| 1. |
- Wang, Yabo, et al.
(författare)
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Potential environmental benefits of integrating flue gas quench in biomass/waste-fueled CHP plants
- 2021
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Ingår i: Energy Science & Engineering. - : John Wiley & Sons. - 2050-0505. ; 9:2, s. 189-199
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Tidskriftsartikel (refereegranskat)abstract
- Due to stricter regulations, large biomass/waste incineration power plants are expected to reduce (i) pollutant emissions through water (such as organic compounds dissolved in the discharge water), (ii) the withdrawal of external freshwater, and (iii) the disturbance to the natural water by increasing the water recycle and internal reuse. To address such challenges, flue gas quench (FGQ) is playing a vital role that links flue gas (FG) cleaning and wastewater treatment. In this study, a detailed analysis based on the material and energy balance is performed regarding the pollutant distribution in the flue gas and the wastewater within a combined heat and power (CHP) plant. The real data from the reference CHP plant were used; and results show that the utilization of FGQ can result in less wastewater discharge (about 73 tonnes/d) together with less pollutant concentration to the municipal wastewater treatment plant, as compared to the system with only flue gas condenser but without FGQ. The integration of FGQ also results in less burden on the external freshwater use by increasing the amount of clean water for internal use (about 57 tonnes per day). In addition, the integration of FGQ can offer a potential annual energy saving of about 13.1 MWh in the municipal wastewater treatment plant due to the less wastewater coming from the CHP plant.
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| 2. |
- Wang, Jinshan, et al.
(författare)
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Integrating sludge drying in biomass fueled CHP plants
- 2021
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Ingår i: Energy, Ecology and Environment. - : Springer Science and Business Media LLC. - 2363-7692 .- 2363-8338. ; 6:1-12
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Tidskriftsartikel (refereegranskat)abstract
- Sludge handling through thermal conversion is environmentally friendly, which, however, requires sludge drying. This work proposed to use the waste heat of flue gas (FG) to dry sludge. The integration of sludge drying in biomass fueled CHP plants can clearly affect the performance of downstream processes in FG cleaning, such as flue gas quench (FGQ) and flue gas condenser (FGC). It can further affect the energy efficiency of (CHP). In order to understand the influence, a mathematical model and an Aspen PLUS model were developed to simulate the drying process and the CHP respectively. Based on simulation results, it has been found that the increase of feeding rate of sludge and the moisture content of sludge after drying can decrease the water evaporation in FGQ. An increase of the feeding rate of sludge in combination with a drop of moisture content of sludge after drying can decrease the heat recovery from FG. After sludge is dried, it can be used as fuel to replace part of the biomass fuels. The amount of biomass saving could be influenced by the dried sludge moisture content and flow rate. The simulation results of co-incineration biomass with sludge show that the moisture content of 40% after sludge drying leads to the maximum biomass saving.
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| 3. |
- Li, Hailong, 1976-, et al.
(författare)
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Performance of flue gas quench and its influence on biomass fueled CHP
- 2019
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Ingår i: Energy. - : Elsevier. - 0360-5442 .- 1873-6785. ; 180, s. 934-945
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Tidskriftsartikel (refereegranskat)abstract
- For biomass/waste fueled power plants, stricter regulations require a further reduction of the negative impacts on the environment caused by the release of pollutants and withdrawal of fresh water externally. Flue gas quench (FGQ) is playing an important role in biomass or waste fueled combined heat and power (CHP) plants, as it can link the flue gas (FG) cleaning, energy recovery and wastewater treatment. Enhancing water evaporation can benefit the concentrating of pollutant in the quench water; however, when FG condenser (FGC) is not in use, it results in a large consumption of fresh water. In order to deeply understand the operation of FGQ a mathematic model was developed and validated against the measurements. Based on simulation results key parameters affecting FGQ have been identified, such as the flow rate and temperature of recycling water and the moisture content of FG. A guideline about how to reduce the discharge of wastewater to the external and the withdrawal of external water can be proposed. The mathematic model was also implemented into an ASPEN Plus model about a CHP plant to assess the impacts of FGQ on CHP. Results show that when the FGC was running, increasing the flow rate and decreasing the temperature of recycling water can result in a lower total energy efficiency.
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| 4. |
- Wang, Bin, et al.
(författare)
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Modelling the Quench Tower in Flue Gas Cleaning of a Waste Fueled Power Plant
- 2018
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Ingår i: JOINT INTERNATIONAL CONFERENCE ON ENERGY, ECOLOGY AND ENVIRONMENT ICEEE 2018 AND ELECTRIC AND INTELLIGENT VEHICLES ICEIV 2018. - : DEStech Publishing Inc. - 9781605955902
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Konferensbidrag (refereegranskat)abstract
- To control the emission of pollutants in the flue gas, a separated flue gas quench was added after flue gas desulfurization and before flue gas condensation. A mathematic model was developed to simulate the heat and mass transfer in the flue gas quench. The model was validated through the comparison with measured data. Based on this model, the impacts of inlet flue gas condition and injected recycling water flow rate on the water consumption of the quench and the temperature of exit flue gas (FG) were studied. The results show that the temperature of exit FG and water consumption increased with the increase of flow rate and moisture content of FG. The temperature of exit FG increased and the water consumption decreased with the increase of droplet water diameter. The temperature of exit FG decreased and the water consumption increased with the increase of water flow rate. In order to cooled and humidified the flue gas sufficiently, the droplet diameter should be limited to 1.2 mm and the water to FG flow rate ratio (L/G) higher than 2.
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| 5. |
- Wei, Wendong, et al.
(författare)
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Embodied greenhouse gas emissions from building China's large-scale power transmission infrastructure
- 2021
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Ingår i: Nature Sustainability. - : NATURE RESEARCH. - 2398-9629. ; 4:8, s. 739-747
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Tidskriftsartikel (refereegranskat)abstract
- China has built the world's largest power transmission infrastructure by consuming massive volumes of greenhouse gas-(GHG-) intensive products such as steel. A quantitative analysis of the carbon implications of expanding the transmission infrastructure would shed light on the trade-offs among three connected dimensions of sustainable development, namely, climate change mitigation, energy access and infrastructure development. By collecting a high-resolution inventory, we developed an assessment framework of, and analysed, the GHG emissions caused by China's power transmission infrastructure construction during 1990-2017. We show that cumulative embodied GHG emissions have dramatically increased by more than 7.3 times those in 1990, reaching 0.89 GtCO(2)-equivalent in 2017. Over the same period, the gaps between the well-developed eastern and less-developed western regions in China have gradually narrowed. Voltage class, transmission-line length and terrain were important factors that influenced embodied GHG emissions. We discuss measures for the mitigation of GHG emissions from power transmission development that can inform global low-carbon infrastructure transitions.
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