常减压装置节能途径探讨

减少工艺用能是常减压装置节能的根本 ,减少初级能、提高能量转化率、提高热回收率是关键。运用三环节模式对常减压装置能耗进行系统分析 ,找出了节能降耗的有效方法。     

直流电晕等离子体重整甲烷二氧化碳制取合成气的研究

为了探究线筒式直流电晕等离子重整CH_4和CO_2制合成气的效果,利用直流电晕放电装置对CH_4和CO_2进行了重整实验。考察了大气压下甲烷含量、放电电压和进气流量对反应物转化率、产物选择性和能量转化效率的影响。结果表明,随着进气中甲烷含量的增大,CH_4转化率下降,CO_2转化率上升,产物选择性和能量转化效率皆先上升后下降;随着电压的增大,原料转化率和选择性皆呈上升趋势,但都存在一个极限值,能量转化效率先上升后下降;随着进气流量的增大,原料转化率和产物选择性皆下降,能量转化效率先上升后下降。整体上,线筒式直流电晕等离子体重整甲烷和二氧化碳制取合成气具有设备简单、产物选择性高和能量转化效率高的优点。     

直流电晕等离子体重整甲烷二氧化碳制取合成气的研究

为了探究线筒式直流电晕等离子重整CH_4和CO_2制合成气的效果,利用直流电晕放电装置对CH_4和CO_2进行了重整实验。考察了大气压下甲烷含量、放电电压和进气流量对反应物转化率、产物选择性和能量转化效率的影响。结果表明,随着进气中甲烷含量的增大,CH_4转化率下降,CO_2转化率上升,产物选择性和能量转化效率皆先上升后下降;随着电压的增大,原料转化率和选择性皆呈上升趋势,但都存在一个极限值,能量转化效率先上升后下降;随着进气流量的增大,原料转化率和产物选择性皆下降,能量转化效率先上升后下降。整体上,线筒式直流电晕等离子体重整甲烷和二氧化碳制取合成气具有设备简单、产物选择性高和能量转化效率高的优点。     

常减压装置节能途径探讨

减少工艺用能是常减压装置节能的根本。减少初级能，提高能量转化率，提高热回收率是关键，运用三环节模式对常减压装置能耗进行系统分析，找出了节能降耗的有效方法。     

三种典型煤化工工艺比较和能量转化率分析

对煤制合成天然气、一步法合成二甲醚、两步法合成二甲醚3种典型煤化工工艺的进行了比较和能量转化率分析,提出一步法合成二甲醚无论在工艺、投资还是在能量转化率上都较其他2种工艺具有优势。     

关于煤化工装置建设几个问题的讨论

探讨了煤化工装置的规模、煤制油的"四高"、煤气化方法的选择和多联产的能量转化率等问题;认为在国内建设新形势下,认真研究煤化工装置建设的规律,有助于推进煤化工的科学发展,为建成经济上发达而又美丽的中国开创新的局面。     

硫铁矿制酸2＋2两次转化工艺过程的选择及工业实践

在国内两转两吸转化工艺多为“3+1”流程的情况下,先后设计了三套“2+2”两次转化流程。在工艺选择过程中,对转化率、各段温度、换热流程作了详细比较。根据当地条件,确定设计的转化率为99.3％;采用~Ⅳ_Ⅲ>Ⅰ—Ⅱ换热流程。通过对温度制度的论证,确定二段进口温度为440～450℃。采用了Browder型换热器和圆缺式折流板、弓形部份不满布管的高效换热器。生产实践证明了“2+2”两次转化流程是成功的。重庆化工厂150t/d装置,当二转入口温度为430℃左右时,总转化率可达99.5％。     

200 kt/a硫磺制酸装置转化器的操作调整

转化率是硫磺制酸装置生产的主要控制参数，是衡量装置生产的经济性及先进性的重要指标之一。介绍了200kt／a硫磺制酸装置转化器的操作情况，转化器各段的转化率、总转化率及分段压力降，通过分析检测结果，阐述了影响转化器转化率的主要因素，并提出了提高转化率的措施。     

炼油厂气体分馏装置用能的集成和优化

一般炼油厂中气流分馏装置应用范围比较广,能量流相对来说比较密集,所以对该装置的节能研究有重要意义。     

影响高压系统二氧化碳转化率的因素分析与优化

尿素装置高压系统的二氧化碳转化率是尿素装置实现经济生产运行的重要指标之一,转化率直接影响到尿素生产成本,在运行中发现转化率均低于设计值。经过分析,认为高压系统氨碳比偏低、水碳比偏高、惰性气体含量偏大是主要原因,通过各项控制措施的实施,实现了二氧化碳转化率的提高。     

Electrical efficiencies of methane fired, high- and low- temperature fuel cell power plants

The important system difference between power plants based on low temperature and high temperature fuel cells is that gas reforming and shift conversion is thermally decoupled from the cell in low temperature cell power plants whereas the gas process steps are performed at close to the elevated fuel cell temperatures in high temperature fuel cell power plants. This article elucidates the consequences: assuming equal electrical efficiencies for the respective cells (50%) it is shown that thermal decoupling leads to energy and exergy losses and sizably lower electrical system efficiencies because heat for the generation of the process steam necessitates the combustion of methane. Also hydrogen losses in the step for preferential oxidation of carbon monoxide (Selox process) and several heat transfer steps add to the lower efficiency of low temperature systems. Low temperature fuel cell power plants need 15–17% more fuel than high temperature fuel cell power plants for the same amount of electric energy. The theoretical comparison of an adiabatic LT and HT fuel cell process reveals that, with postulated electrical cell efficiencies of 50%, the theoretical electrical efficiency of the LT process is 6–7% points lower than that for the HT-process (35 vs. 41%). For exergy efficiencies also taking into account rejected heats, the numbers read 43 and 58%.     

Calcium sulfate whisker prepared by flue gas desulfurization gypsum: A physical-chemical coupling production process

In this paper, the solid waste desulfurization gypsum produced by coal-fired power plants was used as a raw material to prepare calcium sulfate whiskers with high application prospects. Calcium sulfate whiskers with uniform morphology and high aspect ratio can be prepared by hydrothermal method in sulfuric acid solution. A new process of desulfurization gypsum activated by high-energy grinding to reduce the reaction temperature and sulfuric acid concentration was developed. Through the comparison of product morphology, the best grinding time was determined to be 3.5 h. The mechanism of desulfurization gypsum through physical-chemical coupling to reduce energy consumption was clarified. The activation of desulfurization gypsum by grinding and the acidic environment provided by the sulfuric acid solution made the calcium sulfate solution reached rapid saturation and accelerated the nucleation rate. By calculating the conversion and crystallization rate of calcium sulfate whiskers, it was found that there were obvious “autocatalytic” kinetic characteristics during the crystallization process.     

钙基吸收剂碳酸化实验研究

对CaO吸收CO2反应的特性进行了实验研究,采用未反应收缩核模型分析碳酸化反应动力学特性.结果表明,化学反应速率常数在650℃～750℃范围内基本为一常数,产物层扩散系数随着温度的增加而增大.化学反应控制段的活化能Ea=29.70 kJ/moL,产物控制段的活化能Ea=92.80 kJ/moL.温度一定时,随着CO2体积分数增加,碳酸化反应速率加快,转化率增大.     

Calcium sulfate whisker prepared by flue gas desulfurization gypsum: A physical–chemical coupling production process

In this paper, the solid waste desulfurization gypsum produced by coal-fired power plants was used as a raw material to prepare calcium sulfate whiskers with high application prospects. Calcium sulfate whiskers with uniform morphology and high aspect ratio can be prepared by hydrothermal method in sulfuric acid solution. A new process of desulfurization gypsum activated by high-energy grinding to reduce the reaction temperature and sulfuric acid concentration was developed. Through the comparison of product morphology, the best grinding time was determined to be 3.5 h. The mechanism of desulfurization gypsum through physical–chemical coupling to reduce energy consumption was clarified. The activation of desulfurization gypsum by grinding and the acidic environment provided by the sulfuric acid solution made the calcium sulfate solution reached rapid saturation and accelerated the nucleation rate. By calculating the conversion and crystallization rate of calcium sulfate whiskers, it was found that there were obvious “autocatalytic” kinetic characteristics during the crystallization process.     

煤制天然气的能源网络分析图

能源网络图作为能源统计数据分析的有效工具和方法,是评价企业用能效率、发掘能耗薄弱环节、科学制定能源管理政策的重要手段。本文以国内某煤制合成天然气企业为研究对象,并以美国大平原项目为参照,基于能量平衡建立能源网络图对两者能量转化的4个重要环节——购入储存、加工转换、输入分配和最终使用的能量转换效率进行详细地对比分析。结果表明,大平原项目能量转换效率为53.16%,而国内该企业能量转换效率为48.20%,主要体现在终端环节中4个系统的用能效率偏低,需进一步挖掘节能瓶颈和改善用能水平。     

A Comparative Study on a Vertical Stirred Mill Agitator Design for Fine Grinding

Comminution is an energy intensive process. A small change in efficiency can lead to substantial benefits in an overall economy of the process plant. This study focused on the comparison of vertical stirred mill agitator designs. A double helical screw agitator was designed for this purpose. A series of stirred mill experiments were performed with two types of agitator designs a standard pin type and CSIRO’s designed double helical screw stirrers. The effects of operating parameters such as grinding time, stirrer speed, and pulp density on grinding performance was investigated using a magnetite concentrate. Grinding performance was analyzed by considering the product fineness and the energy consumption. The test results show that the grinding time and stirrer speed played a significant role; however, the pulp density had little impact on grinding performance in both cases of agitator designs. The 80% passing target product size of 38 μm was obtained with double helical screw agitator in 20 min of grinding with an expend of 10.53 kWh/t specific energy, whereas, the target product size of 38 μm was achieved with the pin type stirrer at the rate of 21.73 kWh/t. It is evident that grinding in a vertical stirred mill with a double helical screw is more efficient than that using a pin type stirrer in terms of the product size distribution and the specific energy consumption. It is concluded that the double helical screw design provides better energy efficiency compared to the pin type stirrer design. The models were developed for the responses P₈₀ and E_cs. Both models show high regression coefficients thus ensuring a satisfactory of models with experimental data. The model equations developed were then optimized using a quadratic programming to minimize the P₈₀ size at minimum specific energy.     

Optimization of reactors with catalyst decay I — single tubular reactor with uniform temperature

The optimal choice of temperature with time is sought so as to maximize the total amount of reaction in a fixed time in a tubular reactor with uniform temperature and decaying catalyst. The single reaction is assumed to be irreversible with a rate expressible as a product of separate functions of temperature, activity and conversion. The rate of decay of activity is also a product of separate functions of temperature and activity but independent of conversion. To each total reaction time, there is a unique optimal policy. The policies are derived for various cases, distinguished by the ratio of activation energies for reaction and decay. Any optimal policy must end on the upper temperature constraint except for certain special cases. The stationary sub-policy is shown to be one of constant conversion when the inlet conversion is constant. The stationary sub-policy for a variable inlet conversion is also derived. Numerical calculations are presented to illustrate the optimal policies and a comparison of the present results is made with those of previous workers.     

盘江矿区原煤全重介工艺与跳汰粗选-重介精选工艺的比较

对盘江矿区两座选煤厂的洗选工艺进行了详细比较 :跳汰粗选—重介精选工艺有利于煤泥水处理 ,介耗低 ,产品质量稳定 ,缺点是工艺复杂 ,精煤回收率较低 ;原煤全重介工艺简单 ,电耗低 ,易实现自动控制 ,缺点是介耗高 ,煤泥水难于处理 ,设备管路磨损严重 ,维护费用高。通过分析 ,提出了西南地区选煤厂进行技术改造的推荐工艺方案     

Kinetic Investigation of Reaction Between Colemanite Ore and Methanol

In the field of industry, it is very important that boron compounds are produced from boron ores. The aim of this study was to investigate the dissolution kinetics with carbon dioxide of colemanite in methanol medium in a pressure reactor and to derive an alternative process for producing boron compounds. Reaction temperature, stirring speed, solid/liquid ratio, pressure, and particle size were selected as parameters for the dissolution rate of colemanite. It was found that the dissolution rate increased with increase in pressure and reaction temperature, and with decrease in particle size and solid/liquid ratio. No effect of stirring speed was observed on conversion. The dissolution kinetics of colemanite were examined using both heterogeneous and homogeneous reaction models, and it was determined that the reaction rate can be described by a second-order pseudo-homogeneous reaction model. The activation energy was found to be 51.4 kJ/mol.