WASTE-TO-ENERGY TECHNOLOGIES 20/01/2015 This activity received - - PowerPoint PPT Presentation
WASTE-TO-ENERGY TECHNOLOGIES 20/01/2015 This activity received funding from the Department of Industry as part of the Energy Efficiency Information Grants Program. The views expressed herein are not necessarily the views of the Commonwealth of
20/01/2015
This activity received funding from the Department of Industry as part of the Energy Efficiency Information Grants Program. The views expressed herein are not necessarily the views of the Commonwealth of Australia, and the Commonwealth does not accept responsibility for any information or advice contained herein.
'Beyond compost and fertiliser - Using farm waste to generate energy'
Fernando Johnstone & Phil Shorten | January 2015
You have considered the use of alternative fuels such as biomass/biogas at your site… Starting to look at our first opportunity Looked at many options, but none has progressed to implementation Implementing our first project now Have an existing alternative fuel
Agricultural waste: straw, bagasse, nut shells, cotton gin waste, horticultural waste Animal farm waste: manure, slurries, chicken litter Wood waste: woodchips, sawdust, forestry residues Urban waste: municipal solid waste (MSW), commercial and industrial (C&I), sewage waste
Direct biomass combustion: biomass fuel is burnt in excess air to produce heat. Anaerobic digestion: a biochemical process that uses microorganisms to produce a biogas rich in methane, which can be combusted for heat or used as fuel in reciprocating engines for power generation Gasification: gasification of biomass takes place in a restricted supply of air or oxygen and produces a fuel gas that is rich in combustible carbon monoxide, hydrogen and methane (syngas) Pyrolysis: thermal degradation of biomass in the absence of oxygen to produce a combination
Other – biofuels: fermentation, esterification
12 MWth woodchip boiler – Bega, NSW Anaerobic digesters Barrybank Farm, VIC New Energy Waste to Energy project (low temp gasification) – Port Hedland, WA
PRODUCTS
+ food waste
Well proven Cost-effective
Biogas from anaerobic digestion and direct combustion of biomass are more suitable for small to medium-size applications
Is produced by anaerobic digestion of organic waste in an oxygen-free environment (i.e. sealed container: covered ponds or digester tanks) Biogas produced has a methane content of 50 – 70%. Moisture and hydrogen sulphide too! (gas cleaning is important) Digestate is a byproduct with high nutrient value: fertilizer Covered anaerobic lagoons (CAL) are very common in some farms and abattoirs. Lower capital and O&M costs compared to digester tanks.
N/A in Australia Biogas can be also used in gas-fired boilers to generate steam or hot water Food waste is an excellent substrate. Proper screening of MSW is key Pre-treatment such as cutting, shredding or diluting may be required depending on waste characteristics (as received)
Covered pond Digester tank
Digestion in tanks or plug reactors is considered rather expensive for small scale applications (capacity: 5 – 100m3). Better outcomes for farm-scale applications (100 – 800m3), e.g. piggeries Biogas yield (m3/ton) depends on type of material but also on process conditions (temperature, residence time, pH, mixing). Co-digestion with food or crop waste is typically used to improve methane yield. Biogas is typically used in gas-fired boilers (co-firing with natural gas). Use in gas engines is also typical but requires biogas cleaning due to hydrogen sulphide (H2S) content which can corrode internal parts. Biogas yields (Source: Ecofys bv)
1. Drivers: a) Increase in waste and regulation from conversion to intensive operations, e.g. paddock to feedlot b) Rising energy prices c) Increasing waste disposal cost – Landfill levies 2. Barriers: a) Typically large capital costs and limited access to capital: long term projects b) Lack of understanding around waste-to-energy c) Alternative use of waste: waste can be sold as fertiliser, applied on site, or composted and then sold/applied
$1,000s $10,000s $100,000s $ millions
Large farm Small - Medium farm
Greater scale improves profitability….
Piggery size Indicative cost* for biogas project Potential return
Source: Australian Pork Limited & Pork CRC
Waste generation and biogas yields: Source: World Bioenergy Association (WBA) fact sheet
Example: How much biogas is needed for a motor-generator of 100 kWe output capacity? A biogas plant with an installed capacity of 100kWe, an electrical efficiency of 35% and an annual production of 800,000 kWh electricity requires 470,000 Nm³ biogas. This equals the biogas output from a manure slurry of 950 intensively housed milking cows, 6,000 pigs or 45 ha of maize. 6,000 pigs x 1.9 m3 manure/pig = 12,000 m3 manure/yr. 12,000 m3 manure x 42 m3 biogas/m3 manure = 470,000 m3 biogas/yr 470,000 m3 biogas x 50% methane = 235,000 m3/yr of methane 235,000 m3 methane x 37 MJ/m3 = 8,700 GJ/yr of energy 8,700 GJ/yr * 35% generator efficiency = 3,000 GJ/yr or 840 MWh/yr of electricity
system to generate power from methane from an anaerobic (covered pond) system
to generate heat and power
recovery on engine cooling circuit and exhaust (hot water). Running 24/7 and gas is still being flared!
electricity generated. Rest gets exported to the grid.
(electricity & gas). Additional revenue of $5,000 per month for selling power back to the grid. Payback: <3yrs (incl. CFI credits + RECs)
Blantyre Piggery (22,000 pigs)
Covered pond captures methane produced from the anaerobic digestion of pig manure (Source: NSW Farmers) 80kW biogas gensets
Darling Downs Fresh Eggs
Australian egg production sector
be supplied to gas gensets to produce power and heat
farm’s non-peak power requirements and reduce electricity usage by 60%
(electricity & gas)
CEFC and NAB + $330K CTIP funding
Quantum Power built, owns and
using poultry waste from Darling
energy from Quantum at a lower price that grid supplied electricity.
Waste Availability:
combine waste fuels from different sources?
possible?). Are there any seasonal variations? (eg. some crops available only 3-4 months per year)
use & markets? (eg. straw used for fodder) Waste Quality
combustion problem, equipment damage, or represent an environmental risk
materials can be present (eg. treated timber: arsenic)
Existing Infrastructure:
Technology Options:
firing feasible? Do you have layout constraints? Storage and handling equipment require space!
Australia?
Costs:
CEFC)
Savings:
digestate as fertiliser). Export and sell power back to the grid if excess power from cogeneration
required due to large capex requirements
Risks & Barriers:
OEH Finance guide http://www.environment.nsw.gov.au/business/project-financing.htm
NSW Farmers resources to help farmers save energy, including 35 Factsheets on Energy Planning, Energy Purchasing, Efficient Farm Vehicles, Energy & Irrigation, Renewable Energy, Energy in Farm Facilities www.tinyurl.com/NSWFarmersEnergyFactsheets Energy Innovation Planning Tool www.tinyurl.com/NSWFarmersEnergyTool Soon to launch: Solar PV pumping guide Guide to on-farm energy generation Other Web resources AgInnovators Web Portal (aginnovators.org.au) Clean Energy Council (cleanenergycouncil.org.au/) Australian Solar Council (solar.org.au/) RenewEconomy (reneweconomy.com.au)
02 9478 1013 gerryf@nswfarmers.org.au