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Outline
- Introduction
- Methodology
- Results and discussions
- Conclusions
Effect of co-digestion of milk-whey and potato stem on heat and - - PowerPoint PPT Presentation
Effect of co-digestion of milk-whey and potato stem on heat and - - PowerPoint PPT Presentation
Effect of co-digestion of milk-whey and potato stem on heat and electricity generation using biogas as an energy vector Jimmy A. Martnez Ruano, Daissy L. Restrepo Serna, Estefanny Carmona , Carlos A. Cardona Universidad Nacional de Colombia sede
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Non-renewable energy vs renewable energy
Non-renewable
Nuclear Fosil Fuel Oil Coal Natural Gas Energy
Renewable
Energy Hydropower Wind Biomass Geothermal Solar
Introduction Methodology Results Conclusions
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Biogas as energy vector
Introduction Methodology Results Conclusions
Biomass Biomethane (CH4) Carbon dioxide (CO2) Water vapour (H2O) Hydrogen sulphide (H2S) Ammonia (NH3)
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Influence of co-digestion on biogas production
Introduction Methodology Results Conclusions
Co-digestion has an influence on the performance of anaerobic digestion, establishing a possibility to increase the potential of biogas as an energy vector. Co-digestion is the combination of biodegradable raw materials to improve the balance of nutrients in anaerobic digestion.
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Introduction Methodology Results Conclusions
The main objective of this study is to investigate the combined production
- f heat and electricity from biogas as energy vector using Potato Stem
(PS) and Milk Whey (MW). All of this, to determine the economic profit within the framework of the waste integration by anaerobic co-digestion.
Aim of research
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Introduction Methodology Results Conclusions
Characterization of the raw materials
Determination of total solids, volatile solids and ash Particle size reduction ˂1 mm Determination of extractives Determination of cellulose, hemicellulose and lignin
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Introduction Methodology Results Conclusions
Simulation process
Anaerobic Digestion Energy Generation
Biogas Power Electricity MP-Steam Feedstocks Air Digestate Hexausted gas
The production process to generate heat and electricity using biogas obtained from the PS and MW was simulated in Aspen Plus (Aspen Technology, Inc., Houston, USA).
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Introduction Methodology Results Conclusions
Anaerobic digestion
Anaerobic digestion process for biogas production was simulated with a modification
- f the model: A Novel Process Simulation
Model (PSM) developed by Rajendran et. al, 2014.
Source from Rajendran et al, 2014.
Our model considered the protein of MW as soluble protein and that its lipid composition is mainly triolein.No special pretreatments added. For PS, new reaction was added for extractives, where the extend of reaction is 0.5 ± 0.2
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Introduction Methodology Results Conclusions
Heat and electricity
The electricity and heat generation from biogas consisted of two sections: electricity production by means of a gas turbine and heat recovery steam generation.
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Introduction Methodology Results Conclusions
Economic assessment
- The process economic assessment consisted of determining the capital
costs (CAPEX) and operating costs (OPEX) for each of the simulations. Investment Parameters
- Tax rate (25 %)
- Interest rate (17%)
Raw materials
- Potato stem (0.08 USD/kg)
Utilities
- Electricity (0.124 USD/kWh)
Operation
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Introduction Methodology Results Conclusions
Characterization of the raw materials
Potato Stem (PS) Milk-whey (MW) Component % % Cellulose 36.03 ± 0.32
- Hemicellulose
27.18 ± 0.40
- Lignin
11.45 ± 0.56
- Extractives
12.47 ± 0.11
- Ash
2.10 ± 0.21
- Moisture
9.67 ± 0.02 94.08 ± 0.32 Protein
- 1.43 ± 0.15
Carbohydrates
- 3.65 ± 0.37
Fat
- 0.19 ± 0.20
Total Solids (TS) 92.63 ± 0.05 5.69 ± 0.06 Volatile Solids (VS) 90.06 ± 0.03 5.38 ± 0.04
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50 100 150 200 250 MW PS MW + PS
L Biogas/kg feedstock
CO2 Methane 21.92 207.92 137.73
Introduction Methodology Results Conclusions
Anaerobic digestion
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Introduction Methodology Results Conclusions
Heat and electricity production
AD + CHP Milk-whey AD + CHP Potato stem AD + CHP Co-digestion
Milk-whey (MW) Potato stem (PS) PS + MW 2072.05 Water dilution 1311.07 2072.05 3383.75 MP steam 266.4 7 KW + MP steam 1447.2 40 KW + MP steam 1929.6 54 KW +
* Balance in kg/day
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Introduction Methodology Results Conclusions
Economic assessment
0,00 8,00 16,00 24,00 32,00 40,00 MW PS MW + PS M.USD/year
CAPEX General and adminsitrative Cost Plant Overhead Maintenance Cost Operating Labor Cost Total Utilities Cost Total Raw Materials Cost
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Introduction Methodology Results Conclusions
Economic assessment
- 200
300 800 1300 1800 2300 1 2 3 4 5 6 7 8 9 10 11 Net Present Value (M.USD) Year
Milk-whey (MW) Potato Steam (PS) Co-digestion of PS and MW
23 18 13 8 3
- 2
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Introduction Methodology Results Conclusions
Conclusions
The integration of potato stem and milk whey to generate heat and electricity is a promising alternative due to economic profit. This generates a net economic profit of 17.94 M.USD, which is higher compared to stand- alone process. The biogas yield from potato stem was of 207.21 L biogas/kg PS (66.35% CH4), biogas yield from milk whey was of 21.92 L biogas/kg MW (73.55% CH4) and co-digestion was 137.73 L biogas/kg feedstocks (51.08% CH4). The results represent a type of strategy to analyze the integration of different raw material to reach a synergy allowing increasing the economic indexes for new projects.
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Introduction Methodology Results Conclusions
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Introduction Methodology Results Conclusions
Reactions set
Table 2. Reactions for modeling biogas production from potato stem and milk-whey. – Reactions used for PS. – Reactions used for MW. – Reactions used for both feedstocks.
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