The feasibility of integrating biomass steam gasification and syngas - PowerPoint PPT Presentation

The feasibility of integrating biomass steam gasification and syngas biomethanation to store renewable energy as methane gas Lorenzo Menin, Stergios Vakalis, Vittoria Benedetti, Francesco Patuzzi, Marco Baratieri 7 th International Conference on Sustainable Solid Waste Management

High-quality fuels from biomass gasification A glance at future renewable energy systems • Multiple sectors will require diverse renewable fuels and • Fuels with high storage capacity will be required to grant temporal flexibility Thus, sole heat and power production from biomass will not be appropriate: biomass conversion has to shift towards the synthesis of versatile, storable, transportable fuels Heraklion, June 2019 Lorenzo Menin 2

High-quality fuels from biomass gasification Substitute natural gas (SNG) Removal of moisture, tars, impurities Combined heat and power Jet fuel Fischer-T ropsch fuels Raw syngas Gasoline Methanol Biomass Diesel Dimethyl esther Clean syngas (CO, Hydrogen CO2, H2, CH4) SYNGAS CLEANING Biodiesel Substitute Clean syngas natural gas (SNG) Steam gasification BIOMASS GASIFICATION UPGRADING TO FUEL Heraklion, June 2019 Lorenzo Menin 3

Why Methane?  High volumetric energy content : vs  Existing transport and storage infrastructure  Established combustion and conversion technologies across sectors « Natural gas ofgers many potential benefjts […] given limits to how quickly renewable energy options can scale up and that cost-efgective zero-carbon options can be harder to fjnd in some parts of the energy system . The fmexibility that natural gas brings to an energy system can also make it a good fjt for the rise of variable renewables such as wind and solar PV » - International Energy Agency, 2017 Heraklion, June 2019 Lorenzo Menin 4

Methanation processes Catalytic methanation • Operating temperatures: 300-550 °C Hydrogen • Operating pressures: 1-100 bar • Risk of catalyst poisoning Substitute natural gas Carbon monoxide Biological methanation • Operating temperatures: 35-70 °C Carbon • Operating pressures: atm or higher dioxide • Tolerance to feed impurities IN STOICHIOMETRIC RATIOS CATALYTIC OR BIOLOGICAL METHANATION Heraklion, June 2019 Lorenzo Menin 5

Biomethanation of syngas: Substitute Natural Gas from biomass BIOMASS GASIFICATION ENRICHMENT BIOMETHANATION Substitute Natural Gas Cleaning (Biomethane) processes Raw Syngas Biomethanation Clean Distribution and Steam syngas storage gasification Steam Syngas reforming with Methanation feed in Biomass stoichiometric ratios separation Heraklion, June 2019 Lorenzo Menin 6

Biomethanation of syngas: Substitute Natural Gas from biomass and Power-to-Gas services BIOMASS GASIFICATION ENRICHMENT BIOMETHANATION Substitute Natural Gas Cleaning (Biomethane) processes Raw Syngas Biomethanation Clean Distribution and Steam syngas storage gasification EXCESS POWER STORAGE Additional Steam hydrogen Excess renewable Syngas reforming with Methanation feed in Water Biomass energy stoichiometric ratios separation electrolysis Heraklion, June 2019 Lorenzo Menin 7

Integrating biomass gasification and biomethanation Key feasibility questions 1. Yield of biomethane ? 2. Overall production capacity ? 3. Energy efficiency ? 4. Product minimum selling price ? 5. Desirability of biomethane compared to hydrogen ? Heraklion, June 2019 Lorenzo Menin 8

Integrating biomass gasification and biomethanation Study objectives Define a Biomass-to-Biomethane system (A) and a Biomass-to- Hydrogen system (B), both supplemented by water electrolysis . And for both systems: 1. Estimate the system mass balance and production capacity 2. Estimate the system energy balance and efficiency 3. Estimate the minimum selling price of the products 4. Identify system optimization requirements Heraklion, June 2019 Lorenzo Menin 9

System A: Biomass-to-Biomethane Purification Biomethanation Biomass gasification Water-gas shift Syngas cleaning reforming Electrolysis separation Heraklion, June 2019 Lorenzo Menin 10

System B: Biomass-to-Hydrogen separation Tail-gas combustion and energy recovery Heraklion, June 2019 Lorenzo Menin 11

Process techno-economic parameters Process section Parameter Value Reference Cold gas efficiency calculated on syngas 72% Ptasinski (2015) Dual fluidized lower heating value bed gasifier Share of excess electricity input 30% Technical assumption Alkaline water Share of grid electricity input 70% electrolysis Specific electrical consumption 4.6 kWh/Nm 3 H 2 Guillet and Millet (2015) Hydrogen conversion rate 97% Rachbauer et al . (2016) Biomethanation Methane recovery rate 90% Augelletti et al . (2017) Pressure swing adsorption Hydrogen recovery rate 85% Yao et al . (2017) Low-temperature carbon monoxide 47% conversion rate Thermodynamic model in Matlab Water-gas shift with empirical correlations based on reforming literature data High-temperature carbon monoxide 59% conversion rate Heraklion, June 2019 Lorenzo Menin 12

Process financial assumptions and parameters Parameter Value General financial assumptions Plant lifetime 20 years Tax rate 35% Discount rate 7% Materials, utilities, labor Biomass cost 100 €/t Char disposal cost 150 €/t Labor 24.87 €/man-hour Natural gas 0.03 €/kWh Full-price electricity 0.09 €/kWh Surplus renewable electricity 0.05 €/kWh Heraklion, June 2019 Lorenzo Menin 13

System mass balance and production capacity System Product Input Output ID type Biomass Liquid water Steam Biomethane Hydrogen kg/day Nm 3 /day kg/day A Biomethane 60,800 1,160 103,217 26,999 - B Hydrogen 60,800 1,160 103,217 - 4,037 Important comparisons Typical production of European anaerobic digestion biomethane plant: 12,000 - 14,000 Nm 3 /day of biomethane Typical consumption of European ammonia production plant: 160,000 - 315,000 kg/day Typical consumption of European oil refinery: 20,000 - 300,000 kg/day Heraklion, June 2019 Lorenzo Menin 14

System mass balance and conversion efficiency System ID Product type Hydrogen Yield on dry biomass Yield on carbon or hydrogen utilization Nm 3 SNG/kg biomass mol CH 4 /mol C A Biomethane 97.5% 0.44 0.45 kg H 2 /kg biomass mol H 2 /mol H 2 B Hydrogen 85.0% 0.07 0.35 Major conversion limitations with respect to carbon (A) and hydrogen (B) inputs Process A : - carbon losses in scrubbing Process B : - hydrogen losses in PSA tail gas - steam conversion limitations in gasification and water-gas shift reforming - moisture removal Heraklion, June 2019 Lorenzo Menin 15

System energy balance and efficiency System ID Product type Energy input Energy Efficiency output Biomass Thermal Electrical Product Cold gas LHV efficiency MW - A Biomethane 2.1 2.3 10.2 58.4% 13 B Hydrogen 0.8 1.5 5.6 36.6% Energy recovery from PSA tail-gas combustion in Process B Electricity: 1.39 MW High-temperature heat: 2.91 MW Heraklion, June 2019 Lorenzo Menin 16

Breakdown of process energy requirements Energy consumption (MWh/day) System A (Biomethane) Greatest electrical energy requirements 100,0 1. Gas compression (42%) 2. Gasification (29%) 32,66 23,74 3. Pressure Swing Adsorption (13%) 16,34 14,43 10,0 7,24 7,24 4,09 1,68 Greatest thermal energy requirements 1,0 n m n r S S r r s A e e e i o o G G 1. Gasification steam (64%) s S e b b b i i y t t W W P s b b b s l a s y u u u o c s e T T s c r r r i r a L t f H c c p s g i c g s s 2. Water-gas shift steam (28%) s m r e o n a r r a l i i T e e E G o B l t t o c a a o W w s C a g 2 O t n C a l P Electrical energy Thermal energy Heraklion, June 2019 Lorenzo Menin 17

Breakdown of process energy requirements Energy consumption (MWh/day) System B (Hydrogen) Greatest electrical energy requirements 100,0 1. Gas compression (45%) 2. Gasification (23%) 31,47 3. Pressure Swing Adsorption (19%) 16,34 14,43 13,28 10,0 7,24 4,09 1,68 Thermal energy requirements 1,0 r S S r r n m n s A e e e i o o G G Water-gas shift units are only source of s S e b b b i i y t P t s b W W b b a s l s u y u u o c n e T T r i s c r r r e L c c t f s H p i c g g s s heat demand, thanks to PSA tail-gas s m r e o n a a r r l r G i T e e E o l d t t o c a a y o W w s H C a combustion and heat integration g 2 O t n C a l P Electrical energy Thermal energy Heraklion, June 2019 Lorenzo Menin 18

Product minimum selling price and current market prices Minimum selling price Current market prices Product unit Energy unit Product description Product unit System Product price Biomethane from AD of waste and 0.83 €/Nm 3 by-products A Biomethane 2.37 €/Nm 3 B Hydrogen (1) Through biomass gasification and CHP production; (2) Before delivery Heraklion, June 2019 Lorenzo Menin 19

Product minimum selling price and current market prices Minimum selling price Current market prices Product unit Energy unit Product description Product unit System Product price Biomethane from AD of waste and 0.83 €/Nm 3 by-products A Biomethane 2.37 €/Nm 3 0.26 €/kWh 0.16 €/kWh – Biomass-derived (1) renewable electricity 0.27 €/kWh B Hydrogen (1) Through biomass gasification and CHP production; (2) Before delivery Heraklion, June 2019 Lorenzo Menin 20