Chunyuan Ma

A microwave reactor for characterization of pyrolyzed biomass

A microwave reactor (MWR) was designed to investigate microwave-induced pyrolysis of biomass. Condensation of tars on the quartz reactor and the pipelines was prevented by an electric heating device, and a temperature control function allowed determination of product characteristics at constant temperatures. Temperature had an important influence on microwave pyrolysis; the yields of gas products increased from 17.69 wt.% to 22.27 wt.% and the ratio of combustible gas to total gas products increased from 67.21 vol.% to 77.14 vol.% as the temperature increased from 400 °C to 600 °C. A large number of volatiles was released as temperature increased, resulting in an increase in the number of pores of the coke and a uniform pore structure was obtained. The specific surface area of coke increased from 0.89 m(2)/g (400 °C) to 9.81m(2)/g (600 °C) and the pore volume increased from 0.006 cm(3)/g (400 °C) to 0.012 cm(3)/g (600 °C), but the average pore size decreased from 282.16 nm (400 °C) to 46.64 nm (600 °C).

Microwave pyrolysis of wheat straw: Product distribution and generation mechanism

Microwave pyrolysis of wheat straw is studied, combined with analysis of products, the distribution and generation pathway of products are investigated. Only a small amount of volatiles released when microwave pyrolysis of pure straw. Mixtures of adding CuO and Fe3O4 can pyrolyze, and the majority in pyrolysis products is in liquid-phase. Severe pyrolysis occur after adding carbon residue, the CO content in pyrolysis gas products is high, and the maximum volume content of H2 can exceed 35 vol.%. The high-temperature is helpful for increasing the yield of combustible gas in gaseous products, in particular the H2 production, but also helpful for improving the conversion of sample. Pyrolysis is carried out layer by layer from the inside to outside. As the internal material firstly pyrolyze and pyrolysis products released pass through the low temperature zone, the chance of occurrence of secondary reactions is reduced.

Research on the impact assessment of urbanization on air environment with urban environmental entropy model: a case study

A new concept of urban environmental entropy was introduced to investigate the effect of urbanization on air environment considering the fact that rapid development of urbanization may have negative influence on the whole air environment system. The urban environmental entropies which were built based on the generalized thermodynamic entropy and the generalized statistic entropy, respectively. These two entropy models have been used to analyze the relationship between the development of urbanization and air environment. The negative entropy flow mechanism was proposed to reveal the advantages and approaches of regional cities in improving air environment system. A case study on 17 cities in Shandong Province of China showed that the values of urban environmental entropy were negative in most cities from 2001 to 2008, which implies that there is a positive correlation between the development of urbanization and air environment and that is a negative entropy development level in Shandong Province of China. In 2008, the urbanization of Qingdao city and Jinan city improved their air environments. Moreover, restraints for both cities in air environment improvement were recognized according to the analysis of negative entropy flow mechanism.

Study of the Transference Rules for Bromine in Waste Printed Circuit Boards during Microwave-Induced Pyrolysis

ABSTRACT The production of waste printed circuit boards (WPCBs) has drawn increasing global concern, especially because the high bromine (Br) content (5–15%) places obstacles in the way of simple disposal techniques. Microwave-induced pyrolysis of WPCBs provides a promising way to dispose of these hazardous and resource-filled wastes. The transference rules for Br during microwave-induced pyrolysis have been investigated experimentally. It was found that the microwave energy could be used more efficiently to accelerate the heating rate and improve the final pyrolysis temperature by adding some activated carbon (AC) as microwave absorbents. The high temperature and rapid pyrolysis process promoted the yields of gaseous products and the decomposition of brominated compounds into hydrogen bromide and then benefited the capture of Br and the debromination of byproducts. The application of a calcium carbonate (CaCO3) layer overhead led to over 95% debromination of the liquid products and over 50% capture of the total Br. It can be concluded that the presented method is suitable for the control of Br transference in the recycling of WPCBs. This method can also be extended to the disposal of the electronic scraps. IMPLICATIONS Development of environmentally sound treatments for the comprehensive recycling of WPCBs and even waste electrical and electronic equipment (WEEE) is a hot issue all over the world. New ideas and technologies will be continuously developed. The idea of recycling WPCBs by microwave-induced pyrolysis coupled with the debrominating of pyrolysis products by a CaCO3 layer is just a novel one. It has great potential for industrial practice and its implementation will enrich the choices for WEEE recycling.

Research on interactive coupling mechanism and regularity between urbanization and atmospheric environment: a case study in Shandong Province, China

In the logarithmic curves of the per capita GDP and the urbanization, with the traditional environmental Kuznets equation, this paper presented a coupling equation showing the relationship between urbanization and the atmospheric environment. Based on the “double exponential” coupling curve, the principles of flattening, advancing and fast-falling that new coupling curve should be followed were discussed. According to the two indicators of environmental assessment, namely the treatment cost and the deterioration degree of the environment, a new dual four times matrix model with the corresponding countermeasures and environment policy were introduced. Taking Shandong Province as an example, the coupling relationship between urbanization and atmospheric environment was investigated. The coupling curve showed that it was in running-in stage, and atmospheric quality tended to be improved. SO2 curve fluctuated more significantly compared with soot and industrial dust curves. The matrix model shows that the combination of flattening principle and advancing principle is preferable for SO2 emissions, but the fast-falling principle is recommended for soot and industrial dust emissions.

Eco-industry and sustainability for the coal industry – a case study from YZCMG, China

With the rapid growth of its economy in the past two decades, China is facing a serious energy shortage. Energy consumption of China is currently based on coal, but intensive exploitation of coal resources is accompanied by serious threats to the environment. In order to balance economic development, environmental protection, and natural resource conservation, there is an opportunity for development of eco-industry in the coal industry. This paper examines a case study of Yanzou Coal Mining Group (YZCMG), which can be viewed as a typical mining enterprise in China. The aim is to identify the benefits of developing an eco-industry in the coal industry. The significant reduction of environmental pollutants, economic benefits from recycling and reuse of wastes, and increased energy efficiency, together with reduced consumption of natural resources (mainly coal and water), reveal that development of an eco-industry within YZCMG is a promising option. This is also an opportunity for the coal industry to contribute to more sustainable development.

Energy consumption analysis of a supercritical water oxidation pilot plant with a transpiring wall reactor based on energy recovery

AbstractSupercritical water oxidation (SCWO) is a new and promising technology for treating organic waste and recovering energy. High energy consumption is a major problem preventing its commercial application. Energy recovery is the most effective method for reducing energy consumption of an SCWO system. To maximize the energy recovery of the SCWO pilot plant with a transpiring wall reactor, the reactor effluent is used to preheat both feed and transpiring water and produce hot water. An experimental study was conducted to investigate the influence of the operating parameters on energy consumption per unit total organic carbon (TOC) removal (ECPT) for saving the energy of the system. Results show that the effect of feed concentration on ECPT is the most significant and that of high feed concentrations, result in lower ECPT. Lower ECPT is also present at high feed flow rates, but at the expense of the decrease of TOC removal efficiency when the feed flow rate exceeds 14u2009kg/h.

An Exploratory Study of Electronic Waste Treatment: Microwave-induced Pyrolysis

The disposal of waste electrical and electronic equipment (WEEE) or electronic waste is an important issue all over the world. Routine treatment methods were discussed here. However, environmental risks were seldom considered fully by routine methods. Microwave-induced pyrolysis, which is collaboration of microwave heating and tip discharge, was proposed as a novel way to dispose of WEEE. Due to the rapid heating by microwave irradiation, dioxins and furans could be avoided effectively. After pyrolysis, the gas and liquid products could be recovered as fuel gas and chemical feedstock respectively, the abundant metals, such as Fe, Cu, etc., would be more convenient to be separated and recovered from the solid products. Thus, by means of microwave-induced pyrolysis, it is potential to realize metals recycle, products reuse as well as pollution avoidance.

Research on Energy Demand Forecast with LEAP Model Based on Scenario Analysis - A Case Study of Shandong Province

Economy has kept in fast increasing in the past decade in Shandong Province. The boosted economy is companied with the rocked up of energy consumption. Energy shortage is becoming the significant limiting factor for further economic development of Shandong. Combined with the trend of economic development, current situation of energy consumption, progress in industrial restructuring and other related factors, the energy demand of 2010, 2015 and 2020 is forecasted with LEAP model. The result shows that the increasing rate of energy consumption and energy utilization intensity is very high. Economic development will still dependent on the increase of energy consumption heavily in the future. In order to realize sustainable development, Shandong has to achieve a better technological progress, optimized industrial structure and improved energy efficiency.

A continuous microwave/nZVI treatment system for malachite green removal: system setup and parameter optimization

AbstractA continuous microwave/nZVI treatment system was built for the removal of malachite green (MG). Using the system, MG was efficiently degraded in a short hydraulic retention time. Operational parameters, including flow rate of influent, aeration method, microwave power (MP), and pH of MG solution, were optimized. The results indicate that the removal efficiency of MG increased significantly following the decrease in influent flow rate (Qi). At Qixa0=xa04xa0mL/min, the highest removal efficiency of MG reaches 98.5%, while the highest load of MG degradation per gram of nZVI was 74.3xa0mg/g at Qixa0=xa016xa0mL/min. Increasing the MP could slightly increase MG and TOC removal efficiency. And analysis of system shock resistance indicated the use of this system stabilized effluent quality. It was further concluded that MG removal efficiency could benefit from pre-acidification processes to reach the pH range from 5.0 to 7.0 and pre-aeration prior to using the system. The dominant gas product and the residual detected ...