Assessment of Biogas Potential from Agro-Waste in South Africa

Transcription

1 Assessment of Biogas Potential from Agro-Waste in South Africa Drs M.S Thaela-Chimuka, A Kanengoni, F., Nherera-Chokuda and TEAM thaelamj@arc.agric.za

2 INTRODUCTION Identify and assess the obvious options for biogas generation. Particular low hanging fruits. Calculation electricity and heat potential source of energy, focus larger biogas projects and exclude smaller biogas digesters for households

3 INTRODUCTION The study considers data on annual theoretical biogas potentials from four agricultural sectors namely livestock farming, abattoirs, fruit processing and the agro-processing industry.

4 OBJECTIVES Aims: Identify promising solid and liquid substrates (excluding municipal solid waste) significant national potential for biogas production anaerobic digestion. Assess the biogas potential of the promising agricultural solid and liquid substrates.

5 OBJECTIVES cont Investigate options for use of digestate and effluent as a by-product of anaerobic digestion for irrigation and fertilization purposes. Define suitable plant sizes with proposed mixtures of substrates based on assumptions in areas with the larger concentration of the material ( low hanging fruits )

6 Biogas Potential activities on live-stock, Agro-processing and Plant residue together with list of responsible persons Responsible person Institution Activity Livestock Mr. C. Muya (CM) Dr. F. Nherera-Chokuda ARC-API Dairy industry (NC) Mr. K-J Leeuw (KL) & Mr. M, Ratsaka (MR) ARC-API Cattle Dr. A. Kanengoni (AK), ARC-API Piggeries Mrs. P. Sebothoma (PS), Mr. R Thomas (RT), Ms. K. Mphofu (KT) 2.Agro-processing industry Dr. M.S. Thaela-Chimuka (TC), ARC-API Chicken farms (laying hens) Ms. M Mokoma(MK) Ms. P Magama (PM) & K. Mogodu (MD) ARC- Milk-processing industry Mr. K-J Leeuw (KL) & Mr. M, Ratsaka (MR) ARC-API Abattoirs: in conjunction with cattle feedlots Dr. A. Kanengoni (AK), ARC-API Abattoirs: in conjunction with piggeries Mrs. P. Sebothoma (PS), Mr R Thomas (RT), Ms K.. Mphofu Dr. M.S Thaela-Chimuka (TC), ARC-API Abattoirs: in conjunction with chicken farms Ms M Mokoma (MK) Ms. P Magama (PM) & K. Mogodu(MD) ARC- IAE Fresh-produce markets, Sugar industry, Pineapple industry, Fruit pulp: vineyards, Fruit pulp: juice, Breweries and Milling industry 3. Plant residues Ms. P Magama (PM) & K. Mogodu (MD) ARC-IAE Maize residues, Sugar cane residues and other residues still to be identified

7 MATERIALS AND METHODS

8 FEEDSTOCK The study considers data on annual theoretical biogas potentials from four agricultural sectors - Livestock farming, - Abattoirs, - Fruit processing - Agro-processing industry

9 Livestock Dairy industry: feedlots (min 400) Dairy industry: milking parlours (min 400) Cattle feedlot (min 500) Piggeries (min 5,000 pigs) Chicken farms (laying hens) (10,000 )

10 Agro-processing industry Milk-processing industry Abattoirs: conj with cattle feedlots Abattoirs: conj with piggeries Abattoirs: i conj chicken farms

11 Agro-processing industry Fresh-produce markets Sugar industry Pineapple industry Fruit pulp: vineyards Fruit pulp: juice Breweries Milling industry

12 Plant residues Maize residues Sugar cane residues

13 Proposed structure for each feedstock 1) Description of the feedstock a) Characteristics b) Current use 2) Quantities available in tons per year a) Overall b) Seasonality of availability c) Average sizes of farms and processing plants, big players, etc. d) Regional concentrations (provinces) 3) Quantification of the energy characteristics of the feedstock (dry matter, volatile solids content, biogas potential, methane content in the biogas, ) 4) Potential for co-fermentation / mixtures with other feedstocks 5) Use options for the digestive a) Potential future use b) Potential conflicts with current use c) present demand of mineral fertilizer in each province, where possible 6) Energy needs at the site (electricity, heat) with identification of the energy supplier of the analysed farms/industries (Eskom or Municipality) 7) Sources for further information

14 DATA SOURCES ARC milk recording scheme. SA Feedlot Association DAFF Internet search South African Pig Producers Organization (SAPPO). South African Poultry Association (SAPA)

15 DATA SOURCES Company websites, agricultural statistics handbook, PORCUS (the official publication of SAPPO) and newspaper reports SAB miller and Horticultural industry knowledge group (Hortgro) SAWIS (South Africa Wine Industry) and agricultural statistics handbook

16 WASTE GENERATED

17 LIVESTOCK The total waste generated per annum from each sector was calculated by multiplying the average daily manure production of each livestock unit by the total no of units available.

18 LIVESTOCK The waste generated was estimated literature figures Cattle manure production of 12 kg/day (Daniel et al. (2014) and biogas yield of 40 m 3 /ton (TACIS, 1997)

19 LIVESTOCK CONT Pigs daily dung production of 3.6 kg/day (Daniel et al. 2014) and biogas yield of 60 m 3 /ton(tacis,1997) Poultry daily litter production of 0.02 kg (Daniel et al. 2014) per unit and biogas yield of 70 m 3 /ton (TACIS,1997)

20 ABATTOIRS Classification of abattoirs according to the number of slaughter units that can be slaughtered per day as follows: Red Meat Poultry Ostriches Game High Throughput Low Throughput Rural Slaughter unit = 1 bovine 1 fowl 2 Ostriches 1 medium game 6 sheep 1 duck 6 small game 4 porkers 1 pheasant Large game to be determined by 2 baconers 1 guinea fowl PEO 1 sausage pig ½ goose ¼ turkey operational days abattoirs S A 240 days (beef), 365 days (pigs and poultry).

21 ABATTOIRS Pig waste-water generated from pig abattoirs is estimated at 360L per pig (GDARD, 2009). The solid and liquid waste was estimated at 4.4 kg and 5.8 kg per pig respectively (Daniel et al., 2014).

22 ABATTOIRS Chickens According to Malopa (2009), 18 L of wastewater is produced per chicken slaughtered. The blood waste produced is 3% of the body weight when body weight is estimated at 1.8 kg.

23 ABATTOIRS Beef The amount of water used per livestock unit (SLU) is 900 L, 80% of which becomes waste-water (GDARD, 2009). The amount of solid, liquid and blood waste from cattle was estimated as a COD of mg.l -

24 AGRO-PRO Agro-processing Substrate Liquid waste Solid waste Liquor(beer) 6L/L of liquor produces Spent grain: 0.2kg/L beer Spent yeast:0.015 kg/l beer Liquor (wine) 6L/L of liquor produces Grape pomace:0.2 kg/l wine Wine lees: kg/l wine Sugar 0.18 m 3 / ton crushed 5% /ton crushed Deciduous fruit 3 m 3 /ton 25% processed fruit Citrus fruit 1.5 million litres per annum 50% processed fruit Subtropical fruit 3 m 3 /ton 20% processed fruit

25 BIOGAS POTENTIAL

26 POTENTIAL BIOGAS The biogas potential is the product of the waste generated per annum and biogas yield for each livestock. The annual potential energy recovery obtained by multiplying the total annual biogas production by 6kWh, which is the amount of energy contained in 1 m 3 of biogas.

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28 Liquid waste Total COD generated [% waste] COD treated[%ge nerated COD] Biogas yield[m 3 VS] Energy gemerated [6kWh.m -3 biiogas] Electrical energy generated (30% generator efficiency)

29 THANK YOU