: Emulsion polymerization of octamethyl cyclotetrasiloxane (D 4 ) under microwave irradiation (MI) was studied. The polysiloxane (PSi) nanoparticles via cationic ring-opening polymerization of D 4 were obtained by using the dodecylbenzene sulphonic acid (DBSA), sodium dodecylbenzene sulphate (SDBS) and poly(ethylene glycol) monooctylphenyl ether (OP-10) as the catalyst and the emulsifiers respectively. The particle size analyzer and transmission electron microscope (TEM) were used to determine the particle size of PSi emulsions. The results show that, the particle size of PSi emulsions prepared under MI is substantially smaller and the particle distribution is narrower compared with that under conventional heating (CH). With the aid of MI, the polymerization rate and the equilibrium conversion are enhanced. The polydispersity index (PDI) and molecular weight (M w ) measured by GPC indicate that under MI, PDI of PSi is narrower and M w of PSi at high temperature is lower than those under CH.

In order to make better utilization of coal tailings (low quality production after coal preparation) as the resources, the pyrolysis characteristics and product distributions during co-pyrolysis of coal tailings together with biomass at different ratio (20%, 40%, 60% and 80%) were determined in thermogravimetric analysis (TGA) and a fixed bed reactor in this paper. Coal tailings (TC) selected was provided by Hexi coal in Shanxi province, and pine branch wastes (PBW) were used as biomass samples. The result of TGA experiments indicates that the temperature corresponding to the maximum pyrolysis rate exhibited a significant difference between TC and PBW, and the value of the calculated TGA and DTG curves is similar to the experimental ones. In a fixed bed experiments within a temperature range of 25-900°C, gas product yields of co-pyrolysis of TC and PBW are higher than those of the sum of them individually, while tar and char yields were on the contrary. It shows some synergetic effect exists during co-pyrolysis process of TC and PBW blends, and the maximum synergy exhibits with a PBW blending ratio of 40%. CO yield increases up to 30% at 400°C and CH4yield increases up to 11.33% at 700°C compared with the calculated value. These findings can potentially help to understand and predict the behavior of coal tailings/biomass blends in practical systems.

To investigate the effects of gangue on pyrolysis of municipal solid waste (MSW), pyrolysis of MSW with gangue has been conducted by TG and fixed-bed reactor, respectively. The effect of gangue on pyrolysis product yields and compositions of gaseous products was investigated and the obtained results were compared with similar experiments without gangue. It was shown that gangue can improve the pyrolytic reaction of MSW, reduce the char yield, increase the liquid yield. And influences of gangue on yields of H2, CO, CH4 and CO2 were more apparent, the yields of H2, CO and CO2 with gangue were improved 12.5%, 11.8% and 175%, respectively, conversely, the yield of CH4 was reduced 15.4% compared with no gangue.

The aims of this work were to investigate the influence of feedstock properties of different part of cassava residues (cassava rhizome (CR), cassava stalk (CS) and cassava leaf (CL)) and operating temperatures on the pyrolysis characteristics and the kinetic parameters. Pyrolysis experiments of three selected biomass feedstock were conducted using a fixed-bed reactor. It was shown that the bio-oil yield of cassava stalk reached the maxima at 600°C, and the char yield reduced with the temperature, whereas the gas yield increased with temperature. The cassava rhizome presented higher thermochemical reactivity than the other samples. The activation energy of cassava stalks was 37.57 kJ / mol and that of cassava rhizome (39.42 kJ / mol) increased slightly. The activation energy of cassava leaf (22.85 kJ / mol) was lowest of the three samples.