Biological wastewater treatment in biofuel production in oil refinery by using a RBBR-bioreactor
Anttio-Tuulari, Sonja (2018)
Åbo Akademi
2018
Julkaisu on tekijänoikeussäännösten alainen. Teosta voi lukea ja tulostaa henkilökohtaista käyttöä varten. Käyttö kaupallisiin tarkoituksiin on kielletty.
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi-fe201903189148
https://urn.fi/URN:NBN:fi-fe201903189148
Tiivistelmä
The rotating bed biofilm reactor (RBBR) biologically treats wastewaters and it offers efficient solutions for removal of organic compounds, phenols and nitrogen. Its use avoids many of the problems and high needs associated with commonly used activated sludge process such as need for spacious pool systems, high energy consumption and maintenance demands and need for settling tanks and sludge circulation.
Refining of carbon based fossil materials to oil products produces large quantities of wastewater which is treated at oil refineries’ wastewater units. Refining renewable raw materials produce different, more concentrated wastewater high in phosphorous and nitrogen. In Neste refineries in Porvoo, Naantali, Rotterdam and Singapore, renewable feeds are already utilized, but the pressure to produce more renewable fuels is inevitably high due to the government’s legislation, especially in EU-area. Refineries also need to act responsibly and follow the waste water effluent pollutions limits. Thus oil refineries need to find new satisfactory techniques to replace conventional treatment methods in terms of competing with the emissions.
The use of a RBBR is studied in Neste Oyj’s refineries to advance the biological treatment of the wastewater effluent. RBBR is based on carrier technology, where the bioreactor’s operating principle is utilizing centrifugal forces in growing on biofilm. Micro-organisms grow on the surface of the carrier. The bioreactor tolerates shock loads, it is compactly sized, it creates great oxygenation conditions and the high filling ratio results in high efficiency. The used bioreactor type and related bacteria strains are patented.
A pilot test run was performed for the thermo catalytic cracker (TCC-unit) in 2016 at Neste Naantali refinery. The aim of this test run was to study the use of alternative renewable feeds and how it affects the quality of the waste water to be purified. After this test run, laboratory scale pilot-tests were done for the RBBR- bioreactor with the wastewater from the TCC test run. Biological sludge of Porvoo refinery’s wastewater treatment plant was used for these tests.
The aim with this thesis is to study the performance of a RBBR-bioreactor for TCC based wastewater and to optimize the refinery’s waste water treatment purification process. This includes characterizing and defining the different wastewater effluent flows in Porvoo refinery and studying the current wastewater treatment stages of the treatment. Laboratory analysis, simulations and pilot trials are used to find results and conclusions on the design and scale-up a biological treatment system according to the load. This will give an estimate of the efficiency of the biological treatment. This information can be used for the estimation of the future investments in Neste refinery’s wastewater plant.
Efficient methods are needed in Neste’s refinerie’s wastewater treatment plants in order to stay within the local and international emission limits. The Rotating Bed Biofilm Reactor studied was proven to be highly efficient in degrading phosphorous and biological content from wastewater of biofuel production and therefore could be used with the existing equipment or as a separate unit.
Using a RBBR reactor would save space in the waste water treatment plant when compared to activated sludge tanks. For older and currently running refineries this reactor setup is easy to install without full scale turnaround on the wastewater treatment plant. Maintenance and operability is easy if compared to an activated sludge system.
This still leaves room for questions of the efficiency and whether this type of reactor is the best for the wastewaters from biorefining industry. Nevertheless, this type of reactor could out win many of the conventional treatment units while saving energy, space, chemicals and the environment.
Refining of carbon based fossil materials to oil products produces large quantities of wastewater which is treated at oil refineries’ wastewater units. Refining renewable raw materials produce different, more concentrated wastewater high in phosphorous and nitrogen. In Neste refineries in Porvoo, Naantali, Rotterdam and Singapore, renewable feeds are already utilized, but the pressure to produce more renewable fuels is inevitably high due to the government’s legislation, especially in EU-area. Refineries also need to act responsibly and follow the waste water effluent pollutions limits. Thus oil refineries need to find new satisfactory techniques to replace conventional treatment methods in terms of competing with the emissions.
The use of a RBBR is studied in Neste Oyj’s refineries to advance the biological treatment of the wastewater effluent. RBBR is based on carrier technology, where the bioreactor’s operating principle is utilizing centrifugal forces in growing on biofilm. Micro-organisms grow on the surface of the carrier. The bioreactor tolerates shock loads, it is compactly sized, it creates great oxygenation conditions and the high filling ratio results in high efficiency. The used bioreactor type and related bacteria strains are patented.
A pilot test run was performed for the thermo catalytic cracker (TCC-unit) in 2016 at Neste Naantali refinery. The aim of this test run was to study the use of alternative renewable feeds and how it affects the quality of the waste water to be purified. After this test run, laboratory scale pilot-tests were done for the RBBR- bioreactor with the wastewater from the TCC test run. Biological sludge of Porvoo refinery’s wastewater treatment plant was used for these tests.
The aim with this thesis is to study the performance of a RBBR-bioreactor for TCC based wastewater and to optimize the refinery’s waste water treatment purification process. This includes characterizing and defining the different wastewater effluent flows in Porvoo refinery and studying the current wastewater treatment stages of the treatment. Laboratory analysis, simulations and pilot trials are used to find results and conclusions on the design and scale-up a biological treatment system according to the load. This will give an estimate of the efficiency of the biological treatment. This information can be used for the estimation of the future investments in Neste refinery’s wastewater plant.
Efficient methods are needed in Neste’s refinerie’s wastewater treatment plants in order to stay within the local and international emission limits. The Rotating Bed Biofilm Reactor studied was proven to be highly efficient in degrading phosphorous and biological content from wastewater of biofuel production and therefore could be used with the existing equipment or as a separate unit.
Using a RBBR reactor would save space in the waste water treatment plant when compared to activated sludge tanks. For older and currently running refineries this reactor setup is easy to install without full scale turnaround on the wastewater treatment plant. Maintenance and operability is easy if compared to an activated sludge system.
This still leaves room for questions of the efficiency and whether this type of reactor is the best for the wastewaters from biorefining industry. Nevertheless, this type of reactor could out win many of the conventional treatment units while saving energy, space, chemicals and the environment.