IPIECA Bruxelles 1er mars 2011 CO 2 : How refineries managed with ETS IPIECA - Bruxelles 1st march 2011

IPIECA Bruxelles 1er mars 2011 CO 2 in Europe Introduction – market rules for ETS Principles CO 2 emissions in refineries pre-existing tools Adaptation of the tools Uncertainty – still in progress

IPIECA Bruxelles 1er mars 2011 CO 2 in Europe A commercial product since 2005 It has to be « weighed » in such a manner that the buyer is confident in the quantity he paid for. European rules are documented in the EU Commission Decision on MRG (Monitoring and reporting guidelines). How does it work ? Monitoring plan Yearly verification

Regulation IPIECA Bruxelles 1er mars 2011

Method of calculation of CO 2 emissions- Principles Completeness: The search for sources of emissions of individual atmospheric pollutants must cover all activities on site. Traceability - transparency: The assumptions made and the methods used for data reporting must be documented. Records must be kept in order to ensure the traceability of data for checking. All documents relating to the process must be accessible for audit. Consistency: The atmospheric pollutant emission balances must be based on a set of data consistent with the refinerys other balance figures. Accuracy: Emissions must be calculated, insofar as possible, using methods available providing the best degree of accuracy. The uncertainty with which the result is expressed must be the subject of a documented and auditable calculation; Analysis of its components should enable identification of the improvements to be made in order to reduce them and make provision for the corresponding actions when the degree of uncertainty is considered insufficient.

IPIECA Bruxelles 1er mars 2011 Calculation of CO 2 emissions Generic expression : CO 2 = Q i (t) = Flow rate (fuel, flue gas, throughput… ) on which is based calculation of CO 2 emission of the source i, at time t C i (t)= C content of source i Complete combustion is assumed (oxidation factor=1) x Flow rate (t/h) C content (%wt) CO 2 (t/h)

IPIECA Bruxelles 1er mars 2011 Process of CO 2 emission CO 2 Products Crude Fuels air, O 2, H 2 O Furnaces Flares Reactors internal fuels Fuel balance Reaction balance Flares balance

IPIECA Bruxelles 1er mars 2011 CO 2 emissions in refineries pre-existing tools Calculation of the amount of fuel burnt: Essentially by means of pressure difference flow measurement devices Designed to manage energy performance in absolute as well as in trend Production accounting: Accounting at the refinery fenceline ; reconciliation balance for internal flows The difference in mass balance at the refinery fenceline represents the sum of losses + fuel consumption Accounting losses constitutes the reconciliation term

IPIECA Bruxelles 1er mars 2011 Fuel balance Mass balance in = out Enthalpic balance H fuel = H process + thermal losses Produced FG Consumed FG in out H fuel H process Losses (flue, walls) Process in Process out

IPIECA Bruxelles 1er mars 2011 Fuel balance f1f1 fifi fnfn F1F1 FiFi FnFn Raw data Reconciled data

IPIECA Bruxelles 1er mars 2011 Mass balance Fuels Flue gases losses Flares Products - OUT Tanks IN = OUT + Delta stock + fuels + losses Losses = physical losses (flares) + balance term Throughput - IN flares accounting

Usual tool : fuel flow meter Flow rate measurement by means of a pressure differential device Q wt CO2 = Q fuel *%C fuel *44/12 IPIECA Bruxelles 1er mars 2011

Products to fractionation Usual tool: FCC Simplified flow diagram FCC feed flue Reactor Regenerator Q air %N 2air %CO 2 %O 2 %CO %N 2 Others … Flue gas catalyst (based on dry flue gas) N2N2 (1) - Mass balance N 2 : Q N2 smoke + Q N2 to fractionation + 1/2 x Q NOx = Q N2 in (2) - Q smoke = (3) - Q wt CO2 = (% vol CO2 + % vol CO ) * Q smoke * MW CO2 / Soit : Q wt CO2 = f(% vol CO2, % vol CO, % O2,…, Q air, N 2 effluent ) IPIECA Bruxelles 1er mars 2011

How refineries met the requirements Completeness No difficulty to meet Traceability - Transparency Fuel accounting procedures were not well documented and the accounting itself was poorly traced. Actions : Generalization of procedures registered in the documentation system under quality insurance. Generalization of registering all modifications made to the raw set of data in order to obtain the official set Consistency Harmonisation of procedures for material balance Some difficulties in harmonizing monthly data with later corrections (annual data for CO 2 vs monthly data for other purposes)

IPIECA Bruxelles 1er mars 2011 Accuracy : Requirements from the European Decision on MRG Fuels Definition : fuels are grouped by « source stream », defined as « specific fuel type ». Flow rate measurement : annual consumption must be calculated with an uncertainty less than 1,5% C content : Liquid : analysis has to be performed by a laboratory certified ISO or equivalent Gas : the chromatograph must have an initial verification and an annual cross-check. Frequency of sampling : in the base case, 1/day for Fuel Gas FCC CO 2 : annual CO 2 emissions from the FCC must be calculated with an uncertainty less than 2,5% On-line analyser : same requirement as for the chromatograph, assuming a particular interpretation of the Decision.

IPIECA Bruxelles 1er mars 2011 Accuracy : gap analysis Material balance at the refinery fenceline is not accurate enough for the purpose of ETS : Accuracy of the overall balance is set by that of the certified meters i.e. 0,3% The term losses + fuels constitutes approximately 6% of the crude throughput The reconciliation term may therefore constitute 0,3 / 6 = 5 % of the fuel consumption Flow measurement of fuels by simple pressure differential devices does not meet the required accuracy level.

IPIECA Bruxelles 1er mars 2011 Accuracy : Uncertainty calculation Principles: Error propagation law : the simplified rules in the MRG give a good basis for practical use Measurement uncertainty factors are classified according to their level of correlation into 2 categories: correlated or independant. Practical adaptation : Elimination of some over-simplified methods, such as attributing a standard relative uncertainty to measurements obtained by a pressure differential device (see above) Calculation of the total annual amount of a flow : correlation between parameters in 2-dimensions Time correlation Correlation between measurement devices at the same time

IPIECA Bruxelles 1er mars 2011 uncertainty calculation : mass flow with pressure differential device product conditions Measureme nt of P P device PipeAssembling Data treatment Mass flow SG 15 viscosity temperature pression conversion compression Numerical treatment sensibilities Zero drift Scale drift diameter Surface condition diameter Pipe roughness tappings Straight lengths Ambiant conditions edge sharpness

IPIECA Bruxelles 1er mars 2011 C content for fuels No reference standard Organization of Round Robin tests inter companies and inter countries Round Robin tests for Fuel Gas : According to DIN 51666, in progress for EN homologation 1 test / year on 2 measurements by each laboratory, on the same sample A little better than the repeatability and reproducibility of the norm Beware of the risk of air contamination of the sample Round Robin tests for Fuel Oil : According to ASTM D 5291 No problem

IPIECA Bruxelles 1er mars 2011 FCC CO 2 emissions Air flow-rate measurement (Q masse air ) Industrial device better than 1,5% uncertainty? Pitot : no norm available Other : calibration devices for ranges 10 5 Nm 3 /h ? CO 2 concentration in flue gases: Uncertainty Uncertainty on instantaneous measurement >> 2,5 % Uncertainty on annual amount of CO 2 : Reduced by means of periodic gauging : complex mechanisms Result: ?

IPIECA Bruxelles 1er mars 2011 FCC CO 2 emissions: Uncertainties FCC SO2 or CO2 N2 Air rate H2O & N2 to fractionation Result 3% 2%0,5% 4,7%

IPIECA Bruxelles 1er mars 2011 Organisation CO 2 calculations require new tools, also changes in the usual refinery organisation : Tightening of fuel balances : methods similar to legal metrology Coordination between services : Maintenance, material acccounting, environment and mathematical uncertainty calculation

IPIECA Bruxelles 1er mars 2011 Back-up Incertitude du débit mesuré par plaque à orifice Sensibilité de lincertitude de mesure de débit vs étendue déchelle Exemple de feuille de calcul pour la somme de combustibles RRT FG Influence de la réconciliation de données sur lincertitude

IPIECA Bruxelles 1er mars 2011 Incertitude sur une mesure de débit par plaque à orifice (1) La norme ISO donne lexpression de lincertitude du débit Q : Les principaux paramètres dinfluence sont : La masse volumique aux conditions de fonctionnement Le diamètre de la plaque à orifice Et dans une moindre mesure le coefficient de décharge C Par ailleurs, la formule représente lincertitude pour un débit égal à léchelle de mesure. Le pourcentage du débit mesuré par rapport à léchelle de lappareil est un paramètre de premier ordre pour le calcul de lincertitude

Incertitude sur une mesure de débit par plaque à orifice (2) Variation de lincertitude pour 2 couples de valeurs dincertitudes sur le diamètre de la plaque à orifice et du transmetteur de delta P et en fonction des incertitudes sur la masse volumique et du pourcentage de la mesure par rapport à léchelle de mesure. IPIECA Bruxelles 1er mars 2011

Calcul dincertitude

IPIECA Bruxelles 1er mars 2011 RRT for FG

IPIECA Bruxelles 1er mars 2011 Incidence de la réconciliation du bilan combustible Réconciliation de données: Améliore la précision du bilan brut issu des systèmes de mesurage Agit selon 2 mécanismes : Correction derreurs détection des mesures de débit défaillantes. substituer une valeur vraisemblable Réduction de lincertitude proprement dite Prise en compte de mesures de débit redondantes Algorithme de minimisation des erreurs Prise en compte: Réseau de combustibles avec n producteurs et p consommateurs Facteur de réduction de lincertitude (dans un cas simple):