of subcritical CFB boiler whereas the maximum share of biomass with coal was set at 50% with supercritical CFB boiler, consistently with the guidelines provided by the world leading manufacturers of CFB units. A broad range of biomass types was tested to conceive mixtures of fuel capable of preserving quite high performance, despite the energy consumption in pretreatment. However, the overall efficiency penalty, due to biomass co-firing, was found to potentially undermine the benefit of supercritical steam conditions compared to conventional subcritical power cycles. Indeed, the use of low-quality biomass in thermal power generation based on steam Rankine cycle may frustrate efforts to push the steam cycle boundaries.

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