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