Biomass:polystyrene co-pyrolysis coupled with metal-modified zeolite catalysis for liquid fuel and chemical production

Biomass and waste polystyrene plastic (ratio 1:1) were co-pyrolysed followed by catalysis in a two-stage fixed bed reactor system to produce upgraded bio-oils for production of liquid fuel and aromatic chemicals. The catalysts investigated were ZSM-5 impregnated with different metals, Ga, Co, Cu, Fe and Ni to determine their influence on bio-oil upgrading. The results showed that the different added metals had a different impact on the yield and composition of the product oils and gases. Deoxygenation of the bio-oils was mainly via formation of CO2 and CO via decarboxylation and decarbonylation with the Ni–ZSM-5 and Co–ZSM-5 catalysts whereas higher water yield and lower CO2 and CO was obtained with the ZSM-5, Ga–ZSM-5, Cu–ZSM-5 and Fe–ZSM-5 catalysts suggesting hydrodeoxygenation was dominant. Compared to the unmodified ZSM-5, the yield of single-ring aromatic compounds in the product oil was increased for the Co–ZSM-5, Cu–ZSM-5, Fe–ZSM-5 and Ni–ZSM-5 catalysts. However, for the Ga–ZSM-5 catalyst, single-ring aromatic compounds were reduced, but the highest yield of polycyclic aromatic hydrocarbons was produced. A higher biomass to polystyrene ratio (4:1) resulted in a markedly lower oil yield with a consequent increased yield of gas.

Combined Application of Pipe Roof Pre-SUPPORT and Curtain Grouting Pre-Reinforcement in Closely Spaced Large Span Triple Tunnels

The platform of the Badaling Great Wall Underground Station consisted of large span triple tunnels. The triple tunnels passed through several major faults. Based on preliminary in situ monitoring, the interaction behavior among triple tunnels was significantly severe, and the original supports failed to meet the safety requirement. Therefore, pipe roof pre-support (PRPS) and curtain grouting pre-reinforcement (CGPR) were used as the pre-construction techniques. By numerical investigation, the pipe diameter, the arrangement angle of PRPS, and the grouting thickness of CGPR were optimized as 108 mm, 150°, and 3 m, respectively. According to numerical results, PRPS predominantly bore loose rock and reduced mean crown settlement (MCS), while CGPR primarily improved the mechanical properties of rock and decreased the pillar plastic ratio (PPR). PRPS and CGPR had complementary advantages in time, space, and mechanical properties. PRPS could timely form a strong arch structure far ahead of the tunnel face, CGPR could effectively restrict the development of plastic zone. They mutually and actively formed a strong permanent ring in front of the tunnel face. After the field application of PRPS and CGPR, the mean surrounding rock pressure reduced by 33.4%, the MCS reduced by 58.7%, and no support damage was observed. The excavation safety was guaranteed.

CO2 emission from combustion of lignite, waste plastics and biomass mixture pellets

Combustion is a familiar technique for disposal of urban wastes such as plastics when their recycling is impractical. It offers energy recycling and waste diminution. In this paper, combustion behaviours of blend pellets composed of binary and triple mixtures of plastic wastes, biomass and lignite in a laboratoryscale fixed-bed combustion system were examined. The materials chosen as waste plastic, biomass and lignite were, respectively, market plastic bags, furniture plant waste powder and Bing?l Karl?ova lignite. The effect of varied blend pellet composition on the combustion behaviour and CO2 emission in flue gas during combustion was examined. It was observed that the rate and efficiency of combustion increased with increasing plastic ratio in the blend pellets. It was found that the amount of carbon increased with the ratio of waste plastics added to blends, which also increased the CO2 ratio in the flue gas during the volatile matter combustion period. It was concluded that burning waste plastic bags with low-quality lignite or waste biomass could be a viable option to get rid of them and to gain energy.

Preparation and Dyeing of Ethylated Wood Plastic Composites

In this study, ethylated wood powder/polystyrene plastic composite (WPC) was obtained by combining ethylated Chinese Fir powder with polystyrene foam in DMF or CHCl3, and was dyed with disperse dyes. The results show that the compatibility of ethylated fir powder with polystyrene was good when the ratio of wood to plastic ratio is beyond 3:1. The color shade of dyed wood-plastic powder is close to that of dyed polyester fabric and high temperature is favorable for the dyeing of wood-plastic powder. Moreover, dyed wood plastic powder has good washing fastness, which depends on the molecular structure of disperse dyes, dye concentration and dyeing temperature.

Effects of geometric particle sizes of wood flour on strength and dimensional properties of wood plastic composites

The effect of different wood flour sizes on strength and dimensional properties of wood-plastic composites were examined. Wood flour of different particle sizes viz; 1.00mm, 2.00mm and >2.00mm were compounded with recycled low-density polyethylene (LDPE) at different wood/plastic ratio of 1: 1, 2: 3 and 3: 2. The results obtained showed that wood flour size > 2.00mm has the highest MOR and MOE values of 1.206N mm-2 and 2484.72Nmm-2 while wood flour size of 1.00mm had the lowest MOR and MOE values of 0.505Nmm-2 and 2195.89Nmm-2 respectively. Also the results of the physical properties showed that wood flour size of 1.00mm had the lowest thickness swelling percentage with mean values of 0.28% and 2.08% while water absorption percentage has mean values of 0.91% and 10.58% after 2 hours and 24 hours of water immersion respectively. It was observed that wood flour size of 2.00mm and particle size >2.00mm had the highest thickness swelling and water absorption percentages. This showed that strength properties of wood plastic composites increased with increased particle sizes whereas its dimensional properties increased with decreased particle sizes. The results of analysis of variance carried out on mechanical and physical properties showed that particle sizes and wood/plastic ratio had a significant effect on the mechanical and physical properties of wood plastic composites (p 0.05).

Elasto-Plastic Dynamic Responses Analysis of Double-Layer Spherical Lattice Shells under Multiple Earthquake Excitations

Based on the large geometric deformation and nonlinear of material theories, the seismic responses of a double-layer spherical lattice shells structure were studied. The results show that under multi-dimensional earthquake, the maximum displacement and axial stress, as well as plastic ratio of the structure will be obviously increased than those corresponding to the responses under single-dimensional earthquake. When long-period seismic wave was taken as the input wave, the responses of the structure were the maximum.

Study on Horizontal Wells and ERW Drilling Technology of Carrying Cuttings

Hole cleaning was very difficult in horizontal wells and extended reach wells (ERW), which was the technical bottleneck in raising the progress and success rate of petroleum exploration and production at present. A new type of treating agent for drilling fluid (CNRJ), designed for horizontal wells and extended-reach wells, was synthesized. CNRJ was added to drilling fluids, and the rheological properties, temperature-resisting property and suspension performance of drilling fluid system were analysed. The results indicate that CNRJ has good compatibility with drilling fluid system, and the dynamic plastic ratio of drilling fluid system can be adjusted from 0.20 to 1.12. In addition, the drilling fluid system has good static suspension ability for cuttings, good heat resistance and pollution resistance.

Quantification of polypropylene (PP) in wood plastic composites (WPCs) by analytical pyrolysis (Py) and differential scanning calorimetry (DSC)

The common use of wood together with traditional chemical polymers opens new possibilities in the field of sustainable product development. Wood plastic composites (WPCs) are an ideal combination of these raw materials, which can be produced with standard plastic technology such as extrusion or injection moulding. Wood to plastic ratio in a WPC influences quality and price, thus adaptation of analytical tools for material testing and quality assurance is required. In this study, the suitability of analytical pyrolysis (Py) and differential scanning calorimetry (DSC) was investigated to quantify the amount of polypropylene (PP) in WPCs. The reliability of these methods was tested by analysing WPCs with different ratios of wood and PP. The amount of PP can be determined with DSC based on its melting point as the influence of wood is negligible in this context. The increment of typical PP markers and decrement of wood markers was observed and quantified in the pyrograms if the PP content in WPCs was elevated. Thus, the ratio of PP and wood can be reliably quantified by means of online and offline analytical pyrolysis.

Wood/plastic ratio: Effect on performance of borate biocides against a brown rot fungus

The effect of wood/plastic ratio and the presence of a boron compound on resistance to biodegradation of wood plastic composites (WPC's) by the brown rot fungus Gloeophyllum trabeum was investigated in a soil block exposure. Weight losses of all WPC's were generally lower than those of solid wood, even when only the wood component of the WPC was used in calculating weight loss. Higher wood content was associated with greater weight losses, suggesting that the plastic encapsulated wood at lower wood levels. Borates markedly reduced weight losses at all wood/plastic ratios. Weight losses tended to be slightly lower with a Na/Ca borate than with similar levels of zinc borate. Mechanical properties did not correlate well with weight losses under the conditions evaluated, but these effects may have been masked by moisture sorption. The causes and implications of these differences are discussed.