乙烯装置裂解炉节能技术应用分析

裂解炉作为乙烯装置主要能耗设备,其燃料消耗占乙烯生产能耗的80%以上,因此对于裂解炉操作的优化与控制显得尤为重要。介绍了新疆独山子石化公司裂解炉在节能降耗方面所采取的优化措施;清理对流段积灰和对裂解炉燃烧器增加空气预热器。对比了节能措施投用前后的运行数据,分析了节能措施投用后经济指标,并在现有基础上结合装置特点提出优化建议。     

采用CBL裂解节能技术实施裂解炉改造

主要介绍了CBL裂解炉应用的各种先进节能技术。包括裂解炉辐射段节能技术、对流段节能技术及其它设备节能技术。通过分析节能技术的特点及通过改造实例说明改造效果。实践证明,集合了多种节能技术的CBL裂解炉技术先进,节能效果显著。     

裂解炉对流段改造效果与评价

大庆乙烯装置为了实现节能减排,降本增效,对裂解炉对流段进行整体改造,并增加高压蒸汽过热段,停用蒸汽过热炉。文中对裂解炉改造的效果进行分析,意在通过探索,使裂解炉以更加合理的方式运行,实现装置效益最大化。     

裂解炉系统节能优化潜力分析

针对广州乙烯裂解炉建设早，存在技术落后、能耗高、与现有裂解原料不匹配等问题，从设计、工艺运行及新技术应用等方面进行分析，同时结合以往装置节能改造情况，对裂解炉目前存在的在节能降耗方面突出问题，主要围绕如何降低裂解炉燃料、蒸汽消耗及电力消耗等提出再优化裂解炉空气预热器热源、改造风机、降低排烟温度等措施，降低裂解炉动力消耗。优化措施实施后，能降低裂解装置能耗（标油）10 kg／t乙烯以上。     

PyroCrack1-1型裂解炉在乙烯装置上的应用

为降低乙烯装置能耗，消除装置隐患、增加效益，提高企业的市场竞争力，中国石油吉林石化公司有机合成厂在2004年乙烯装置改造中，新建了2台林德PyroCrack1-1型裂解炉。该型裂解炉采用双辐射段炉膛，单对流段设计，可在一侧炉膛烧焦的同时，另一侧进行裂解。文中从设备结构、工艺操作、检查维护等方面对PyroCrack1-1型裂解炉进行了介绍。PyroCrackl-1型裂解炉的投用，既满足了乙烯装置平稳运行的要求，同时又兼顾了节能和装置后续发展的需求。     

裂解炉空气预热技术在燕山乙烯装置上的应用

介绍了燕山乙烯装置裂解炉空气预热器的预热技术、节能原理及运行。通过对比空气预热器投用前后裂解炉运行状况,得出结论：空气预热器在裂解炉上的应用能使裂解炉炉膛内温度分布得到改善,节约燃气用量,烟气量减小,排烟温度降低,达到节能降耗的目的。     

空气预热器在KBR13万t／a乙烯裂解炉上的应用

乙烯生产的能耗,其中80％以上消耗为裂解炉的燃料气消耗,因此裂解炉燃料气消耗成为决定乙烯生产能耗高低的重要因素,裂解炉的节能在乙烯装置生产过程中具有非常重要的意义,兰州石化460kt／a乙烯装置裂解炉增加空气预热器,合理利用资源,达到节能目的。     

氯乙烯新建氧氯化装置简介

我厂新增3.4万t/aVCM改扩建工程主要包括100单元直接氯化单元改造,新增8万t/a氧氯化单元,裂解炉节能扩能改造,EDC、VCM精馏单元扩能改造及DCS系统升级扩容改造。100单元改造和EDC、VCM改造已经于1998年完成,2000年6月新的氧氯化单元也一次开车成功。该单元采用德国HOECHST的贫氧氧氯化法,使用乙烯、氯化氢和氧     

辽化乙烯装置GK-Ⅲ型裂解炉改造

F108炉是辽阳石化公司在1987年建造的GK-Ⅲ型管式裂解炉，公称设计能力为年产乙烯250kt。为适应裂解乙烷的需要，对辐射炉管进行改造。同时，最初设计时F108炉对流段无超高压蒸汽过热段（HPSSH），其产生的饱和蒸汽送到蒸汽过热炉进行过热。随着装置内其它裂解炉相继改造及重建，均相应地增加了超高压蒸汽过热段，原先的蒸汽过热炉将准备拆除。因此，需要对F108裂解炉的对流段进行改造，在其对流段增加超高压蒸汽过热段。通过一系列的改造满足了F108裂解乙烷的需要。     

GK-Ⅵ型裂解炉对流段改造

中国石油辽阳石化分公司烯烃厂裂解装置有3台GK-Ⅵ型裂解炉,在运行过程中,由于裂解炉对流段结垢造成烟气阻力增大,引风机负荷逐渐提高至最大,导致裂解炉加工能力降低,燃料气消耗增加,热效率降低,烟气热损失增大,能耗增加。2011年7月对GK-Ⅵ型裂解炉对流段进行改造。改造后,解决了裂解炉运行中存在的问题,提高了裂解炉的热效率,降低了装置能耗。     

喷流-移动床RDF热解燃烧温度和气体分布

根据RDF（Refuse Derived Fuel）先部分燃烧部分热解然后再气相燃烧的设想,设计了下部为喷流-移动床热解室、上部为气相燃烧室的两段反应器,对实验室中制备的RDF在该反应器中进行部分燃烧部分热解然后气相燃烧的性质进行了研究. RDF颗粒连续加入到热解室中,实现了在少量空气作用下部分燃烧并在较低温度下部分热解,热解气体与二次空气在上部燃烧室中高温燃烧.主要考察了喷动气量,水平辅助气量和二次气量对反应器温度分布以及气体产物分布的影响.     

Anti-wear hierarchical TiC enhanced cermet coating obtained via electrical discharge coating using a reduced graphene oxide nanosheets mixed dielectric

The use of a powder mixed dielectric is one of the promising measures to overcome defects such as non-uniform thickness, voids and micro-cracks of hard coatings obtained via the electrical discharge coating (EDC) process. The quest for finding appropriate powders suspended in EDC dielectric still continues. In this paper, reduced graphene oxide nanosheets (RGONS) are explored as the additives of EDC dielectric to fabricate TiC containing composite coatings with superior tribological performance. The influences of RGONS on the surface integrity, microstructure and tribological performance of the as-prepared coatings are investigated. RGONS with lipophilic modification effectively reduce spark energy and disperse the discharges throughout the machined surface due to their uniform dispersion in the discharge gap. This allows the formation of compact coatings with banded microstructure composing of a mixture of equiaxed and columnar TiC grains within the martensite matrix. Such unique microstructure improves the as-prepared coatings’ resistance to adhesion and abrasion wear, as well as fatigue and fracture. As a result, they show obviously lower coefficient of friction and wear rate compared to the coatings obtained using a bare dielectric.     

Pilot Development of Polygeneration Process of Circulating Fluidized Bed Combustion combined with Coal Pyrolysis

A pilot polygeneration process of a 75 t h^–1 circulating fluidized bed (CFB) boiler combined with a moving bed coal pyrolyzer was developed based on laboratory‐scale experimental results. The process operation showed good consistency and integration between boiler and pyrolyzer. Some critical operating parameters such as hot ash split flow from the CFB boiler to the pyrolyzer, mixing of hot ash and coal particles, control of pyrolysis temperature and solid inventory in the pyrolyzer, and pyrolysis gas clean‐up were investigated. Yields of 6.0 wt‐% tar and 8.0 wt‐% gas with a heating value of about 26 MJ m^–3 at 600 °C were obtained. Particulate content in tar was restrained less than 4.0 wt‐% by using a granular filter of the moving bed. Operation results showed that this pilot polygeneration process was successfully scaled up.     

二氯乙烷裂解管式反应器二维模拟

建立了二氯乙烷在管式反应器中进行气相热裂解的二维模型 ,模型考虑了二氯乙烷热解生成氯乙烯的主反应和生成焦前体的副反应以及气体密度变化对裂解反应的影响 .模拟计算表明 ,二氯乙烷和氯乙烯的浓度沿径向分布平坦 ;但是管内近壁面处由于存在边界层 ,始终存在着明显的径向温差 ;近管壁处始终是裂解的高速率区 ,副反应也主要发生在管壁区 .表明确定最优的炉管管径时必须考虑提高裂解速率与降低结焦速率之间的平衡 .在距进口量纲 1管程 0 .3左右的管壁处裂解速率达到最高 ;副反应速率的最大点位于出口管壁处 .与工业数据比较后发现 ,炉管出口的转化率、选择性、出口压力和温度等数据与模型预测值一致 ,表明模型具有较高的可信度     

Corneal Stromal Cell Growth on Gelatin/Chondroitin Sulfate Scaffolds Modified at Different NHS/EDC Molar Ratios

A nanoscale modification strategy that can incorporate chondroitin sulfate (CS) into the cross-linked porous gelatin materials has previously been proposed to give superior performance for designed corneal keratocyte scaffolds. The purpose of this work was to further investigate the influence of carbodiimide chemistry on the characteristics and biofunctionalities of gelatin/CS scaffolds treated with varying N-hydroxysuccinimide (NHS)/1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide hydrochloride (EDC) molar ratios (0–1) at a constant EDC concentration of 10 mM. Results of Fourier transform infrared spectroscopy and dimethylmethylene blue assays consistently indicated that when the NHS to EDC molar ratio exceeds a critical level (i.e., 0.5), the efficiency of carbodiimide-mediated biomaterial modification is significantly reduced. With the optimum NHS/EDC molar ratio of 0.5, chemical treatment could achieve relatively high CS content in the gelatin scaffolds, thereby enhancing the water content, glucose permeation, and fibronectin adsorption. Live/Dead assays and interleukin-6 mRNA expression analyses demonstrated that all the test samples have good cytocompatibility without causing toxicity and inflammation. In the molar ratio range of NHS to EDC from 0 to 0.5, the cell adhesion ratio and proliferation activity on the chemically modified samples significantly increased, which is attributed to the increasing CS content. Additionally, the materials with highest CS content (0.143 ± 0.007 nmol/10 mg scaffold) showed the greatest stimulatory effect on the biosynthetic activity of cultivated keratocytes. These findings suggest that a positive correlation is noticed between the NHS to EDC molar ratio and the CS content in the biopolymer matrices, thereby greatly affecting the corneal stromal cell growth.     

DMTMM-mediated grafting reaction of glucuronic acid on chitosan

Compared with traditional conjugates 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide (EDC) and N-hydroxysuccinimide (NHS), 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride (DMTMM) is an emerging biological coupling reagent and has been used in the amidation of hyaluronic acid. In this paper, DMTMM was used to achieve the amidation of chitosan (CS) with glucuronic acid (GA) in an aqueous medium to generate a GA-CS derivative. The grafting efficacy was preliminarily compared with the EDC/NHS-mediated reaction. As a result, the substitution degree of 17.6% for DMTMM-mediated grafting and 13.1% for EDC/NHS chemistry indicated that DMTMM-mediated synthesis of GA-CS appeared to be more efficient. The reaction kinetics experiments showed that GA-CS derivative with a degree of substitution up to about 26.1% was obtained using equal molar ratios of DMTMM and GA exceeding CS at room temperature. These results indicate that employing DMTMM as a coupling agent is a feasible and promising strategy for the amidation modification of chitosan.     

Upgrading of derived pyrolysis vapors for the production of biofuels from corncobs

A bubbling fluidized bed pyrolyzer was integrated with an in-situ honeycomb as a catalytic upgrading zone for the conversion of biomass to liquid fuels. In the upgrading zone, zeolite coated ceramic honeycomb (ZCCH) catalysts consisting of ZSM-5 (Si/Al=25) were stacked and N₂ or recycled non-condensable gas was used as a carrier gas. Ground corncob particles were fast pyrolyzed in the bubbling bed using fine sand particles as a heat carrier and the resulting pyrolysis vapors were passed on-line over the catalytic upgrading zone. The influence of carrier gas, temperature, and weight hourly space velocity (WHSV) of catalyst on the oil product properties, distribution and mass balance were studied. Using ZCCH effectively increased the hydrocarbon yield and the heating value of the dry oil, especially in the presence of the recycled noncondensable gas. Even a low usage of zeolite catalyst at WSHV of 180 h⁻¹ was effective in upgrading the pyrolysis oil and other light olefins. The highest hydrocarbon (≥C2) and liquid aromatics yields reached to 14.23 and 4.17 wt-%, respectively. The undesirable products including light oxygenates, furans dramatically decreased in the presence of the ZCCH catalyst.     

磷酸腺苷对蚕丝织物的生物阻燃耐久整理

为了满足对蚕丝织物生态阻燃的需求，以1-(3-二甲氨基丙基)-3-乙基碳二亚胺 (EDC)和 N-羟基琥珀酰亚胺(NHS)为催化剂将磷酸腺苷(AMP)引入蚕丝织物。采用FTIR、SEM、EDS等对改性前后丝织物的化学结构、表面形貌和元素含量进行表征，采用极限氧指数仪、垂直燃烧测试仪、锥形量热仪和热重分析仪对其阻燃性能和热稳定性进行测试，同时对改性前后丝织物的拉伸断裂性能和织物风格等物理机械性能进行测试。结果表明，改性丝织物表面呈现颗粒状覆盖物，且均匀分布着磷元素。改性丝织物增重率达13.3%时，极限氧指数达30.10%，相比于原丝织物失重率降低13.1%，热释放速率降低30.6%，损毁长度减少11.1 cm，并出现明显炭层。经50 次洗涤后，改性丝织物极限氧指数仍能达到25%以上，说明改性丝织物具有较好的耐洗性能。     

Characterization of a lab-scale platinum filament pyrolyzer for studying the fast devolatilization of solid fuels

Platinum filament pyrolyzers achieve very high temperature and heating rate and can provide useful parameters for practical applications in combustion, pyrolysis and gasification processes. The critical use of an experimental instrument is necessary to provide reliable data. In this work, a commercial pyrolyzer (CDS Pyroprobe 2000) is characterized to obtain a correspondence between the nominal and the effective operating conditions. This is the basis for the modeling estimation of the effective thermal history of the sample during each experimental run. The experimental results obtained performing the devolatilization of coals, biomass and waste fuels using the pyrolyzer are compared with those obtained in a conventional thermogravimetric balance, to evaluate the effects of extremely different operating conditions. The amount of volatile released programming the most severe thermal conditions using the pyrolyzer (thus in conditions more similar to large-scale plants) differs significantly from that of thermogravimetric runs. Global kinetics are obtained fitting the experimental results and using the thermal history of the sample from the model results. They depend strongly on the conditions used for the devolatilization. Global kinetics obtained in the thermogravimetric balance runs (low heating rate) overestimate the rate of devolatilization in the pyrolyzer (high heating rate).