Ammonia-Cyanuric Acid Co-Production in Boiler Denitrification System.

In response to the issues of poor economic efficiency and high CO2 emissions in the urea-to-ammonia technology of thermal power plants, this paper innovatively proposes a new ammonia production process for thermal power plants. This process utilizes the waste heat of thermal power plant boilers and conducts urea pyrolysis through two-stage heating to prepare ammonia and cyanuric acid. From this, the prepared ammonia can be used in the denitrification process of thermal power plants, and the prepared cyanuric acid can bring additional benefits to thermal power plants. The optimal process scheme was determined through orthogonal experiments of urea pyrolysis. And with the help of Aspen Plus software, a whole-process modeling analysis of urea pyrolysis experiments was carried out to investigate the influences of the melting temperature, melting time, reaction temperature, and reaction time on the process. The results show that when the melting temperature was 160 °C, the melting time was 45 min, the reaction temperature was 240 °C, and the reaction time is 20 min, which was the best scheme, 18.45% ammonia and 52.35% cyanuric acid could be obtained. Through the combined analysis of the Aspen Plus simulation and urea pyrolysis experiments, it was found that the melting temperature should be controlled within 160-167 °C, the melting time should be controlled within 40-45 min, the reaction temperature should be controlled within 240-245 °C, and the reaction time should be controlled within 15-20 min. Compared with the existing urea-to-ammonia process, this process has the advantages of nearly zero emissions and good economic benefits, thus providing reliable research data support for future industrialization.

Experimental Study on Preparation of Inorganic Fibers from Circulating Fluidized Bed Boilers Ash.

The ash generated by Circulating Fluidized Bed (CFB) boilers is featured by its looseness and porosity, low content of glassy substances, and high contents of calcium (Ca) and sulfur (S), thus resulting in a low comprehensive utilization rate. Currently, the predominant treatment approach for CFB ash and slag is stacking, which may give rise to issues like environmental pollution. In this paper, CFB ash (with a CaO content of 7.64% and an SO3 content of 1.77%) was used as the main raw material. The high-temperature melting characteristics, viscosity-temperature characteristics, and initial crystallization temperature of samples with different acidity coefficients were investigated. The final drawing temperature range of the samples was determined, and mechanical property tests were conducted on the prepared inorganic fibers. The results show that the addition of dolomite powder has a significant reducing effect on the complete liquid phase temperature. The final drawing temperatures of the samples with different acidity coefficients range as follows: 1270-1318 °C; 1272-1351 °C; 1250-1372 °C; 1280-1380 °C; 1300-1382 °C; and 1310-1384 °C. The drawing temperature of this system is slightly lower than that of basalt fibers. Based on the test results of the mechanical properties of inorganic fibers, the Young's modulus of the inorganic fibers prepared through the experiment lies between 55 GPa and 74 GPa, which basically meets the performance requirements of inorganic fibers. Consequently, the method of preparing inorganic fibers by using CFB ash and dolomite powder is entirely feasible.

AMP-activated protein kinase suppresses the in vitro and in vivo proliferation of hepatocellular carcinoma.

AMP-activated protein kinase (AMPK) is a central metabolic sensor and plays an important role in regulating glucose, lipid and cholesterol metabolism. Therefore, AMPK is a key therapeutic target in diabetes. Recent pilot studies have suggested that diabetes drugs may reduce the risk of cancer by affecting the AMPK pathway. However, the association between AMPK and the proliferation of hepatocellular carcinoma (HCC) is unknown. In this study, we investigated the relationship between AMPK activity and the proliferation of HCC in cell lines, nude mice and human clinic samples. We first investigated the relationship between AMPK activity and cell proliferation in two HCC cell lines, PLC/PRF/5 and HepG2, by two AMPK activators, 5-aminoimidazole-4-carboxamide-1-h-D-ribofuranoside (AICAR) and metformain. AICAR and metformin treatment significantly inhibited the proliferation of HCC cells and induced cell cycle arrest at G1-S checkpoint. We then observed that metformin abrogated the growth of HCC xenografts in nude mice. The clinical pathology of AMPK activity in HCC, including cell proliferation, differential grade, tumor size and microvessel density, was studied by using 30 clinical tissue samples. In HCC tissue samples, phosphorylated AMPK was expressed mainly in cytoplasm. AMPK activity decreased significantly in HCC in comparison with paracancerous liver tissues (P<0.05). AMPK activity was negatively correlated with the level of Ki-67 (a marker of cell proliferation), differential degradation and tumor size (P<0.05), but not with microvessel density, hemorrhage or necrosis in HCC. Our findings suggest that AMPK activity inhibits the proliferation of HCC and AMPK might be an effective target for prevention and treatment of HCC.