Refinery Stream Composition Data - Update to Speciation Data in API 4723

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Organization: API
Publication Date: 1 December 2018
Status: active
Page Count: 276


Passage of the Clean Air Act Amendments of 1990 created a number of new compliance challenges for the United States refining industry. To provide improved approaches to meeting these challenges and allow leveraging of research expenditures, a number of the members of the Petroleum Environmental Research Forum (PERF) formed the Cooperative Air Program (CAP). The CAP consisted of a number of individual research projects, including a project to develop industry-representative concentration profiles for refinery process streams. This effort was undertaken to improve emissions estimates for regulatory applicability determinations, operating permits, risk assessments, and other applications. The results of the CAP work were published as API Publication 4723, Refinery Stream Speciation [1].

The refinery stream speciation profiles presented in API 4723 were developed from available stream sampling data from participating PERF companies. Most of these data were collected in the 1980s and 1990s. The speciation profiles were based on analyses from 31 refineries, over 20 different process units, and 65 refinery process streams. One of the most significant observations was the wide range of the reported concentrations for some of the chemical species. Since process units usually monitor and control operations based on physical properties such as temperature or pressure, the range of compositions in a specific process stream may vary widely depending on the product slate, processing severity, and other factors.

Since the publication of API 4723 in 2002, new regulatory requirements have resulted in many changes in refinery processes that may have altered process stream compositions. Changing feedstocks, new process additives, and new catalysts may also have affected the concentrations of chemical species present in specific process streams.

Based on an assessment of the range and depth of more recent stream speciation data, PERF elected to update the stream speciation profiles using more recent composition sampling. The updated profiles are provided in this report. PERF members believe that the newer data are more representative due to improved sampling and analytical techniques and that these newer analyses better reflect changes in refinery operations over recent years.

A large database of records was collated for the current study, representing information from 25 refineries. Each record includes the annual average concentration of a chemical species in a given process stream for a given refinery. For this report, dataset refers to a collection of records for a given process stream and chemical species combination.

The original study reported on 24 chemical species and the current study provides data on 89 species. The original study reported on 65 refinery process streams and the current project provides data on 68 process streams.

The process units and streams considered are shown in Table 1.

This report is divided into a number of sections that describe the data collection and analysis procedures, contain tables of stream compositions, and provide a graphical presentation of the data.

Section 2 provides a summary of the data gathering methodology. It contains a list of the process units and streams, and the chemical species included in the study.

Section 3 provides the data analysis methodology, including summaries of data quality and quantity.

Section 4 provides the stream composition data in tabular form. First, the number of annual average concentration values used in the current study for the process streams are presented. This is followed by a table listing the number of annual average concentration values by chemical species. The remaining tables provide statistical information for each process unit and associated stream, including the minimum, maximum, and most likely values (MLVs) of the concentration of each compound. These tables (Tables 7 through 74) are the main product of this study.

Section 5 provides a comparison of this updated study to the data in API 4723.

Appendix A contains the process flow diagrams from the original study that were provided as a reference to refineries submitting data.

Appendix B provides graphical presentations of the data by process unit and stream. These graphs show the current study data, current study MLV, and original study MLV for groups of species in each process unit.

Appendix C provides the formulas used within the statistical program (R code) for data conversion to weight percent. See Section 3.1 for further discussion.

The material contained in this report will be of use in estimating the emissions of specific chemical species, preparing permit applications, and performing other environmental assessments. API, PERF, and the project participants make no claims as to the suitability or acceptability of the stream composition data reported herein for specific reporting or regulatory purposes.

Document History

December 1, 2018
Refinery Stream Composition Data - Update to Speciation Data in API 4723
Introduction Passage of the Clean Air Act Amendments of 1990 created a number of new compliance challenges for the United States refining industry. To provide improved approaches to meeting these...