煤炭地下气化炉联合气化技术研究

针对中国煤炭地下气化炉形式单一、产量较低的现状,介绍了地下气化炉联合布置的各种形式,为地下气化规模化和产业化提出了一条新的思路。

水煤浆气化技术关键参数的选择探讨

根据近年国内多个煤化工企业水煤浆气化的实际数据,对影响水煤浆气化效益的关键参数进行了技术选择分析。分析结果表明:气化规模的选择应与气化炉型相匹配,单炉日投煤量大于1 000 t时,应主要选择多喷嘴对置式气化炉;有效气含量是非常重要的经济技术指标,将有效气体积分数提高2%,可以使生产能力60万t/a的甲醇厂因增产获得经济效益2 550万元;煤浆浓度直接决定了气化炉有效气含量,若将60万t/a甲醇厂的水煤浆质量分数从60%提高到67%,可多生产甲醇4万t,能带来6 800万元的经济效益。因此,水煤浆浓度越高越好,但目前的制浆工艺还不能大幅提高水煤浆浓度。废锅流程是今后水煤浆气化发展的重点,废锅节能节水是一项很有发展前景的技术路线,特别适合西部缺水地区。

Quantitative Simulation of Dynamic Changes in Cultivated Land in Areas of Reclamation and Returning Cultivated Land to Forest or Pastures under RCPs Climate Scenarios

Northeast China as one of important agricultural production bases is an area under reclamation and returning cultivated land to forests or pastures. Therefore, it is of great practical significance in guaranteeing the sustainable development and national food security to study the spatial and temporal variation of cultivated land in Northeast China under future climate scenarios. In this study, based on data of land use, natural environment and social-economy, dynamics of land system（DLS） model was used to to simulate the spatial distribution and changing trends of cultivated land in the typical areas of reclamation and returning cultivated land to forest or pastures in Northeast China during 2010-2030 under land use planning scenario and representative concentration pathways（RCPs） scenarios quantitatively.The results showed that the area of cultivated land had an overall decreasing trend under the land use planning scenario, but the area of upland field increased slightly from 2000 to 2010 and then declined greatly, while the area of paddy field continuously declined from 2000 to 2030. Under the Asia-Pacific Integrated model（AIM）scenario, the total area of cultivated land had a tendency to increase considerably,with the upland field expanding more obviously and the paddy field declining slightly.In addition, the cultivated land showed a greater decreasing trend under the model for energy supply strategy alternatives and their general environmental impact（MESSAGE） scenario compared to the land use planning scenario. Moreover, analysis on the conversion between different land use types indicated that the reclamation and returning cultivated land to forests or pastures was likely to continue under future scenarios, but the frequency of occurrence could decrease as the time goes by. The conclusions can provide significant decision-making information for the rational agricultural planning and cultivated land protection in Northeast China to adapt to the climate change.

Design and Development of a Laboratory Scale Biomass Gasifier

A laboratory scale downdraft biomass gasifier was designed to deliver a mechanical power of 4 kW and thermal power of about 15 kW. The gasifier was manufactured as a single piece having a water seal and cover. The gasifier was tested in natural downdraft and forced downdraft mode. Ignition of the fuel beneath the grate, during natural downdraft mode, using wood shavings as fuel, produced gas which burned with a blue flame for 15 minutes. Ignition at the throat, using either palm kernel shells or wood shavings, during the natural downdraft mode, the gasifier did not produce syngas. During the forced downdraft mode, fuel was ignited at the throat. Gasification was successful with the palm kernel shells, during forced downdraft, which produced gas which burned steadily with luminous flame for 15 minutes per kilogram of biomass fed. However, wood shavings experienced some bridging problems during the forced downdraft mode of operation. The fuel conversion rate of the gasifier, when using palm kernel shells as fuel in forced downdraft mode, was 4 kg/h. Forced downdraft mode of operation yielded better results and is the preferred operation of the gasifier.

Impact of Regional Development on Carbon Emission: Empirical Evidence Across Countries

Global warming is recently an urgent issue worldwide. The increase of carbon emissions induced by human economic activi- ties has become a major driving force behind global climate change. Thus, as a matter of social responsibility, reasonable carbon con- straints should be implemented to ensure environmental security and sustainable development for every country. Based on a summary of studies that examined the relationship between carbon emissions and regional development, this paper shows that human activity-led carbon emission is caused by the combination of several influencing factors, including population size, income level, and technical pro- gress. Thus, a quantitative model derived from IPAT-ImPACT-Kaya series and STIRPAT models was established. Empirical analysis using multivariate nonlinear regression demonstrated that the origins of growing global carbon emission included the increasing influ- encing elasticity of the population size and the declining negative effect of technical progress. Meanwhile, in context of classification of country groups at different income levels, according to the comparison of fluctuating patterns of the influencing elasticity, technical progress was found as the main factor influencing carbon emission levels in high-income countries, and population size might he the controlling factor in middle-income countries. However, for low-income countries, the nonlinear relationship between carbon emission and its influencing factors was not significant, whereas population growth was identified as an important potential driving force in future carbon emissions. This study can therefore provide a reference for the formulation of policies on carbon constraints, especially to de- velop more efficient carbon mitigating policies for countries at different income levels.

Simulation of hydrocarbons pyrolysis in a fast-mixing reactor

Currently, thermal decomposition of hydrocarbons for the production of basic petrochemicals(ethylene, propylene) is carried out in steam-cracking processes. Aside from the conventional method, under consideration are alternative ways purposed for process intensification. In the context of these activities, the method of hightemperature pyrolysis of hydrocarbons in a heat-carrier flow is studied, which differs from previous ones and is based on the ability of an ultra-short time of feedstock/heat-carrier mixing. This enables to study the pyrolysis process at high temperature(up to 1500 K) at the reactor inlet. A set of model experiments is conducted on the lab scale facility. Liquefied petroleum gas(LPG) and naphtha are used as a feedstock. The detailed data are obtained on temperature and product distributions within a wide range of the residence time. A theoretical model based on the detailed kinetics of the process is developed, too. The effect of governing parameters on the pyrolysis process is analyzed by the results of the simulation and experiments. In particular, the optimal temperature is detected which corresponds to the maximum ethylene yield. Product yields in our experiments are compared with the similar ones in the conventional pyrolysis method. In both cases(LPG and naphtha), ethylene selectivity in the fast-mixing reactor is substantially higher than in current technology.

The Shanghai Wuzheng Engineering Technology LimitedLiability Company in collaboration with China HuanqiuContracting and Engineering Corporation will providethe technology and project design to the commercial andengineering scale-up project for manufacture of ethyleneglycol （EG） from syngas launched by the Zhejiang RongshengHolding Group Company. Currently the projectdesign activity is being carried out successfully.

In this study, the heteroatom classes and molecular structures of nitrogen compounds in vacuum residue arecharacterized by the electrospray ionization （ESI） Fourier transform ion cyclotron resonance mass spectrometry （FT-ICRMS） combined with the Fourier transform infrared （FT-IR） spectroscopy. The results demonstrate that three basic nitrogencompounds, N1 （in which a molecule contains one nitrogen atom, similarly hereinafter）, N1O1 and N2, are identified bytheir positive-ion mass spectra, and three non-basic nitrogen compounds, N1, N1O1, and N1S1, are characterized by theirnegative-ion mass spectra. Among these nitrogen compounds, the N1 class species are the most predominant. Combinedwith the data of ESI FT-ICR MS and FT-IR, the basic N1 class species are likely alkyl quinolines, naphthenic quinolines,acridines, benzonacridines, while the abundant non-basic N1 class species are derivatives of benzocarbazole. In comparisonwith CGO, the N1 basic nitrogen compounds in VR exhibit a higher average degree of condensation and have much longeralkyl side chains.