biogas in south africa - sairec · biogas basics: biogas is produced when any type of organic...
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BIOGAS BASICS: Biogas is produced when any type of organic material decomposes in the absence of oxygen – an anaerobic digestion process (AD). Biogas consists of methane, CO2 and trace gasses (H2S). Methane: source of energy (same as LPG), mainly to produce renewable energy/electricity Methane can be used as energy source for - Cooking - Light - Hot water - Generate electricity - Vehicular biogas
ADDITIONAL BENEFITS: Biogas plants do not ONLY produce electricity!
(Solar, wind & hydro produce only electricity)
• Sustainable waste management (abattoirs, manure, processing plants, cheese factories, breweries, etc) • CHP from gensets (free heat energy) • Digestate is an organic compost (additional revenue stream) • Use of CO2 in green houses • Carbon footprint/carbon neutrality • Green jobs (5/MW compared to 0.9/MW for solar!) • Skills transfer (introduction of new technology)
BIOGAS IN SOUTH AFRICA: For all intents and purposes there is NO biogas industry in South Africa There are only around 700 digesters in the whole of SA!
Of these: • Approx 40% at existing WWTW • 50% small scale domestic /rural digesters • and only around 10% commercial installations
China: 17 million India: 12 million Uganda: 600 Germany: 1000 commercial digesters per year (1 every 8 hours of the day!)
TYPICAL FEEDSTOCKS
• Sewerage waste: domestic, municipal, schools, hotels, etc • Food waste: domestic & industrial/commercial, incl. fats and oils • Manure: pig, cattle - dairy or feedlot, chicken, etc • Agricultural: vegetables, fruit, maize, sugar cane, etc • Commercial: abattoirs, cheese factories, breweries, wine estates, processing plants, fruit & veg packaging plants, etc
Wastewater MWth MWe
Domestic black water Municipal WWTP 842 253
Animal husbandry Feedlots (solids & liquids) 215 65
Rural cattle (kraaled at night - solids only) 3445 1035
Dairies (solid & liquid) 121 36
Piggeries (solid & liquid) 715 215
Poultry (solid only) 2976 894
Red meat & Poultry Abattoirs (liquid waste only) 55 17
Olive production 4 1
Fruit processing Waste water only, no pulp or pomace 68 20
Winery 3 1
Distillery Grain, grape & sugarcane (molasses) 70 21
Brewery 17 5
Textile industry 22 7
Pulp and paper 100 30
Petrochemical waste 48 14
8701 2613
Courtesy of: WRC Energy from Wastewater Feasibility Study
ESSENCE REPORTS compiled by UCT
Study conducted by UCT on energy potential
from Waste Water in SA
TYPICAL DIGESTER DESIGNS
DOMESTIC / RURAL DIGESTERS: • Fixed Dome Digester (Chinese) • Floating Dome Digester (Indian/Gobar Gas) • DIY Biobag Digester Kit • Plastic Roto moulded digesters • In-situ cast concrete digester (Puxin)
AGRICULTURAL/INDUSTRIAL DIGESTERS: • Lagoon Digester • Plug Flow digester • Complete Mix Digesters (CSTR) • Up-flow Sludge Blanket Digester (UASB)
Biobag Digester
In-situ cast Puxin Digester
Brick & Mortar fixed dome digester
TYPICAL SMALL SCALE DIGESTER DESIGNS
PLUG FLOW DIGESTER: DAIRIES
Application: • Feedstock: 8 -12% solids • Primarily for used for cow manure digestion:
• Dairies (specifically housed) • None in SA yet
• Continuously Stirred Tank Reactor
• The CSTR Digester is a collective term for hardware to contain, heat & stir (agitate) waste inside the digester.
Typical applications: Abattoirs Food processing plants Fruit/vegetable packaging
100kW Abattoir Digester:
Jan Kemp Dorp Courtesy: iBERT
400kW Abattoir Digester:
Springs Courtesy: BiogasSA
CURRENT DIGESTER PROJECTS IN SA
CURRENT STATUS OF BIOGAS INDUSTRY IN
SOUTH AFRICA
CHALLENGES: • No feed-in tariff • General lack of awareness (both in government as well as private sector) • Lack of local experience (particularly on operational side) • Challenges around financial viability, specifically on the smaller scale (< 1MW)
- Only clients that perceives value in additional benefits (waste management, reduction of carbon footprint, compost sales, ‘free’ thermal, etc)
• Excessively long approval processes (license, EIA, PPA, wheeling agreements, MFMA, etc) • Funding reluctance from banks (again for plants < 1MW) • IPP process – complicated, costly, only above 1MW (most projects below 1MW)
POSSITIVES: • Creation of SABIA (Southern African Biogas Industry Association) in 2013 • Establishment of the National Biogas Platform and various working groups • Creation of the Biogas Info Hub funded by GIZ • First national biogas conference sponsored by DoE November 2013 – again in March 2015, planned for March 2016 • Pro-active support from GIZ, UNIDO • Growing awareness on all levels of government • Better tariff for biogas in latest REIPPP round (R1.47/kWh) – this could see more biogas projects applying for the Small Scale REIPPP process • Keen interest from European biogas companies and equipment suppliers to seek business in SA • Positive entrepreneurial spirit in SA – biogas projects being built despite the challenges faced by the industry!