Performance Of CaO Research Articles

Assessing variances in the impact of intrinsic minerals on NO and N2O precursors during sludge pyrolysis

This study proposed a novel strategy to control nitrogen oxides (NOx) precursors by directing nitrogen to adhere to the fuel-N→NH3→N2 pathway. The research aimed to illuminate the regulatory effects of CaO, Fe2O3, and their mixtures on NO and N2O precursors (NH3, HCN, and HNCO) during sludge pyrolysis, further sought to establish scientific correlations with varying temperatures and differentiate their impact. The findings indicated that unlike NH3, HNCO is generated from the cleavage of amides, sharing its origin with HCN. Notably, the sensitivities of three conditioners to different functional groups result in distinct impacts on precursor emissions. CaO interacted with –OH and N-H functional groups, releasing NH3. Fe2O3, being more responsive to C-H and C-C groups, contributed to HNCO emission. At 750 °C, a CaO-Fe2O3 mixture created CaxFeyOz, which selectively reacted with N-H and C≡N, facilitating the conversion of HNCO and HCN to NH3. While temperature is a crucial factor in the performance of CaO, its impact on Fe2O3 is primarily confined to transformation of heterocyclic and nitrile. Below 350 °C, Fe2O3 favored the evolution of nitrogen into heterocyclic compounds within tar. Conversely, above 490 °C, it inhibited the formation of nitrile in char, promoting the dehydrogenation of tar into unsaturated aromatic structures. The CaO-Fe2O3 mixtures exhibited a superposition of individual effects from CaO and Fe2O3, with CaxFeyOz stimulating N2 emission. Importantly, among three conditioners, Fe2O3 showed the most significant abatement effect on NOx precursors, primarily through nitrogen fixation in char, nitrogen enrichment in tar, and precursor oxidation. This research contributes innovative perspectives on nitrogen regulation in nitrogen-rich fuels, the utilization of NH3, and effective NO and N2O control.

In-situ synthesis of a novel CaO·4B2O3 · 2H2O–SiO2 nanocomposite and its influence on mechanical property and flame retardancy of polypropylene

A novel CaO·4B2O3·2H2O–SiO2 nanocomposite with good thermal stability has been in situ synthesized, in which the SiO2 nanospheres are supported on the CaO·4B2O3·2H2O nanosheets. As a comparison, single CaO·4B2O3 ·2H2O nanosheet with the thickness of 100 nm, single SiO2 nanosphere with the diameter of about 100 nm, and their physical mixture were also prepared, respectively. On the basis of characterizations of XRD, FT-IR, TGA, SEM and TEM, the fire performance of CaO·4B2O3 ·2H2O–SiO2 nanocomposite to polypropylene was studied. It is demonstrated that the flame retardancy of prepared sample was prominently stronger than those of single CaO·4B2O3 ·2H2O nanosheet and their physical mixture. Furthermore, the mechanical property of polypropylene/CaO·4B2O3·2H2O–SiO2 composite was also assessed. The possible formation mechanism of the nanocomposite and its flame-retardant mechanism were put forward. It has prospect as possible flame retardant to polypropylene and other polymers.

3-6-2 CaO/酸化クロム担持型酸化チタン内包カプセルを用いた光エネルギー駆動型BDF合成反応における光量の影響(Session 3-6 BDF I)

3-6-2 CaO/酸化クロム担持型酸化チタン内包カプセルを用いた光エネルギー駆動型BDF合成反応における光量の影響(Session 3-6 BDF I)

Effect of CaO on conversion of lignite to hydrogen-rich gas in supercritical water

Conversion of Xiaolongtan lignite to hydrogen-rich gas was performed in supercritical water under conditions of 450–80°C, 23–38 MPa, and 1–30 min in the presence of CaO. The effects of Ca/C molar ratio and reaction conditions on the product distribution and yields of gas products were investigated. The yield of CO 2 in gas product decreased and that of hydrogen increased with the increase in Ca/C molar ratio. At a Ca/C molar ratio of 0.42, nearly all CO 2 is fixed and the molar fraction of hydrogen in gas product is about 48%. The increase in temperature leads to an increase in the carbon conversion and the yield of hydrogen, and the performance of CaO is significant at higher temperatures. Higher reaction pressure favors the conversion of coal and the formation of H 2 and CH 4. The effect of residence time is less significant compared with Ca/C molar ratio and temperature. Experiments of char gasification in SCW were also conducted. It shows that the addition of CaO can promote carbon gasification reaction and increase the yields of H 2 and CH 4.