1、API PUBL*3LLOL 93 0732290 I Executive Summary II Environmental 05288b0 3LT . Design I . z - Considerations .I -for I / Units , U _ I I. API PUBLX3LLOL 93 0732290 0528863 256 = Environmental Design Considerations for Petroleum Refining Crude Processing Units Executive Summary Health and Environmental
2、 Affairs Department API PUBLICATION NUMBER 31 1 O1 FEBRUARY 1993 PREPARED UNDER CONTRACT BY: THE M.W. KELLOGG COMPANY HOUSTON, TEXAS American Petroleum Institute API PUBL*3LLOL 93 m 0732290 O528862 192 m FOREWORD API PUBLICATIONS NECESSARILY ADDRESS PROBLEMS OF A GENERAL NATURE. WITH RESPECT TO PART
3、ICULAR CIRCUMSTANCES, LOCAL, STATE, AND FEDERAL LAWS AND REGULAmONS SHOULD BE REVIEWED. TURERS, OR SUPPLIERS To WARN AND PROPERLY TRAIN AND EQUIP THEIR EMPLOYEES, AND OTHERS EXPOSED, CONCERNING HEALTH AND SAFETY RISKS AND PRECAUTIONS, NOR UNDERTAKING THEIR OBLIGATIONS UNDER LOCAL, STATE, OR FEDERAL
4、LAWS. NOTHING CONTAINED IN ANY API PUBLICATION IS TO BE CONSTRUED AS API IS NOT UNDERTAKING TO MEET THE DUTIES OF EMPLOYJXS, MANUFAC- GRANTING ANY RIGHT, BY IMPLICATION OR OTHERWISE, FOR THE MANU- FACTURE, SALE, OR USE OF ANY METHOD, APPARATUS, OR PRODUCT COV- THE PUBLICATION BE CONSTRUED AS INSURIN
5、G ANYONE AGAINST LIABJL- ERED BY LETTERS PATENT. NEITHER SHOULD ANYTHING CONTAINED IN Y FOR INFRINGEMENT OF LETTERS PATENT. Copyright Q 1993 American Petroleum institute ii API PUBL*3LLOL 93 W 0732290 0528863 O29 ACKNOWLEDGMENTS THE FOUOWING PEOPLE ARE RECOGNIZED FOR THEIR CONTRIBUTIONS OF TIME AND
6、EXPERTISE DURING THIS STUDY AND IN THE PREPARATION OF THIS REPORT API STAFF CONTACT(s) Barbara Bush, Health and Environmental Affairs Department Genevieve iaffly, Manufacturing, Distribution use of vacuum pumps to replace all or part of the steam jet ejector system to provide the vacuum for the vacu
7、um tower; use of reboiled sidestrippers on the atmospheric tower rather than open steam stripping to reduce the quantity of sour condensate; replacement of first generation low NO, burners with new generation low NO, burners in furnaces; use of catalytic and non-catalytic processes for the selective
8、 reduction of NO,; reuse of stripped sour water to replace clean process water as desalter water; and 2 API PUBL*3LLO1 93 O732290 0528866 38 heat integration for maximum energy utilization (commonly referred to as pinch analysis). 1.2 Limitations of Study Results Numerous pollution prevention concep
9、ts have been evaluated and reported in this study, but no optimum or “best“ design is implied. This study was as comprehensive as time allowed, but doubtlessly there are other pollution prevention measures that have potential application to crude units. Each refiner will need to make an assessment o
10、f his refinerys requirements and then consider the ideas that best suit those needs. Corporate planning, engineering, regulatory, and operations personnel will be able to use the ideas and techniques reported in this study as an initial step toward a more thorough case-by-case evaluation of pollutio
11、n prevention for the crude units at individual refineries. 1.3 For a model new crude unit (Case 1), the following pollution prevention ideas may be considered in the design stage and are reported in Section 6: Pollution Prevention Ideas for Model New Crude Unit Apply pinch analysis to the crude preh
12、eat train heat integration (refer to Appendix I). Increase crude preheat temperature and minimize heat losses to air and cooling water. O Increase crude distillation column pumparounds from two to four. Reboil sidestrippers with a heat transfer oil rather than by steam stripping. Lower vacuum column
13、 flash zone pressure from 35 to 20 mmHgabs. This will lower furnace fired duty and reduce cracking of the feed to lighter products and wet oil/recovered oil. 3 API PUBL*3LLOL 93 D O732290 052BBb7 774 Use a liquid ring vacuum pump in place of the third stage steam jet ejector on the vacuum tower over
14、head. b Strip desalter brine for benzene removal before sending brine to wastewater treatment. Send recovered benzene to gasoline blending. e Install new generation low NO, burners. Use selective catalytic reduction (SCR) to reduce NO, in funiace flue gas. e Scrub furnace flue gas for removal of SO,
15、 when firing high sulfur fuel oil. a Optimize water reuse by application of sidesiream softening to blowdown streams. b Apply advanced process control to optimize energy utilization. Install analyzers to provide continuous pollutant monitoring. b Employ specialized hardware and inspection & maintena
16、nce (I&M) to eliminate fugitive emissions of volatile organic compounds (VOC): - Select leakless or graphite packed valves. - Use sealless design pumps or pumps with double seals. - Minimize flanges and install sealing rings on leaking flanges. - Blind, plug, or cap open-ended vent and drain valves.
17、 4 API PUBLX31101 93 O732290 0528868 600 - Route relief valves to flare and add rupture disks. - pipe compressor seal vents back to process and vent compressor distance pieces to refinery flare. - Install a maintenance drain-out (MDO) system to eliminate open discharges from drains. - Totally close-
18、loop all samplers. 1.4 Pollution Prevention Ideas for Revamp of Conventional Crude Unit For the revamp of an existing conventional crude unit (Case 2), the following pollution prevention ideas may be considered and are reported in Section 7: Apply pinch analysis to the crude preheat train heat integ
19、ration. Increase crude preheat temperature and minimize heat losses to air and cooling water. Keep equipment and piping relocation to a manageable minimum. e Reboil the atmospheric column sidestrippers (except for high boiling point Atmospheric Gas Oil) with heat transfer oil rather than by steam st
20、ripping. Install two new sidestrippers and modify one existing sidesiripper. e Lower vacuum column flash zone pressure from 35 to 20 mmHgabs. Use liquid ring vacuum pump in place of the third stage steam jet ejector on the vacuum tower overhead. Add parallel ejectors to the first and second stages.
21、e Strip desalter brine for benzene removal. 5 API PUBLX3LLOL 93 0732290 0528869 547 Retrofit new generation low NO, burners and install SCR units for post-combustion NO, reduction. a Scrub flue gas for removal of SO, when fing high sulfur fuel oil in heaters. o Optimize water reuse by application of
22、 sidestream softening to blowdown streams. a Apply advanced process control to optimize energy utilization. Install analyzers to provide continuous pollutant monitoring. Employ specialized hardware and I&M to reduce fugitive emissions of VOC: - Improve I&M program (leak definition, monitoring freque
23、ncy, and repair response time). - Selectively retrofit leakless or graphite packed valves. - Selectively retrofit sealless design pumps or pumps with double seals. - Minimize flanges and install sealing rings on leaking flanges. - Blind, plug, or cap open-ended vent and drain valves. - Route relief
24、valves to flare and/or add rupture disks. 6 API PUBL*3LLOL 93 0732290 0528870 2b9 - Pipe compressor seal vents back to process and vent compressor distance pieces to refinery flare. - Install a MDO system to eliminate open discharges from drains. - Totally close-loop all samplers. 1.5 Summary of Fin
25、dings Air emissions, wastewater effluents, solid wastes, energy consumption, and costs are summarized in Table 1.1. Figures 1.1 through 1.4 give graphical representations of air emissions, wastewater loads, and solid waste generation. The findings of this pollution prevention study on refinery crude
26、 units are summarized below: A generic systematic methodology for conducting pollution prevention studies on process units can be applied to the crude unit in a typical refinery. 0 There is a correlation between energy efficiency and environmental effectiveness: the more efficient the crude unit, th
27、e less it pollutes. O The total energy usage in the crude unit can be reduced by improving heat integration in the crude preheat train through pinch analysis. O Reductions in wastewater generation can be achieved by energy reduction and stream recycling. 7 API PUBL+33303 93 m 0732290 0528873 lT5 m e
28、 Reductions in solid and hazardous wastes can be achieved by water recycling and preventing the mixing of hazardous and non- hazardous waste streams. If the heaters burn high sulfur fuel, limestone scrubbing for SO, reduction will generate non-hazardous sludge. e NO, emissions can be reduced by new
29、generation low NO, burners, SCR units, and Flue Gas Recirculation (FGR). e The total annual benzene quantity (TAB) in wastewater can be reduced by steam stripping. Fugitive emissions from piping components can be reduced by hardware improvements and stringent inspection 8z maintenance programs. 8 AP
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31、I I I I I I l I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I l I I I I I I I l I I I I I I l I I I I I I I I I I l I I I I I I I I I I I I I I I I I I I I I I I I I I I I I l I l I I I I I I l l I I I I l I 06 I .:. l- i . I I I l I I I I r I It- ir VI . 7 IN I I . IP o O O o I I l r . I I l O O0 O0 O O O O *m O O O 8 o“ s o cv F v) CU!. -* 0, F- Washington, D.C. 20005
