1、Carbon Content, Sampling, and CalculationAPI TECHNICAL REPORT 2572 FIRST EDITION, MAY 2013Special NotesAPI publications necessarily address problems of a general nature. With respect to particular circumstances, local, state, and federal laws and regulations should be reviewed.Neither API nor any of
2、 APIs employees, subcontractors, consultants, committees, or other assignees make any warranty or representation, either express or implied, with respect to the accuracy, completeness, or usefulness of the information contained herein, or assume any liability or responsibility for any use, or the re
3、sults of such use, of any information or process disclosed in this publication. Neither API nor any of APIs employees, subcontractors, consultants, or other assignees represent that use of this publication would not infringe upon privately owned rights.Users of this technical report should not rely
4、exclusively on the information contained in this document. Sound business, scientific, engineering, and safety judgment should be used in employing the information contained herein.API publications may be used by anyone desiring to do so. Every effort has been made by the Institute to assure the acc
5、uracy and reliability of the data contained in them; however, the Institute makes no representation, warranty, or guarantee in connection with this publication and hereby expressly disclaims any liability or responsibility for loss or damage resulting from its use or for the violation of any authori
6、ties having jurisdiction with which this publication may conflict.API publications are published to facilitate the broad availability of proven, sound engineering and operating practices. These publications are not intended to obviate the need for applying sound engineering judgment regarding when a
7、nd where these publications should be utilized. The formulation and publication of API publications is not intended in any way to inhibit anyone from using any other practices.Any manufacturer marking equipment or materials in conformance with the marking requirements of an API standard is solely re
8、sponsible for complying with all the applicable requirements of that standard. API does not represent, warrant, or guarantee that such products do in fact conform to the applicable API standard.All rights reserved. No part of this work may be reproduced, translated, stored in a retrieval system, or
9、transmitted by any means, electronic, mechanical, photocopying, recording, or otherwise, without prior written permission from the publisher. Contact the Publisher, API Publishing Services, 1220 L Street, NW, Washington, DC 20005.Copyright 2013 American Petroleum InstituteForewordNothing contained i
10、n any API publication is to be construed as granting any right, by implication or otherwise, for the manufacture, sale, or use of any method, apparatus, or product covered by letters patent. Neither should anything contained in the publication be construed as insuring anyone against liability for in
11、fringement of letters patent.Suggested revisions are invited and should be submitted to the Standards Department, API, 1220 L Street, NW, Washington, DC 20005, standardsapi.org.iiiContentsPage1 Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
12、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Terms, Definitions, and Symbols. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12.1 Terms and Definitions. . . . . . . . . . . . . . . . . . . . . . . . . . . .
13、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12.2 Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Sample Collection and Handling . . . . . .
14、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33.2 Gas Fuel Sa
15、mple Collection and Handling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33.3 Liquid Fuel Sample Collection and Handling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33.4 Frequency of Sam
16、pling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 Sample Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
17、. . . 34.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34.2 Chromatographic Analysis of Fuel Samples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
18、. . . . . . . . . . . . 44.3 Test Methods for Determination of Carbon Content . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 Determination of Carbon Content and Calculation of Emissions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45.1
19、 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45.2 Carbon Content of a Pure Component . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
20、. . . . . . . . . 45.3 Carbon Content Calculated from Product Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45.4 Estimation of Carbon Content from Other Fuel Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65.5
21、 Calculation of Emissions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76 Reporting Period Carbon Content Uncertainty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
22、 76.1 Objective. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76.2 Reporting Period Carbon Content Calculated from Multiple Gas Samples . . . . . . . . . . . . . . . . . . . . . . . . . 7
23、Annex A (informative) Estimation of Carbon Content Correlation to Fuel Properties. . . . . . . . . . . . . . . . . . . . . 10Annex B (informative) Estimation of Carbon Content Uncertainty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16Bibliography . . . . . . . . . . . . .
24、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23FiguresA.1 Calculated Carbon Content to Relative Density Correlation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12A.2 Nitrogen Upset F
25、uel Carbon Content Calculated from Monte Carlo Simulation Results . . . . . . . . . . . . . 13A.3 Nitrogen Upset Fuel Carbon Content vs Relative Density . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13A.4 Multiple Component Variations Carbon Content Calculated from Mont
26、e Carlo Simulation . . . . . . . . . . 14A.5 Multiple Component Variations Fuel Carbon Content vs Relative Density . . . . . . . . . . . . . . . . . . . . . . . . 14B.1 Spot Sample Adjusted Carbon Content to Relative Density Correlation . . . . . . . . . . . . . . . . . . . . . . . . . . 17B.2 Quart
27、erly Sampling and Relative Density Calculations Compared to Quarterly Sampling . . . . . . . . . . . 19B.3 Monthly Sampling and Relative Density Calculations Compared to Monthly Sampling . . . . . . . . . . . . . 21B.4 Composition Variability of the Four Fuel Streams. . . . . . . . . . . . . . . . .
28、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22Tables1 Example Carbon Content Calculation for a Fuel Mixture Reported in Mole Fraction . . . . . . . . . . . . . . . . . 52 Example Carbon Content Calculation for a Fuel Mixture Reported in Mass Fraction . . . . . . . . . . . . . . . . 6A.1
29、 Average Process Composition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10A.2 Average Process Composition Plus Nitrogen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11B.2 S
30、pot Sample Sets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18B.3 Stream Compositions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31、. . . . . . . . . . 18B.4 Summary of Improvement in Annual Carbon Content Determination . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19B.5 Summary of Standard Deviation, Uncertainty, and Quarterly/Monthly Sampling Data. . . . . . . . . . . . . . . 20vIntroductionCarbon emission quantities
32、 can be calculated from either the volume/mass of fuel or feedstock fed to a process (asapplicable) and carbon content of the process or fuel supply, or by directly measuring volume/mass emissions. This Technical Report (TR) provides guidance on the sampling and calculation of carbon content of proc
33、ess or fuelsupplies. The API companion technical report, API TR 2571, Fuel Gas Measurement, can be referenced for guidanceon measuring the volume/mass of process fuel gas or feedstock, and the API Compendium of Greenhouse GasEmissions Estimation Methodologies for the Oil and Natural Gas Industry can
34、 be reference for guidance on thecalculation of emissions.vi1Carbon Content, Sampling, and Calculation1 ScopeThis Technical Report (TR) provides guidance and a methodology for determination of carbon content from hydrocarbon-based petroleum and petrochemical products, and the uncertainty of the aver
35、age carbon content as calculated from multiple samples taken during a reporting period. This method is intended to make use of industry-accepted mixture property data and test methods with no new or modified test methods introduced in this document. The method is applicable to carbon-content-based r
36、eporting or trading for all gaseous and liquid hydrocarbons.This TR provides references and supplemental information on applicable industry practices based on the published resources, existing industry standards, industry-accepted physical constants or properties of hydrocarbons for measurement, sam
37、pling, sampling frequency, and analysis of hydrocarbon samples.2 Terms, Definitions, and Symbols2.1 Terms and DefinitionsFor the purposes of this document, the following definitions apply.2.1.1 accuracyThe ability of a measurement instrument to indicate values closely approximating the true value of
38、 the quantity measured.2.1.2 biasAny influence on a result that produces an incorrect approximation of the true value of the variable being measured. Bias is the result of a predictable systematic error.2.1.3 calibrationThe process or procedure of adjusting an instrument so that its indication or re
39、gistration is in satisfactorily close agreement with a reference standard.2.1.4 carbon contentThe fraction of carbon in the fluid expressed as percent by weight.2.1.5 compensationThe adjustment of the measured value to reference conditions (e.g. pressure compensation).2.1.6 continuous emission monit
40、oring system CEMSThe equipment required to sample, analyze, measure, and provide, by means of monitoring at regular intervals, a record of gas concentrations, pollutant emission rates, or gas volumetric flow rates, individually or in combination, from stationary sources.2.1.7 flowing compressibility
41、The compressibility of the fluid at actual flowing temperature and pressure.2 API TECHNICAL REPORT 25722.1.8 flowing densityThe density of the fluid at actual flowing temperature and pressure.2.1.9 fuel gasTypically a mixture of light hydrocarbon and other molecules (e.g. H2, N2) in a gaseous state
42、that are consumed in fired heaters. Fuel gas is often a mixture of recovered gaseous molecules from plant operations and purchased natural gas.2.1.10 higher heating valueHHVThe high or gross heat content of the fuel with the heat of vaporization included. The water is assumed to be in a liquid state
43、.2.1.11 influence parameterAny factor that impacts the performance of the measuring device, hence the uncertainty and accuracy of the measurement. Examples are process temperature, pressure, fluid composition, upstream straight length, etc.2.1.12 inspectionA visual assessment or mechanical activity
44、(e.g. instrument lead line blow down or orifice plate cleanliness) that does not include comparison or adjustment to a reference standard.2.1.13 meter condition factor An estimate of additional uncertainty based on a technical judgment of the physical condition of the meter in lieu of the ability to
45、 inspect.2.1.14 metering or measurement systemA combination of primary, secondary and/or tertiary measurement components necessary to determine the flow rate.2.1.15 performanceThe response of a measurement device to influence parameters such as operating conditions, installation effects, and fluid p
46、roperties.2.1.16 range of uncertaintyThe range or interval within which the true value is expected to lie with a stated degree of confidence.2.1.17 uncertaintyDescribes the range of deviation between a measured value and the true value, expressed as a percentage. For example, a device with an accura
47、cy of 2 % would have an uncertainty of 2 %.2.1.18 verificationThe process or procedure of comparing an instrument to a reference standard to ensure its indication or registration is in satisfactorily close agreement, without making an adjustment.CARBON CONTENT, SAMPLING, AND CALCULATION 32.2 Symbols
48、For the purposes of this document, the following symbols apply.AWCarbonatomic weight of carbon (e.g. 12.011)CC carbon content expressed as the weight fraction of carbon to the componentCCAveragereporting period average carbon contentCCMixturecarbon content weight fraction of mixtureMWComponentmolecu
49、lar weight of component (e.g. 44.0956 g/mole for propane) MWimolecular weight of component in the number of carbon atoms in the component (e.g. for propane, C3H8, n = 3)Xmimole fraction of component iXwimass fraction of component i standard deviation3 Sample Collection and Handling3.1 GeneralThe primary purpose of sample collection and handling is to ensure that a representative sample of the product is taken and that the sample is handled in a manner that does not compromise composition of the sample. 3.2 Gas Fuel Sample Collection and HandlingAPI MPMS Ch. 14.1 4provides guidance on
