From SSO To BiomethaneAt Municipal Digester : The Winterthur/ Switzerland Case Study Peter Chromec, Senior Sales Manager Hitachi Zosen Inova Ltd. Zurich, Switzerland
The Place: Cities and area around Winterthur and Frauenfeld City of Frauenfeld: - 25 000 inhabitants - Weekly SSO collection - Paper and Cardboard10 times per year - Bring-in for metals, glass, plastics, etc. - Weeklyresidual MSW City of Winterthur: 100 000 inhabitants - Weekly SSO collection (containeror paper bag) - Paper and Cardboard separately every 2 weeks - Metals every 2 months - Bring-in for glass, plastics, metals, batteries, clothes - Weeklyresidual MSW (pay as you throw) 230 000 people 95 000 tpy MSW, thereof: 0% dir. to landfill 50% separately collected and recycled: 26% biowaste 16% paper/cb 6% glass 2% metals, batteries 50% energy recovery BioCycle Refor 2015: From SSO to Biomethane at Municipal Digester 2
The Vision: 2 tonnes CO 2 -eq per year and inhabitant (primary energy) EC Joint Research Centre 2014 BioCycle Refor 2015: From SSO to Biomethane at Municipal Digester 3
The Vision: 2 tonnes CO 2 -eq per year and inhabitant From 6.4 t CO 2 eq per person and year (2008) the city of Winterthur plans to achieve a 2 t goal by 2050 as per their WINERGY 2050 plan A short term goal was a reduction by 0.6 t CO 2 eq per person and year until 2020 t CO 2 eq / p. y. 7 6 5 4 3 2 1 0 1990 2010 2030 2050 0-0.1-0.2-0.3-0.4-0.5-0.6-0.7-0.38-0.22 7 % of Goal 2 is achieved by the SSO AD plant 1 Goal 1: Reduction of consumption Goal 2: Lower carbon footprint of energy used BioCycle Refor 2015: From SSO to Biomethane at Municipal Digester 4
The Location: Site Selection Inerts Landfill HHW drop-off Frauenfeld Location close to Winterthur-North highway exit Next to landfill (inert material) same access road Next to main Natural Gas pipeline Next neighbors ~500 yards away Only 1.5 acres (6500 m 2 ) total space Winterthur BioCycle Refor 2015: From SSO to Biomethane at Municipal Digester 5
The Solution: Kompogas AD plant for SSO - summary One Kompogas PF1500 digester module 1) more than covers the Cities requirements: 25 000 tpy (23 000 Mg/a) feedstock capacity 2) 150 scfm (80 Million scf per year) biogas Upgraded to biomethane: ~ 40 Million scf per year ~ 37 000 MMBTU/year biogas energy content Compressed to Renewable CNG at 3 gas stations in town ~ 300 000 DGE/year (Diesel Gallon Equivalents) ~ increases renewable content in CNG to ~10% 10 000 tpy quality compost 2) 10 000 tpy liquid fertilizer 2) picture 1) multiple modules can be combined in larger plants 2) The feedstock capacity and compost/fertilizer quantities depend on the actual feedstock properties. For higher biogas potential feedstock capacities are correspondingly lower. BioCycle Refor 2015: From SSO to Biomethane at Municipal Digester 6
Kompogas AD plant Winterthur: Feedstock DM 40-55 % odm 55-75 % N 2-3 g/l Nm 3 /Mg FM: 90-105 few impurities small amount of food waste plenty of green/ yard waste Biowaste Collection Methods: container grass/leaves in paper bag branches bound Impurities: Sand, gravel, stones, metals (nails, gardening tools), plastics, cans, bottles, clay pots BioCycle Refor 2015: From SSO to Biomethane at Municipal Digester 7
Liquid Foodwaste Reception In addition to Biowaste (yard and solid residential foodwaste) the plant is equipped with a liquid foodwaste reception Fats, Oils, Greases allow the use of excess digester capacity for disposal of liquid foodwastes: PF-1500 Reactor Capacity is limited by max gas production of approx. 200 scfm Biogas This Biogas capacity can only be reached with minimum specific gas production feed Feed mixtures with mainly yardwaste and little foodwaste are below that level The reactor contains about 20% Biogas capacity reserve which can be exploited with high-gas-potential liquid feedstock BioCycle Refor 2015: From SSO to Biomethane at Municipal Digester 8
Comparison Biowaste Reception Concepts Both: Receiving and storing the incoming product from trucks Buffer capacity to decouple delivery and operation schedules Mixing very wet material with dry and structured material Lower construction cost Compatible with difficult ground Allows visual inspection of feed Needs less space Needs less labor (no double handling) Fully automated crane Tipping floor waste pit (receiving bunker) BioCycle Refor 2015: From SSO to Biomethane at Municipal Digester 9
Kompogas AD plant Winterthur: Pre-treatment Due to the high feedstock quality, feedstock can be automatically directly tipped into the feed pit as per delivery schedule (Monday Friday) picked up by a crane as per digester feed requirements (continuous 24/7) Shredded, screened and transported by conveyor to the digester BioCycle Refor 2015: From SSO to Biomethane at Municipal Digester 10
Kompogas AD plant Winterthur: PF1500 Digester Schredded and screened feedstock is transported to the digester and pushed underneath the digestate level with a feed screw conveyor In the digester the agitator assures suspension of all materials and degassing of substrate An extraction pump either recirculates inoculate or pushes digestate back to the building BioCycle Refor 2015: From SSO to Biomethane at Municipal Digester 11
Kompogas AD plant Winterthur: the Kompress TM Digestate from Kompogas fermenter is virtually completely degassed and has ~25% DS Either mix with other yardwaste in (existing) composting plant Or dewater with Kompress yields: ~40% DS fresh compost ~10% DS liquid digestate which can be land-applied after sedimentation Hydraulic drive Digestate Reliable bearings and seals Various screen segments Liquid easy to maintain 12 Compost BioCycle Refor 2015: From SSO to Biomethane at Municipal Digester 12
Kompogas AD plant Winterthur: Compost production and use Fresh compost can easily be stabilized/ aerated/ matured/ screened Stabilized and screeed compost is sold to farmers around the site BioCycle Refor 2015: From SSO to Biomethane at Municipal Digester 13
Kompogas AD plant Winterthur: Liquid digestate production and use Digestate sedimentation and storage internal external (as needed) Liquid Digestate application on fields: water/nutrients BioCycle Refor 2015: From SSO to Biomethane at Municipal Digester 14
Kompogas AD plant Winterthur: Odor control Odor sources: Air is aspirated: - Feedstock storage (starts smelling already during collection) - Digestate (anaerobic conditions turn nitrogen to ammonia) - all along the building - at specific odor sources, such as press BioCycle Refor 2015: From SSO to Biomethane at Municipal Digester 15
Kompogas AD plant Winterthur: Biogas Pre-treatment Biogas accumulates under the reactor roof and is extracted via a series of safety devices Biogas is water-saturated and contains H 2 S which both are reduced before further use A Biogas flare serves as redundancy for the Biogas systems BioCycle Refor 2015: From SSO to Biomethane at Municipal Digester 16
Comparison Biogas Upgrading Technologies Amine Scrubber Membrane BioMethane quality Highest (> 99 %vol) High (> 97 %vol) Methane slip Lowest (< 0.1 %) Low (< 0.5 %) BioMethane pressure Low (0.7-2 psig) Medium (120-240 psig) Electricity need ~2.5 kwh/1000scf ~ 7 kwh/1000scf Heat need ~0.05 MMBTU/1000scf none HZI BioMethan : Highest quality biogas upgrading technology available at Hitachi Zosen Inova. BioCycle Refor 2015: From SSO to Biomethane at Municipal Digester 17
Kompogas AD plant Winterthur: Amine Scrubbing Winterthur decided to inject BioMethane into the gas grid so they can use it in various existing CNG gas stations around town Winterthur town grid pressure is about 30 psi - less than available after membrane system Regulations allow BioMethane sale of gross production under a FIT (35 $/mmbtu incl. RIN) Winterthur decision: Amine scrubbing, Water Scrubbing and Pressure Swing Adsorption compared (membrane not considered mature enough in 2010) Highest Biomethane purity Lowest Biomethane loss (no treatment of CO 2 stream) MP pipeline injection for distrubuted use in town CNG gas stations was best option BioCycle Refor 2015: From SSO to Biomethane at Municipal Digester 18
Kompogas AD plant Winterthur: meets CA Rule 30 300 280 CARule 30: CO 2 limit 3.0 vol% 3 2.8 260 240 220 200 180 Biogas Flowrate Biomethane Flowrate CO2 Concentration O2 Concentration 2.6 2.4 2.2 2 1.8 Flowrate [Nm3/hr] 160 140 120 100 80 60 1.6 1.4 1.2 1 0.8 0.6 Concentration [vol-%] 40 20 0 CA Rule 30: O 2 limit 0.2 vol% 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 0.4 0.2 0 BioCycle Refor 2015: From SSO to Biomethane at Municipal Digester 19
Kompogas AD plant Winterthur: Gas Stations The City of Winterthur can cover about 10% of their natural gas fuel demand by Kompogas BioCycle Refor 2015: From SSO to Biomethane at Municipal Digester 20
Kompogas AD plant Winterthur: Conclusions Simple, standardized ~25 000 tpy Kompogas PF1500 Plant for all local organic wastes Low space requirements (1.5 acres onlywith compressed layout) Highest feedstock and biogas use flexibility (pipeline injection, CNG, CHP) Reliable and stable operation (highest degree of automation possible) BioCycle Refor 2015: From SSO to Biomethane at Municipal Digester 21
US Contact: Hitachi Zosen Inova U.S.A. LLC Norcross, GA 30092 (678) 987 2500 william.skinner@hz-inova.com markus.stangl@hz-inova.com