Presentation of Vapour Recovery Systems. By Ties Mulder Process and Implementation Consultant June 2005

Transcription

1 Presentation of Vapour Recovery Systems By Ties Mulder Process and Implementation Consultant June 2005

2 History of Vapour Recovery & Technologies developed Worldwide Emission legislation Closed circuit European recovery system for truck Implementation of Vapour Recovery systems on terminals Recovery product, rate, tax refund Safety aspects, ATEX, SIL 2/64

3 History of Vapour Recovery & Technologies developed Worldwide Emission legislation Closed circuit European recovery system for truck Implementation of Vapour Recovery systems on terminals Recovery product, rate, tax refund Safety aspects, ATEX, SIL 3/64

4 First Systems First systems = thermal destruction (air assisted flare) Energy consumption : high Destruction : 97 % efficiency Maintenance : low 4/64

5 First Recovery Systems First recovery systems installed in the United States Flare gas recovery using compression and cooling Outlet to Flare Vapour Inlet Cooler Energy consumption : high Emissions : 80 % efficiency Maintenance : medium Separator Compressor Recovered Liquid 5/64

6 Adsorption systems Early 70s : first activated carbon / vacuum system (Rheem Brothers - USA) Clean air outlet Top product vented to atmosphere Glycol Separator Gasoline supply Energy consumption : low Emissions : 80 % efficiency Maintenance : high Vapour Inlet Activated Carbon Filters Re-absorber Vacuum Pump Gasoline return 6/64

7 Deep cooling systems Deep cooling -35 C (Edwards - USA) Clean Air Outlet De-icing heater Cooling Elements Chiller Energy consumption : high Emissions : < 80 g/m 3 Maintenance : very high Vapour Inlet Pure Product 7/64

8 Evolution of Adsorption systems... First patent by McGill in 1978 based on Rheem brothers with recycling of absorber top Clean air outlet Energy consumption : low Top product returned to inlet Emissions : 35 g/m 3 Maintenance : high Glycol Separator Gasoline supply Replacement of deep cooling by Vapour Inlet Activated Carbon Filters Re-absorber adsorption systems in USA Vacuum Pump Gasoline return 8/64

9 Evolution of Adsorption systems Since 1980 s : Activated carbon / Liquid ring vacuum systems as known today Clean Air Outlet Purge Adsorbers Vapour Inlet Energy consumption : high Emissions : < 35 g/m 3 Maintenance : high Absorber Suppliers patents in several European countries Absorbents Cooler EG Separator Vacuum Pump 9/64

10 Alternative solutions Fear of patent infringement Development of alternative solutions in Europe Cold absorption system : Coolsorption / Kappagi Membrane system : Vaconocore / Preussag Activated carbon + cold re-absorption : Kaldair Cogeneration : Petro-Plus (Qlear) / Schwelm Absorption / Adsorption / Absorption : Mc Gill Introduction by Germany and Switzerland of extremely low emissions Development of complex hydride systems Cold adsorption + Steam regenerated carbon : Coolsorption Membrane + Vacuum regenerated carbon : Vaconocore LRVP + Roots blowers : John Zink Thermal balance adsorption : Ties Mulder 10/64

11 Cold absorption system Clean Air Outlet Absorbents Inlet Vapour Inlet Cooler Absorber Heater Reabsorber Absorbents Return Nonane Circuit Splitter Chiller 11/64

12 Membrane system Clean Air Outlet Evnt. 2 nd Stage Vapour Inlet Separator Cooler Membrane Vacuum Pump Compressor 12/64

13 Thermal Balance Adsorption Clean Air Outlet Adsorption Filters Absorber Vapour Inlet Condenser Separator Vac pump Absorbents Heat exchanger 13/64

14 Latest developments Latest developments : Dry screw pumps systems by CarboVac Outlet Energy consumption : low Emissions : < 10 g/m 3 Maintenance : low Replacement of glycol systems by dry systems Inlet Activated Carbon Beds P Dry Screw Vacuum Pump Re-Absorber Absorbants Circulation 14/64

15 Actual situation Activated carbon = highly favourite solution since 1980 More than 90% of all recovery systems in the world In the USA, destruction by combustion still represents 40% But restrictions are coming due to : New CO 2 limitation policies (Kyoto protocol) Adoption by Petroleum Companies (BP, Shell) of internal green policies (engagement to reduce 50% of CO2 emissions) Replacement of destruction by recovery solutions 15/64

16 History of Vapour Recovery & Technologies developed Worldwide Emission legislation Closed circuit European recovery system for truck Implementation of Vapour Recovery systems on terminals Recovery product, rate, tax refund Safety aspects, ATEX, SIL 16/64

17 VOC effects VOC emissions impact on the human health (carcinogenic components) pollution of the troposphere (ozone creation) In Europe, 17 million tons /year of VOC released in the atmosphere in Implementation of legislation and several regulations in particular on emissions in hydrocarbon storage and transfer terminals 17/64

18 USA 1st Clean Air Act In the 80ies, 1st legislation : Clean Air Act on VOC Emission limit : 80 g/m 3 loaded In 1982, emission limit reduced to 35 g/m 3 loaded (general case) and locally to 10 or 6 g/m 3 loaded. Complex control measurement method to prove compliance. First with balloons and mass balance Later by using CIM and CEM 18/64

19 European legislation European Directive EC94/63 35 g / m 3 of air emitted (often 10 g / m 3 is desired - Oslo protocol) 3 phases : 1998 : a VRU for all new terminals + terminal > tons/year of gasoline 2001 : a VRU for terminal > tons/year 2004 : a VRU for terminal > tons/year Application for fuels with RVP > 276 mbar TA-Luft 01 in Germany, LRV in Switzerland If emission mass flow > 3 kg/h : 150 mg HC/ m 3 of air emitted (20. BImSchG) 5 mg / m 3 for benzene Methane is excluded (difficult to recover, only destruction possible by combustion with secondary emissions) 19/64

20 Emission control In USA : emissions measured as a function of loaded gasoline Complex system required for EPA compliance test Measurement of the entire volume during 6 hours Measurement of the average hydrocarbon concentration Measurement of the total volume of gasoline loaded during 6 hrs Calculation of the mass emitted/litre loaded averaged over 6 hrs Continuous measuring system with complex and expensive devices CIM : Control Inlet Monitoring CEM : Continuous Emissions Monitoring In Europe : emissions measured as real emission concentration Simple emissions monitor in the outlet line (infra-red detector) 20/64

21 Energy consumption versus emissions 0,3 Energy consumption (kwh/m3 treated) 0,25 0,2 0,15 0,1 0,05 EU Emissions Israeli Emissions TA-Luft Emissions Emission limit (g/m3) N.B : Data based on LRVP Systems 21/64

22 Recovery chain Refinery Losses : 0,1 kg/m3 Emission reduction measures up to 99% Total efficiency of the recovery chain is never better than the weakest link Terminal Losses : 1 kg/m3 Emission reduction measures up to 90% Service-station Car filling Losses : 1 kg/m3 Emission reduction measures up to 99,99 % Losses : 1 kg/m3 Emission reduction measures up to 99% 22/64

23 History of Vapour Recovery & Technologies developed Worldwide Emission legislation Closed circuit European recovery system for truck Implementation of Vapour Recovery systems on terminals Recovery product, rate, tax refund Safety aspects, ATEX, SIL 23/64

24 EC Directive 94/63 Stage 1 and 2 for fuel distribution... Stage 1 : Recovery of the vapour from the service-station ground tank to the truck and Recovery of the vapours from truck loading on the terminal. Stage 2 : Recovery of the vapour from the car fuel tank to the ground tank Not ratified by some countries in Europe due to lack of efficiency 24/64

25 EC Directive 94/63 Stage 1 and 2 for fuel distribution At the Service Station Stage 2 Car At the Terminal Stage 1 To VRU 25/64

26 Implementation of Stage 1... Service-station : Pressure / vacuum relief valve to be installed in the ground tank vent line Vapour return connection to be installed on the tank vent line Truck Truck modified to bottom loading Overfill protection All compartments connected to a central vapour collecting line equipped with 4" API coupler with check valve. 26/64

27 Implementation of Stage 1 Terminal : Modification from top loading to bottom loading Installation of a Vapour Recovery System Vapour collecting line to the Vapour Recovery System Use of a dedicated gasoline tank for recovered product Installation of floating roof in fixed roof type storage tanks or complete balancing of the vapour space to the VRU Integration of a new process in the terminal and adaptation of operating and safety procedures 27/64

28 Stage 1 example with fixed roof tanks Vapours Emitted Pressure Vacuum Valve Detonation Arrestor Ventilator P PT Loading Operation Tanks Absorbents Vapour Recovery Unit 28/64

29 Implementation of Stage 2 Cars : Installation of small canister in gasoline cars (91/441/CEE) Installation of large canister resisted by automobile industry Service-station Installation of vapour balance system between car fuel tank and ground tank For every litre of gasoline filled into the tank, one litre of vapour is returned to the ground tank Efficiency not demonstrated Solutions not promoted by Oil Companies 29/64

30 Typical vapour composition (Truck loading) During the loading of gasoline and diesel in trucks, the concentration of the vapours may vary between 0 to 50 % Vol. depending of : the nature of the products previously loaded. the loading station (equipped or not acc. to Stage 1 and 2 of the EC Directive) Theses hydrocarbons are generally composed of : C % Vol. C C C C C C Benzene Toluene C4 and C5 represent around 90% of the hydrocarbons at the inlet vapours 30/64

31 History of Vapour Recovery & Technologies developed Worldwide Emission legislation Closed circuit European recovery system for truck Implementation of Vapour Recovery systems on terminals Recovery product, rate, tax refund Safety aspects, ATEX, SIL 31/64

32 How to size a VRU Important data for VRU sizing for truck and rail car loading: Peak flow rate = max. flow rate generated by the loading facility (i.e max. number of loading points connected simultaneously x flow rate per point) Determination of the pressure drop of the VRU and the vapour collecting system Determination of the lines size, carbon bed diameter All vapours have to pass through the VRU. Influence on price is small. Max. throughput per cycle = max. vapour amount generated in 15 minutes (for truck loading) (i.e number of loading bays x volume loaded per cycle or vessel capacity) For continuous throughputs the cycle time is usually fixed at 12 minutes Determination of the activated carbon volume in the beds Max. throughput per 4 hour period = evaluation of the intensity of the activities at the terminal during the busiest period Determination of the required vacuum capacity Determination of the re-absorber and absorbents circulation pumps Max. daily throughput = evaluation of the loading profile per day Adjustment of the vacuum capacity 32/64

33 Typical compartment truck Compartment cover serves as pressure safety relief valve Vapour Collector connected to each compartment 4 API Vapour Coupler 33/64

34 Vapour Collecting System Truck loading Application Pressure Vacuum Safety Valve Vapour Line Detonation Arrestor Vapour arm Position Switch Level Switch Drain valve VRU 34/64

35 Vapour Collecting System Truck loading Application 35/64

36 Vapour Collecting System Truck loading Application 36/64

37 Vapour Collecting System Truck loading Application 37/64

38 Absorbent Circulation System VRU P501 P601 38/64

39 Civil works 39/64

40 Civil works 40/64

41 Electrical works : communication signals Gasoline Operations Room PC & interactive keyboard in out Cabling Vapour pipe work Nitrogen Water Vapour Recovery Unit Cabling Air Control building modem Air Compressor (instrument quality) Modem line Open/close Emergency Vent Emergency vent valve position Power Input (start/stop truck loading) Gasoline pump start /stop/running signal Site ESD signal VRU running VRU alarm Foundation drainage 41/64

42 Electrical works Safe Area Hazardous Area Control Room Cables 42/64

43 Electrical cables schematics Electrical Room PLC I VRU Power feed cable J M Instrument cables Power cables to Motors PC PC Monitoring Customer signals 43/64

44 Operational connection schematic Control Cabinet Power Cabinet CONTROL ROOM Modem VRU SUPPLIER E-Motors Instrumentations Modem LOCAL REPRESENTATIVE Modem 44/64

45 VRU Location Important parameters : Pressure drop of the vapour line - EU Directive : 55 truck coupler -Typical ΔP of a 4" API vapour coupler : -Typical ΔP of a vapour arm + hose : -Typical ΔP of an anti-deto FA : -Typical ΔP of a VRU : Max available ΔP of vapour line : 3 mbar 12 mbar 5 mbar 25 mbar 10 mbar Pressure drop of the gasoline circulation lines - Supply pump : usually close to the tank or in the pump station - Return pump : usually on the VRU foundation Accessibility for maintenance works Electrical cable routing 45/64

46 History of Vapour Recovery & Technologies developed Worldwide Emission legislation Closed circuit European recovery system for truck Implementation of Vapour Recovery systems on terminals Recovery product, rate, tax refund Safety aspects, ATEX, SIL 46/64

47 Quality of the recovered product Gasoline Application Recovered product mostly C4 and C5. Tendency to increase the absorbent s RVP Tendency to increase the absorbent s temperature Selection of a absorbent tank with a reasonable throughput 47/64

48 Typical Recovered Product Hypotheses : Vapour inlet concentration : Average outlet concentration : Average MW : Calculation : Mass of hydrocarbons at inlet per m -3 = 40 % Volume 2g / Nm (Gasoline vapours) 0.4 x x 10-3 = 1160,7 g / m -3 Masse of hydrocarbons in the outlet per m -3 inlet = 2 x (1-0.4) = 1.2 g / m -3 Masse of hydrocarbons recovered g / m -3 of inlet vapour The recovery rate : The effective recovery rate is 1.49 litre per m 3 Vapour recovery rate %. Inlet vapour 48/64

49 Tax refund in Europe Recovered product not easily measured Recovered product = only a small % of the return absorbent flow Accuracy of the metering devices not sufficient Agreement between tax authorities and oil companies to implement a fixed rate equal to 1.4 to 1.5 litre per m 3 of gasoline entering the terminal 1.4 litre/ m 3 of the gasoline throughput exempted from taxes 49/64

50 History of Vapour Recovery & Technologies developed Worldwide Emission legislation Closed circuit European recovery system for truck Implementation of Vapour Recovery systems on terminals Recovery product, rate, tax refund Safety aspects, ATEX, SIL 50/64

51 VRU Safety VRU are installed in environment containing combustible liquid and explosive gases Risks of fire and explosion with toxic emissions Preventive measures and risk analysis have to be performed : HAZOP ATEX explosion protection document (EXDOC) SIL safety integrity level risk assessment 51/64

52 ATEX Philosophy Four possible types of equipment : Assemblies Assemblies with fully specified configuration of parts Assemblies with various configuration Installations Electrical equipment VRU is an assembly with fully specified configuration of parts ( of the ATEX guideline) 52/64

53 3.7.1 Resume VRU = assembly of two different pieces of equipment : Equipment with CE marking (ATEX) : Manufacturer may presume conformity of these pieces Equipment without CE marking : Manufacturer has to cover those parts with his own conformity assessment of the whole assembly EC declaration of conformity for the whole unit ( ) Manufacturer assumes responsibility for compliance with the directive Manufacturer should provide a conformity assessment of the whole assembly Manufacturer provides clear instructions for assembly / installation / operation / maintenance in the operating manual. 53/64

54 VRU Safety features Some of the VRU safety features The whole system is explosion pressure proof to 9 barg All valves with open / closed limit switches Gasoline pumps installed below liquid level High and low level switches on the re-absorber column Temperature monitoring in the activated carbon beds Outlet temperature of the vacuum pump < 50 C Detonation arrestor in the inlet Two positive closing valves in each gasoline circulation line etc... 54/64

55 VRU Explosion proof design 55/64

56 Detonation arrestor in inlet line and Valves with limit switches 56/64

57 Gasoline return pump 57/64

58 Level control and switches 58/64

59 Temperature sensors and indicators in carbon bed 59/64

60 Dry Vacuum Pump Temperature Monitoring 60/64

61 Two safety valves in each gasoline circulation line 61/64

62 Safety Integrity Level... EN Safety integrity level risk assessment of a dry screw VRS : 4 elements to be assessed Consequence of the risk (C) Minor Injury Serious Injury or permanent incapacity Fatality or catastrophic incapacity Frequency of exposure (F) Rare to more often (0-10%) Frequent to permanent (10-100%) 62/64

63 Safety Integrity Level EN Possibility of avoidance of a hazardous event (P) Possible under certain conditions Almost impossible Demand rate (W) High W3 Low W2 Very low W1 Result of SIL risk assessment is Category a No special safety requirements 63/64

64 Result of SIL risk assessment Consequence of Risk (C) Minor Injury <1 Toxonomy Serious Injury or permanent incapacity <=1 Fatality or catastrophic incapacity C1 1 C2 >1 C3 >10 C4 Frequency of Exposure (F) Toxonomy Rare to more often ( 0-10% ) Frequent to permanent ( % ) F1 F2 F1 F2 F1 F2 Possibility of avoidance of a hazardous event (P) Possible under certain conditions P1 P1 P1 P1 P1 P1 Toxonomy Almost impossible P2 P2 P2 P2 P2 P2 Demand Rate (W) Toxonomy High W3 a b Low W2 a Very Low W1 a 1 a Result of the Risk Reduction Estimation = a, no special safety requirements 64/64