Cassava chips and marketing

Cassava chips
Cassava chips are non fermented cylindrically shaped products of about 3-5mm in diameter, obtained from freshly harvested cassava tubers. The chips are important ingredients for compounding livestock and fish feeds. Though Cassava provides good carbohydrates that can be substituted for the grains in animal feed, it must not be used as a sole ingredients because it is deficient in nutrients such as proteins, vitamins and minerals. Therefore it must be combined with feeds that are rich in these nutrients. Cassava chip is also being used in the production of ethanol (biofuel) which is now gaining ground as alternative source of energy to fossil fuel.

Marketing of cassava chips
With the increase in cassava processing activities and introduction of various cassava products, the market for cassava products is expanding. Both local and foreign buyers are going to places for cassava chips as raw materials for industries.

Local feed producers are buying and using cassava chips to compound animal feeds at a reduced cost.

Ethanol producing companies which are springing up in the country need cassava chips for production of ethanol.

China companies need large quantities of starch and cassava chips and they are looking up to Nigeria, being the largest producer of cassava in the world.

European importers are also looking up to Nigeria for large quantity of cassava chips for their livestock industries. They are using cassava chips to compound livestock feeds for production of milk, meat, eggs and other materials. Major cassava importing countries are China, Japan, Indonesia, United States, Canada and European countries. These countries are also using cassava chips and starch for their biogas projects.

Read: Industrial processing of cassava to starch

Stages involved in Industrial processing of cassava to starch

Cassava tubers are transported in trucks to the factory, weighed with weighing machine, and samples will be randomly picked to evaluate starch contents and determine the price. The tubers are then poured on the floor, waiting for processing.

Washing of the tubers
After inspection of cassava for quality, it will be thoroughly washed to remove all dirt before being passed into hewing and peeling machine where it will be cut into smaller pieces and peeled.

Grinding
The peeled and clean cassava tuber will be passed into the grinder where it will be ground into smaller pieces (1-2inches). The pieces will be poured into pounding machine for extraction of starch from cellulose. The machine can have 3 to 4 sets of extractors of varying mesh sizes. Small quantity of sulphuric acid will be added to the starch to prevent fermentation through microbial activities. The cellulose (pulp) removed from the starch will be dried in the sun and used as animal feed. It can also be added to cassava chips to produce cassava pellets.

Starch production
The starch water separated from the pulp will be passed through centrifugal separators or hydro cyclone to remove all pulp and get quality cassava starch. The time of processing must be as short as possible in order to get high quality starch. This will prevent reduction of starch through chemical and biochemical reactions from the microorganisms.

Drying and packing
The starch will be passed into stream pipe of hot air (about 200°C) and high pressure from the furnace. The starch is blown up the chimney with the force of hot air and will then fall into the cyclone. Starch received in the cyclone is hot, fine and dry, but must be cooled down immediately in a cold cyclone before being poured into the sieve to get very fine powder which is packed and bagged. The process must take short time to prevent condensation of starch granules and decomposition of the starch.

Photo credit: Thaitapiocalstarch.com

Read: Cassava cultivation in Nigeria

Read how Uganda is turning animal wastes to wealth

Nigerian cities and communities that turn several animals daily into meat but get rid of the wastes to places where they are not used for anything can benefit from this ongoing project in Uganda.

Uganda’s largest slaughterhouse runs 24 hours a day, turning up to 700 cattle, 200 sheep and 300 chickens each day into meat for the local market.
But the energy-thirsty Kampala City Abattoir is often brought to a stutter by the city’s daily power outages, which can last up to 12 hours. At those times, it is forced to rely on polluting diesel generators that are expensive to run.

Then there’s the problem of the large amounts of blood, wastewater and other waste produced, much of which is drained directly into nearby Murchison Bay in Lake Victoria.

Across East Africa, increases in processing of agricultural products – a change meant to boost local economics and provide jobs – is being accompanied by an increase in organic waste dumped into bodies of water and open landfills.
But a pilot project to turn that waste into biogas is getting started this month in Uganda, Ethiopia and Tanzania.

Funded by the Swedish International Development Cooperation Agency (SIDA) through the Bio-resources Innovations Network for Eastern Africa (Bio-Innovate), the effort aims to provide training and technology to agricultural factories to help them generate their own power, save on electricity and cut down on climate-changing emissions.

Capturing cheap energy
At the Kampala City Abattoir, the changeover is already underway.
To turn waste into power, the slaughterhouse puts its waste and wastewater through a fermentation process that releases methane, which is then captured and burned to produce electricity.
The facility uses the biogas it produces to power its generator.

“We are generating on average about 10 to 15 cubic metres of biogas daily,” said Joseph Kyambadde, head of biochemistry at Makerere University and one of those involved with the project.
“With 60 cubic metres of gas we (would be) able to run about 15 security lights, 15 deep freezers and 15 refrigerators at the abattoir, helping save around 8 million Ugandan shillings ($2,800) per month,” he said.

To add to the project’s green credentials, it uses solar panels to heat water and raise the temperature in the digester, to allow it to produce the most burnable methane, said Robinson Odong, a biological sciences lecturer at Makerere University and a manager of the biogas project.

Besides helping the slaughterhouse get around the city’s frequent blackouts, using biogas for energy has cut the plant’s monthly diesel bill by 90 percent.
“We are now spending 300,000 Ugandan shillings ($105) per month on diesel instead of 3.5 million shillings ($1,200), as the generator now runs on biogas during power blackouts,” said Nsubuga Muhamed, the Kampala City Abattoir secretary.

Plans to scale up
According to Odong, the project currently treats 40 percent of the Kampala abattoir’s waste, though the facility plans to eventually treat 100 percent.
“There are plans to upscale the technology to completely rely on biogas and sell the excess (energy) to the national grid,” said Kyambadde of Makerere University.

Using $275,000 in SIDA funding, backers hope to replicate the project across Uganda, said Allan Liavoga, manager of the Bio-Innovate project.
Uganda’s government is also watching the effort closely, to see if it might offer one answer to Uganda’s energy problems.

“We are an energy-poor country, with 95 percent of rural households having no access to electricity,” said Ronald Kaggwa, an environmental economist at the Uganda National Environmental Management Authority.

If the biogas project is scaled up, it could allow Ugandans who live too far from the power grid to generate their own energy, he said.
And if the country could turn more of its waste and wastewater into biogas, it would also be closer to its goals of switching to greener power sources and reducing deforestation, officials say.

“About 15-20 percent of our felled trees are used to produce charcoal (which is in) demand in urban areas,” Kaggwa said. But “biogas will help us save our forests,” he said. (Reporting by Sophie Mbugua; editing by Laurie Goering)

Source: webforum.org

Biogas production and uses

Biogas is the gas produced from digestion of organic materials under anaerobic condition, and the gas can be used for heating, lighting and to generate electricity.

Digestible organic materials or substrates are fed into biogas plant. Solid wood (lignin) cannot be digested and should not be fed into the plant.

Suitable materials for substrate:
* Plant leftovers from the garden, park, parks and surroundings
* Peels, wastes of fruits and vegetables  and food leftovers at home
* Liquid and solid manure of animals: pig, cattle, poultry and other animals
* sewage and waste water sludge from waste water treatment. This substrate may contain phosphorus, nitrate, heavy metal and may not be considered as high quality substrate.
* Energy crops such as grains.
* Industrial food wastes from processing of fruits, vegetables and meat.

Maximum potential of gas production per tonne of substrate
* Cow manure - 25m3/ton
* Pig manure   - 35m3/ton
* Whey              - 55m3/ton
* Spent grains - 75m3/ton
* Loppings.      - 110m3/ton
* Domestic organic wastes - 120m3/t
* Industrial food waste - 220m3/t
* floating slurry - 400m3/t
* waste food, grease and oil - 600m3/t
             Source: wikipedia

The following inputs are toxic and should be avoided in the plant:
* Antibiotics
* Denitrification agents
* Zinc, copper, ammonia, fatty acids and hydrogen sulphide

Temperature of the plant should be regulated and made constant by stiring the substrate regularly.

During the digestion, the substrates are transformed into methane, carbon dioxide and small quantity hydrogen sulphide, nitrogen, hydrogen and oxygen.

Percentage by composition of biogas
Methane CH4.    50 - 75%
Carbon dioxide   25 - 50%
Nitrogen.              0 - 10%
Hydrogen.            0 - 1 %
Hydrogen sulphide  0 - 3%
Oxygen.                0 - 5%

Conditions reqd for anaerobic digestion
* Temperature between 15 - 55%
* PH value between 6.5 - 8.0
* Avoid antibiotics

Environmental benefits of biogas production
* It reduces emission of methane
* Reduces dependence on energy
* Provides quality organic fertilizer and
* Reduces unpleasant odour.

Anaerobic digestion process
The process passes through 4 phases before completion
Phase 1
Hydrolysis by anaerobic bacteria that convert
Carbohydrates  into sugar,
Fats into fatty acids, and
Protein into Amino acids

Phase 2
Acidification by acid forming bacteria that convert
Sugar into carbonic acid,
Fatty acids into alcohol,
Amino acids into hydrogen, ammonia and carbon dioxide

Phase 3
Acetoficsation by acid bacteria that convert
Carbonic acids into acetic acids,
Alcohol to hydrogen and carbon dioxide

Phase 4
Methanogenesis by methane forming bacteria that convert
Acetic acids to methane and carbon dioxide

Components of biogas plant
Digester: it contains the substrate and passes the digestate out. The digestate is used as fertilizer.
Stirrer or mixer: used to stir the substrate and make it homogeneous
Gas holder:  it collects the gas from the digester.

Benefits of biogas
* Renewable source of energy
* Provides income for farmers
* Reduces green house emissions
* Reduces odour, destroys pest and weed seeds
* Provides quality organic fertilizer

Feeding the biogas (small-scale production)
The plant can be fed initially with cow dung mixed with water at 1:1 by volume, fill to half of the digester and allow to stay for a week. Thereafter, subsequent addition of other organic materials can be done daily until the plant is full. Large-sized organic waste materials should be chopped into pieces before they are fed into the plant. Different organic materials (animal dungs, poultry wastes, weeds food leftovers  etc) can be mixed together and fed into the plant. Place the biogas plant where it will get maximum sunlight throughout the day.

Testing the gas
The gas produced initially will contain a lot of impurities and may not burn. You need to empty the gas once or twice before it  starts to burn readily or when the quality has increased. Biogas can not be used directly without removing the impurities such as water vapour, carbon dioxide, hydrogen sulphide and dirty particles. Biogas can be mixed with and supplied as natural gas after all impurities have been removed.

Types of biogas plant
There are different designs and types of biogas plants. Available materials, environmental and ecological conditions are put into consideration for construction of biogas plant.

* Floating Drum Plant: This consists of a digester and gas holder placed on it. The gas holder floats on the the digestate  and moves up and down according to the quantity of gas stored

* Fixed Dome Biogas Plant: This consists of a closed, dome shaped digester with immovable gas holder and a displacement pit, also known as compensation tank in which digested slurry is collected.

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Small-scale processing of Cassava tubers

Apart from products such as lafun, fufu and gari, cassava tubers are being processed into flour, tapioca, starch, industrial alcohol and other products in large quantities.

Cassava flour
Cassava should be processed into flour with 24 hours from the time of harvesting.

Method
* Get freshly harvested cassava tubers, wash before    peeling, peel and wash again
* Grate and press the water out within 1-2 hours
* Spread on a clean and raised platform until it dries  completely
* Mill and sieve with a fine net
* Pack in a clean, sealed or airtight container.

Vitamin A cassava can processed as stated but don't expose it to much sunlight. Ultra Violent rays break down and denature vitamin A.

Cassava products

Details coming ...