E-Gas气化炉二段积灰原理及控制手段浅析

中海油惠州石化有限公司煤制氢装置为全国首套也是唯一的E-Gas气化装置,因其气化炉含灰合成气的上行流程和干法除灰工艺问题,二段极易积灰,导致合成气通道变小,影响装置长周期安全运行。现收集和总结装置近年来的数据,针对E-Gas气化炉运行二段积灰现象进行原理分析,从而加以控制,以达到装置“安稳长满优”运行的目标。

高石油焦比例进料在E-Gas气化炉上的应用

石油焦作为焦化装置的聚合产物,具有灰熔点高、重金属含量高、灰分低、热值高的特点。在国内气化装置上,无论GE还是四喷嘴气化炉,石油焦的掺混比例都不高,正常运行不超过50%。中海油惠州石化有限公司煤制氢的E-Gas气化炉使用石油焦和煤掺混,在石油焦比例高达80%的情况下,气化装置运行平稳,各项技术指标稳定,表明该装置对石油焦原料具有较强的适应性。

Effect of slag composition on corrosion resistance of high chromia refractory bricks for industrial entrained-flow gasifier

The slag composition corresponding to different coals varies significantly,which directly affects the operation of industrial entrained-flow gasifier and the service life of refractory bricks.In this study,the corrosion resistance of several typical coal slags for gasification on high chromia refractory bricks was comparatively investigated by static laboratory crucible tests and thermodynamic simulations.The results demonstrated that the corrosion degree of high chromia refractory bricks by different coal slags was high-Ca/Na slag>high-Fe slag>high-Si/Al slag.The surface structure of the refractory was relatively flat after corrosion by high-Si/Al slag,and the primary corrosion reaction was the partial dissolution of the matrix by the slag.High-Fe slag was prone to the precipitation of iron phases as well as the formation of(Mg,Fe)(Al,Cr)_(2)O_(4)composite spinel layer at the slag/refractory interface.The high-Ca/Na slag was susceptible to react with the refractory to yield a low melting point phase,which led to the destruction of the matrix structure of the refractory and an isolated distribution of particles.In addition,the monoclinic ZrO_(2) in the refractory reacted with CaO in the slag to formed calcium zirconate,which loosened its phase toughening effect,was the primary factor that aggravated the refractory corrosion.

Comparison of Combustion Characteristics of Tars Produced with Tobacco Stem Biomass Gasification

In order to study the combustion characteristics of tar in biomass gasifier inner wall and gasification gas,“tobacco stem semi-tar inside furnace”,“tobacco stem tar inside furnace”and“tobacco stem tar out-of-furnace”were subjected to thermogravimetric experiments,and the combustion characteristics and kinetic characteristics were analyzed.The result shows that“tobacco stem semi-tar inside furnace”has the highest value and“tobacco stem tar out-of-furnace”is has the lowest value on ignition characteristics,combustion characteristics and combustible stability;“tobacco stem semi-tar inside furnace”has the lowest value and“tobacco stem tar outside furnace”has the highest value on burnout characteristics;“tobacco stem tar outside furnace”has the highest value and“tobacco stem tar inside furnace”has the lowest value on integrated combustion characteristics.

基于虚拟仪器的E-Gas性能测试系统设计

针对传统仪器在电子节气门(E-Gas)性能测试中存在的不能自定义和灵活性差等不足,本文将虚拟仪器技术引入到E-Gas性能测试中,开发了基于虚拟仪器的E-Gas性能测试系统。本系统灵活地运用了PID控制策略和虚拟仪器开发软件,实现了E-Gas任意开度的高速控制和切换。实际的E-Gas产品测试证明,通过调节PID算法的参数,系统可以对不同的E-Gas产品完成开度全开时间参数、全闭时间参数、任意位置时间参数和冲击性能的测试,测试的时间精度可达0.1ms。系统运行稳定,使用方便。

CFD simulation on the gasification of asphalt water slurry in an entrained flow gasifier

Gasification technology is suggested to utilize asphalt particles, which are produced in the heavy oil deep separation process of using coupled low temperature separation of solvent and post extraction residue. In this work, the asphalt particles were first slurried with water and then gasified to produce synthesis gas. The gasification process of asphalt water slurry in an entrained flow gasifier was simulated using a three-dimensional computational fluid dynamics （CFD） model based on an Eulerian- Lagrangian method. The trajectories and residence time of asphalt particles, and the reaction rates, gas species distribution, temperature field and carbon conversion in the entrained flow gasifier were obtained. The predicted results indicated that the asphalt water slurry was a good feedstock for gasification. Moreover, the effects of particle size, oxygen equivalence ratio, and mass content of asphalt particles on the gasification performance of asphalt water slurry were investigated. These results are helpful for industrial application of asphalt water slurry gasification technology.

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.

Assessment of coal gasification in a pressurized fixed bed gasifier using an ASPEN plus and Euler–Euler model

With the help of Aspen Plus,a two-dimensional unsteady CFD model is developed to simulate the coal gasification process in a fixed bed gasifier.A developed and validated two dimensional CFD model for coal gasification has been used to predict and assess the viability of the syngas generation from coal gasification employing the updraft fixed bed gasifier.The process rate model and the sub-model of gas generation are determined.The particle size variation and char burning during gasification are also taken into account.In order to verify the model and increase the understanding of gasification characteristics,a set of experiments and numerical comparisons have been carried out.The simulated results in the bed are used to predict the composition of syngas and the conversion of carbon.The model proposed in this paper is a promising tool for simulating the coal gasification process in a fixed bed gasifier.

Numerical Simulation of Thermal Stress Field of Water-cooled-wall Pulverized-coal Gasifiers

A local thermal stress model of water-cooled-wall pulverized-coal gasifier was built, and ANSYS was used to simulate the stress field in the gasifier operation to research the damage of refractories and slag layer caused by the thermal stress. The results reveal that:（1） the maximum stress of water-cooled-wall gasifier appears at the interface between anchor nails and refractories as well as the interface between refractories and the slag layer, and the maximum stress of slag layer appears on the surface of the slag layer;（2） the increase of slag layer thickness can significantly reduce the thermal stress at the interface between anchor nails and refractories, but increase the thermal stress between slag layer and refractories;（3） when the therma I conductivity is 2-6 W · m-1 · K-1, the thermal stress increases rapidly with the increase of the thermal conductivity, but when the thermal conductivity is 6-10 W · m-1 · K-1, the thermal stress is basically stable;（4） the higher the cooling rate, the faster the decreasing speed of the temperature and thermal stress.

E-Gas气化技术及其应用分析

本文从技术的工艺流程、技术特点、性能指标等方面,介绍E-Gas气化技术,并对其工业应用领域进行分析。E-Gas气化技术生产的合成气中含1%～5%的甲烷,较适用于IGCC和合成天然气产业。

Variation of toxic pollutants emission during a feeding cycle from an updraft fixed bed gasifier for disposing rural solid waste

The variation of toxic pollutants emission during a feeding cycle was examined by field monitoring from a batch feeding updraft fixed bed gasifier for disposing rural domestic solid waste. Results showed that the content of oxygen in flue gas gradually increased, while SO_2 and HCl in flue gas decreased with time after feeding in a whole feeding cycle. Although large amount of CO was produced during the gasifying, low CO content in flue gas could be obtained after the heat treatment with an electric heating device. The distribution characteristics of dioxin congeners in flue gas indicted the re-synthesis of dioxins after flue gas heating, and the increase of oxygen promoted the synthesis of dioxins. The emission content of dioxins could meet the standard(0.1 ng I-TEQ·m^(-3),GB18458-2014) of China when the oxygen content was controlled below 8.3%. Hence, for a batch feeding gasifier,low oxygen condition should be offered by reducing air intake at the later stage of feeding cycle in order to decrease the re-synthesis of dioxins after the flue gas heating.

Damage Mechanism of High Chrome Bricks for Opposed Multi Nozzle Gasifier and Their Improvement

To reveal the damage mechanism of high chrome bricks for opposed multi nozzle gasifier with expanded diameter,the chemical composition and the morphology of a used high chrome brick were researched using XRF,SEM and EDS,and the properties of the high chrome bricks were improved by adding ultra fine alumina,alumina-chrome-iron oxide synthetic material with spinel structure,and chromium metal.The results show that(1)the high chrome brick is seriously damaged by the chemical dissolution of chrome as well as the chemical reactions at the slag/brick interface,the slag penetration and the structural spalling;(2)FeO in the slag reacts with Cr_(2)O_(3)in the brick to form a FeCr_(2)O_(4)layer on the particle surface thus leading to spalling;CaO reacts with SiO_(2)and Al2O3 in the brick forming a metamorphic layer of low melting point materials;due to the different thermal expansion coefficients of the metamorphic layer and the original brick,cracks appear and continue to expand and deepen under multiple temperature and pressure fluctuations thus leading to spalling of brick layer;(3)the improved brick has decreased apparent porosity,increased bulk density and compressive strength,and better thermal shock resistance compared with the original brick;after one cycle of on-site application,the furnace lining surface is smooth and flat with little damage,indicating that the improved high chrome bricks basically meet the working condition requirements of the opposed multi nozzle gasifier with expanded diameter,however,the final effects need to be evaluated in detail after the whole furnace service.

Life Cycle Cost of Electricity Generation from Biomass Gasifier

India is having more than 500,000 villages of which about 85% have been electrified. But as per RGGVY （Rejiv Gandhi Grammen Vidyutikaran Yojana）, the rate of village electrification is much lower as household connectivity has been fairly low. The rest 15% villages and a larger proportion of households have to be electrified. Villages have been a major concern as cost of electrification is fairly high. The most favored alternative to any kind of users is generation of electricity from diesel generating sets and renewable sources of energy. But the capital cost of renewable energy equipments is fairly high. Gradually, there is a reduction in the prices of these systems due to availability of better technological options and they are becoming competitive to grid electricity. In this paper, an attempt has been made to calculate the cost of production of electricity from stand-alone, off-grid devices biomass gasifiers （both dual fuel and pure gas type） and compare with that of diesel generating sets by using the concept of LCC （life cycle costing） and Homer software. It is found that the cost of per unit electricity generation （kWh） has been always the lowest in comparison to diesel generating sets even if the price of biomass increases to some extent.

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.

E-gas气化反应器衬里结构的有限元分析和优化

为了验证E-gas气化反应器衬里结构的合理性,利用计算机数值模拟对气化反应器的温度场分布进行有限元分析。结果表明,气化反应器绝大部分炉壁温度处在合理范围之内,但两处托砖板区域存在超温风险。对两处托砖板的结构进行细化分析,查找引起温度偏高的原因,提出优化的建议。

Syngas cleaning with nano-structured micro-porous ion exchange polymers in biomass gasification using a novel downdraft gasifier

Sulphonated nano-structured micro-porous ion exchange polymers, known as sulphonated PolyHIPE Polymers （s-PHPs） were used in syngas cleaning to investigate their impact on tar composition, concentration and dew point depression during the gasification of fuel cane bagasse as a model biomass. The results showed that the s-PHPs used as a secondary syngas treatment system, was highly effective at adsorbing and reducing the concentration of all class of tars in syngas by 95%-80% which resulted in tar dew point depression from 90 ~C to 73 ~C. It was shown that tars underwent chemical reactions within s-PHPs, indicating that tar diffusion from syngas was driven by chemical potential. It was also observed that s-PHPs also captured ash forming elements from syngas. The use of s-PHPs in gasification as well as in an integrated thermochemical biorefinery technology is discussed since the tar loaded s-PHPs can be used as natural herbicides in the form of soil additives to enhance the biomass growth and crop yield.

浅谈GE与E-GAS气化技术对比

对比研究了GE气化技术和E-Gas气化技术的工艺特点,分析两种技术在烧嘴布置、投料方式、合成气冷却和合成气净化方面的特点,并简要介绍了两种气流床气化工艺的运行情况。

Refractories Utilizability for Slagging Gasifiers

Slagging coal gasification process became a highlight of coal chemical industry in China during the last decade. Refractory lining＇ s life of slagging gasifiers is one of the most critical factors for a cost - effective operation. The paper introduces current status of coal gasification in China, lining structure of slagging gasifiers and performance of refractory lining. It also summarizes the major factors impacting on refractory wear in slagging coal gasifiers in four Chinese chemical plants, based on ten years of industrial experience. The utilizability is discussed in terms of cost -effectiveness of high chromia refractories and possibility of the alternatives.

Study on Microstructure and Slag Corrosion Mechanism of High Chrome Bricks for Gasifier

Research was focused on slag corrosion mechanism of high chrome bricks used for different types of gasifier by comparing the structure of high chrome bricks for petroleum coke gasifier and water-coal slurry gasifier with slag corroded testing brick and water coal slurry gasifier through Scanning Electron Microscope （SEM） examination and X-ray diffi＇action. Results show that for high chrome brick used for petroleum coke gasifier, corrosion is mainly caused by Cr2O3 in the brick and V2O5 in molten slag and liquid phase generation at low temperature; for high chrome brick used for water-coal slurry gasifier, corrosion is caused by dissolution of Cr2O3 in molten slag and corrosion of ZrO2. For LIRR-HK95 brick, it performs better petroleum coke corrosion resistance than the others due to the optimal composition and structure.

E-GAS气化炉及热通道设备设计、制造、安装特殊控制措施

结合中海油惠州炼化二期2200万t/a炼油改扩建及100万t/a乙烯工程煤气化制氢联合装置国内首套E-GAS气化炉成功安装的经验,对E-GAS气化炉及热通道系统设备在设计、制造、安装方面特殊控制措施进行了分析,为国内外炼油化工装置同类设备的安装提供了可借鉴的经验。