Biogas TECHNOLOGY For a sustaINable development in AFRICA
Björn Martén, Chairman
GEIST
Kärlingesund 209,451 97 Uddevalla, Sweden
ABSTRACT: One of Africa’sr greatest challenges is to create water and food security. Over 200 million people in Africa are cronically undernourished. Many people suffer from health problems due to consumption of drinking water contaminated by leaking pit latrines. By improving soil fertilty and offering proper sanitation those problems can be curbed and it is this context where biogas technology and IWESS Integrated Energy and Sanitations Solution can make a contribution.
The basic idea is to prevent landgrabbing, lower dependence on cattle raising and turn waste and waste water into a resource that will curb soil degradation, eutrophication desertification, deforestation and global warming by introduction of biogas technology and the Industrial Cow concept. Introduction of source separated wastewater, IWESS and biogas technology can pave the way for a sustainable development based on organic farming and use of biogas for vehicles and cooking fuel. It will create an oppurtunity for farmers to lower the meat production and create a sustainable economy whitout heavy subsidies, thus paving the way for farmers in developing countries to compete at the global market.
Keywords: Biogas, industrial cow, waste, soil fertility, vehicle fuel, rescuing of rainforests
BACKGROUND
The NGO GEIST and its members have been working with development of sustainable technologies and Education for Sustainable Development, ESD, in Sweden for more than 25 years. Swedish Biogas Federation was initiated 1987 and the same year the first biogas car project in Sweden started, conversion of a Volvo 244 from gasoline to biogas. It continued with a Volvo 940 that was further developed and became the start of the Volvo bifuel concept that was introduced at the exhibition Clean Cars of Tomorrow 1994 in Paris. In 1998 the first digester running on 100% grass was started in Lilla Edet. Since 2001 GEIST have been working with sustainable development projects in Africa, involving
i.a. conversion of polyethylene water drums to digesters and eco toilets and establishment of a resource center for development of sustainable system solutions and ESD.
1 Why Biogas?
The most unknown renewable energy source is biogas. It has a unique environmental perspective that will be used for solving problems with soil degradation, sanitation, water scarcity, killing smoke from fire places, deforestation, global warming due to uncontrolled release of methane from i.a. land fills and pit latrines and exhaust emissions from vehicles
It is vital to note that one of the most extraordinary challenges our modern civilisation has to master is how to stop soil degradation and maintain soil fertility. In The world 70% of the arable is threatened by desertification. With the increasing global population, it is obvious that we need to take immediate actions to cure this problem and that is where the implementation of biogas infrastructure comes about.
1.1 Maintenance of soil fertility
The main output from the biogas plant is the digester residue, a moll and nourish rich fertilizer that can be used to maintain a living soil and thus securing food supply and curbing desertification worldwide. Up till now the lack of manure has limited the growth of organic farming. Introduction of Biogas technology will change this for the better. A digester is like an industrial cow that produces fertilizer and biogas. Adding moll to the land will increase the water retaining capacity of the soil thus minimizing the water demand. The nitrogen content in the digester residue can be taken up directly by the plants and this minimizes nitrogen leakage to the environment.
1.2 Sustainable Bio fuel production
A global strategy for bio fuel production involves food sovereignty, securing of biodiversity, mitigation of GHG-emissions and securing biomass demand for biochemicals like plastics and rubber. Biogas is the only bio fuel that has the capacity to meet those demands. The main reason is that the main output is fertilizer, bio manure, that can secure soil fertility and pave the way for introduction of organic multi cropping and saying no to land grabbing and monocultures involving use of chemical pesticides, chemical fertilizer and GMO – crops and violation of food and water security.
Another reason is that the raw material for biogas production is extremely flexible. Biogas can be produced from any organic matter i.a. organic waste from households and industries, sludge, manure, energy crops, crop residues and algae. Still another reason is that the use of biogas is extremely flexible. It can be used for cooking, lightning, industrial applications, cogeneration of electricity and hot water, fuel cells and as vehicle fuel.
Thermal gasification of biomass will increase the biogas still further and the process gives up to three times higher energy output compared to converting the same amount of biomass to ethanol.
1.3 Optimal energy balance and safe market
The decomposition of organic matter in a digester is an exciting process involving many different bacteria that has developed their teamwork during millions of years. To produce the same amount of fuel energy, ethanol production consumes up to 4 times more energy than the biogas production. Biogas can be produced for a local market and from locally available raw materials, thus minimizing transport energy and securing a safe and stable price market for the biogas since it can’t be imported on commercial basis.
1.4 Cleanest bio fuel
Biogas has also the lowest exhaust emissions of all bio fuels and contains no cancerous aldehydes that you find in the exhaust emissions from i.a. ethanol cars. Bio methane can be used in normal diesel engines when mixed with 10 % diesel. Thus biogas can be an environmentally attractive substitute for both gasoline and diesel.
1.5 Healthy women
By substituting wood fuel with biogas for cooking, deforestation could be curbed worldwide
In The world around 70% of the cooking fuel is made from firewood. The smoke from fireplaces is causing a deadly health threat upon the women when cooking. Around 1.8 million women dies every year due to lung diseases caused by smoke from fireplaces. Getting the wood fuel is very time consuming and imposes a very heavy working load on the women. Substituting wood fuel with biogas will create a healthy environment for the women
1.6 Better immune defence and fertility
Biogas technology will also pave the way for introduction of 100% organic farming without use of chemical pesticides and thus improving immune defence and fertility
1.7 Healthy children
Lowered demand for wood fuel will increase the potential for fruit tree plantings. More fruit, biogas stoves and proper sanitation will improve health for the children
1.8 Rescuing of Rainforests
The rainforests are treasuries of Mother Earth that it has taken millions of years to develop and now are threatened by extinction. They are able to create rain clouds that distribute water from the rainforest to surrounding regions and thus prevent drought problems in other countries. The rainforest is also an important carbon dioxide sink. As long as the canopy is there it can prevent carbon dioxide emissions from the soil.
They are also a unique resource for producing medicines and food that will secure global health. Species, still unknown, from the rainforests, can help mankind to cure diseases worldwide. There is extremely little knowledge about the species in the rainforest. Their mechanical, and chemical design is a masterpiece of engineering, and a wonderful source book for learning about sustainable design for engineers worldwide. Unfortunately this book is still unknown to 99.99% and it is in the process of loosing pages every day without even being opened. Over 100 species get extinct every day due to the clearing of rainforests. Biogas technology will offer exploiters of the rainforest an opportunity to operate outside the rainforest through the introduction of sustainable system solutions involving reestablishment of soil fertility for abandoned land.
2 Sustainable sanitation
Environmetal problems are generally closely connected thus creating a need for sustainable system solutions with a holistic approach.
To meet the UN millennium development goals by 2015 and curb global environmental problem we need to develop multipurpose solutions with the goal of creating a more sustainable way of living where the current problems are correctly linked to a holistic solution.
Sustainability can only be reached if certain basic
criteria are fullfilled. One example is that the system solution can not be dependent on storages and linear flows. If you pick marbels from a bag and never put any back, the bag will become empty. Thus, one obstacle to overcome in reaching sustainability is to introduce recirculation of lifesupporting recources like water and nutrients. This is where IWESS will make a contribution. The concept of IWESS involves recycling of our waste water into our consumption chain. In addition, an implementation of IWESS will also improve the possibilities of solving a number of numerous related environmental and health problems.
When comparing the organic components of domestic waste which are mainly water and nutrients, it can easily be realized that part of the current problems are not caused by lack of resources but because of poor resource management. By designing waste management systems, based on source separation and recycling, the previously mentioned problems can be solved.
2.1 Current water and waste management system solutions
Today there are two major waste management systems that are in use and being promoted around the world especially in developing countries. The systems are commonly called the flush-and-discharge and the drop-and-store systems. For a long time the flush-and-discharge has been regarded as the perfect sanitation system, especially for urban areas. It is still desired in a lot of the developing countries and is often sponsored by international donors. The drop-and-store is often used in rural areas with very limited financial resources and is considered an inferior, temporary solution compared to the flush-and-discharge.
2.2 Pit latrines
The majority of the people in the world are using the so called drop-and-store system. The pit latrine is one example causing uncontrolled contamination of groundwater risk for overflow during heavy rains. These and additional disadvantages increase in severity when the system is merged into urban areas The drop and store system also suffer from the disadvantage of not allowing for nutrient recirculation.
2.3 MIFSLA system principle
The flush and discharge system principle, most common in urban and developed areas, is highly energy consuming and inefficient concerning transportation,
centralized processing and disposal of the treatment products. This traditional waste management system follows a principle which can be called MIFSLA, Mix First and Separate Later, where you actually only move the problem around whitout solving it.This method also uses large volumes of treated water for the transportation only and it does not involve any solution for a recirculation of nutrients, mainly phosphorous, back to the agriculture.
In one year the average person in Sweden using the MIFSLA system, flushes 400-500 litres of urine and 50 litres of faeces together with 15000 litres of pure water. The mixture, called black water, is then mixed again with an additional 15000 – 30000 litres of water from bath, kitchen and laundry water – referred to as grey water. Before arriving to the sewage treatment plant, water from industries are also added to the waste water. Pipe infiltration. caused by insufficient sealing and cracks due to poor maintenance will also mix with the waste water before it is entering the sewage plant. The dangerous component, the 50 litres of faeces, is contaminating not only the urine but also tens of thousands of litres of almost clean water.
Figure 1. Waste water constitutents
The system most commonly used in the developed world is the flush-and-discharge method with the principle of mixing grey water and black water, transporting it, and later, treating it in a centralized plant. This traditional waste management principle has also been used in most of the larger urban settlements of developing countries.
2.4 Eutrophication
The output from the treatment process include two phases, one solid and one liquid.. The solid waste is most often deposited in lack of further treatment solutions. Run off from these deposits, caused by rain, then transport them to surface water sources and finally, to the oceans from where they are practically impossible to retain. The liquid treatment product is even more polluted than the initial grey water. and contains vast amounts of nutrients, now contributing to eutrophication in rivers, lakes and oceans. Eutrophication is also the result from the nutrients reaching the same surface water sources due to run off from the solid waste.
All the nutrients in the waste are either deposited or disposed. No recirculation to farming land, from which the nutrients originates will take place. Instead they need to be continuously regenerated by artificial fertilizers, containing phosphourous mined in quaries. These deposits of phosphorous are just like the fossil fules, depletable. The phosphorous is also a key building stone for all life on eartht that can’tbe replaced, thus creating a situation that is a far more critical than the oil crisis.
In developing countries, with lack of financial capital, the chemical fertilizers need heavy subsidies to become available for the local farmers. Agriculture in developing countries, is one of the largest and most important contributors to the national economy. Lack of recycling systems for fertilizer might affect the financial growth and food security, due to lowered incomes and food shortage.