1/31/2017 Kim Jones, David Ramirez , Shooka Khoramfar Department of Environmental Engineering, Texas A&M University-Kingsville, Kingsville, TX 78363, USA Project consultant: James Boswell, Boswell Environmental, Montgomery, Texas Project Sponsor: Carolyn LaFleur , Houston Advanced Research Center (HARC) Project partners: George King, Sam Pittman, Cody Garcia, Apache Resources Production Facility Inno novati tive e Biologi logica cal l Emissions ssions Treatmen ment t Technolo nology gy to Reduce e Air Poll llutio ution n for Petroleu oleum and Petroc oche hemic mical al Operati tions ons
Potential opportunities for biological air emission control Waste Water during Drilling, Process equipment such as Fracturing and Natural Gas Compressors and motors on the Condensate storage tanks Production drilling and production sites Based on Occupational Safety and Health Administration (OSHA), permissible exposure limit (PEL) (8 h TWA) of benzene for general industry = 1.0 ppm 2
Why biological treatment ? • Biological treatment of air emissions offers a cost-effective and sustainable control technology for industrial facilities facing increasingly stringent air emissions limits. • This system uses the capacity of microorganisms to degrade air toxins (HAPs, Hazardous Air Pollutants), like benzene without the use of natural gas as fuel or the creation of secondary pollutants. • The replacement of conventional thermal oxidizers with biofilters will yield natural gas savings alone in the range of thousands of dollars to over $1 million per year per unit. • Any new technology that could replace a single thermal oxidizer (100,000cfm size) could provide a savings of more than 4,166 MM BTUs of natural gas annually (based on 8,760 hrs of operation and 0.475 MM BTU per hour of usage). That represents enough natural gas to comfortably heat or cool approximately 120 homes annually for each thermal oxidizer or flare replaced. • Water vapor, carbon dioxide and biomass are the products of aerobic biodegradation of organic pollutants. However, the carbon emissions in biologically based units is much less than incinerators and flares. 3 (Source: Boswell, 2008)
Successful pilot scale sequential treatment for VOC emissions at different industries Forest product plant, Paint & Coatings Eugene, Stimson Lumber Co. Gaston, Oregon Oregon 4
Process description • The goal of this project is to demonstrate a novel sequential treatment technology that integrates two types of bio-oxidation systems biotrickling filter and fixed bed biofilter for controlling petrochemical industries air emissions. • This coupled design can be optimized to maximize the conditions for microbial degradation of VOC vapors. • The first bed takes the highest inlet VOC loadings, to remove the more water soluble organics, while the secondary bed acts as an overload and polishing stage to remove more complex organic compounds. • The first unit also controls the incoming air stream temperature and regulates humidity and dampens fluctuations in contaminant loadings. • Less hydrophobic pollutants can be removed in the first stage Bio-trickling Chamber by the biofilm on the surfaces of the X-Flow media and microbes in the sump and more hydrophobic compounds should be removed within the Bio-Matrix Chamber periodically sprayed with sump water to maintain proper moisture for best biofilm development. • Water entering the biotrickling filter is collected in a sump, monitored for water quality parameters, and continuously sprayed onto the top of the X-flow media bed in the BTF. • The flowing water phase benefits the biotrickling filter by providing a continuous supply of nutrients, removing possible degradation by-products, suspending biomass for continual reseeding of the system, and aiding in the transfer of hydrophilic pollutants onto the biofilm. 5
Objectives for the Apache (TAMU #2 tank battery) field test 1 Sampling and characterization of some field VOCs emissions 2 Design, build, process test and implementation of a field scale sequential treatment unit in 12 months Demonstrate the ability of bio-oxidation systems to treat variable 3 loadings of VOC emissions as experienced in refineries and production facilities during routine operations, process turnarounds or upsets Optimize the process for the ability to efficiently degrade mixtures of 4 hydrophobic compounds typically encountered in refinery and oil and gas production facility emissions 6
Characterization of VOCs GC-FID PID GC-MS 7
Biotrickle filter media (First vessel) 8
Biofilter media (Second vessel) 9
Key design and operational parameters pH and Conductivity Nutrient Temperature concentration Water flow rate Pressure Key design and Biofilter bed Air flow rate moisture operational parameters 10
Field scale unit start up at Apache TAMU #2 tank battery- 10 May 2016 to 1 August 2016 The field unit consists of a skid mounted two vessel system (100 cubic feet of total treatment volume) made of fiberglass with corrosion resistant schedule 80 PVC piping (Diamond Fiberglass Fabricator, Victoria, TX). 11
Field scale unit start up at Apache TAMU #2 tank battery- 6 May 2016 12
Field scale unit start up at Apache TAMU #2 tank battery- 28 April 2016 to 30 May 2016- Date Completed task Load the BF media to the second vessel 04/28/16 Safety meeting, Generator set up, Sampled of the headspace for GC-MS analysis, Loaded the BTF media to the first vessel, Checked the immediate area around the system for hydrocarbon content with a 05/05/16- 05/25/16 photoionization detector (PID), Inoculation of the system with oily water and compost tea, Checked the water pump and blower performance Inoculation of the system with the CITGO’s 05/30/16 Corpus Christi Refinery wastewater 13
Main dimensions and characteristics of the two tanks BTF BF 4 4 Bed height (ft) Diameter (ft) 4 4 Ratio height to diameter 1 1 Recirculation tank volume (gal) 100 100 Water make-up tank volume 300 (gal) Air flow rate (ft 3 /min) 25 25 Recirculation flow rate 3.5 (optimization possible) 3.5 (optimization possible) (gal/min) 24/7 2 min every 8 hr (optimization Spraying frequency possible) 300 300 Gas velocity, (ft/min) EBRT (min) 2 (optimization possible) 2 (optimization possible) 14
GC-MS characterization from the headspace of the Apache TAMU #2 tank battery Peak # Component Retention Time Conc. (ppm) Butane 9.51 6709 1 Isobutane 9.21 5118 2 Pentane 10.88 4233 3 Butane, 2-methyl- 10.45 4189 4 Hexane 13.03 1553 5 Pentane, 2-methyl- 12.29 1497 6 Cyclohexane, methyl- 16.16 896 7 Heptane 15.50 649 8 Cyclopentane, methyl- 13.75 534 9 Toluene 16.93 282 10 Octane 17.83 218 11 Benzene 14.32 197 12 Nonane 19.90 110 13 p-Xylene 19.22 87 14 15
Fluctuation in VOC concentration at inlet of the bio-oxidation unit – 1 August 2016- Apache TAMU #2 tank battery 1200 VOC (ppm isobutylene equivalent) 1000 800 600 400 200 0 8:24 AM 9:36 AM 10:48 AM 12:00 PM 1:12 PM 2:24 PM 3:36 PM Time 16
PID measurements from the inlet and outlet of the bio-oxidation unit- 10 May 2016 to 29 July 2016- Apache TAMU #2 tank battery 1000 900 VOC (ppm isobutylene equivalent) 800 700 600 500 400 300 200 100 0 10-May 20-May 30-May 9-Jun 19-Jun 29-Jun 9-Jul 19-Jul 29-Jul Time Inlet Outlet 17
Removal efficiency of the biooxidation unit- 10 May 2016 to 29 July 2016- Apache TAMU #2 tank battery 70% Average RE of the system (July month): 53% Average RE of the BTF (July month): 40% 60% Average RE of the BF (July month): 23% 50% 40% RE (%) 30% 20% 10% 0% 10-May 20-May 30-May 9-Jun 19-Jun 29-Jun 9-Jul 19-Jul 29-Jul Time BTF removal efficiency Overall removal efficiency BF removal efficiency 18
Performance characteristics of the BTF unit using GC- FID- Sampling at 28 July using 3 tedlar bags Inlet Outlet Retention time RE (%) Compound concentration concentration (min) (ppm) (ppm) p-Xylene 1.57 587 228 61% o-Xylene 4.44 498 322 35% Benzene 6.41 44 31 30% 19
Biofiltration Summary • In spite of the hydrophobic nature of the pollutants, a relatively high VOC removal was observed in the BTF unit probably due to high biofilm growth and continuous spraying of water and nutrients. • BF watering is an important operational parameter since it directly influences the water content and the pH value on the filter media. At the Apache site, given the very warm temperatures during the field biofiltration test, increased irrigation of the BF unit was probably needed. • The surprisingly high VOC removal capabilities of the BTF unit suggests that a combination of both suspended growth and attached growth biofilms may provide an important new approach toward biotreatment optimization of VOCs for the oil and gas and petrochemical industries • The bio-technology employed in this project may be a cost-effective treatment technique to mitigate VOC emissions from oil and gas facilities and should be evaluated as a possible MACT (Maximum Achievable Control Technology) to control HAPs. 20
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