绝热卡计技术与应用

Jun.5/20130绝热卡计技术与应用Jun.5/20131内容•基本概念•绝热卡计之发展与种类•绝热卡计之原理与测试•绝热卡计应用于失控反应之危害评估•应用于永光公司制程Jun.5/20132一、基本概念•全球重大化灾事故的25%起因于失控反应与紧急排放设计不当。•在美国1976年至1986年间51件失控反应与紧急排放设计不良事故造成约1.6亿美元损失，平均每次事故损失约300万美元。Jun.5/20133一、基本概念•石化公司：Knowhow母公司大多已经评估失控反应并使用DIERS技术设计紧急排放系统。•特化公司：自行研发，大多未评估失控反应并未使用DIERS技术设计紧急排放系统。(Designbase涵盖事故原因，则可控制，但失控反应引发重大化灾仍时有所闻)Jun.5/20134一、基本概念进行绝热卡计测试：Sampleorprocesschemistry依各公司的规定与管制流程Jun.5/20135一、基本概念USCBS(美国化学灾害调查委员会)事故调查报告(1980-2001共167reactivechemicalincidents)：•GapsinexistingOSHAandEPAregulation.•Over50%ofthe167incidentsinvolvedchemicalsnotcoveredbyOSHAandEPAregulation.•NFPAinstabilityratingsusedinOSHAPSMstandardforemergencyresponsehavesignificantlimitations.Jun.5/20136一、基本概念一般原则：(1)DSCorDTA实验放热量高于250J/g。(2)国内外类似制程发生重大化灾。(3)制程曾经有overflow、incident或nearmiss。Jun.5/20137一、基本概念一般原则：国内外制程或危险物发生重大化灾(1)cumeneoxidatedtoCHPthentophenol(2)MEKoxidatedtoMEKPO(3)NH4NO3(4)EO(5)Nitrationprocess(Stirrerfailure)(6)压克力(光阻)聚合制程Jun.5/20138一、基本概念一般原则：(4)剧烈放热反应：如硝化、氢化、磺化、氧化、偶氮化等。(5)使用不安定化学品：NH4NO3,硝化物、Azide,有机过氧化物、Metalhydride、偶氮化合物等。Jun.5/20139一、基本概念公司研发与制程：依WI需进行绝热卡计测试(1)放热反应：使用锌粉(over-flow？)(2)使用有机过氧化物：ROOH(国内外事故)(3)使用硝基化合物：Aromaticnitro-compound(失控反应后果严重)Jun.5/201310二、绝热卡计之发展与种类绝热卡计之发展：acceleratingratecalorimeter(ARC)1976至1980TheDowChemicalCompanyD.I.TownsendThermochimicaActa,vol.37(1980),1-30.(300次citation)“Thermalhazardevaluationbyanacceleratingratecalorimeter(ARC)”Jun.5/201311二、绝热卡计之发展与种类第一个绝热卡计为何称为acceleratingratecalorimeter(ARC)？而不是AdiabaticCalorimeterJun.5/201312二、绝热卡计之发展与种类绝热卡计之种类ARC(acceleratingratecalorimeter)Phi-TecPressureDewarcalorimeter(Dewar)AutomaticPressureTrackAcceleratingCalorimeter(APTAC)VentSizingPackage(VSP)Jun.5/201313三、绝热卡计之原理与测试加速热(绝热)卡计操作原理绝热条件：withoutheatflowbetweensystemandsurrounding(1)ARCoradiabaticcalorimeter:Byheatingtheovenofthecalorimeter(Treactant=Toven)(2)Dewaroradiabaticreactor:adiabaticconditionbetweenreactantandenvironmentJun.5/201314三、绝热卡计之原理与测试DSC之优缺点(1)Sampleweight:4-10mg(2)Screenbyprogrammedheatingorisothermaltest(3)Sensitivityatabout0.1mw/mg(4)Withoutstirrer(5)Cannotaddanotherreactant(6)Nopressuredata(7)Simpleoperationandfast(8)ChemicalkineticsonlyforsimplereactionJun.5/201315三、绝热卡计之原理与测试一般原则：fromliterature(1)Runawayincidentoccurredinstoragetank(2)Emergencyreliefinprocessreactor(3)Overflowinprocessreactor(4)Processdevelopment(5)Heatofreaction250J/g(reactant)(6)Materialwithunstablefunctionalgroup(7)Verificationoftheworstcasepossibleinreactor(8)VentSizingoremergencyreliefsystemdesignJun.5/201316三、绝热卡计之原理与测试追热(绝热)原理：(1)ARC:Heat-wait-searchmode(2)Self-heatrateonsetorsetinitialself-heatrate,thenturnoffthemain(radiation)heaterandstartupthe(oven)guardheaterJun.5/201317三、绝热卡计之原理与测试追热(绝热)原理：说明：(1)此时样品自行放热，环境也使用加热器加热oven维持与反应物等温，因温度升高与Arrhenius公式，放热速率随T而加速，故称为acceleratingratecalorimeter(ARC)，而非AdiabaticCalorimeter。(2)(dT/dt)：T对时间t的微分，Townsend称之为self-heatrate。Jun.5/201318三、绝热卡计之原理与测试加速热卡计(ARC)特性：(1)Ovenweight约1Kg,追热慢(self-heatrate15K/minisreliable)(2)Testbomb:Ti,s.s.,HCalloy,Sphericalshape,10ml(3)Withoutstirrer(4)Thermalinertia(Φ):1-15(5)Sensitivity:self-heataslowas0.02K/min(6)Withoutthefunctionofadditionofanotherreactantorgasreactant(7)T=25to500℃,P=1bartoabout100barJun.5/201319三、绝热卡计之原理与测试排放测试热卡计(VSP)介绍(PHI-TEC类似)：(1)Heat-wait-searchandadiabatic+temperaturerampmode(forsimulatingfirecase)(2)Testbomb:Ti,s.s.,HCalloy,canshape,110ml(3)Withmagneticormechanicstirrer(4)Thermalinertia(Φ):aslowas1.1(5)Sensitivity:self-heataslowas0.05K/min(6)Additionalreagentsorgasesmaybeadded(7)T=25to500℃,pressuredifferencecanbeaslargeas200psi(8)Canbeusedforrelieftestindeterminingthetwo-phaseflow(topventingorbottomdumping)Jun.5/201320三、绝热卡计之原理与测试压力补偿加速热卡计(APTAC)介绍(1)Heat-wait-searchandadiabatic+temperaturerampmode(2)Testbomb:Ti,s.s.,HCalloy,Sphericalshape,130ml(3)Withstirrer(4)Thermalinertia(Φ):aslowas1.1(5)Sensitivity:self-heataslowas0.02K/min(6)Additionalreagentsorgasesmaybeadded(7)T=25to500℃,P=1bartoabout136barJun.5/201321三、绝热卡计之原理与测试Dewar绝热卡计介绍(较少使用，但德国较常用)(1)Adiabaticmode(byheatingtheoven)(2)Metalflask:s.s.,500or1000ml(3)Withstirrer(4)Thermalinertia(Φ):1.1to1.2(5)Sensitivity:self-heataslowas0.01K/min(6)Additionalreagentsorgasesmaybeadded(7)T=25to300℃,P=1bartoabout50barNote:AblastenclosureisstronglyrecommendedforthelargetestamountJun.5/201322三、绝热卡计之原理与测试Jun.5/201323三、绝热卡计之原理与测试Jun.5/201324三、绝热卡计之原理与测试Jun.5/201325三、绝热卡计之原理与测试Jun.5/201326三、绝热卡计之原理与测试热惯量(Φ)对于苯乙烯失控反应的影响Jun.5/201327三、绝热卡计之原理与测试热惯性或Φ-因子：小于1.5与实场反应器相近，可直接应用。Φ=2代表有50%热量由反应物流失至bomb。失控反应严重性减缓。),1測試罐樣品樣品的熱容量測試罐的熱容量樣品的熱容量樣品加測試罐的熱容量bsCmCmCmssbbssJun.5/201328三、绝热卡计之原理与测试VSP或PHI-TEC的热惯性或Φ可小于1.5，至约1.1或1.2。改进早期ARCΦ2缺点。此时Sample用量约50mlARCVSPms=10gms=100gCs=0.5cal/g℃Cs=0.5cal/g℃mb=23gmb=23gCb=0.11cal/g℃Cb=0.11cal/g℃Jun.5/201329三、绝热卡计之原理与测试Solenoid阀控制器排放测试槽排放缓冲器Jun.5/201330三、绝热卡计之原理与测试VSP测试罐密闭式(ClosedSystem)顶部排放式(OpenSystem,TopVenting)底部排放式(OpenSystem,BottomVenting)Jun.5/201331四、绝热卡计应用于失控反应之危害评估(1)可能发生的最坏状况(Credibleworstcase)之绝热卡计实验(2)绝热卡计是有计划目的使反应失控或热爆炸(3