ZrMn Oxides for Aqueous-Phase Ketonization of Acetic Acid: Effect of Crystal and Porosity.

Aqueous-phase ketonization of bio-based acetic acid is important to improve the conversion efficiency of biomass resources. In this study, ZrMn mixed oxides (ZrMnOx ) with high aqueous-phase ketonization activity are synthetized through a carbonization/oxidation method (COM) and solvothermal method (STM). The results show that ZrMnOx prepared by COM possesses tetragonal ZrO2 , and hausmannite Mn3 O4 is observed only at a high oxidation temperature of 750 °C. Low-temperature and long oxidation results in decreased crystallinity and crystallite size, which is related to highly dispersed Mnn+ species. The catalysts with improved acid sites possess high ketonization activity. Surface areas and pore size of ZrMnOx synthetized by STM are controlled by the solvents for thermal treatment. Compared with water as solvent, ethanol increases the surface area and pore size, resulting in high ketonization activity.

Study on pyrolytic kinetics and behavior: The co-pyrolysis of microalgae and polypropylene.

In the current work, the co-pyrolysis kinetics of Dunaliella tertiolecta and PP were investigated via TGA, while TG-FTIR and TG-MS were used for the analysis of gas-phase components and volatiles transition. The TGA results show that PP with certain small particle size accelerates the pyrolysis process of the microalgae, while the existence of D. tertiolecta delayed that of PP. This significant interaction achieves maximum when mass ratio of PP and D. tertiolecta is 6:4. The activation energy estimated from FWO kinetic model also supports this interaction. The TG-FTIR and TG-MS results show that a significant decrease of CO2 occurs at PP and D. tertiolecta mass ratio of 6:4, indicating that small molecules (such as radicals) released by PP might react with CO2 produced by D. tertiolecta or carbonyl groups in the microalgae.

[TG-FTIR analysis of thermal degradation of bischofite's crystals with aniline hydrochloride].

The dehydration of bischofite is the key to the use of magnesium resource. Double salts or complex method is an important way to prepare anhydrous magnesium chloride. The crystals of bischofite and aniline hydrochloride were prepared through lowering the temperature of the mixture's aquatic solution slowly. The pyrolysis of aniline hydrochloride, bischofite and the crystals was qualitatively analyzed by TG-FTIR under 400 degrees C. We infered the reaction process through qualitative detection of escaping gas of each decomposition step. The Experimental results showed that there were three steps in the thermal decomposition of bischofite. In the first step, nearly four crystallized waters decomposed, while hydrolysis and decomposition took place together in the next two steps, but hydrolysis was the main reaction at the lower temperature (205-235 degrees C), and comparative decomposition was the main one at the higher temperature (235-287 degrees C). In the experimental temperature range, aniline hydrochloride didn't decompose. Water and aniline hydrochloride left the crystals at different temperature, and no hydrolysis reaction occurred. Anhydrous magnesium chloride can be prepared though this way.

[Radiolysis of aqueous solution of thiocyanate by gamma-rays].

Radiolysis of aqueous solution of thiocyanate by 60Co gamma-rays was studied. In condition of pH = 1 and pH = 3,25 mg/L SCN- was decomposed under the dose of 6 kGy, with decomposition rate of 98.11% (pH = 1) and 95.97% (pH = 3) respectively. 25 mg/L SCN- (pH = 7) was decomposed under the dose of 9 kGy and the decomposition rate is 99.33%. In the alkaline condition, pH = 10 and pH = 12, the dose of 18 kGy was need, and the decomposition rate is 99.64% and 99.93% respectively. High SCN- concentration means that more radiation dose is need. From the comparison of before radiolysis and after radiolysis's TOC (total organic carbon) and TN (total nitrogen) of SCN- solution, little TOC and TN was removed. The determination of SO4(2-) and NO3- concentration indicated that sulfur element was removed and converted to SO4(2-), and nitrogen element rarely converted to NO3-, but converted to other forms of nitrogen.

[Radiolysis of aqueous thiocyanate and its complicated system].

We studied the 60Co gamma-ray radiolysis of thiocyanate aqueous solutions in the presence of free radical scavengers, determination of cyanide of radiated thiocyanate solutions, degradation of cyanide and thiocyanate complicated system and cyanide, thiocyanate and copper (I) cyanide complicated system. The presence of NaHCO3 and n-butanol made the degradation efficiency of thiocyanate decreased, in the radiation procession of thiocyanate, cyanide was produced; and the possible reaction equation is SCN(-) + 8*OH-->SO4(2-) + CN(-) +4H2O, in the cyanide and thiocyanate system, the thiocyanate degradation rate can obtained 30%, free cyanide degradation was little effected by coexistence of thiocyanate; and due to strong complex ability of copper (I), the main form of copper (I) cyanide is Cu(CN)3(2-), the total cyanide of the system can't be degraded completely and degradation rate is about 80%.