Mitigation approaches and techniques for combustion power plants flue gas emissions: A comprehensive review.

Population growth and urbanization are driving energy demand. Despite the development of renewable energy technologies, most of this demand is still met by fossil fuels. Flue gases are the main air pollutants from combustion power plants. These pollutants include particulate matter (PM), sulfur oxides (SOx), nitrogen oxides (NOx), and carbon oxides (COx). The release of these pollutants has adverse effects on human health and the environment, including serious damage to the human respiratory system, acid rain, climate change, and global warming. In this review, a wide range of conventional and new technologies that have the potential to be used in the combustion power plant sector to manage and reduce flue gas pollutants have been examined. Nowadays, conventional approaches to emissions control and management, which focus primarily on post-combustion techniques, face several challenges despite their widespread use and commendable effectiveness. Therefore, studies that have proposed alternative approaches to achieve improved and more efficient methods are reviewed. The results show that new advances such as novel PM collectors, attaining an efficiency of nearly 100 % for submicron particles, microwave systems, boasting an efficiency of nearly 90 % for NO and over 95 % for SO2, electrochemical systems achieving above 90 % efficiency for NOx reduction, non-thermal plasma processes demonstrating an efficiency close to 90 % for NOx, microalgae-based methods with efficiency ranging from 80 % to 99 % for CO2, and wet scrubbing, exhibit considerable potential in addressing the shortcomings of conventional systems. Furthermore, the integration of hybrid methods, particularly in regions prioritizing environmental concerns over economic considerations, holds promise for enhanced control and removal of flue gas pollutants with superior efficiency.

Exergy-economic assessment of a hybrid power, cooling and heating generation system based on SOFC.

In this research, a combined cycle using a solid oxide fuel cell system, a single-stage H2O-NH3 absorption chiller and a residential hot water HX, is developed for the electricity production, hot water and cooling all at the same time, and it is studied from an exergy, energy, and exergoeconomic standpoint. Performance of system under the design condition is analyzed and the mathematical model is simulated. After analyzing the results in the initial input mode, changing the fuel cell current density effect and fuel utilization factor on the system efficiency is evaluated. The result indicates that total energy is 4.418 kW, the total exergy efficiency is 37.8%. And the overall irreversibility is 1.650 kW. On the other hand, the air HX, fuel cell and water HX are designed as elements that must be given more attention than others from the exergoeconomic perspective, because they have nearly the most amount of price compared to other parts.

Assessment of the circulatory concentrations of cathepsin D, cathepsin K, and alpha-1 antitrypsin in patients with knee osteoarthritis.

BACKGROUND: Evidence has shown that cysteine protease enzymes, such as cathepsin D, cathepsin A, cathepsin K, and alpha-1 antitrypsin (AAT) are involved in the chronic degenerative joint process. This study aimed to determine the potential involvement of cathepsin K, cathepsin D, and AAT in patients with osteoarthritis (OA). METHODS: This study was performed on 31 patients with knee OA and 29 age- and sex-matched healthy subjects (both with Fars ethnicity from Iran). American College of Rheumatology (ACR) criteria were used to diagnose OA patients. The clinical status of the patients was scored by Western Ontario McMaster Universities Osteoarthritis (WOMAC), and pain intensity was measured by the Visual Analog Scale (VAS). The serum level of AAT was measured using high-resolution cellulose acetate electrophoresis. Additionally, serum levels of cathepsin D and cathepsin K were measured by enzyme-linked immunosorbent assay (ELISA). RESULTS: The findings showed that the serum level of cathepsin K was significantly increased in OA patients compared to healthy subjects (P = 0.01), while there was no significant difference between serum level of cathepsin D in study groups (P = 0.2). In addition, the serum concentration of AAT was significantly decreased in OA patients compared to healthy subjects (P = 0.003). There was a significant correlation between WOMAC score and age (r = 0.644, P = 0.0001) and VAS (r = 0.866, P < 0.0001) in OA patients. CONCLUSIONS: The decreased level of AAT in OA patients and a rise in serum level of cathepsin K are involved in the pathogenesis of OA via stimulation of bone resorption and cartilage degradation.