Preparation of mesoporous activated carbons from coal liquefaction residue for methane decomposition

Mesoporous activated carbons were prepared from direct coal liquefaction residue （CLR） by KOH activation method, and the experiments were carried out to investigate the effects of KOH/CLR ratio, solvent for mixing the CLR and KOH, and carbonization procedure on the resultant carbon texture and catalytic activity for catalytic methane decomposition （CMD）. The results showed that optimal KOH/CLR ratio of 2 ： 1; solvent with higher solubility to KOH or the CLR, and an appropriate carbonization procedure are conductive to improving the carbon pore structure and catalytic activity for CMD. The resultant mesoporous carbons show higher and more stable activity than microporous carbons. Additionally, the relationship between the carbon textural properties and the catalytic activity for CMD was also discussed.

Optimization for microwave-assisted direct liquefaction of bamboo residue in glycerol/methanol mixtures

Bamboo residues were liquefied in a mixture of glycerol and methanol in the presence of sulfuric acid using microwave energy. We investigated the effects of liquefaction conditions, including glycerol/methanol ratio, liquefaction temperature, and reaction time on the conversion yield. The optimal liquefaction conditions were under the temperature of 120 °C, the reaction time of 7 min, the glycerol–methanol–bamboo ratio of 8/0/2（W/W）, and the microwave power of 300 W. Maximum conversion yield was 96.7 %. The liquid products were separated into two contents（water soluble part and precipitate part） by addition of a sufficient amount of water. By Fourier transform infrared（FT-IR）, the water soluble content mainly contained glycerol and its derivate and carbohydrate degradation products, and the precipitate content was mainly lignin derivatives.

Study on the corrosion of refractory materials by coal blended with the extraction residue of direct coal liquefaction in a simulated gasification atmosphere

Utilizing the extraction residue(ER)of direct coal liquefaction residue as a gasification feedstock has significant economic value.But the characteristic of high ash and iron in the ER would increase the risk of corrosion of the refractory materials and affect the long-term operation of the gasifier.In this work,corrosion experiments of molten slag derived from a mixture of 20 wt%ER and 80 wt%coal on a high-chromia refractory brick and SiC brick were carried out using a rotary-drum furnace in a simulated gasification atmosphere.The experimental results show that the viscosity of the poured slag is larger as compared to the initial ash sample at the same temperature,which suggests that the viscosity-temperature relationship of the poured slag should be used as the reference for the operation temperature of the gasifier to ensure that the slag can flow during operation.For a high-chromia refractory brick,iron oxides in molten slag could react with Cr_(2)O_(3) in the refractory matrix but,because the aggregate was not found to be damaged,the damage to the matrix structure was the key factor for causing the corrosion of the high-chromia refractory brick.Metallic iron was observed in the exposed SiC brick,which indicated that the reaction between the iron oxides in the slag and SiC occurred,forming metallic iron and SiO_(2).The corrosion of a SiC brick by molten slag depended mainly on the dissolution of Al_(2)O_(3) particles and the reaction between iron oxides in the molten slag and SiC particles.Therefore,the high iron content in coal ash had a serious influence on the corrosion of refractory materials.More efforts need to be made on coal blended with ER as a gasification feedstock in the future.

DCLR Modifi ed Petroleum Asphalt Optimization and Mixture Road Performance

In recent decades,modified asphalt materials have been used in enhancing the traffic load on the roads.The main objective of this paper is to explore the modifi cation effect of direct coal liquefaction residue(DCLR)on as-phalt binders and investigate the effectiveness of DCLR in improving the performance of asphalt road.This paper prepared modifi ed petroleum as-phalt under diff erent process conditions and tested its penetration,softening point and ductility index.Based on the experimental data,according to gray correlation degree,the performance for the asphalt was compared.The performance for the modified asphalt is simulated and predicted using poly-nomial functions.The modifi ed asphalt was analyzed by FT-IR,TGA,SEM and HPLC.The results show that the optimal process conditions for DCLR modifi ed asphalt are shear mixing time of 45 min,shear mixing tempera-ture of 150℃ and shear mixing rate of 4000 r/min.The predicted fit with the experimental data of 0.993 further demonstrates the effectiveness of the method.The characterization results show no significant chemical change between the DCLR and the asphalt.DCLR can significantly improve the high temperature performance and water stability of the asphalt,but it has little impact on its low temperature performance.

Influence of specimen-reconstituting method on the undrained response of loose granular soil under static loading

This paper describes the results of an experimental study on the undrained shear behaviour of loose sand collected from the location close to the epicenter of the recent Chlef （Algeria） Earthquake （October 10,1980）.The study focuses on the effects of the mode of the soil deposition on the liquefaction resistance of the Chlef sand.For this purpose,the results of undrained monotonic triaxial compression tests performed on samples with initial density of 0.29 under initial confining pressures ranged from 50 kPa to 200 kPa are presented.The specimens were prepared by two depositional methods namely dry funnel pluviation and wet deposition.It was found that there was a marked difference in the undrained behaviour of sand in terms of maximal deviatoric stress,peak strength,residual strength and excess pore water pressure,even though the density and stress conditions were identical.The conclusion was that the soil fabric was responsible for this result.The results indicated also that at low confining pressures,the specimens reconstituted by the wet deposition method exhibited complete static liquefaction （zero effective confining pressure and zero stress difference）.