共查询到20条相似文献,搜索用时 421 毫秒
1.
Tae-Jin Kang HyeJung Park Hueon Namkung Li-Hua Xu Jung-Hyun Park Iljeong Heo Tae-Sun Chang Beom Sik Kim Hyung-Taek Kim 《Korean Journal of Chemical Engineering》2017,34(10):2597-2609
Various techniques have been developed to increase the efficiency of coal gasification. The use of a catalyst in the catalytic-steam gasification process lowers the activation energy required for the coal gasification reaction. Catalytic-steam gasification uses steam rather than oxygen as the oxidant and can lead to an increased H2/CO ratio. The purpose of this study was to evaluate the composition of syngas produced under various reaction conditions and the effects of these conditions on the catalyst performance in the gasification reaction. Simultaneous evaluation of the kinetic parameters was undertaken through a lab-scale experiment using Indonesian low rank coals and a bench-scale catalytic-steam gasifier design. The composition of the syngas and the reaction characteristics obtained in the lab- and bench-scale experiments employing the catalytic gasification reactor were compared. The optimal conditions for syngas production were empirically derived using lab-scale catalytic-steam gasification. Scale-up of a bench-scale catalytic-steam gasifier was based on the lab-scale results based on the similarities between the two systems. The results indicated that when the catalytic-steam gasification reaction was optimized by applying the K2CO3 catalyst to low rank coal, a higher hydrogen yield could be produced compared to the conventional gasification process, even at low temperature. 相似文献
2.
We have developed a process model to simulate the behavior of an industrial-scale pressurized Lurgi fixed-bed coal gasifier using Aspen Plus and General Algebraic Modeling System (GAMS). Reaction characteristics in the fixed-bed gasifier comprising four sequential reaction zones-drying, pyrolysis, combustion and gasification are respectively modeled. A non-linear programming (NLP) model is developed for the pyrolysis zone to estimate the products composition which includes char, coal gases and distillable liquids. A four-stage model with restricted equilibrium temperature is used to study the thermodynamic equilibrium characteristics and calculate the composi-tion of syngas in the combustion and gasification zones. The thermodynamic analysis shows that the exergetic effi-ciency of the fixed-bed gasifier is mainly determined by the oxygen/coal ratio. The exergetic efficiency of the proc-ess will reach an optimum value of 78.3%when the oxygen/coal and steam/coal mass ratios are 0.14 and 0.80, re-spectively. 相似文献
3.
针对w(水焦浆)和氧焦比预测优化过程未采用严格反应机理模型,工艺参数的预测优化与实际生产存在较大偏差的情况,以UniSim Design流程模拟软件为工具,采用Gasifier反应器严格机理模型建立了1.5 MPa多喷嘴对置式水焦浆气化炉模型,并根据工业数据对水焦浆气化炉进行标定,标定结果相对误差小于2%,同时研究了氧焦比和w(水焦浆)对焦煤气化工艺参数的影响。结果表明:w(水焦浆)和氧焦比是影响水焦浆气化过程和粗煤气组成的关键因素,通过气化炉模型标定和优化分析,石油焦的氧焦比控制范围为0.95~1.10,为焦煤浆气化工艺生产实践指导提供了理论依据。 相似文献
4.
5.
6.
7.
采用Aspen Plus流程模拟软件模拟了水煤浆水冷壁废锅气化过程,并将模拟结果与工业运行数据对比,验证了模型准确性。在此基础上,分析了气化压力和水煤浆浓度对气化温度、有效气产量、合成气组成、氧煤比、比氧耗和比煤耗等气化参数的影响。结果表明,气化压力对气化过程基本没有影响,可根据需要选择适宜压力;当保持氧气流量恒定时,随水煤浆浓度增大,有效气含量增加,气化温度升高,即提高水煤浆浓度易导致气化炉飞温,因此进一步研究了在前述模拟条件不变,且保持气化温度恒定时,水煤浆浓度变化对气化参数的影响。结果表明,随水煤浆浓度增大,氧煤比降低,有效气含量增加,比氧耗、比煤耗降低,因此在气化炉不超温的情况下,应尽量提高水煤浆的浓度,以降低系统能耗。 相似文献
8.
串行流化床煤气化试验 总被引:3,自引:3,他引:0
针对串行流化床煤气化技术特点,以水蒸气为气化剂,在串行流化床试验装置上进行煤气化特性的试验研究,考察了气化反应器温度、蒸汽煤比对煤气组成、热值、冷煤气效率和碳转化率的影响。结果表明,燃烧反应器内燃烧烟气不会串混至气化反应器,该煤气化技术能够稳定连续地从气化反应器获得不含N2的高品质合成气。随着气化反应器温度的升高、蒸汽煤比的增加,煤气热值和冷煤气效率均会提高,但对碳转化率影响有所不同。在试验阶段获得的最高煤气热值为6.9 MJ8226;m-3,冷煤气效率为68%,碳转化率为92%。 相似文献
9.
SeIk Park JoongWon LeeHeaKyung Seo GwangSin KimKi-Tae Kim 《Fuel Processing Technology》2011,92(7):1374-1379
The IGCC (Integrated gasification combined cycle) is known as one of the coal fueled power generating technologies with the highest efficiency and lowest emissions. To achieve the required higher efficiency and lower emission performance, Korea's 300 MW IGCC RDD&D (Research Development, Demonstration and Dissemination) project was launched in December 2006 under the leadership of the Korea Electric Power Corporation (KEPCO), with the support of the Korea Ministry of Knowledge Economy. Our research group, the KEPCO Research Institute, set up a coal gasifier for the pilot test and conducted many experiments for the parametric study in this project.Our group focused its research on the effect of different types of coal and oxygen supply angles on the optimum O2/coal ratio for gasification. Through this study we found that using higher oxygen content coal reduced the optimum O2/coal ratio for gasification. However, there was no apparent relationship between the oxygen supply angle and the optimum O2/coal ratio. And, two types of coal burners having different oxygen supply angles were used to conduct the feasibility study on a variable angle burner for the coal gasifier. 相似文献
10.
运用Gibbs自由能最小化方法模拟气流床煤气化炉 总被引:23,自引:0,他引:23
基于 Aspen Plus工业系统流程模拟软件 ,运用 Gibbs自由能最小化方法建立了气流床煤气化炉的模型 .研究了气化炉的主要操作参数 (即水煤浆浓度、氧煤比、碳转化率和气化温度 )对气化结果的影响 .对模拟结果进行了分析 ,发现模型基本正确 ,可应用于一些反应机理复杂的气化工艺的化学和热力学平衡计算 .模拟结果表明 ,氧煤比和水煤浆浓度是影响气化炉出口煤气组成的主要因素 ,气化炉温度随着氧煤比的增加而增加 ,也随着水煤浆浓度的增加而增加 .结果还表明 ,氧煤比对气化结果的影响比水煤浆浓度的影响更为显著 相似文献
11.
Cheol-Oong Kim Ryang-Gyoon Kim Zelin Wu Chung-Hwan Jeon 《Korean Journal of Chemical Engineering》2016,33(6):1767-1776
A mathematical model is developed to simulate a pilot Shell entrained-flow coal gasifier. Submodels of specific structures of the gasifier are established to simulate the complicated gasification process. The model includes the total energy conservation equation and mass conservation equations for the gas components, solid flow, and gas flow. It simulates the influence of the gasifier structure and dimensions and can calculate the effects of changing almost every important operation parameter, e.g., the syngas composition, gasification temperature, carbon conversion ratio, walllayer temperature, and slag mass flow rate. The model can predict the syngas composition under a limited residence time condition. Furthermore, it considers the heat transfer coefficient of each layer of the water wall to calculate its heat loss and temperature. Thus, the model also reflects the influence of performance parameters of the gasifier’s water wall. The slag mass flow rate on the wall is calculated using a slag submodel. 相似文献
12.
Yongseung Yun Seung Jong Lee Jin-Pyo Hong 《Korean Journal of Chemical Engineering》2011,28(5):1188-1195
A one-stage coal gasifier was modified to accommodate the two stages of coal feeding. Operating characteristics were compared
between the one-stage and two-stage gasification in terms of syngas composition, carbon conversion, shape and inner structure
of produced slags, characteristics of particle size distribution in entrained fines, and effects on particulate removal facilities.
Temperature at the second stage of the gasifier resulted in lower values, which confirms the performance of the second stage
as a reduction area by endothermic reactions. The results suggest that the 10–20% increase in coal feeding to the second stage
might not cause much loss in carbon conversion. Produced slag and the performance of metal filters and water scrubber were
similar with the earlier results from one-stage gasification tests. The two-stage gasification appears to help in increasing
the cold gas efficiency for the certain operating range. Two-stage gasification had an impact on the 0.1–1 μm size of entrained
fines, which appear to be cenospheres that occur during the rapid quenching in temperature. 相似文献
13.
Hyun-Min Shim Su-Yong Jung Hong Yue Wang Hyung-Taek Kim 《Korean Journal of Chemical Engineering》2009,26(2):324-331
Gasification technology, which converts fossil fuels into either combustible gas or synthesis gas (syngas) for subsequent
utilization, offers the potential of both clean power and chemicals. Especially, IGCC is recognized as next power generation
technology which can replace conventional coal power plants in the near future. It produces not only power but also chemical
energy sources such as H2, DME and other chemicals with simultaneous reduction of CO2. This study is focused on the determination of operating conditions for a 300 MW scale IGCC plant with various feedstocks
through ASPEN plus simulator. The input materials of gasification are chosen as 4 representative cases of pulverized dry coal
(Illinois#6), coal water slurry, bunker-C and naphtha. The gasifier model reflects on the reactivity among the components
of syngas in the gasification process through the comparison of syngas composition from a real gasifier. For evaluating the
performance of a gasification plant from developed models, simulation results were compared with a real commercial plant through
approximation of relative error between real operating data and simulation results. The results were then checked for operating
characteristics of each unit process such as gasification, ash removal, acid gas (CO2, H2S) removal and power islands. To evaluate the performance of the developed model, evaluated parameters are chosen as cold
gas efficiency and carbon conversion for the gasifier, power output and efficiency of combined cycle. According to simulation
results, pulverized dry coal which has 40.93% of plant net efficiency has relatively superiority over the other cases such
as 33.45% of coal water slurry, 35.43% of bunker-C and 30.81% of naphtha for generating power in the range of equivalent 300
MW. 相似文献
14.
《Fuel Processing Technology》2001,69(1):29-44
The gasification of two different coals and chars with CO2 and CO2/O2 mixture in a 48-mm-i.d. circulating fluidized bed (CFB) gasifier is investigated. The effects of operation condition on gas composition, carbon conversion and gasification efficiency were studied. A simple CFB coal gasification district mathematical model has been set up. The effects of coal type and CFB operating conditions on CFB coal gasification are discussed based on the CFB gasification test and model simulation. The main operation parameters in CFB gasification system are coal type, gas superficial velocity, circulating rate of solids and reaction temperature. It is found that CO concentration and carbon conversion increase with increasing solids circulating rate and decreasing gas velocity due to the increase in gas residence time and solids holdup in the CFB. The carbon conversion increases with increasing temperature and O2 concentration in the inlet gas. The experimental results prove that the CFB gasifier works well for high volatile, high reactivity coal. 相似文献
15.
Duan Feng Bao-Sheng Jin Ya-Ji Huang Bin Li Yu Sun Yiming Wu Ming-Yao Zhang 《Korean Journal of Chemical Engineering》2010,27(6):1707-1714
High temperature preheated air and steam as gasifying agent and coal gasification was performed in a pressurized turbulent
circulating fluidized bed (CFB) gasification pilot plant to investigate the pressurized gasification process and estimate
its potential. Within the scope of this paper this test facility as well as its operation behavior was described. Furthermore,
the parameter pressure has been investigated regarding its influence on the syngas composition and was presented and discussed
in the following. The results show that the gasification quality is improved at higher pressure because of the better fluidization
in the reactor. Coal gasification at a higher pressure shows advantages in lower heat value and carbon conversion. With the
gasifier pressure increased from 0.1MPa to 0.3MPa, the gas heating value is increased by 15%. Increasing the gasifier pressure
would increase the carbon conversion from 57.52% to 76.76%. Also, the dry gas yield and efficiency of cold gas increase little
with the increase of the gasifier pressure. The operating parameter of pressure exists at optimum operating range for this
specific CFB coal gasification process. 相似文献
16.
Hai-Kyung Seo Seik Park Joogwon Lee Miyung Kim Seok-Woo Chung Jae-Hwa Chung Kitae Kim 《Korean Journal of Chemical Engineering》2011,28(9):1851-1858
The effects of operating factors on a gasification system were reviewed by comparing a computational simulation and real operation results. Notable operation conditions include a conveying gas/coal ratio of 0.44, an oxygen/coal ratio of 0.715, a reaction temperature of 1,000 °C, and reaction pressure of 5bar in the case of Adaro coal; based on this, the cold gas efficiency was estimated as 82.19%. At the point of the reaction temperature effect, because the cold gas efficiencies are more than 80% when the reaction temperatures are higher than 900 °C, the gasifier inner temperature must remain over 900 °C. At high reaction temperature such as 1,400 °C, the reaction pressure shows little effect on the cold gas efficiency. The addition of steam into the gasifier causes an endothermic reaction, and then lowers the gasifier outlet temperature. This is regarded as a positive effect that can reduce the capacity of the syngas cooler located immediately after the gasifier. The most significant factor influencing the cold gas efficiency and the gasifier outlet temperature is the O2/coal ratio. As the O2/coal ratio is lower, the cold gas efficiency is improved, as long as the gasifier inner temperature remains over 1,000 °C. With respect to the calorific value (based on the lower heating value, LHV) of produced gas per unit volume, as the N2/coal ratio is increased, the calorific value per syngas unit volume is lowered. Decreasing the amount of nitrogen for transporting coal is thus a useful route to obtain higher calorific syngas. This phenomenon was also confirmed by the operation results. 相似文献
17.
灰熔聚流化床粉煤气化技术加压大型化研发新进展 总被引:2,自引:0,他引:2
灰熔聚流化床粉煤气化技术历经20余年的研发和工程化放大,低压气化技术已日趋成熟,并用于氮肥企业原料气改造和新建甲醇合成厂。该气化技术可使用不同灰含量和灰熔融性温度的煤,过程效率也较高,符合我国资源特点。为此在山西省发展和改革委员会的支持下,中科院山西煤化所和山西晋煤集团合作成立的“山西省粉煤气化工程研究中心”正在建设3.0MPa加压灰熔聚流化床粉煤气化中试平台,2006年年底已建成,预计于2007年3月进行加压气化试验,2007年完成加压灰熔聚流化床煤气化工业装置设计软件包的编制,形成具有我国自主知识产权、适应中国煤炭特点的大规模加压灰熔聚流化床粉煤气化技术。本文介绍了灰熔聚流化床粉煤气化过程,指出它的优点、缺点、适用范围、技术现状和发展方向,并对加压灰熔聚气化中试技术进行了简介。 相似文献
18.
《Fuel》2006,85(12-13):1935-1943
This paper presents modeling of a coal gasification reaction, and prediction of gasification performance for an entrained flow coal gasifier. The purposes of this study are to develop an evaluation technique for design and performance optimization of coal gasifiers using a numerical simulation technique, and to confirm the validity of the model. The coal gasification model suggested in this paper is composed of a pyrolysis model, char gasification model, and gas phase reaction model. A numerical simulation with the coal gasification model is performed on the CRIEPI 2 tons/day (T/D) research scale coal gasifier. Influence of the air ratio on gasification performance, such as a per pass carbon conversion efficiency, amount of product char, a heating value of the product gas, and cold gas efficiency is presented with regard to the 2 T/D gasifier. Gas temperature distribution and product gas composition are also presented. A comparison between the calculation and experimental data shows that most features of the gasification performance were identified accurately by the numerical simulation, confirming the validity of the current model. 相似文献
19.
壳牌煤气化工艺流程中合成气反吹系统方案改造的探讨 总被引:1,自引:0,他引:1
针对壳牌煤气化工艺流程中的合成气反吹系统进行方案改造,反吹介质可由洗涤后的粗合成气改为高温高压氮气。改造后,出气化装置的合成气组份可以满足下游装置的工艺要求,同时又可以节省大量的工程投资。从工艺技术和经济技术两方面考虑,此改造方案切实可行。 相似文献