Friday, 19 August 2011

Hygiene and Sanitation Program for a Multi Food Products Processing Pilot Plant

A Detailed and Operational Hygiene and Sanitation Program for a Multi Food Products Processing Pilot Plant
 The Department pilot plant is a multi food products processing establishment that is used by students and food business incubates. This plant receives a range of raw materials, packaging materials and personal with interests in processing different food products such as fruit and vegetable products, beef products and cereals.
Sanitation within the food industry means to the adequate treatment of food-contact surfaces by a process that is effective in destroying vegetative cells of microorganisms of public health significance, and in substantially reducing numbers of other undesirable microorganisms, but without adversely affecting the product or its safety for the consumer
Sanitation and hygiene programs start with a commitment to construct, upgrade, and maintain the process stream so that all aspects of good sanitation are adhered to both in letter and in intent.
Without complete dedication to these objectives, any program, no matter how well founded, is doomed to failure.
Good sanitation and hygiene in food plants is necessary for the prevention of food poisoning and to reduce food spoilage. The main factors affecting this are biological, but others such as chemical and physical factors also contribute. Bacteria, yeasts and fungi are the most important microorganisms where food is concerned. Many of them have beneficial effects and have been used for a long time in production and preservation of food while others are pathogenic or can spoil food and there by render it unfit for human consumption.

The production of safe food products requires that the sanitation and hygiene system be built on a solid foundation. To be successful, a sanitation and hygiene operating plan, must be implemented in the food plant, and that food processing must be conducted in a manner preventing contamination of the ingredients or product and minimize growth of micro organisms.
The goal of this sanitation and hygiene program is to provide a clean manufacturing operation capable of producing wholesome and safe food products. The program is to provide a guidance and training for pilot plant employees (people working in the pilot plant) in good sanitary and hygienic practices and be able to identify process stages that are pivotal in producing acceptable quality food products. Also, the program is to keep management informed of the sanitary conditions of the pilot plant and its workers.
 The pilot plant supervisors are responsible for implementing and daily monitoring of Sanitation and hygiene practices and recording the findings and any corrective actions. Also, the plant supervisors are responsible for training and assigning specific duties to other employees and monitoring their performance within the Sanitation and hygiene operating program. All records, data, checklists, and other information pertaining to the hygiene and sanitation of the pilot plant will be maintained on file and made available to inspection personnel.
The element of hygiene and sanitation programme would include; development of sanitation standard operating procedures, master cleaning schedule, pre-operation sanitation, operational sanitation, verification and logging sanitation procedures, validation of cleaning and sanitation, microbial assessment of food environments, assignment and management of sanitation personnel.
Water source:  All water at pilot plant should be first chlorinated before it is allowed to circulate into the plant. This should be done at the water reservoir tank to insure that it meets the UNBS microbial standards for potable water.  Backflow devices should be installed on lines where chemical applications are made.  Potable drinking water should be available for employees.
Records of water source and testing frequency form, daily checklist and verification checklist should be kept by the plant supervisor.

Worker Hygiene & Practices to Prevent Contamination of Food Products
Personal hygiene refers primarily to the personal cleanliness and related habits of the food worker. In spite of following all the procedures for pilot plant hygiene described above, products from this facility can still be faced with problems of food safety if no particular attention is given to worker hygiene and practices. The personal hygiene aspects of people operating in a facility are the factors that prevent food positioning. Therefore you need rules for personal hygiene for food handlers. These rules need to be explained and understood by all food handlers and people working in the pilot plant. These rules need to be linked with a cultural pattern of cleanliness and cleanliness in food preparation if they are to be more meaningful.
Goal of personal hygiene and sanitation is to prevent employees from becoming a source of contamination
All employees of the pilot plant must follow good personal hygiene practices, which include:
Physical examination.
Pre-employment health examination, with additional requirement that these examinations be repeated at regular intervals for people operating the pilot plant. Having this done is an excellent opportunity to impress the importance of good health and hygienic habits on new employees of the pilot plant.
Special attention should be given to upper respiratory complaints and skin surface infections because these symptoms spread organisms such as staphylococci.
Patients with lesions should not be considered for employment that involves food contact until the infections is completely healed.
The clothing of food workers must be clean, neat and without adornment such as jewelry or sequins. Having an overall clean appearance, clean clothes, and no open toed shoes, sandals and sleeveless shirts in food processing and handling areas should be the priority.
 Uniforms and cover coats should be used as they are excellent means of maintaining neatness and have a powerful psychological impact on workers attitude towards good sanitation. Uniforms and cover coats should be light coloured to show need for cleaning.
All members of staff and the employees must wash their working gumboots, head gears, overalls and laboratory coats at least after every 3 days.
Gumboots used in the pilot plant should be white in colour. This is because the white color can easily show the need for cleaning.
Toilet Facilities.
The toilets should be stocked with toilet paper.  Hand washing stations with running water that is stocked with disposable paper towels and hand soap and trash receptacles be maintained.  Signs should be posted at each hand washing station that instructs employees on the proper ways to wash their hands.  Toilet and hand washing facilities are cleaned daily when in use.
Hand washing.
Employees in food processing and handling areas must wash their hands before beginning work, each time after using the toilet, before returning to work after a break or lunch and after any time their hands may become soiled. When washing hands, pilot plant personnel should use soap. In most situations, bar soap, preferably a brand containing a bactericidal or bacteriostatic agent will be satisfactory. Soap and germicides used in the plant should not contain a strong perfume. While convenient to use, liquid soaps are not recommended as they become contaminated with bacteria of the genus pseudomonas hence becoming important sources of these pathogen in the food processing environment.
Bars of soaps should be replenished and used bars be disposed of in such a way that they do not enter the product stream.

Skin lubricants and barrier creams e.g. those used on hands after washing should not be permitted in the pilot plant because many are heavily perfumed and in addition, bottles or tubes of these creams may end up in the food production area which poses a safety risk.
Hand drying can be by the use of cloth, continuous roll type towels or paper roll towels and paper sheet towels. Communal towels for hand drying pose a risk not only to food produced within the plant but to the workers themselves.
Hand washing sinks need a simple modification to a foot operated water valve.
Operations such as meat cutting and pineapple peeling need to use disposable gloves. Where chain mail gloves and gauntlets are used, they should be washed in a standard dishwasher to remove food residues and a final germicide soak or rinse in quaternary ammonium compound is recommended.
Periodic and random hand subs of pilot plant workers for total plate counts in the microbial laboratory should be done to generate date to be used to improve workers attitude to sanitation and hygiene.
Hair. Hair of all types normally is heavily contaminated with microorganisms. Routine wearing of hair covering by all personals entering or working the plot plant should be mandatory. Example of hair coverings are the disposable hair nets or hair restraints and head gears.
Workers whose job requires that they have direct contact with food or food contact surfaces should not wear jewelry. A prohibition against Jewelry and other personal items that can fall into food products e.g. food and beverages, chewing gum and tobacco should be enforced. This can be augmented by measures taken to emphasize these restrictions and make them easier to accept. For example wall clocks can be installed at strategic locations within the processing area so that workers can accept to stop wearing watches.
Since it is a multi product facility, pilot plant workers should remain in their work area during their shift unless they have received permission from their supervisors.
With the exception of a scheduled tasting panel, the consumption of food including beverage and chewing gums, within the food processing area should be prohibited. The food being processed should never be consumed near a process line. When taste-testing is necessary, the product should be removed to a separate room designed for this purpose. In this way, eating utensils, spent packaging, expectorated food, should be controlled and properly disposed of.
Restroom facilities.
Food should never be stored in lockers. This is because abandoned or infrequently used lockers in which food is stored are one of the primary sources of insects’ infestations in the plot plant. Employees should be warned not to store food in this way and at least a bimonthly inspection of lockers be under taken.
Consumption of beverage, snacks and lunches also should be confined to specific areas of the pilot plant and should be kept clean and free of insects.
Foot baths/dips at the entrance.
Water in the footbath should be at least change two times in a 24 hour but 4 times would be preferred. 200ppm of hypochlorite should be added to water in a water bath.
All people working in the pilot plant must make a stop in a water dip as they enter into the pilot plant.
All people working in the pilot plant should not move out of the facility with gumboots. Gumboots should be left in the wash rooms before continuing out of the plant.
All of the required employee practices listed above should be taught in the food hygiene and sanitation training that each pilot plant employee should receive. The training program can be supplemented with posters, slogans and information sheets propagandizing the need for good health habits.
Cleaning of the Pilot Plant Equipment
The arrangements for cleaning equipment that comes in contact with products are an essential part of a food processing plant. It must be born in mind that food manufacturers are always obliged to maintaining high hygienic standards; this applies both to the equipment and to the staff involved in production. These obligations are considered under Trade, Moral, and Legal obligations that every food industry must meet if it is to operate.
Cleaning Objectives
The following terms are used to define the degree of cleanliness:
• Physical cleanliness – removal of all visible dirt from the surface;
• Chemical cleanliness – removal not only of all visible dirt but also of microscopic residues which can be detected by taste or smell but are not visible to the naked eye;
• Bacteriological cleanliness – attained by disinfection;
• Sterile cleanliness – destruction of all micro-organisms.
 Equipment can be bacteriologically clean without necessarily being chemically clean. In food industry, cleaning operations objective is to achieve both chemical and bacteriological cleanliness. The equipment surfaces should be first thoroughly cleaned with chemical detergents and then disinfected.
Circulatory cleaning-in-place (CIP) system should be used to most parts of the processing plant machinery to achieve good cleaning and sanitation results and to some extent machines like the blender, and the meat mincer should be cleaned by dismantling them first, after which they are re-assembled ready for production.
Cleaning operations should be performed strictly according to the proved, worked out procedure in order to attain the required degree of cleanliness. The sequence followed during cleaning should be exactly the same every time it is done. The cleaning should be done by people who are going or used the machine, supervised and proved by pilot plant supervisors before and after every production session.
A standard cleaning procedure for each machine should be written down and pinned against the machine to show steps to be followed during cleaning.
Cleaning –in –Place System (CIP)
Cleaning-in-place means that rinsing water and detergent solutions are circulated through tanks, pipes and process lines without the equipment having to be dismantled. CIP is defined as circulation of cleaning liquids through machines and other equipment in a cleaning circuit. The passage of the high-velocity flow of liquids over the equipment surfaces generates a mechanical scouring effect which dislodges dirt deposits. This is mainly applied to the filling machines, continuous pasteurizer and evaporator. The cleaning procedure should comprise the following steps:
1-Recovery of product residues by scraping, drainage and expulsion with water.
2- Pre-rinsing with water to remove loose dirt. Pre-rinsing should be carried out immediately after the production run to avoid the food residues from drying and sticking to the surfaces, which would make them harder to clean.  It should be done with warm water not exceeding 55 oC to avoid film formation on surfaces of equipment.  Pre-rinsing should continue for about 10 minutes until the water leaving the system being cleaned is clear, as any loose dirt left will increase detergent consumption.
3- Cleaning with detergent; Circulation of lye-an alkaline detergent solution (0.5 – 1.5%) for about 30 minutes at 75 o C should be done. During cleaning with the detergent, the following variables should be monitored to obtain satisfactory results; the concentration, temperature, mechanical effect on the cleaned surfaces and duration of cleaning (time)
4-Rinsing with clean water for approximately 5 minutes and then a sample of the rinse water should be taken to the laboratory to verify the absence of caustic soda residues by use of the phenolphthalein indicator.
5- Disinfection with chemical agents (chlorine), 200gm in 500 liters of pasteurized water and run for about 30 minutes. The cycle should ends with a final rinse with good quality water to ensure all the chlorine is done away with.
6- Scald with hot water in the morning prior to production should be done. Rinsing thoroughly with hot water until the smell of chlorine is no longer felt for any equipment is necessary. Then production can start.

Clean Out of Place (COP)
All equipment that cannot be cleaned using CIP procedure should be disassembled, cleaned, and sanitized before starting production. The sanitary procedure for cleaning and sanitizing equipment should be as follows.
a. All equipment should have product debris removed.
b. Equipment should be rinsed with water to remove remaining debris.
c. An approved cleaner should be applied to equipment and properly cleaned.
d. Equipment should be sanitized with approved sanitizer and rinsed with potable water.
e. The equipment is then reassembled.
Implementing, Monitoring and Recordkeeping should be done by the pilot plant supervisors to perform daily organoleptic sanitation inspection after preoperational equipment cleaning and sanitizing. The results should be recorded on a Preoperational sanitation form. If found to be acceptable, the appropriate line should be checked. If corrective actions are needed, such actions should be documented.
Corrective Actions
The pilot plant supervisors are to determine that the equipment on hand does not pass organoleptic examination, so the cleaning procedure and inspections should be repeated. The pilot plant supervisors should monitor the cleaning of the equipment on hand and should retrain employees if necessary. Corrective actions are recorded on Pre-Operational sanitation forms.
Work Environment-House Keeping and Floor Cleaning of the Pilot Plant.
Before production begins and any time the environment gets dirty, it should be cleaned. The floor, walls and outside the equipments should be cleaned with liquid soap or caustic soda in water using brushes.  After every 3 days, the floors should be sanitized using a hypochlorite or Oxonia solution. The equipment and all the other items in the pilot plant should be cleaned and organized to demonstrate the element of good housekeeping.
Verification of the Cleaning Effect
Verification of the effect of cleaning can be done in two forms: visual done by plant supervisors and while bacteriological inspection can be done by taking swabs from the inside of the equipments, around valves on the pipe work and hands of people who are likely to come in contact with the products during production. Tests for total plate count and presence coli forms can be carried out. The swabbing should be done on a weekly basis.
Cleaning of Facilities Including Floors, Walls, and Ceilings.
Cleaning procedures should include:
a. Debris should be swept up and discarded in the bins.
b. Facilities are rinsed with potable water.
c. Facilities are cleaned with approved cleaner/detergent and scrubbed using a brush.
d. Facilities are rinsed with potable water.
Cleaning of floors and walls should be done at the end of each production day. Ceilings should be cleaned as needed.
The pilot plant supervisor should perform daily organoleptic inspection before operation begins. Results should be recorded on a preoperational sanitation form.
When the pilot plant supervisor finds that the facilities do not pass organoleptic inspection, the cleaning procedures and inspections should be repeated. The pilot plant supervisor inspects the cleaning of the facilities and retrains employees as needed. Corrective action to prevent direct product contamination or adulteration should be recorded on Pre-operational sanitation forms.
Sanitary procedures for processing.
Processing should be performed under sanitary conditions to prevent direct and cross contamination of food products.
Pilot plant employees(people working in the pilot plant) should clean and sanitize hands, gloves, knives, other hand tools, cutting boards, etc., as necessary during processing to prevent contamination of products.  All equipment tables and other product contact surfaces should be cleaned and sanitized throughout the day as needed.
Outer garments such as aprons and gloves are hung in designed areas when employees leave processing area. Outer garments are maintained in a clean and sanitary manner and are changed at least daily and more often if necessary.
Monitoring and Recordkeeping.
The pilot plant supervisors should be responsible for ensuring that employees’ hygiene practices, sanitary handling procedures and cleaning procedures are maintained. The pilot plant supervisors should monitor the sanitation procedures during the day and results then recorded on an Operational Sanitation Form daily.
Corrective Action
The pilot plant supervisors should identify sanitation problems and stops production if necessary and notify processing employees to take appropriate action to correct sanitation problems. If necessary, processing employees should be retrained and corrective actions recorded on Operational Sanitation form.
Cleaning equipment storage and maintenance.
Cleaning equipments like brushes, squeezers should be properly identified e.g. table squeezers and floor squeezers should be in different colours and should be kept at different points to avoid contamination.
Storage of cleaning equipments should be properly done and be disinfected at the end of the a cleaning operation.
Receiving & Storage of Raw Materials including packaging materials
Goal here is to prevent contamination and cross-contamination of raw materials and finished food products.
Raw materials and packaging materials should be purchased from UNBS approved suppliers, and have documentation that packaging materials are approved by UNBS.
On receiving the packaging materials, they should be kept in designated packaging material stores and should be place on racks preferably plastic racks but not on the floor direct.
Food ingredients such as preservatives should be kept in their packaging until ready for use.
The packaging material preparation for use should be conducted according to the valid sterilizing processes as per the production procedure in order to reduce harmful pathogens to safe levels.
The raw materials entering the pilot plant should be of sound quality and with the help of the plant supervisors operators can be able to establish the quality standards of their process raw materials.
Raw materials entering the pilot plant should use a different route with the finished product leaving the plant to avoid any possibility of cross contamination.
Pest Control
The goal is to exclude pests using safe and effective procedures.
The pilot plant should follow a pest control program that minimizes pest entry points and harborage sites by these methods:
    Use of approved pesticides according to national standards by UNBS,
·         Poison bait stations should be used only outside of buildings, that are tamper-resistant, labeled and inspected regularly,
·         Live traps, glue boards or mechanical traps should be spaced no more than 30 feet apart along the inside walls of buildings and both sides of an entrance, excluding breezeways and processing area. A pest control log should be maintained.
Records of Pest control report (in house or outside firm), facilities map showing location of pest control devices, daily checklist, and verification checklist.
Equipment Maintenance and Calibration
This aims at prevention of microbial, chemical, and physical hazards from occurring as a result of improperly maintained equipment. Equipment, temperature probes, supporting hardware used to monitor time and temperatures should be maintained and calibrated on a regular basis according to the equipment maintenance schedule to assure that all equipment is in proper working order and does not contribute to product contamination.  Cleaning and maintenance checks should be scheduled regularly on air handling, cooling, and other equipment used in the pilot plant food production areas so that they function properly and do not contribute to contamination of food.  Only food grade lubricants should be used on food contact surfaces and machinery.  Equipment, tools and used parts should be removed after servicing an area.
Records of equipment maintenance schedule, master calibration schedule, calibration records and verification checklist should be taken by note of by the pilot plant supervisors
Temperature and Humidity Control
Where appropriate and applicable, the temperature and humidity of storage rooms for raw materials, ingredients, packaging materials and food should be maintained and monitored periodically.
Returned Food
Foods returned from retail outlets must be clearly indentified and stored in a designated area for proper disposition. Storage conditions need to be such that the safety of the returned food is not compromised.
Non-Food Chemicals
Detergents, sanitizers, or other chemicals must be properly labeled, stored and used in a manner to prevent contamination of food, packaging material, and food contact surfaces. Chemicals must be stored in a dry, well ventilated area which must be separate from the food handling area.
Proper Labeling, Use, and Storage of Potentially Hazardous Chemicals
The goal here is to prevent contaminations from potentially hazardous chemicals.
Original chemical containers are labeled with the name of chemical, the manufacturer’s name and address and instructions for use. Secondary or working containers should be marked with the name of the chemical and instructions for use.  Food products should not be put in an empty chemical container and chemicals should not be put in an empty food container. 
An up to date inventory of hazardous chemicals should be maintained in the pilot plant.  A notebook containing all Material Safety Data Sheet and chemical labels should be available to all employees at all times.
Employees who apply chemicals should receive safety training. Employees working with chemicals are required to watch the Penn State video on potential hazards before using any chemical or pesticide.   Chemical compounds should be used according to label directions.
All chemicals are stored in a designated secure room which is dry, clean, and well organized.
Records of list of potentially hazardous chemicals, material safety data sheets, chemical labels and verification checklist should be taken by the plant supervisors.
Waste management
Waste in the pilot plant is of two types namely; biodegradable e.g. fruit peeling and non biodegradable waste e.g. plastic bottles and polythene. This calls for proper management through sorting say by separating of collecting bins. A bin for each type should be put in place and waste is separately disposed off. Waste containers should be clearly identified.           
This is the drainage channel in the pilot plant. It should cover with covers having perforations to allow waste water to pass and retain the solid waste without joining the channel that leads to waste treatment area.
The biodegradable waste can be decomposed for biogas and manure (in form of a slurry) production. The biogas can be used in water heating operations in the pilot plant.
The non biodegradable waste after sorting can be given to recycling company to use for production of other packaging grades of non food uses.
Outside Surroundings
Outside surroundings should be evaluated for sources of contamination such as vermins, birds harborage areas, drainage problems, odor problems, debris, refuse, and pollution-smoke, dust, other contaminants. Appropriate steps must be taken to contain and control any potential source of contamination.
Finished Products.
All finished products should not come in contact with raw products or material in order to avoid cross contamination.
Finished products should leave their processing tables when are in their secondary packaging e.g. juice bottles in boxes. Boxes containing finished products and the unused boxes should be placed on racks and plastic racks are preferred to wooden racks.
The finished products
store must be clean and properly maintained to prevent pests and their contamination.
John A. Troller 1993, Sanitation in Food Processing, second edition published by the academic press, Inc.  A division of Harcourt Brace and Company.
Jowitt R, 1980. Hygiene Design and Operation of Food Plant published by Ellis Horwood Ltd
Banadda E Nobel, 2008. Sanitation and Waste management course notes

Thursday, 18 August 2011

Determining the superiority and amount of Biogas produced from different Ugandan feedstock.

Determining the superiority and amount of Biogas produced from different Ugandan feedstock.

Biogas refers to a gas made from anaerobic digestion of agricultural and animal waste. Also Biogas refers to a colorless gas made from anaerobic digestion of organic agricultural waste and animal manure; it burns with a clear blue flame similar to LPG gas, thus it is useful as a fuel substitute to firewood, manure, agricultural residues, diesel, and petrol. Its by-product (slurry) can be used as an organic fertilizer to boost agriculture hence promoting food security in a community. Biogas can also be used to run a generator to produce electricity.
Biogas originates from bacteria during the process of bio-degradation of organic materials under anaerobic (without air) conditions. The natural generation of biogas is an important part of the biogeochemical carbon cycle. Methanogens (methane-producing bacteria) are the last link in the chain of micro-organisms that degrade organic materials and return the decomposed products to the environment. It is in this step of the biogeothermal carbon cycle that biogas, a source of renewable energy, is generated.

 Farming is the major rural activity in Uganda, but this does not generate sufficient income. As in most of Africa, fuel wood and charcoal are the primary sources of energy for Uganda’s rural and urban population. On average each rural household spends ten hours per week searching for fuel wood. In urban or peri-urban areas, households spend considerable amounts of money on fuel wood and charcoal. Consumption of charcoal and fuel wood is a serious factor in deforestation, air pollution and carbon diox­ide emissions. When all forest uses are included, the deforesta­tion rate in Uganda is around 100,000 hectares per year. In addition, Uganda’s 15 million cattle also produce greenhouse gas emissions; dung that is left to degrade produces significant amounts of methane and carbon dioxide.

Problem Statement;
According to the renewable energy policy for Uganda, Uganda’s forest resources are an essential foundation for the country’s current and future livelihood and growth and over 90 percent of the energy consumed is obtained from the forests for cooking. This leads to deforestation and high carbon dioxide (CO2) emissions in the atmosphere.
Furthermore, the burning of wood and charcoal leads to serious indoor air pollution, which is especially for women and children a health risk. The use of biogas for cooking can reduce deforestation, carbon dioxide (CO2) emissions and indoor air pollution, since burning biogas is much cleaner than burning wood and charcoal.

The energy deficit in poor household results in practical setbacks such as inadequate lighting (paraffin lamps, candles or wood fires), inadequate cooking fuel and thus fewer hot, cooked meals. The setbacks caused by energy poverty in turn have consequences in the standard of living of the poor through illness on a more frequent basis (with consequences on income), difficulty in doing schoolwork and so on. Access to clean and convenient energy services are therefore vital to the alleviation of poverty.

Therefore, biogas is an essential component for socio-economic development. Poverty shows itself in a number of ways, and is particularly evident and can have drastic consequences in energy affairs. The inability to access convenient, clean, energy services leads to outcomes that make it harder for those trapped in poverty to escape it. The effort and time often associated with the utilization of low quality fuels and energy conversion technologies decreases the overall productivity of households and communities. The cost of cooking and lighting energy in households, large institutions (schools, prisons, hospitals etc) is very high. In these institutions, there are potential sources of organic matter from either meals prepared/waste product (like peelings, mowed grass, leaves from trees) which are susceptible to ferment for biogas production. Biogas would reduce the wastage of organic waste like vegetable and slaughter remains and transform it into energy and fertilizer. Also, the impact on the natural resources would be limited as firewood is substituted by biogas for cooking. Biogas as a renewable energy source could be a relative means of solving the problems of rising energy prices, energy deficit, waste management and in the long run creating sustainable development.

Energy is an essential ingredient for socio-economic development and economic growth. From the foregoing, it is clear that energy is an essential input to all aspects of modern life (Prenma consulting, 2010). If the use of biogas in Uganda could be propagated, it would ensure more energy autonomy at rural, semi-urban and urban locations.

Major Objective:
The main objective of the project is to identify among the different available local feed stocks in Uganda (banana peels, rice strays, pineapple waste, cow dung, pig dung, and maize stocks) the best for Biogas production in terms of quantities and quality of the gas produced.

Specific Objectives:
  • To design a prototype biogas digester for laboratory use, that can easily be transformed to suit rural, semi rural and urban settings. Thus, this work will focus on building biogas plant prototypes which will use selected feedstock available in Uganda and testing the quality and quantity of biogas produced.  
  • Identifying Feed stocks (banana peels, rice strays, pineapple waste, and maize stocks) available in Uganda; location and quantities of the feedstock will be recorded since different feedstock varies in their physical, chemical and biological characteristics, and biogas potential.
  • To design a method for shredding the selected feedstock available in Uganda. The shredding method will be used to reduce the size of the feedstock before fermentation.
  • Fermentation of the identified feedstock to produce biogas.
  • Measuring the quantities/amounts of biogas produced by the different feedstock 24 hour.
  • Determine appropriate amount of biogas from each feed stock needed in cooking given amount of food as a measure for the quality of the produced biogas.
Different feedstock materials of the equal quantities produce different quantities and quality of biogas


Biogas technology offers a good potential energy option for Uganda through its various advantages. The promotion of biogas plants supports the achievement of the millennium development goals in Uganda in the following ways:
MDG: 1 Eradicate extreme poverty and hunger; Reduce extreme poverty by half Biogas plants reduce financial and economic costs expended on fuel for cooking and, to a lesser extent, also lighting. The produced bio-slurry is a potent organic fertilizer and may reduce the use of chemical fertilizer. In general, biogas households are not typically the ones in developing countries that suffer from extreme poverty, although many of them are poor. However, the biogas dissemination process and the resulting reduced claim on common ecosystem services do affect the livelihood conditions of (very) poor non biogas households through:  Construction and installation of biogas creates employment. Also Biogas saving on the use of traditional cooking fuels increases the availability of these fuels for (very) poor members of the community.

MDG 3: Promote gender quality and empower women; Eliminate gender disparity in primary and secondary education. Women and girls predominantly spend time and energy on providing traditional energy services. Housekeeping and absence of proper illumination creates barriers for women and girls in accessing education and information, as well as their mobility and participation in ‘public’ activities. Domestic biogas reduces the workload – collection of firewood, tending the fire, cleaning soot of cooking utensils - by two to three hours per household per day. Biogas illumination is highly appreciated for lighting, facilitating reading / education / economic activities during the evening.

MDG 7: Ensure environmental sustainability
Domestic biogas can help to achieve sustainable use of natural resources, as well as reducing greenhouse gas (GHG) emissions, which protects the local and global environment. Application of bio-slurry improves soil structure and fertility, and reduces the need for application of chemical fertilizer. Use of biogas can halve the proportion of people without sustainable access to safe drinking water and basic sanitation. Biogas reduces fresh water pollution as a result of improved management of dung. Connection of the toilet to the biogas plant significantly improves the farmyard sanitary condition.

MDG 6: Combat HIV/AIDS, malaria and other diseases
The target of MDG6 is to have halted by 2015 and begun to reverse the incidence of malaria and other major diseases. Half of the world’s population cooks with traditional (mostly biomass-based) energy fuels whose collection becomes increasingly cumbersome. Indoor air pollution from burning of these fuels kills over 1.6 million people each year (The World Health Organization), out of which indoor smoke claims the lives of nearly one million children under age five per year. Diseases that result from a lack of basic sanitation, and the consequential water contamination, cause an even greater death toll, particularly among young children: Biogas stoves substitute conventional cook stoves and energy sources, virtually eliminating indoor smoke pollution and, hence, the related health risks (e.g. respiratory diseases, eye ailments, burning accidents). Also Biogas significantly improves the sanitary condition of the farm yard and its immediate surroundings, lowering the exposure of household members to harmful infections generally related to polluted water and poor sanitation.

Design the prototype biogas digester

Design and build affordable prototype biogas digesters for fermenting different feedstock; this should be simple and easy to operate.

 Capacity of the prototype digesters (6) will be 10 liter, with diameter of 60 cm and height of 90 cm. They will have an inlet (influent) and outlet (effluent) pipes, gas pipes, gas holder (gas collection bag), water traps (to control pressure) and gas burners.

The pilot plant (prototype biogas digesters) will be located at Faculty of Science, Kyabogo University where it will be monitored and all the necessary parameters recorded (quality and quantity of gas produced from the individual feedstock).
Sketch of a proposed biogas digester is shown below

Six 50 liter plastic buckets will be purchased with all the required pipes and accessories. A circular hole of about two inches will be made at the lower part (ten centimeters from the bottom) of the poly tank, this is where the inlet 1 inch PVC pipe will be fixed. Another hole of about 2 inch will be made on the opposite side of the poly tank for the outlet PVC pipe.
A gas pipe with its accessories will be fixed at the top of the digester and then connected to the gas storage bag. Please, refer to the budget for the needed materials.

Digester of 50 liter capacity can produce biogas required for quantity and quality establishments.
Life span of the digester is at least 4months
Rate of biogas production depends on several factors (temperature, type and nature of feedstock, pH, C/N, TS, VS)
1 kg of feedstock banana peelings can produce 0.1 m3 of biogas; m3 is a cubic meters (a unit of measure)
 Retention time for each feed stock for example banana peelings is 20 days Retention time: This is the average length of time the liquid influent remains in the digester for treatment. Retention time varies with feedstock and digestion temperature; precooked feedstock needs short retention time compared to raw feedstock and manure.

Determine appropriate amount of biogas for cooking 250ml of water as a measure for the quality of the produced biogas.

Materials needed for a biogas  project
Unit cost
PVC Bucket diameter 96 cm,
height 88 cm 50 L capacity
Plastic funnel
Sealant (to seal all connections etc )

Gas pipe, 1.905 cm diameter,
length 6 m
Flexible rubber tube (5 m)
Gas storage bags
feedstocks and water for
3  months

Casual Labour for  2  months
Gas meters
Communication for 3 months

Stationary (paper, printing, pens etc)

Transport for 3 months

Liquid soap
10 L
Hand towels
1 box
Heat resistant rubber tubes

Grand Total

Project plan
It is estimated that the project will take about 16 weeks. A detailed schedule is provided below.

Project plan
Activity/Time in week
Purchasing materials

Identifying feed stock

Designing of a prototype digester

Designing a shredding method

Feedstock Fermentation

Measuring Quantities of Biogas produced

Measuring quality of Biogas produced

Data Analysisi

Report Writing, printing and Handling in