Abstract: Analyzing from the micro level of the basic unit of environmental protection industry -- enterprise, this paper takes relevant information of more than 8000 key enterprises in China's environmental protection industry from 2018 to 2020 as the big data training samples, and uses BP neural network method to identify the key production factors that have great impact on the output of the whole China's environmental protection industry and its main subdivisions. The results show that China's environmental protection industry is still in the growing stage in the current stage, with significant capital pulling, technological innovation driving, and management innovation also plays an important role. There are differences in the performance of water, air and solid waste in the environmental protection industry. In detail, R&D expenses from the government plays the most important role in water pollution prevention and control industry. Technology innovation plays the most important role in air pollution prevention and control industry. And staff play the most important role in solid waste treatment and resource recycling industry. PubDate: Wed, 31 May 2023 09:16:02 +000
Abstract: The rise of the unconventional oil and gas (UOG) industry over the last two decades has transformed the domestic energy outlook but raised concerns over environmental impacts. With the evolution of Environmental Social Governance (ESG) reporting allowing for a transparent view of oilfield operations, the evaluation of corporate sustainability has become increasingly feasible. Even with increased reporting, there have been very few quantifiable metrics for sustainable water management practices in the UOG industry due to the focus being primarily on methane emissions in recent years. This study aims to provide a practical, quantitative, and concise method (two-parameter based - Quadrant Plot) to evaluate UOG operators' performance in minimizing the negative impacts of freshwater use for drilling and fracking. Parameters (%Freshwater and %Salt Water Disposal) used in this performance matrix have been optimized to gather as much information as possible and while being compatible with operators' existing data collection. This study discusses how the Quadrant Plot could quantify the water performance using private and public data from over 20 unconventional oil and gas operators. This quantitative assessment not only enables the determination of a static performance score but also allows for the depiction of changes in performance over time. PubDate: Tue, 23 May 2023 04:49:38 +000
Abstract: Computational Fluid Dynamics simulation of a natural convection solar tunnel dryer with a bare flat-plate chimney is presented. The chimney’s function is to create airflow in the dryer through the buoyancy effect by re-heating the air coming from the drying unit and is therefore a major factor in the drying rate. CFD simulation was therefore employed to study the temperature and airflow in the dryer and determine the areas that could be improved upon. The design of the solar tunnel dryer geometry used in this simulation was done in SOLIDWORKS 2016 whereas the simulation of temperature distribution of airflow inside the dryer was performed using SOLIDWORKS 2016 flow simulation program in a steady-state regime. The boundary conditions were set using the obtained experimental data. The simulation results showed that the chimney losses heat, that there is air recirculation in the collector, that the airflow experiences some pressure loss as it moves from the drying chamber to the chimney, and that there is some reduction of the velocity in some parts of the dryer. The simulated and experimental collector efficiencies were found to be 33.09 and 37.63%, respectively, giving a mean relative deviation of collector temperature of 5.1%. To improve the performance of the dryer, insulating and glazing of the chimney is suggested as well as using a curved joint between the chimney and the drying chamber. PubDate: Thu, 02 Mar 2023 00:53:49 +000
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