BP Refinery Kwinana has undertaken many cleaner production and environmental improvements in accordance with company policy and its commitment to continual environmental improvement. It has been particularly active in minimising water use, energy efficiency and greenhouse gas abatement, protecting ground and coastal waters, and reducing VOC and other air emissions.
BP Refinery Kwinana was built in 1955 on the eastern shore of Cockburn Sound, approximately 30 km south of Perth in the Kwinana Industrial Area. Neighbouring industries include a variety of mineral and chemical processing companies.
Crude oil is delivered by ships to BP Refinery Kwinana, where it is refined into a wide range of products for distribution throughout WA. These products include LPG, petrol and diesel for motor vehicles; aviation gasoline and jet fuel; lubricating oils and bitumen.
In accordance with BP's Health, Safety and Environmental Policy and its expectation of no damage to the environment, the prevention of pollution arising from the Refinery's operations is of the highest priority. BP Refinery Kwinana is committed to continuous improvement with regard to its environmental performance and the Refinery has an environmental management system certified to the International Standard ISO 14001. Key environmental goals stated in BP Refinery Kwinana's Environmental Policy include:
- Protecting Cockburn Sound and water resources, including groundwater and scheme water
- Reducing greenhouse emissions
- Reducing volatile organic compounds (VOC) emissions
- Reducing other atmospheric emissions, including sulphur dioxide and nitrogen oxides
- Supplying clean fuels to help improve Perth's air quality, including supplying only lead-free motor spirit to WA.
A wide range of processes and activities related to oil refining, storage and distribution are carried out at BP Refinery Kwinana. An outline of these processes and activities is provided below:
- Crude oil enters BP Refinery Kwinana via tankers, which are moored at the Refinery's jetties in Cockburn Sound. The crude oil is then pumped to storage tanks to enable any water present from the oil production process to settle to the bottom of the tanks. This water must be removed before the crude oil can be fed to the Refinery to prevent it causing corrosion or other problems in the process units. Once settled, the water is drained to the Refinery's sewer system.
- In the main refining process the crude oil is subjected to a combination of heat, pressure and catalysts. The Crude Distillation Units break the crude oil into specific streams which are fed to a number of units to produce the variety of hydrocarbon products that we use in our daily lives.
- The residue from the crude oil distillation process is a low value component which is fed to the Residue Cracking Unit (RCU). The RCU "cracks" or dissects the long-chain hydrocarbon compounds in the residue into smaller compounds of greater value.
- Fuel gas, a supplementary product of refining, provides energy for the furnaces which heat the various hydrocarbon streams as they flow through the different process units. Using fuel gas enables efficient process management as well as reducing emissions from the flaring alternative.
- Since 1985 natural gas has been used as the supplementary feed to the furnaces instead of fuel oil which helps to reduce sulphur dioxide, nitrogen oxides and carbon dioxide emissions. Low NOx furnace burners also help reduce nitrogen oxide emissions.
- The Refinery has two Sulphur Recovery Units (SRUs). Their purpose is to remove hydrogen sulphide from the furnace fuel gas prior to the fuel gas being burnt in the furnaces, thus greatly reducing sulphur dioxide emissions. A by-product is liquid sulphur which is sold to another company for the production of agricultural fertilisers.
- The Refinery has two flares which provide a safe pressure relief system in case of process upsets. Occasionally, small alterations in temperature and pressure can generate excess gas. To protect equipment and staff, this pressure is relieved by diverting the excess gas to flare.
- The Refinery's electricity and steam supplies are generated at the Edison Mission Cogeneration Plant in Kwinana using natural gas.
- The Refinery has an extensive oil spill and emergency response plan consisting of preventative and response measures.
- Waste gases from Refinery operations may include sulphur dioxide, hydrogen sulphide, carbon monoxide, carbon dioxide, volatile organic compounds (VOCs) and particulates. VOCs are fugitive hydrocarbon emissions generated from the refinery from storage tanks, sewers, process units, flanges, valves, seals and other fittings.
- Wastewater is treated onsite and is generated from many sources including manufacturing processes, crude oil dewatering, contamination in the ballast water (from older ships using the same tanks for cargo and ballast), water from washing out ships' holds and jetties, and wastewater from draining product tanks. Storm water on the site is also treated since it may contain some contaminants. Salt water used for cooling does not normally come into direct contact with any hydrocarbons during the cooling process and hence requires no further treatment before being returned to Cockburn Sound.
The Refinery uses a number of different water streams for a variety of different purposes.
- Process water (groundwater) is used for cooling water makeup (to replace evaporative and blowdown losses), in the Alkylation Unit and Steam Generation Area (SGA) cooling towers.
- Salt water from Cockburn Sound is pumped through the Refinery to cool heat exchangers on a number of different process units.
- Steam is used in a number of different areas within the Refinery. About 1/3 of the Refinery steam requirement is raised onsite through the Refinery Waste Heat Boilers, with the remaining demand sourced from Mission Energy Cogeneration Unit.
- Scheme (potable) water from the Water Corporation is used for processes requiring high grade water, such as boiler feed water, drinking water, safety showers and eye wash stations.
- All other processes within the Refinery now use low grade water, consisting of groundwater from the Refinery production bores and returned/reused process water.
Cleaner production initiatives
Various initiatives have been implemented under the broad headings of energy, materials and water efficiency
BP Refinery Kwinana initiated a water reuse and minimisation programme in 1997 with three main objectives: to minimise water use; to maximise water reuse in Refinery processes, either after or before treatment; and to use low quality water (bore water) in place of potable water where practical.
The approach adopted involved four main steps: Step one involved a detailed analysis of the costs of wastewater treatment at the wastewater treatment plant; step two involved the development of a detailed water balance; step three involved the setting of targets for potable water usage, bore water usage, total water usage, flow to the wastewater treatment plant, water efficiency and percentage of condensate returned to the Refinery systems. Step four involved examining all areas in the Refinery to determine where low quality water could be substituted for high quality water, and identifying areas where process usage could be reduced and returns increased.
An innovative aspect of the programme was approaching water management with a whole refinery perspective. All areas were targeted in order to save as much water as possible. All employees were encouraged to discuss and put forward ideas on water conservation, recycling or reuse. Monthly meetings were held within the Refinery to discuss water minimisation. Initiatives included:
- Recycling process water used in the Bypass Seal Pot of the Residue Cracker Unit CO Burner. Operating conditions required 200-300 kL/day of water to prevent high flue gas back pressure causing the Seal Pot to blow and consequently shutting the CO burner down. Previously this overflow was directed to sewer. A head tank and recycling system was installed, and pH and chloride testing was carried out to enable the operation to be carried out under suitable conditions.
- A Refinery wide steam trap programme aimed at reducing steam leakage and improving condensate return.
- Replacement of Alky Cooling Tower makeup water with process water to reduce scheme water usage.
- Improved process water return where feasible eg. from cooling pumps. Previously half of the total process water was not returned to the refinery.
- Modifications to operating procedures for Fremantle, Kewdale and black oil pipeline pumps to minimise process water use.
- Maintenance on leaking 'fixed 'fire systems.
- A project to recover lubes condensate losses.
- A focus on reducing hydrocarbon spills to reduce process water usage
- Reuse of stripped sour water as wash water on the Crude Unit desalters. This wash water is used to extract salts from crude oil to prevent corrosion and minimise catalyst use.
Energy efficiency and greenhouse emissions:
Following the signing of the Kyoto Protocol in 1997, climate change and reducing greenhouse emissions became a major issue for BP and the world. BP has set a target of reducing its global greenhouse gas emissions by 10% from a 1990 baseline over the period to 2010, exceeding the reduction then agreed in 1997 by the industrialised nations. BP has committed to developing an internal emissions trading scheme. BP Refinery Kwinana is part of the BP Australia Greenhouse Challenge which focuses on improvement in such areas as energy efficiency, process efficiency, enhancement of carbon sinks and the effective use of resources.
In addition, BP Refinery Kwinana has implemented both onsite and offsite initiatives to reduce greenhouse emissions. Offsite initiatives include tree plantation, salinity reduction and habitat conservation projects with social as well as environmental benefits. BP Refinery Kwinana's carbon sequestration project has achieved recognition through being a finalist, runner up or winner of various environmental awards. Various onsite initiatives to reduce greenhouse emissions have been implemented since 1996. A number of these initiatives are summarised below:
- A 'no economic flaring' policy was introduced in 1997, with reductions in flaring achieved by optimisation of plant throughputs and fuel gas usage, and increased fuel gas sales.
- A Cogeneration Plant was commissioned in 1996, in conjunction with Mission Energy, for the combined production of electricity and steam. This plant provides 100% of the refinery's 40MW power needs, thereby eliminating the need for electricity from the grid.
- Commissioning of the Cogeneration Plant reduced fuel gas usage as the Refinery was able to shut down the onsite steam boilers.
- A major study was completed in 1997 to identify areas for energy improvement through to the year 2006.
- A steam trap management program was initiated to minimise steam energy losses.
- Catalytic Reformer furnace air system modifications were carried out to improve furnace efficiency.
- Vacuum Distillation Unit modifications were carried out to increase efficiency and reduce energy use and CO emissions per unit throughput, these included a more efficient furnace and upgrades to the unit internals.
- Crude Distillation Unit 1 furnace was upgraded in March 2000 to improve its efficiency
- A comprehensive Energy Strategy was developed as part of a long term plan to reduce energy consumption and greenhouse emissions.
Catalytic reformer furnace and the East flare
- The wastewater treatment plant has been in operation since 1994. In the first stage of the treatment process the free oil is separated from the wastewater and sent back to the refinery for reprocessing. The separated wastewater is pumped to an Equalisation Tank where it is held and pH adjusted to the required conditions of the treatment plant.
- The second stage involves the removal of small suspended oil particles in the Dissolved Air Flotation Unit by binding the small particles into larger ones so that they can float and be skimmed off. Up to this stage the treatment process is covered to prevent VOC emissions.
- The final stage involves the removal of dissolved contaminants and nutrients in the Activated Sludge Units (ASUs), where biological breakdown occurs. The wastewater then enters the clarifiers, where micro-organisms are settled before returning to the ASUs. The wastewater is then directed to the polishing ponds, which are another special feature of the treatment plant. Aerators aid the break down of any remaining organic compounds.
- Treated wastewater is discharged to Cockburn Sound under carefully controlled conditions and to strict regulatory requirements. Average daily discharges would place BP Refinery Kwinana as one of the best refineries in the world for wastewater quality.
- In 1992 the copper Chloride Sweetening Unit was replaced with a new Gasoline Minalk (Minimum Alkalinity) Unit. Gasoline from the Crude Distillation Units is contacted with dilute caustic solution to remove hydrogen sulphide, before being mixed with weak caustic solution and air to convert any odorous mercaptans present into disulphides. A new Minalk Unit was also built to replace the old sweetening unit to treat catalytically cracked spirit from the RCU using a weak caustic solution instead of 10% caustic solution. This significantly reduced the phenolics extracted into the caustic, thereby reducing phenolics discharged via wastewater to Cockburn Sound.
Wastewater treatment plant
In 1995 BP started a VOC reduction programme with the aim of reducing emissions to one quarter of 1994 levels by the end of 1998, based on capital investment in best available technology and improvements in process design. Initiatives included:
- Systematic leak detection and repair or replacement of fittings emitting fugitive VOCs.
- Fitting all floating roof tanks with secondary seals.
- Converting tank stillwells from a "slotted" to a 'hole " design.
- Reduction of the hydrocarbon load on the sewer system and examining the possibility of sealing in the sewer emissions.
- Modifications to process units to reduce the possibility of hydrocarbon venting.
The programme target was met, with an 81% reduction in VOC emissions achieved by the end of 2000. Further initiatives are planned to decrease VOC emissions.
The main source of small airborne particulates is the Residue Cracking Unit. Coke forms on the catalyst in the RCU, which fouls the refining process. The waste gases generated during the removal of the coke are discharged through the RCU stacks. However due to the high velocities and temperatures of the waste gas, particulates become entrained in the gas flow. To reduce particulates emissions, cyclones were installed on the RCU's stacks. These create a centrifugal force that physically separates the particulates from the gas, thereby allowing the particulates to be reused. Additional cyclones are planned to further reduce particulate emissions.
Other atmospheric emissions
The Refinery has introduced many new processes to reduce its sulphur dioxide emissions, including the Sulphur Recovery units and other processes described above. Hydrogen sulphides and nitrogen oxides have been reduced as described in the process section above.
Soil and groundwater
BP Refinery Kwinana has developed a Subsurface Oil Strategy consisting of the following:
- Removing all sources of oil to the ground eg. through leak prevention and detection and draining all oily waste to the wastewater treatment plant.
- Recovering as much underground oil as possible. When the Refinery was built it was accepted practice for refineries to water drain crude oil and product tanks to the ground, as the standards of spill prevention and drainage were low in the past. The site has 34 actively pumped recovery wells which are routinely emptied by vacuum tanker.
- Prevention of migration to Cockburn Sound. Continuous monitoring is carried out and no recent migration has been detected.
- Cleaning up residual contamination. The Refinery has sponsored research by CSIRO into techniques for in-situ remediation and ex-situ treatment, including mixing with organic matter and soil for agricultural compost.
- Treatment of contaminated soil by landfarming, involving controlled application of oily waste to soil and inducing biological breakdown; and biopiles, using similar biological processes but in aerated piles l.5m high on a lined permanent sand pad.
Landfarming of oily waste using rotary hoe
The various initiatives have resulted in significant financial and environmental benefits as detailed below:
The water reuse and minimisation programme resulted in a decrease in total water usage from 7250 kL per day in 1996 to 5640 kL per day in 1999, and a decrease in potable water usage from 6150 kL per day in 1996 to 1833 kL per day in 1999. The programme also provided significant environmental benefits by reducing contaminant loads (eg oil loading decreased from 17kg/day in 1996 to 1kg/day in 1999) in the Refinery's marine discharge, due to decreased flows (1996 -5258 m³/day; 1999 - 3894m³/day) to the wastewater treatment plant.
The benefits from specific initiatives were:
|Water minimisation initiative
|Recycling: Residue Cracker Unit
||50-150kL/day and cost savings
|Steam trap programme
||Reduced leakage, improved condensate return
|Alky Cooling Tower
||Potable water usage reduced up to 500kL/day
|Black oil pipeline pumps
||Total water savings 90kL/day
|Fixed fire system leaks
||Reduction of approximately 36kL/day
|Reducing hydrocarbon spills
||Process water reduced by 200kL/day
|Reuse: Stripped Sour Water
||Process/total usage reduced 500-900kL/day
Another significant environmental benefit was that, by the Refinery significantly reducing potable water use, the load on this vital resource was reduced.
Significant savings have been achieved, in addition to reduced greenhouse gas emissions and associated cost savings.
The benefits from specific initiatives were:
||Benefit (annual CO² reduction )
|No economic flaring
|| 16,600 tonnes
|| 137,000 tonnes
|Steam boiler shutdown
|| 33,000 tonnes
|Steam trap programme
|| Significant energy savings
| Package boiler
|| 12,000 tonnes
| Catalytic Reformer furnace
|| Significant savings
| Vacuum Distillation Unit
|| Significant savings
| Crude Distillation Unit 1
|| 8,000 tonnes
All of the initiatives implemented have resulted in environmental, compliance, economic and reputational benefits. Combined with the water and greenhouse initiatives the Refinery's public 'licence to operate' has been enhanced, in addition to improved operational and economic efficiency.
The first Minalk Unit resulted in the 3kg/day discharge of copper being eliminated and the second Minalk Unit reduced the discharge of phenolics by 106 kg/day. As both of these units use lower strength caustic than previously; this has resulted in the use of 35% less caustic and significant cost savings as well as environmental benefits.
VOC emissions experienced an 81% reduction by the end of 2000, in addition to environmental and compliance benefits. Sulphur dioxide emissions have been reduced by approximately 80% since 1985.
Cleaner production incentives
In addition to BP Refinery Kwinana's commitment to environmental improvement, these initiatives have been driven by cost, efficiency, regulatory and corporate compliance considerations.
No significant barriers were encountered in implementing these initiatives, other than the challenges of initiating new processes and ensuring that they are economical.
- Rod Lukatelich
- Environmental Manager
- BP Refinery Kwinana
- PO Box 2131
- Rockingham WA 6168
- Ph: 61 8 9419 9483
- Fax: 61 8 9419 9836
- Email: LukateRJ@az1.bp.com
- Web site: http://www.bp.com/ (BP Worldwide)
- http://www.bp.com.au/ (BP Australia)
- Date of implementation: 1997-2001.
- Date of further initiatives: Ongoing.
- Case study prepared: June 2001 by Centre of Excellence in Cleaner Production, Curtin University of Technology
- Date last modified: June 2001.