anaerobic digestion of petroleum hydrocarbon (phc) anaerobic digestion of petroleum hydrocarbon...

Download Anaerobic Digestion of Petroleum Hydrocarbon (PHC) Anaerobic Digestion of Petroleum Hydrocarbon (PHC)

Post on 30-Aug-2019

0 views

Category:

Documents

0 download

Embed Size (px)

TRANSCRIPT

  • Anaerobic Digestion of Petroleum Hydrocarbon

    (PHC) Waste

    Ahmed Al Shehhi and Isam Janajreh Masdar Institute of Science and Technology

    Abu Dhabi, UAE 54224

  • 11

    22

    33

    44

    55

    1

    2

    3

    4

    56

    87

    Introduction

    Overview

    Methodology

    Material characterization

    Theoretical Estimation of landfill-gas

    Experimental

    Results

    Conclusion

    Outline

  • United Arab Emirates represents the seventh proven reserve of oil & gas worldwide and tenthlargest producers of crude oil and natural gas. Crude oil exports amounted to 2,794 millionbarrels per day (bpd) and 54,245 million cubic meter natural gas in 2015

    Estimates show that daily production of 200500 barrels of petrochemicals generates nearly10,000 m3 annually of sludge which creates environmental stress and pollution [1]

    The oily sludge is described as a remnants obtained from the water, oil, fat , solids and organiccompounds.

    Different treatment methods, such as incineration, pyrolysis, landfilling, and biodegradationhave been explored to deal with such oily sludge waste

    In Abu Dhabi, BeAAT a specialized treatment facility for petroleum waste, was established tosafely receive, manage, treat and dispose hazardous waste generated by ADNOC Group and toensure that human health and the environment are adequately protected

    BeAAT methods of treatment focus on thermochemical and stabilize landfilling. This workfocus on the anaerobic PHC decomposition in bioreactor for the generation of landfill gas sideto/or an alternative to the thermal method

    Introduction

    1

    2

    3

    4

    5

    6

    87

    [1]A. Gafarov, A. Panov, A. Filonov, and A. Boronin, "Change in the composition of a bacterial association degrading aromatic compounds during oil sludge detoxification in a continuous-flow microbial reactor," Applied Biochemistry and Microbiology, vol. 42, pp. 160-165, 2006.

  • Treatment Method Quantity CharacteristicsSolidification 10,000 tones / year Spent catalyst, ceramic balls, inorganic wastes

    Centrifugation 5,000 tones / yearWastewater treatment sludge, PHC sludge, APIseparator sludge

    Thermal Desorption 7,000 tones/year Drill cuttings, contaminated soilIncineration 5,500 tones / year Organic wastesPhysical/Chemical Treatment 35 tones / year Acidic and alkaline wasteMercury Distillation 50 tones /year MercuryLandfill Class I & II 85,000 m3 total capacity All wastes treated by other unitsEvaporation Pond 3,000 m3 total capacity Drill cuttingsTOTAL throughput (design) 25,000 t/year All the above

    1

    2

    3

    4

    5

    6

    87

    Petroleum Waste in Abu Dhabi is processed by BeAATwhich is a subsidiary of Takreer, the national refinerycompany of Abu Dhabi, BeAAT is specialized in thetreatment of hazardous waste. On a yearly basis theyreceive:

    Drill cuttings from Off-shore: ~ 2500 tons/year

    Contaminated Soil from On-shore: ~ 4500 tons/year

    A. R. A. Hosni, "An overview of beaat plant," Japan environment symposium, 2013.

    Introduction (Contd)

  • Type of Anaerobic Digestion Temperature Substrate SMY (L kg-1) ReferenceMesophilic & Thermophile 35-65 Cattle manure 240-280 Varel (1980) [7]Physrophelic 20 Cow feces 184.5 24 Saady and Masse (2014) [6]Thermophile 65 Cattle manure 165 Ahring (2001)[8]Mesophilic 30 Dairy cattle manure 164 Shyam (2002)[9]Mesophilic 35 Dairy cattle feces 148 41 Moller (2004) [10]Mesophilic 30 Dairy cattle manure 135 Somayaji Khanna (1994)[11]Physrophelic Beef cattle manure 85 Schfer (2006)[5]Mesophilic 35 Refinery Residuals - Nasirpour, N. et al. [12]

    [5]Schfer,W.,Lehto,M.,Teye,F.,2006.Dryanaerobicdigestionoforganicresiduesonfarm afeasibilitystudy.Agrifood ResearchReports77.MTTAgrifood ResearchFinland..[6]Mass,D.,Saady,N.(2014).Psychrophilicdryanaerobicdigestionofdairycowfeces:Longtermoperation.WasteManagement,36(2015),86928692.[7]Varel,V.H.,Hashimoto,A.G.,Chen,Y.R.,1980.Effectoftemperatureandretentiontimeonmethaneproductionfrombeefcattlewaste.Appl.Environ.Microbiol.40,217222.

    Bioreactor landfilling is the state of the art technique of landfilling that speeds up the degradation ofsolid wastes by controlling the moisture content via leachate recirculation and water addition.

    While, the conventional landfill (dry tomb) works by reducing the moisture content of the landfill inorder to lower its leachate and LFG emissions albeit it still persist at low rates, causing slowness inthe degradation of wastes and occupying more space than bioreactor landfills.

    Anaerobic digestion has been the best waste management practice used for both pollution control andenergy recovery. Many agricultural and industrial wastes contain high levels of easily biodegradablematerials and thus are ideal for anaerobic digestion

    1

    2

    3

    4

    5

    6

    87

    Literature ReviewOverview

  • Methodology

    1

    2

    3

    4

    5

    6

    87

    Bioreactor landfill has the potential to fully degrade waste in tenyears instead of many decades as the case of classical dry tomblandfill. It generates faster Landfill gas (LFG) for fuel utilization.

    none

  • 1

    2

    3

    4

    5

    6

    87

    (C6H10O5)n + n H2O n C6H12O6C6H12O6 CH3 (CH2)2 COOH + 2H2 + 2 CO2

    C6H12O6 + 2H2 2 CH3CH2COOH + 2H2O C6H12O6 + 2 H2O 2CH3COOH + 4H2 + CO2

    CH3(CH2)2COOH + 2H2O 2 CH3COOH + 2 H2CH3CH2COOH + 2H2O CH3COOH + 3 H2 + CO2

    CH3COOH CH4 + CO24H2 + CO2 CH4 + 2 H2O2

    In the hydrolysis step, the complex organic compounds are solubilized andconverted into smaller sized organic compounds by extracellular enzymes.

    In this stage, conversion of propionic and butyric acids into acetic acid occurs as described in the following reactions

    Finalconversionstageinwhichtheformationofmethanegaseitherfromacetateorcarbondioxidereduction,ittakesplacefollowingtheseequations

    Theoretical Methodology

    The organic acids are then broken into acetic acid.

  • Material characterization

    1

    2

    3

    4

    5

    6

    87

    Proximate analysis

    Thermo-Gravimetric Analysis (TGA) 4 different batches tested 3 times.

    Batch Moisture [wt%]Volatiles

    [wt%]Fixed carbon

    [wt%] Ash

    [wt%]

    Sample 1 7 16 14 63Sample 2 6 16 13 65Sample 3 10 21 17 52Sample 4 12 18 14 56Average 9 17 14 60St. Dev. 2.63 2.34 1.92 6.34

    TGA Curve of Sample 1

  • 1

    2

    3

    4

    5

    6

    87

    Ultimate analysis

    Element Sample1 Sample2 Sample3 Sample4 AverageC [wt.%] 14.4 13.1 18.3 20.2 16.5H [wt.%] 1.4 1.3 1.2 1.4 1.3O [wt.%] 9.2 14.0 17.9 9.7 12.7N [wt.%] 0.1 0.0 0.0 0.2 0.1S [wt.%] 1.1 0.6 0.3 0.2 0.6H2O [wt.%] 7.1 5.7 10.2 12.0 8.6Ash [wt.%] 63 65.2 52.1 56.1 60.2Molecular Formula CH1.138O0.477

    N0.004S0.029CH1.151O0.802N0.003S0.016

    CH0.749O0.730N0.001S0.007

    CH0.821O0.361N0.007S0.007

    CH0.965O0.593N0.004S0.015

    M [kg/kmol] 21.772 6.53 24.66 18.93 22.97

    The volatile matter of the petroleum waste consisted primarily of five elements: carbon, hydrogen, nitrogen, oxygen and sulfur

    2

    W FO = 1W FCW FHW FNW FSW FmoistureW Fash

    Account for H2 Weight Fraction in Moisture:

    O2 found by difference:

    Molar Composition:

    Normalizing for Carbon:

    ,

    Material characterization

  • Theoretical Estimation of landfill-gas

    1

    2

    3

    4

    5

    6

    87

    Waste Stream Molecular formula Moisture Volatiles solid AshPHC CH0.965O0.593N0.004 9% 17% 60%WWTS CH0.091 O0.565 N0. 2 62% 27% 5%MSW CH1.58 O0.63 N0.016 12% 58% 22%

    Anaerobic Gas Yield PHC WWTS MSW 60% PHC & 40% WWTSWeight of the methane (kg) 11.57 8.8 22.1 10.46Weight of carbon dioxide (kg) 35.56 41.55 51.67 37.95Volume of the methane (m3) 7.32 5.56 13.97 6.61Volume of carbon dioxide (m3) 8.15 9.53 11.85 8.70Percentage of the methane % 47.29 36.87 54.11 43.12Percentage of carbon dioxide % 46.65 46.65 46.65 46.65Total theoretical amount of landfill-gas generate (L kg-1) 13.4 49.027 111.2 27.65Specific methane yield (N L CH4 kg-1) 6.34 18.07 60.17 11.92

    To estimate the rate of production of methane Numerous samples of the PHC sludge from BeAATwere obtained and subjected to homogenization. This is followed with TGA proximate and Flash200elemental analyses. The estimated theoretical yield follows the biodegradation stoichiometricfollowing equation:

    4 2 34

    4 2 38

    4 2 38

  • 1

    2

    3

    4

    5

    6

    87

    Landfill Gas Emissions Model

    10.

    Landfill gas emissions model is used to simulate the gas generation as time elapsed in years ordecades to come [13]. Theoretically obtained amount is compared to the landfill generation modelcreated by USEPA.

    Methane Generation Rate, k 0.02 year-1Potential Methane Generation Capacity, Lo 15 m3/MgNMOC Concentration 8000 ppmv as hexaneMethane Content 43 % by volume

    00,010,020,030,040,050,060,07

    1 9 17 25 33 41 49 57 65 73 81 89 97 105

    113

    121

    129

    137

    M3 /yaer

    Years

    Totollandfillgas Methane CarbonDioxide

    0

    20

    40

    60

    80

    100

    120

    1 10 19 28 37 46 55 64 73 82 91 100

    109

    118

    127

    136

    M3 /yaer

    Years

    Totollandfillgas Methane CarbonDioxide

    0

    1

    2

    3

    4

    5

    1 10 19 28 37 46 55 64 73 82 91 100

    109

    118

    127

    136

    M3 /yaer

    YearsTotollandfillgas Methane CarbonDioxide

    100Kgofwasteonetime

    7toneofwasteonetime

    7toneofwastefor25years

    Theoretical Estimation of landfill-gas

    [13]LandfillGasEmissions