实施"油改气"开辟渣油型大化肥新的原料路线

分析宁夏石化分公司一化肥渣油气化炉实施"油改气"的可行性,在研究国外成功改造经验的基础上对一系列气化炉实施"油改气",一系列改造取得成功后对二系列也实施"油改气".介绍改造的主要内容、改造中遇到的问题及对策、技术经济评价及优化方案.改造后基本达到设计指标,吨氨制造成本降低280元,经济效益显著.     

空温式气化器综述

空温式气化器是一种将LNG转化为NG的气化装置,它利用空气作为热源,通过空气的自然或强制对流与翅片管内的低温流体换热,不消耗其它能源。该气化器结构简单,制作成本小,操作简单,适用于占地面积较大的小型LNG气化站。     

1.5 MPa多喷嘴对置式水焦浆气化炉的模拟与优化

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。     

Effect of the type of bed material in two-stage fluidized bed gasification reactors on hydrogen gas synthesis and heavy metal distribution

Different bed materials were tested for two-stage fluidized bed gasification, and the hydrogen gas composition and heavy metal distribution in the syngas were investigated. Silica sand, zeolite, calcium oxide, calcined coal, and activated carbon were used. For the results, using activated carbon resulted in the most significant increase in hydrogen after second stage (16.3 mol%) and had highest ratio of hydrogen gas in the syngas (53.1 mol%). For distribution of heavy metals, using activated carbon as bed material in the second stage, the concentration of trapped heavy metals was the highest. Regarding the emission of heavy metals, the use of calcined coal and silica sand resulted in the greatest emission concentration, and activated carbon had the lowest emission concentration. Therefore, to increase the amount of hydrogen gas produced in the gasification process and limit the emission of heavy metals, activated carbon is the best choice of these five bed materials.     

气化炉激冷室下降管内气液两相热质同时传递过程数值研究

采用流体体积双流体模型对德士古水煤浆气化炉激冷室下降管内气液两相热质同时传递过程进行数值研究,并建立了水蒸气在气相主体中的组分传输模型。数值预测的下降管内温度分布规律与实验结果吻合较好。据此探讨了相变对下降管内液膜流动形态的影响以及流动对水蒸气分布的影响,研究结果表明,相变对液膜形态有显著影响;气体对水蒸气的携带作用使得下降管内水蒸气沿高度方向上呈大梯度分布,出口处水蒸气浓度最高,下降管内存在气体带液的现象。     

撞击气流床气化炉内雾化过程中颗粒运动特性

基于实验室规模的撞击气流床气化炉,以水煤浆为原料进行气化实验,采用高温内窥镜及工业相机组成的可视化成像系统,在操作条件下,对水煤浆雾化过程进行拍摄。运用图像处理算法来识别和检测所得图像中的颗粒信息,利用颗粒示踪算法对颗粒进行轨迹测算。对颗粒的平均粒径、速度及角度进行统计分析。结果表明,喷嘴出口射流区内平均粒径主要集中在325～375 μm,相较于原煤颗粒较大;大部分颗粒速度集中在1～2 m·s^-1且运动过程中速度变化不大;大部分颗粒运动方向不随时间而变化,呈简单直线运动;颗粒轨迹呈现以喷嘴为起始点的扇形射线。     

Enhanced Hydrogen Generation from Empty Fruit Bunches by Charcoal Addition into a Downdraft Gasifier

Hydrogen production by co-gasification of empty fruit bunches of palm oil could be enhanced by adding charcoal. Physiochemical characterization of raw feedstocks was performed to determine their exergy potentiality. The raw feedstocks, gasified charcoal, and the end product of produced gas were analyzed by different techniques. Gasification experiments were performed using a pilot-scale downdraft gasifier. The heating value, composition of product gas, yield of hydrogen, and exergy efficiency were used to verify the improvement of hydrogen production during the co-gasification process. Charcoal with empty fruit bunches of palm oil leads to a much higher yield of hydrogen than lower charcoal ratios or solely empty fruit bunches. This enhanced hydrogen fuel can contribute to future energy demand.     

Corrosion of phosphate added high-chrome refractory materials in an entrained-flow gasifier

Durability of the refractory liner located in an entrained-flow gasifier is one of the main factors affecting the efficiency and cost of gasification process. This study investigates the corrosion mechanism of phosphate added high-chrome refractories in a commercial entrained-flow gasifier and the effect of phosphate additives on the improvement of service life combining thermodynamic simulation calculations. The microstructures, chemical compositions, and mineral phases of the corroded samples were analyzed by scanning electron microscopy (SEM and EDS) and X-ray powder diffraction (XRD). The results demonstrated that chemical corrosion mainly occurred at the slag-matrix interface and the junction of aggregates and matrix regions. Complex spinel solid solutions were formed at the slag-refractory interface. Phosphate additives decomposed into gaseous products (such as O₂, P₂O₃) and diffused into the interior of refractories at or close to the slag-refractory interface, not only causing an oxidizing environment but also increasing the phosphate contents in the interior of refractories. Phosphate additives in the infiltration layer occupied the gaps between crystal grains of (Cr, Al)₂O₃ solid solutions, reduced the infiltration of silicate phases, and absorbed Ca and Na in the slag, which subsequently increased the viscosity of the slag.     

Experimental investigation on co-gasification of coffee husk and sawdust in a bubbling fluidised bed gasifier

Energy can be extracted from biomass through gasification. The gasification process is influenced by the physico-chemical nature of the biomass selected for gasification. Ash content and composition of the biomasses are likely to affect the gasification process. Clinker formation in the reactor bed caused by melting and agglomeration of ashes will affect the gasification process in fluidised bed gasifiers. The agglomeration tendency of the biomass is examined by carrying out the Energy Dispersive X-ray Spectroscopy analysis on biomass ash to identify the presence of elements like potassium and sodium responsible for agglomeration. Experimental investigations on the gasification of coffee husk revealed that coffee husk is prone to agglomeration even though the hydrogen yield is more. However, gasification of saw dust is not vulnerable to agglomeration. Co-gasification of coffee husk with sawdust (which is less prone to agglomeration) is investigated experimentally.     

气流床气化炉托砖架温度分布研究

托砖架用于支撑耐火砖的重要，高温会降低其强度，造成耐火砖塌陷的生产事故，所以温度分布研究至关重要，建立了通用三维传热模型，应用有限单元法，计算了不同结构和不同工况下托砖架的温度分布，结果表明：在托砖架上部增加20mm耐火纤维会较大幅度降低托砖架最高温度，在炉壳外部增加翅片也能降低托砖架最高温度，但幅度不大，如果既增加耐火纤维又增加翅片将会对托砖架起到良好的保护作用。