*5.1.9. Animal Waste*

Rural population burn dried animal dung as a fuel, and this is a major source of energy. If a programme is institutes to use the dung as raw material for biogas production, it could ben‐ efit the livestock keepers. India for example has pursued a programme to generate biogas from gas with some success. However, at the moment there are more than 6,000 small scale biogas plants operating. The number is small compared to number of livestock the country having (Table 8).

**Name of Livestock**

**Table 8.** Livestock statistic for the country

duce biogas or fermented to produce ethanol.

compost or used to fuel bioenergy plants

**Figure 12.** Wood waste in Mwanza Municipality

*5.1.10. Food Industry Wastes*

*5.1.11. Industrial Waste*

**YEARS**

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257

**2006 2007 2010 2011** Cattle 18,500,000 19,100,000 19,200,000 21,300,000 Goats 13,500,000 13,600,000 13,700,000 14,000,000 Sheep 3,500,000 3,600,000 3,600,000 3,800,000 Chicken 30,000,000 31,000,000 33,000,000 40,000,000

The hotels, restaurants, Schools, and community kitchens produce a lot of waste such as vegetable peels, uneaten food, e.g. rice, bread, vegetables, etc., plate and dish washings, fruits and vegetable rejects. Similarly, a huge amount of wastes are generated from confec‐ tionary industry. Solid waste from these industries include peelings and scraps from fruits and vegetables, food that does not meet quality control standards, pulp and fibre from sugar and starch extraction, filter sludge and coffee grounds are disposed of and left to lot in the open space. However, all of these wastes make potential feedstock for biogas generation by

Liquid wastes are generated by washing meat, fruit and vegetables, blanching fruit and veg‐ etables, pre-cooking meats, poultry and fish, cleaning and processing operations and wine making. These wastewaters contain sugars, starches and other dissolved and solid organic matter. There is a potential for these industrial wastes to be anaerobically digested to pro‐

Such waste consists of lawn and tree trimmings, whole tree trunks, wood pallets and any other construction and demolition wastes made from timber (Figure 12). The rejected woody material can be collected after a construction or demolition project and turned into mulch,

anaerobic digestion. Usually these wastes are disposed of in landfill dumps [16].

The advantage, from and environmental aspect is that methane that would be released is captured and used to generate heat for cooking purposes. This could reduce the pressure on forests and deforestation. Methane is about twenty times more potent than carbon dioxide as a greenhouse gas and oxidising it while producing usable heat make sense from a climate point of view.

The solid residue remaining from fermentation process could be used as fertilizer in grow‐ ing other biomass sources such as maize, wheat, cassava, etc.

The challenge is how to quantify the energy potential from animal waste in the country. Ad‐ vanced investigation is needed. Figure 11 shows cow dung, which is used as source of ener‐ gy in rural areas.

#### **Figure 11.** Cow dung

Decomposition of animal manure can occur either in an aerobic or anaerobic environment. Usually under aerobic condition, carbon dioxide (Co2) and stabilized organic material are produced. While under anaerobic conditions, methane (CH4), carbon dioxide (Co2) and sta‐ bilized organic material are produced. Basing on statistical data given in Table 9 the quanti‐ ty of animal manure produced annually can be substantial for generation of methane (CH4) and hence energy potential of animal manure is significant. At the moment there are more than 6,000 biogas plants in the country, which use animal manure as their raw material.


**Table 8.** Livestock statistic for the country

#### *5.1.10. Food Industry Wastes*

*5.1.9. Animal Waste*

256 New Developments in Renewable Energy

having (Table 8).

point of view.

gy in rural areas.

**Figure 11.** Cow dung

Rural population burn dried animal dung as a fuel, and this is a major source of energy. If a programme is institutes to use the dung as raw material for biogas production, it could ben‐ efit the livestock keepers. India for example has pursued a programme to generate biogas from gas with some success. However, at the moment there are more than 6,000 small scale biogas plants operating. The number is small compared to number of livestock the country

The advantage, from and environmental aspect is that methane that would be released is captured and used to generate heat for cooking purposes. This could reduce the pressure on forests and deforestation. Methane is about twenty times more potent than carbon dioxide as a greenhouse gas and oxidising it while producing usable heat make sense from a climate

The solid residue remaining from fermentation process could be used as fertilizer in grow‐

The challenge is how to quantify the energy potential from animal waste in the country. Ad‐ vanced investigation is needed. Figure 11 shows cow dung, which is used as source of ener‐

Decomposition of animal manure can occur either in an aerobic or anaerobic environment. Usually under aerobic condition, carbon dioxide (Co2) and stabilized organic material are produced. While under anaerobic conditions, methane (CH4), carbon dioxide (Co2) and sta‐ bilized organic material are produced. Basing on statistical data given in Table 9 the quanti‐ ty of animal manure produced annually can be substantial for generation of methane (CH4) and hence energy potential of animal manure is significant. At the moment there are more than 6,000 biogas plants in the country, which use animal manure as their raw material.

ing other biomass sources such as maize, wheat, cassava, etc.

The hotels, restaurants, Schools, and community kitchens produce a lot of waste such as vegetable peels, uneaten food, e.g. rice, bread, vegetables, etc., plate and dish washings, fruits and vegetable rejects. Similarly, a huge amount of wastes are generated from confec‐ tionary industry. Solid waste from these industries include peelings and scraps from fruits and vegetables, food that does not meet quality control standards, pulp and fibre from sugar and starch extraction, filter sludge and coffee grounds are disposed of and left to lot in the open space. However, all of these wastes make potential feedstock for biogas generation by anaerobic digestion. Usually these wastes are disposed of in landfill dumps [16].

Liquid wastes are generated by washing meat, fruit and vegetables, blanching fruit and veg‐ etables, pre-cooking meats, poultry and fish, cleaning and processing operations and wine making. These wastewaters contain sugars, starches and other dissolved and solid organic matter. There is a potential for these industrial wastes to be anaerobically digested to pro‐ duce biogas or fermented to produce ethanol.

#### *5.1.11. Industrial Waste*

Such waste consists of lawn and tree trimmings, whole tree trunks, wood pallets and any other construction and demolition wastes made from timber (Figure 12). The rejected woody material can be collected after a construction or demolition project and turned into mulch, compost or used to fuel bioenergy plants

**Figure 12.** Wood waste in Mwanza Municipality

Industrial waste such as bagasse (Figure 13) from sugar plants find application in co-genera‐ tion process, which generates electricity that is used by the same plant. The excess is sup‐ plied to the nation grid

has significant environmental advantage over the use of fossil fuels. An appropriate level of biomass energy use can have less environmental impact than our current use of fossil fuels.

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259

Main barriers to wide spread uses of biomass in the country for modern power generation are:

**•** Dependence on technology advances from outside instead of development of indigenous

Biomass feedstock can be converted into useful forms of energy using a number of different processes. This is possible in the country because there is potential biomass that could be used for the process. However, before conversion processes can be initiated, factors that in‐

Biomass can be converted into three main products [18].Two related to energy i.e. power or heat generation and transportation, and one as a chemical feedstock. Conversion of biomass

fluence the choice of conversion [17] have to be established. The critical factors are:-

**•** Lack of internalization of external costs in power generations;

**6.2. Barriers**

**•** Low conversion efficiency;

**•** Competition for feed stock use; and

**•** Fertilizers and chemical uses; and

**•** Biodiversity conservation

**7. Biomass conversion**

**•** Environmental standards;

**•** Economic conditions; **•** Project specific factors.

Risks associated with widespread use of biomass are:

**•** The type and quantity of biomass feedstock;

**•** The desired form of energy i.e. end-use requirements ;

**•** Feed stock availability;

**•** Lack of supply logistics.

**•** Intensive framing;

technology;

**6.3. Risks**

**•** Cost

**Figure 13.** A heap of bagasse at Sugar Factory
