the ohsol presentation
TRANSCRIPT
DAWOOD COLLEGE OF ENGINEERING & TECHNOLOGY
DEPARTMENT OF CHEMICAL ENGINEERINGBATCH 09
AN EMULSION BREAKING PROCESS TO RECOVER OIL FROM REFINERY WASTE
EMULSIONS OR SLUDGE.
THE OHSOL PROCESS
Abdul Waheed Maken (Group leader) D-09-CH-709
Arsalan Qadir D-09-CH-719
Mohammad Amin D-09-CH-721
Yasir Hussain D-09-CH-785
Afzal Aziz D-09-CH-793
Abdul Sami D-09-CH-803
INTERNAL ADVISOR: EX. PROF. DR. HAROON JANGDA
EXTERNAL ADVISOR: ENGR. NOOR-UL-HAQ (ENAR)
OBJECTIVE
The objective is to;Highlight the environmental impacts associated with
refinery wastes. Introduces a new process especially for refineries. Include most of the material associated with OHSOL
Process. Discuss and aware about the advantages of OHSOL
process. Discuss technical and economic viability of process.Recommend the process for future. To simulate on HYSYS by creating a representative
feed stream and do some designing work also.
INTRODUCTION TO REPORT
REFINERY WASTE
TYPES OF WASTES
OILY WASTESFree oil dissolved in process waste or in hazel form which is recovered through API separator.
SLUDGES The main difference between oily waste and sludge waste is related to the amount of organic and inorganic solids in the waste stream. Sludge contains high amount of solids which settles with time.
SOURCES OF REFINERY WASTES
The primary sources of oily waste streams include;
Dissolved air flotation float Slop oils API separator sludge Desalter bottoms Tank bottoms Heat exchanger bundle cleaning sludge
PHYSICAL CHARACTERISTICS
ENVIORNMENTAL IMPACTS
ENVIORNMENTAL IMPACTS
Oil refineries are one of the major sources producing
environmental pollutants and pollutions.
Effect on aquatic environment Toxicity Fate of the effluent Health effects on animals Health effects of some pollutants on humans
NEQS STANDARDS
NEQS sets standards for pollutants in Pakistan. NEQS
has defined maximum allowable concentrations for 32
pollutants in municipal and liquid industrial effluents.
o Allowable oil and grease in wastewater is 10ppm.
EMULSION
An emulsion is a stable mixture of oil and water that does not separate by gravity alone.
For an emulsion to exist there must be two mutually immiscible liquids, an emulsifying agent (stabilizer), and sufficient agitation to disperse the discontinuous phase into the continuous phase.
A stable or “tight” emulsion occurs when the water droplets will not settle out of the oil phase due to their small size and surface tension. The problem is further compounded in the presence of solids.
INTRODUCTION TO EMULSION
TYPES OF EMULSIONS
1. Water-in-oil (W/O)2. Oil-in-water (O/W)3. Multiple/complex emulsions (water-in-oil-in-
water)
WATER-IN-OIL (W/O)
OIL-IN-WATER (O/W)
WATER-IN-OIL-IN-WATER
DESTABILIZING EMULSIONS
The factors that enhance or speed up emulsion
destabilizing or emulsion breaking are:
Temperature Agitation or shear Residence or retention time Solid removal Controlling of Emulsifying agents
EMULSIFYING SKIN SURROUNDING THE DROPLETS
MECHANISM INVOLVED IN DEMULSIFICATION
Demulsification, the separation of an emulsion into its
component phases, is a two-step process.
Flocculation or Aggregation During flocculation, the droplets clump together, forming aggregates or “floccs.”
Coalescence During coalescence, water droplets fuse or coalesce together to form a larger drop.
METHODS OF EMULSION TREATMENT
METHODS OF EMULSION TREATMENT
Emulsion separation into oil and water requires thedestabilization of emulsifying films around water
droplets.This process is accomplished by any, or a combination, ofthe following methods:
o Adding chemical demulsifiers. o Increasing the temperature of the emulsion. o Applying electrostatic fields that promote coalescence. o Reducing the flow velocity that allows gravitational
separation of oil, water, and gas.
METHODS OF EMULSION TREATMENT
Generally emulsions can be treated in four ways:
Thermal Method (e.g coker )Mechanical Method (e.g three phase
centrifuge )Electrical Method (e.g desalter )Chemical Method (e.g settling tank )
THE OHSOL PROCESS
THE PROCESSA continuous mechanical emulsion breaking process that ruptures the emulsion through rapid expansion of the droplets through nozzle and recovers the component phases from emulsions i.e. oil, water and solids.
APPLICATIONThe process is applicable to a wide range of refinery waste materials, including slop oils, API separator sludge, desalter bottoms or rag layer, dissolved air flotation float, crude tank sludges, oil field waste emulsions, waste pits, pounds, lagoons emulsions or sludges.
INTRODUCTION TO PROCESS
PERF 91-14 PROJECT
OHSOL PFD
FEEDTANK F
LAS
H D
RU
M
CONDENSER
COALESCER3 PHASE
SEPARATOR
CENTRIFUGE
VIBRATORY SCREEN
COALESCER
DESANDER HYDROCYCLONES
DEOILER HYDROCYCLONES
WATER
GASES
OIL
WATER
OIL
OIL
WATER
SOLIDS
OIL
WATER
WATER
SLURRY
SOLIDS
WATER
WATER+OIL
OIL
A B C
PROCESS CONDITIONS
Streams Ranges
Feed temperature 145-190 C
Feed pressure 50-250 psig
Temperature after flash 99-110 C
Pressure after flash 1-20 psig
Water vaporize 10-25%
REFINERY INTEGRATION
ADVANTAGES
A continuous process. Effectively breaks oil-water-solids emulsions. Can also treat oil field waste emulsions. Capable of being made a centralized emulsion treating plant to
handle all waste streams in the refinery. Strips benzene and light hydrocarbons. Eliminates the need for downstream processing, such as in
conventional emulsion treating, filter presses, belt presses, centrifuges, thermal dryers and slop tanks.
Utilities and energy requirements are low. Less maintenance requirements. All equipments are stationary except centrifuge. Environmental friendly. No process safety issues because there is no high temperature and
high pressure. Less chemical dozing required. Process capable to handle emulsions with oil and water, no limit.
Solids up to 15%.
TECHNICAL AND ECONOMICALFEASIBILITY
FEASIBILITY
If the facility is production constrained by available heat and additional heat is required to handle emulsions as in Coker, the Ohsol process can reduce the heating requirements and facilitate increased throughput.
If emulsion separation is limiting throughput due to residence time requirements as Settling tank process, the Ohsol process will eliminate this requirement by removing the emulsion from the separators.
If emulsion breaking process is totally dependent on chemical dosage as in settling tank process, the Ohsol process can greatly reduce the amount of chemical dosage and time for separation.
SIMULATION ON HYSYS
FEED PREPARATION BASIS
Feed is prepared by taking individual three stream of oil water and solid and use static mixer to make emulsion .
CDU BOTTOMS were selected because they mostly contain >C20 hydrocarbons. Diluents (between C5-C12) were selected to reduce the viscosity of feed and increase the solvency of oil phase.
Solid is created by using option hypothetical solids selected represents the properties of clay particles;
size=15 micron, molecular weight=300, density= 2600 kg/m3 Composition of FEED
water=42.49%, solids=13.04% and CDU bottom= 44.47% , Diluents are added less than 2 wt% .
Thus a representative stream (feed) was created which resembles to refinery emulsions or sludges, which here is basically a heavy slop oil, and attempt was made to simulate according to Ohsol process.
HYSYS PFD
ESTIMATED RECOVERY FROM 5500 BPD PLANT
5500 bpd feed which contains;Oil=44.47% water= 42.49% solids= 13.04%Oil in feed=2674 barrels/day
Oil recovered from 3phase separator=800.7 Lb/h
Oil present in deoiler feed =37494.67Lb/h
Oil recovered from deoiler(if 90% effi)=33745.2Lb/h
Total oil recovered from deoiler and 3phase separator= 3454.9 Lb/h
Which is 92.7% of feed oil or 2480 barrels/day
Therefore out of 2674 barrel oil 2480 barrel was recovered till deoiler hydrocyclone.
But it can be recovered more up t0 95% or more if , 3 phase CENTRIFUGE and COALESCERS are used.
Therefore out of 2674 barrel oil 2480 barrel was recovered till deoiler hydrocyclone.
The remaining oil goes with solids or water phase .
MATERIAL BALANCE
MASS BALANCE OF FLASH DRUM
ENERGY BALANCE OF FLASH DRUM
MATERIAL BALANCE OF 3 PHASE SEPARATOR
ENERGY BALANCE AROUND CONDENSER
MASS BALANCE AROUND DESANDER HYDROCYCLONE
40145.78 30170.19
9975.59
Total= 40145.78 lb/h Total= 40145.78 lb/h
EQUIPMENT DESIGNING
FLASH DRUM
3 PHASE SEPARATOR
DESANDER HYDROCYCLONE
CONDENSER
CONCLUSION
The OHSOL process has a potential to overcome refinery waste emulsion problems and it can also handle tough emulsions. As compared to other processes, this process is a continuous process and also can be used in oil fields.
Due to low utilities requirements and complexibility, the process can be integrated in refineries. This new process has a potential to become a future technology for handling and treating emulsions.
The process also fulfils the regulated discharge parameters as set by EPA and is capable to handle future tough regulations as expected. Contaminants in lesser quantity are discharged from OHSOL process.
Due to the scarcity of crude oil likely in near future, this type of technology should be incorporated for maximum recovery. Also to reduce the environmental impacts some technology should be utilized.
Adverse consequences have been reported from refinery wastes in some parts of the world.
In large refineries the problem of emulsions or sludge are likely to persists and are generated in large quantities which cannot be treated by equipments like API separators, DAF, etc. Other treatment methods for instance chemical treatment cannot be utilized as a continuous solution due to various factors like costs, time, changing conditions of emulsions, etc.
The OHSOL process can be utilized in refineries of Pakistan especially to those processing one lac bpd or more.
THE END
QUESTIONING SESSION