outcom6 Flashcards
how many Safe Operation Systems you have in refinery
1) pressure relive system
2) Air Emission Monitoring
3) water Emission monitoring
4) Solid Waste Monitoring
The relief device has a set point pressure which is below the maximum allowable working pressure ( T or F )
T
The pressure is the percentage increase above MAWP……………………………
Accumulation
pressure is the percentage increase in pressure above a set point
over pressurization
MAWP
maximum allowable working pressure
give me Sources of Air Emissions and example ( 737)
1) Combustion Emissions
2) Equipment Leak Emissions ( Fugitive Emissions)
3) process vent emission
example
1) heater stack gas – co ,co2 , Nox
2) flaring co,co2,NOX
3) catylatic regeneration
4) Fugitive Emissions h2s
give me Sources of water Emissions and example
1) cooling water
2)Process Wastewater
3) Surface Water Runoff
example
1) Amines
2) COD
3) BOD
4) H2S , Mercaptans
COD
Chemical Oxygen Demand
BOD
Biochemical Oxygen Demand
Approximately 3.5-5 cubic meters of wastewater per ton of crude are generated ( T or F )
T
Refineries generate solid wastes and sludges ranging from 3 to 5 kg per ton of crude processed. ( T or F)
T
Refinery solid wastes are typically in the form of
sludge
………………… is generated from Petroleum Refineries gravitational separation of oil/water/solids during the storage or treatment of process wastewaters. ………………… is also generated from cooling waters segregated for treatment from other process or oily cooling waters
sludge
give me Sources of solid Wastes
1) Crude oil/desalted sludge
2) Coke dust
3) Spent catalysts
4) Neutralized alkylation sludge
5) Heat exchanger sludge
6) Tank bottom sludge
Environmental impacts of Desalting
Purpose of Desalting: remove corrosive salts along with some of the metals and suspended solids from crude oil before processing.
1) Air Emissions: CO, SOx, NOx
2) Effluent to Water: Oil, H2S, NH3
Amount of wastewater produced = 2.1 Gal/Bbl crude oil processed
3) Residual waste generated: Sludge contains salts, iron rust, clay, sand, me
Environmental impacts of Distillation
Purpose of Distillation: To separate the ingredients of crude oil into several valuable products.
1) Air Emissions: CO, SOx, NOx
2) Effluent to Water: Oil, H2S, NH3
3) Amount of wastewater produced= 26 Gal/Bbl crude oil processed
4) Residual waste generated: Typically little or no residual waste generated.
Environmental impacts of Coking
To produce distillate naphtha and gas oils from heavy residuum.
1) Air Emissions: CO, SOx, NOx,
2) Effluent to Water: H2S, NH3
3) Amount of wastewater produced= 1.0 Gal/Bbl crude oil processed
4) Residual waste generated: Coke dust (Carbon particles and hydrocarbons).
Environmental impacts of Heat Exchanger Cleaning
Purpose of Heat Exchanger Cleaning is to remove fouling from the inside surfaces of heat exchangers.
1) Air Emissions: Periodic fugitive emissions (hydrocarbons
2) Effluent to Water: Oily wastewater generated
3) Residual waste generated: Heat exchanger sludge
Environmental impacts of Storage Tanks
Purpose of Storage Tanks is to store refinery feedstock and products.
1) Air Emissions: Fugitive emissions (hydrocarbons)
2) Effluent to Water: Water drained from tanks contaminated with tank contents.
Residual waste generated: Tank bottom sludge
Air emissions are more difficult to capture than wastewater or solid waste. (T or F )
T
air emissions are the largest source of untreated wastes released to the environment ( T or F )
T
The categories for pollution management of waste are:
Estimation of emissions
Waste treatment and control
Waste minimization and prevention
NOx Emission Treatment
Selective Catalytic Reduction (SCR) systems, Selective Non Catalytic Reduction (SNCR) systems
VOC Emission Treatment:
incineration in a CO boiler
CO boiler Emission Treatment:
incinerators or boilers generally oxidize 95% or more of the CO emissions to carbon dioxide
Wet gas scrubbing (WGS) technology allows refiners to meet FCC emission regulations.
WGS
Wet gas scrubbing
Waste Management ( Wastewater )
Primary
1) separation of hydrocarbons from wastewater by gravity separation or skimming , filtration
2) Acidic wastewater is neutralized using ammonia or soda ash.
3) Alkaline wastewater is treated with sulphuric acid, carbon dioxide-rich flue gas or sulphur
Secondary Treatment
Oily water is segregated into two streams: low (160–250 ppm) and high oil content (>250 ppm).
1) The low stream no further treatment.
2) A high oil stream is treated using API oil/water separator followed by dissolved air floatation (DAF) separator
3) Activated carbon is used to remove heavy hydrocarbons from light organic gas streams in the refinery.
4) Removal of soluble and insoluble organic and inorganic contaminants from refinery wastewater streams is performed by employing ultra-filtration and membrane separation.
5) The high oil content water goes into a second stage, which utilizes physical or chemical methods to separate emulsified oils from the wastewater
DAF
dissolved air floatation
Tertiary Treatment Operations
These treatments include chlorination, ozonation, ion exchange and activated carbon adsorption
Compressed oxygen is diffused into wastewater streams to oxidize certain chemicals or to satisfy regulatory oxygen-content requirements.
- Solid Waste
Treatment of these wastes includes incineration, land treating off-site, land filling on-site, land filling off-site and other treatment methods
