1、I/PETRO PUBL 4692-ENGL L999 1111 0732290 Ob27397 b9 A DECISION-MAKERS GUIDE TO DISPERSANTS A REVIEW OF THE THEORY AND OPERATIONAL REQUIREMENTS HEALTH AND ENVIRONMENTAL SCIENCES DEPARTMENT PUBLICATION NUMBER 4692 MARCH 1999 American Petroleum Institute STD*API/PETRO PUBL 4692-ENGL 1999 I 0732290 Oh27
2、338 BT5 = American Petroleum Institute American Petroleum Institute Environmental, Health, and Safety Mission and Guiding Principles MISSION The members of the American Petroleum Institute are dedicated to continuous efforts to improve the compatibility of our operations with the environment while e
3、conomically developing energy resources and supplving high quality products and services to consumers. We recognize our responsibility to work with the public, the government, and others to develop and to use natural resources in an environmentally sound manner while protecting the health and safety
4、 of our employees and the public. To meet these responsibilities, API members pledge to manage our businesses according to the following principles using sound science to prioritize risks and to implement cost-effective management practices: - PRINCIPLES e e e To recognize and to respond to communit
5、y concerns about our raw materials, products and operations. To operate our plants and facilities, and to handle our raw materials and products in a manner that protects the environment, and the safety and health of our employees and the public. To make safety, health and environmental consideration
6、s a priority in our planning, and our development of new products and processes. To advise promptly, appropriate officials, employees, customers and the public of information on-significant industry-related safety, health and environmental hazards, and to recommend protective measures. To counsel cu
7、stomers, transporters and others in the safe use, transportation and disposal of our raw materials, products and waste materials. To economically develop and, produce natural resources and to conserve those resources by using energy efficiently. To extend knowledge by conducting or supporting resear
8、ch on the safety, health and environmental effects of our raw materials, products, processes and waste materials. To commit to reduce overall emission and waste generation. To work with others to resolve problems created by handling and disposal of hazardous substances from our operations. To partic
9、ipate with government and others in creating responsible laws, regulations and standards to safeguard the community, workplace and environment. To promote these principles and practices by sharing experiences and offering assistance to others who produce, handle, use, transport or dispose of similar
10、 raw materials, petroleum products and wastes. STD.API/PETRO PUBL 4692-ENGL 1999 0732290 Ob27379 731 A Decision-Makers Guide to Dispersants A Review of the Theory and Operational Requirements Health and Environmental Sciences Department API PUBLICATION NUMBER 4692 PREPARED UNDER CONTRACT BY: D.K. SC
11、HOLZ, J.H. KUCKLICK, R. POND, A.H. WALKER, A. BOSTROM, AND P. FISCHBECK SCIENTIFIC AND ENVIRONMENTAL ASSOCIATES, INC. CAPE CHARLES, VIRGINIA MARCH 1999 American Petroleum Institute STD=API/PETRO PUBL 4b92-ENGL I999 0732290 Ob27400 283 = API PUBLICATIONS NECESSARILY ADDRESS PROBLEMS OF A GENERAL NATU
12、RE. W“ RESPECT To PARTICULAR CIRCUMSTANCES, LOCAL, STATE, AND FEDERAL LAWS AND REGULATIONS SHOULD BE REVIEWED. API IS NOT UNDERTAKING To MEET THE DUTIES OF EMPLOYER!$ MANUFAC- TURERS, OR SUPPLIERS TO WARN AND PROPERLY TRAIN AND EQUIP THEIR EMPLOYEES, AND OTHERS EXPOSED, CONCERNING HEALTH AND SAFETY
13、RISKS AND PRECAUTIONS, NOR UNDERTmG THEIR OBLIGATIONS UNDER LOCAL, STATE, OR FEDERAL LAWS. NOTHING CONTAINED IN ANY API PUBLICATION IS To BE CONSTRUED AS GRANTING ANY RIGHT, BY IMPLICATION OR OTHERWISE, FOR THE MANU- FACTURE, SALE, OR USE OF ANY METHOD, APPARATUS, OR PRODUCT COV- ERED BY LETTERS PAT
14、ENT. NEITHER SHOULD ANYTHING CONTAINED IN ITY FOR I“GEMENT OF LETTERS PATENT. THE PUBLICATION BE CONSTRUED AS INSURING ANYONE AGAINST LIABIL- All righri reserved No part of this work may be reproduced, stored in a retrieval system, or transmitted by my mea, electronic, mechanical, photocopying, reco
15、rding, or otherwise, without prior written permission from rhe publisher: Contact the publishel; API Publishing Services, i220 L Street, N.W. Washington, D.C. 2OWS. Copyright Q 1999 American Petroleum institute iii Previous page is blank. THE FOLLOWING PEOPLE ARE RECOGNIZED FOR THEIR CONTRIBUTIONS O
16、F TIME AND EXPERTISE DURING THIS STUDY AND IN THE PREPARATION OF THIS REPORT: API STAFF CON“ ACT Alexis Steen, Health and Environmental Sciences Department MEMBERS OF THE OIL SPILL SCIENCE AND TECHNOLOGY WORK GROUP David Fritz, Chairperson, Amoco Dan Allen, Chevron North America E . 7 3 Comparison o
17、f the Relative Oil Concentrations of Oil Droplets into the Water Column Over Time Resulting From Natural Dispersion and Chemical Dispersion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15 Boat/Ship-base
18、d Dispersant Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 DC-3 Spraying Dispersant . . . . . . 26 Helicopter Spraying Dispersant . . . . . , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26 . 4 5 6 LIS
19、T OF TABLES Table Page 1 Persistence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3 2 3 4 5 Dispersants Listed on the NCP Product
20、Schedule as of December 1997 . 5 Salinities of Various Water Bodies . 19 Comparison and Defuiition of Sea Conditions . 20 Relative Dispersibility Categories for Various Crude Oils and Refined Products, Based on API Gravity Values and Pour Point 22 Dispersant Use for Major Oil Spills in the United St
21、ates, 1969- 1998 . . . . . . . , . . . . . .24 A Summary of Dispersant Pre-authorization, as of December 1998 by RRT Region . . . . . . . , . . . . . . . . . .29 6 7 STD-API/PETRO PUBL 4b92-ENGL 1449 0732240 Ob27407 638 W OVERVIEW The American Petroleum Institute (APO commissioned the preparation of
22、 three booklets to help bridge the gap in the understanding of dispersant use, effectiveness, and effects. This booklet (second in the series) focuses on chemical dispersant technology and the information needs of decision-makers when attempting to make informed decisions regarding the use of chemic
23、al dispersants, their potential benefits and risks. Crude oil is a complex mixture of thousands of different compounds, composed primarily of carbon, hydrogen, sulfur, nitrogen, and oxygen. Hydrocarbons (composed solely of carbon and hydrogen atoms in various combinations) are the most abundant comp
24、ounds found in crude oils. Dispersants are chemicals composed of surface-active agents (surfactants) and solvents. The surfactants in the dispersants reduce the interfacial tension of the water and promote the break-up of the slick into fine droplets, facilitating the dispersion of the oil into the
25、water column. They act to prevent the recoalescence of suspended, chemically dispersed oil droplets. The solvent component of chemical dispersants assists surfactants in the penetration and alignment within the oil. Dispersants are designed to break up surface slicks and disperse the oil as fine dro
26、plets into the water column immediately under the slick. These chemicaily dispersed droplets will be further diluted within the water column as the droplets are subjected to natural dispersion through advection forces. Chemical dispersants lower the water interfacial tension, thus enabling wave acti
27、on to transfer the oil from one location (the water surface) to another (spread out within the water column). An energy source (often in the form of wave action) is required to mix the chemically dispersed oil droplets into the water column. Some of the smaller oil droplets can remain dispersed in t
28、he water column for a long time. Use of dispersants is considered a viable response technique as they may: 1. 2. 3. 4. 5. 6. 7. reduce the overall impact of oil on many habitats; prevent oil from stranding on sensitive shorelines and other economically important resources (e.g., boats, marinas, shel
29、lfish beds); reduce potential damage to birds, marine mammals, and other natural resources that could be impacted by oil on the water surface; provide a clean-up option when other response techniques are less effective (e.g., waves too high for booms and skimmers); enhance microbial degradation and
30、evaporation by increasing the surface area of the oil droplets; remove the oil from the action of the wind that may ultimately bring the oil ashore; and reduce the formation of tarballs and mousse. Previous page is blank. STDmAPIIPETRO PUBL 4692-ENGL 1999 O732290 0627408 574 m a a e e There is a gre
31、ater potential that esources that exist in the water column (e.g., fish) will be exposed to chemically dispersed oil droplets than if the slick were to remain untnated on the water surface (note that there are exceptions to every genedizaion). Exposure potential is greatest directly under the slick
32、and would diminish with depth and distance from the oil source. Chemically dispersed oil droplets (generally less than 10 to 20 microns in diameter) will remain in the water column for extended perios of time, where the chemically dispersed droplets will undergo natural weathering processes (dissolu
33、tion, biodegradation). Concentrations of oil dispersed under slicks are typically greater when oil is chemically dispersed than if left to naturally disperse. Naturally dispersed oil concentrations are typically measured in the 100-500 ppb (0.14.5 ppm) range for the upper three meters of the water c
34、olumn under freshly spilled andor released oils. Peak concentrations of chemically dispersed oil in the upper three meters of the water column are typically less than 10 ppm, but have been measured for brief periods in the 20-50 ppm range; these concentrations are generally greater than those measur
35、ed for natural dispersion, by a factor of 40 or more. Pre-spill planning is necessary to facilitate the use of chemical dispersants during actual spill response decision-making. The decision to use chemical dispersants is based on several factors afecting each incident, including: 1. environmental i
36、ssues: sea state, salinity, water temperature, and specific issues related to the ecosystem at risk; 2. oil issues: chemical composition of the oil, the degree of weathering the oil has undergone; and 3. dispersant issues: federal and state approval for use, availability, and application personnel a
37、nd strategy. Application rates are important; the average recommended dispersant-to-oil ratio is 1 to 20. However, during recent spills off Great Britain, dispersant-to-oil application ratios averaged from 1 to 65 to as little as 1 to 80. In order to disperse heavy or weahered oils, a dispersant to
38、oil ratio greater than 1 to 20 may be necessary. Several application systems have proven to be effective in applying chemical dispersants (vessel-based, fixed wing aimaft or helicopter systems). Applying chemical dispersants effectively requires trained and skilled personnel. Following a dispersant
39、application, it is valuable to monitor the application to determine if the dispersant was applied at the appropriate dosage in the correct locations, if the dispersant is working effectively, and if there are any obvious (qualitative) ecological effects. Data obtained from monitoring are used to imp
40、rove future dispersant use decision-making through long-term data gatherhg. STD=API/PETRO PUBL Yh92-ENGL 1999 I 0732290 Ob27409 400 W INTRODUCTION Purpose of Section Consider this.an oil tanker has grounded offshore, releasing some or . Introduce fie subject. all of its cargo. It is your job to reco
41、mmend response options to protect the sensitive nearshore environment. One of the recommendations that the Purpose and Or- gonization of the booklet. you are considering is the use of chemical dispersants on the already expanding surface slicks. You need a concise, complete, and easy-to- use summary
42、 of dispersant technology, to refresh your memory and sup- port your decisions. This booklet is designed to fill that need. PURPOSE OF BOOKLET This booklet was developed for oil spill response decision-makers, to provide an accurate summary of chemical dispersant technology. To make informed decisio
43、ns on using dispersants, or any countermeasure, it is important fxst to have a clear understanding of the potential ben- efits and risks. How do these chemicals work? Are they safe to use? Why should they be used? Under what conditions are chemical dispersants appropriate? What are the operational i
44、ssues involved with chemical dispersant applications? All of these answers are found in this booklet, in an easy-to-use format supplemented with diagrams and figures. To address chemical dispers- ant technology fully, this booklet has been divided into three parts. Part I provides a brief review of
45、oil chemistry: more details can be found in the first booklet in this series, “Fate of Spilled Oil in Marine Waters: Where Does It Go, What Does It Do, and How Do Dispersants Affect It?“ Part II provides a detailed discussion on chemical dispersants and their mechanism of action. This section briefl
46、y compares and contrasts chemi- cal dispersion with natural dispersion and dissolution. Part III comprehensively reviews the operational issues associated with chemical dispersant applications, including: application rates and vari- ables that affect these rates, equipment needs, effectiveness issue
47、s, moni- toring issues, and application limitations and restrictions. 1 STD-API/PETRO PUBL 4692-ENGL 1999 E 0732290 Ob27430 322 Purpose of Pari I To review information on general oil properties. Hydrocarbons are chemi- cal compounds found within crude oils and refined prod- ucts that are composed so
48、lely of carbon and hydrogen at- oms in various combinations. Hydrocarbons are the most abundant compounds found in crude oils; up to 85 percent. Truce Metuis, such as nickel, vanadium, iron, alumi- num, sodium, calcium, copper and others, are chemical ele- ments ypically found in small quantities in
49、 petroleum. Asphuhnes and Waxes are complex hydrocarbons ittat contain trace elements in their structure: these com- pounds are considered rela- tively inert and resistent to most weathering processes. Examples of Light-weight Molecules Found in Oil I pentane H H H benzene 01 Example of Medium- weight Molecules Found in Oil I phenanthrene I PART I: OIL CHEMISTRY REVIEW The chemical components and characteristics of crude and refined oils are reviewed in this section. An individual oils chemistry influences dispersion processes and dispersa
