Experiment Research on Gasification Character of Pulve-rized Coal at Medium Temperature

In this paper, effect of gasification temperature and residence time on gasification characteristics of typical pulverized coals under atmosphere pressure were studied on a one-dimensional electric heating drop tube furnace system to evaluate gasification characteristics of pulverized coal at medium temperature. The results show that the gasification rate increases with the raising of the gasification temperature under the temperature among 1150℃and1450℃, and as the temperature is above1350℃, the increasing rate become slower. Cold gas efficiency?and?carbon conversion meet the maximum value when the temperature approaches the ash fusion point of coal. With the further rise of the temperature, ash on the surface of the char starts to be melted,?the gasification reaction rate decreases, due to the hindrance of the effective contact between coal char and gasification agent. The gasification efficiency would become steady when the residence time exceeds 8s.

Research on coal staged conversion poly-generation system based on fluidized bed

A new coal staged conversion poly-generation system combined coal combustion and pyrolysis has been developed for clean and high efficient utilization of coal.Coal is the first pyrolysed in a fluidized pyrolyzer.The pyrolysis gas is then purified and used for chemical product or liquid fuel production.Tar is collected during purification and can be processed to extract high value product and to make liquid fuels by hydro-refining.Semi-coke from the pyrolysis reactor is burned in a circulating fluidized bed(CFB)combustor for heat or power generation.The system can realize coal multiproduct generation and has a great potential to increase coal utilization value.A 1 MW poly-generation system pilot plant and a 12 MW CFB gas,tar,heat and power poly-generation system was erected.The experimental study focused on the two fluidized bed operation and characterization of gas,tar and char yields and compositions.The results showed that the system could operate stable,and produce about 0.12 m^(3)/kg gas with 22 MJ/m^(3)heating value and about 10 wt%tar when using Huainan bituminous coal under pyrolysis temperature between 500 and 600℃.The produced gases were mainly H_(2),CH_(4),CO,CO_(2),C_(2)H_(4),C_(2)H_(6),C_(3)H_(6)and C_(3)H_(8).The CFB combustor can burn semi-coke steadily.The application prospect of the new system was discussed.

Three Stage Equilibrium Model for Coal Gasification in Entrained Flow Gasifiers Based on Aspen Plus

A three stage equilibrium model is developed for coal gasification in the Texaco type coal gasifiersbased on Aspen Plus to calculate the composition of product gas, carbon conversion, and gasification teml^erature. The model is divided into three stages including pyrolysis and combustion stage, char gas reaction stage, and gas p.hase reaction stage. Part of the water produced in thepyrolysis and combust!on stag.e is assumed to be involved inthe second stage to react with the unburned carbon. Carbon conversion is then estimated in the second stage by steam participation ratio expressed as a function of temperature. And the gas product compositions are calculated from gas phase reactions in the third stage. The simulation results are consistent with published experimental data.

Geological conditions of coal and gas(oil)-bearingbasins in China

There are various types of coal basins in China. Indosinian movement can be re- garded as their evolutionary limit, and the basins can be divided into two developmental stages, three structural patterns and two sedimentary environments. However, only those coal measure strata that have been deeply buried in the earth are possible to be converted into coal and gas (oil)-bearing basins. Among which, only part of the coal measures possess the essential geo- logical conditions to the formation of commercial humic oil. However, humic gas will be the major exploration target for natural gas in China. Among various coal basins, foreland basins have the best prospect for humic gas. Rift (faulted) basins accumulate the most abundance of humic gas, and are most favorable to generate humic oil. Craton basins have relatively low abundance of humic gas, but the evolution is rather great. The three kinds of coal basins mentioned above constitute China’s three primary accumulation areas of humic gas: western, central and offshore areas. The major basins for humic gas field exploration include Tarim, Ordos, Sichuan, East China Sea and Yingqiong basins.

洁净型煤NO_(x)生成特性与排放规律实验研究

为了研究民用洁净型煤中NO_(x)生成特性与排放规律,通过管式炉燃烧实验装置研究了燃烧温度、燃烧氛围、氧浓度、一次风比例、模拟烟气再循环和半焦掺混比例等因素对于洁净型煤NO_(x)排放的影响。结果表明:在900~1200℃范围内,NO_(x)随着燃烧温度升高而呈线性趋势下降;在O_(2)/N_(2)和O_(2)/CO_(2)气氛下,氮转化率总体上均随着氧气浓度增加而下降,随着一次风比例的增加,NO_(x)生成量整体呈上升趋势;采用烟气再循环方式有利于降低氮转化率,但只有烟气再循环比例较大时,NO_(x)才有明显下降;在600℃、800℃、1000℃三种温度下制备半焦,当制焦温度为600℃时,半焦与型煤掺混后NO_(x)排放量最低,并且氮转化率随着半焦比例的增加而下降。

Sensitivity analysis of a methanol and power polygeneration system fueled with coke oven gas and coal gas

The sensitivity analysis of a polygeneration energy system fueled with duo fuel of coke oven gas and coal gas is performed in the study,and the focus is put on the relations among syngas composition,conversation rate and performance.The impacts of the system configuration together with the fuel composition on the performance are investigated and discussed from the point of cascading utilization of fuel chemical energy.First,the main parameters affecting the performance are derived along with the analysis of the system configuration and the syngas composition.After the performance is being simulated by means of the Aspen Plus process simulator of version 11.1,the variation of the performance due to the composition of syngas and the conversion rate of chemical subsystem is obtained and discussed.It is obtained from the result that the proper conversion rate of the chemical subsystem according to the specific syngas composition results in better performance.And the syngas composition affects the optimal conversion rate of the chemical subsystem,the optimal point of which is around the stoichiometric composition for methanol production(CO/H_(2)=0.5).In all,the polygeneration system fueled with coke oven gas and coal gas,which can realize the reasonable conversion of syngas to power and chemical product according to the syngas composition,is a promising method for coal energy conversion and utilization.

京津冀天然气替代民用煤环境影响模拟分析

针对京津冀地区雾霾频发的现状,梳理京津冀地区空气质量与燃煤消费量的关系,分析民用煤被天然气替代对大气空气质量改善的积极作用。为了量化这种作用,选取型煤、烟煤两种常用的民用煤排放因子及天然气供暖热水炉排放因子,计算天然气替代民用煤带来的污染物减排量。为了更直观地反映这些减排量对北京市环境的改善效果,根据气象资料,运用Models-3/CMAQ模型,结合SMOKE源排放模型及WRF气象模型等组成空气质量模式系统模型,对污染物减排量所带来的减排效果进行模拟预测。结果表明:2020年民用煤全部煤改气后北京市的PM 2. 5年日均质量浓度下降约28μg/m^3,下降幅度约39%,天然气的发展对环境改善的效果非常明显。