Biogas Generation from Agricultural Wastes An Egyptian Experience in a Nile Delta Village (El Nenaiea) Eng. HASSAN GOMAA Environment & Renewable Energy Consultant-Egypt UNESCO-Africa Engineering Week with Africa Engineering Conference THEME: EFFECTIVE WASTE MANAGEMENT IN AFRICA Kigali Convention Center Rwanda 25th 29th September2017
Biogas Generation from Agricultural Wastes An Egyptian Experience in a Nile Delta Village (El Nenaiea) Eng. HASSAN GOMAA Environment & Renewable Energy Consultant-Egypt
INTRODUCTION: In this paper, we shall present an application of using a specific renewable energy technology appropriate for use and replication in many of our African villages and the countryside. The El Neneiea project serves a factory for drying vegetables and fruits mainly Onions, Leek, Garlic, Carrot, Parsley, Beet, Tomato, Orange, Lemon, etc.
INTRODUCTION: A biogas facility was established to: provide gas fuel to save part of the huge amount of diesel oil consumed for dehydration. producing compost to be used as a fertilizer. waste treatment and disposal. The first phase of the project saves 10% of the fuel consumption (around 1.5 tons/day and it is intended to cover 100% in the coming phases in the near future. Biomass/biogas has generally many advantages.
Renewable Energy: The African countries are endowed with a variety of renewable energy sources mainly hydro, solar, wind and biomass. The biomass represent a very important source. We as African engineers, our role are to develop utilization of our available renewable energy resources to outmost possible for the sustainable development of our countries economically, socially and environmentally. Energy is a key element for development particularly for the African countries generally characterized by relatively low per capita specific energy consumption. Renewable energy offers a very encouraging energy source for the well fair and sustainable development of the African countries as it will not only accelerate development but also preserve the environment.
Biomass and Biogas : Biomass is one of most important renewable energy technologies used, which depends mainly on utilizing all kinds of organic residues and wastes such as agricultural, trees and crop residues, animal residues such as animal dung and municipal wastes such as city refuses and solid wastes as well as sewages. Biogas is a special type of biomass technologies in which wet agricultural waste as well as sewage and animal dung are digested anaerobically to produce biogas that can be burned to produce energy for different purposes leaving digested material as a valuable fertilizer.
Biomass and Biogas : Biogas technology has several advantages mainly: Disposing of the agricultural waste in a safe way to prevent the otherwise potential of both land and water pollution leading to health problems. Generating a useful gas that can be used as a source of energy to power agriculture industry and households. Prevent potential formation of more serious greenhouse gasses such as methane. It will ultimately produce compost that can be used as land fertilizer. Increasing the efficiency of energy extraction. Raising the income and social standard in the rural areas. Offering new job opportunities.
Biogas activities in Egypt: Small-scale Biogas Activities: Estimates from the Agricultural Research Center (ARC) and National Research Center (NRC) show that there are 4000 small biogas (household) digesters installed in Egypt, less than 25% of them are in operation condition. Approximately 200-300 new plants are constructed every year. Meanwhile, the total potential for small biogas plants in Egypt is estimated to be more than 1 million units. Large Scale Biogas Activities: On the large-scale level, due to heavy energy subsidies, biogas activities have not moved away from the laboratory or pilot scale, unlike countries with no subsidies. So only few larger plants (up to 200 m3) have been constructed. A huge biogas plant of 220 000 m3 digester volume equipped by a 18 MW electric power generation plant has been constructed by GOST and started operation, within the El-Gabal El-Asfer sewage treatment plant for Cairo Fig 1. Fig. (1) El-Gabal El- Asfer Biogas plant in the Cairo sewage treatment plant
Biogas technology: It is a technology for analysis/digestion of organic waste under anaerobic conditions in the presence of a high percentage of moisture inside digesters (fermenters) established for this purpose. Multiple dynamic activities of microbes and microorganisms genres act without human intervention or selection, except only creating the best conditions; [Temperature ~ (35 or 55 0C), Ph (PH~7), Waste type (C/N = 30), solid content ~ (10%), Stirring during fermentation, using prefixes and steroids (starter), presence of inhibitors, retention time] to increase digestion/fermentation activity to the fullest extent possible. This results in a gas mixture generation composed of (55 70%) methane and (42-29%) Carbon dioxide (3-1)% nitrogen & other gases (e.g. hydrogen sulfide). This gas fuel mixture (biogas) is lighter than air and nontoxic, colorless burning in blue clean flame, fit for use in internal combustion engines or stoves and furnaces after minor modifications. The material remaining after digestion can be used as compost or fertilizer or rich animal feed (according to the type of primary waste) The following figure (Fig. 2) shows the sequence/ stages of anaerobic organic waste fermentation and gas fuel production
Biogas technology: Fig. (2) Three phase anaerobic digestion of organic material and factors affecting biogas generation
. Biogas integrated systems components: Basic components: Digester, waste entry, digested waste exit systems, gas holder. Secondary components: The first storage space, waste preliminary processing area, heating& agitation systems, manure storage & processing systems. Supplementary components: Waste transport and collection systems, manure transport& spreading systems, gas distribution network, electric generator and distribution network. Fig. (3) Biogas Integrated System Components
Biogas digester: A digester must have a suitable space allowing anaerobic digestion conditions and achieving the suitable conditions for the high activity of microorganisms. The digester volume must be enough for the available quantity of residues after being mixed with water by a certain percentage. It must have a space to assemble and store the product gas to pull when needed for use. It also shod have convenient way to introduce organic matter to the extent and in the form required, as well as a means to remove them after fermentation or digestion to ensure continued efficient operation. Fig. (4) Household Small Biogas simple design Digesters
El Nenaiea Industry and Trading Co. Factory El Nenaiea Industry and Trading Company have a factory for vegetable and fruits dehydration with capacity of 100 125 ton/day. The out coming wastes and residues are about 10-15% from the main capacity of the factory production lines. Dehydration process is a heavy energy consuming (20 30 ton of Diesel oil/day). Due to the increase of energy prices in Egypt after decreasing the fuel subsides, this will make a heavy increase to the product prices of the company.
Fig. (5) Waste disposal method before the biogas project & after no waste accumulation El Nenaiea Industry and Trading Co. Factory One of the promising way to avoid this increase of prices is to make benefit of the company available wastes as a source of renewable energy through Biogas technology and this will classify the company products as green products and this will open more marketing opportunities. The factory industrial organic waste
Nenaiea factory biogas project : Primary stage: Manufacturing experimental models of biogas digesters (10 & 1000 liters size) for running experiments using the experimental models to evaluate the factory waste. The results were positive. Biogas digester (10 liters size) Biogas digester (1000 liters size) Fig. (6) Experimental models of biogas digesters (10 & 1000 liters size)
Nenaiea factory biogas project : First stage (the first industrial model): First stage final Design Idea: Fig. (7) First stage Design concept
Nenaiea factory biogas project : Steps of implementation: Fig. (8) Building the body of the main basin fermenter in the treatment area Fig. (9) Installation of the main pump and its connections for feeding & agitation, and heating & gas systems
Nenaiea factory biogas project : Steps of implementation: Fig. (10) Design and manufacturing of the gas-collecting tank and installing it above the fermenter Fig. (11) Installing the burner unit which works with Deuel diesel & biogas Fig. (12) Development of Biogas generation During starting period
Nenaiea factory biogas project : Digester start up and the its Biogas generation rate: Fig. (13) Maim components of the digester and its Biogas generation rate
Nenaiea factory biogas project : Second stage project o Why we go to 2 nd stage: Through the deepening of local manufacturing, we proposed the project "development and creation of economic units to treat organic waste of food industries (liquid and wet) for production of bio-fuel (Biogas) to run the boilers and for electricity generation as well as the production of organic fertilizer and irrigation water applying (anaerobic fermentation technology) The project is an application for the principal investigator patent (municipal & industrial wastewater treatment fragmented system that can be produced in mass production works: (anaerobically or aerobically and anaerobically + aerobically) approved No.: 21867
Nenaiea factory biogas project : Second stage project o How we go to 2 nd stage: The Innovative system of high efficiency and productivity can be applied in many sites such as food factories, villages, resorts, camps and special settlements. Shown before. The proposed project adopts a short-term different stages approach implying that successful completion of a specific stage would be an input to following stage and not start from scratch. Two experimental models of a high efficiency digester were manufactured and used for testing different types of organic waste generated by the factory. After the promising results a digester as an industrial model of 450 m 3 has been built with the factory available capabilities and started and operated successfully using the available organic material in the factory. The operation measurements and results can be used for scaling up targeting complete usage of all wastes to meet all energy needs of production.
Nenaiea factory biogas project : Second stage project o How we go to 2 nd stage: The project has specific goals and multi- specialties are employed for evaluation of the previous phases (the first industrial model) and add any complementary systems such as output gas processing and add the combustion systems' suitable for consumption as diesel alternative fuel, as well as increasing the capacity by an additional digester model/models to get benefit of all amounts and types of organic wastes that have not been used. The new digesters will be designed and implemented as a repetitive modules which can be implemented quickly, efficiently and of high quality in the sites with similar conditions. A project team of different parties will be formed to evaluate each previous phase, design, implementation and operation of the targeted models comprising experts in civil engineering, mechanical electric, bio-chemistry with the beneficiary.
Nenaiea factory biogas project : Second stage project o How we go to 2 nd stage: The beneficiary is one of the leading companies involved in drying vegetables and fruits within a group of companies specialized in the manufacturing of metallurgical equipment and particularly stainless steel and ready to finance with his kinships covering project manufacturing value.
Nenaiea factory biogas project : Second stage project o How we go to 2 nd stage: The biogas plant main components and flow diagram: Animal fresh manure Fluidized bed portion Fixed bed & Fluidized bed digester Fixed bed portion Biogas up grade Liquid waste Plant residues Acid phase Up graded Biogas Conical screw press Fluidized Plant residues Liquid fertilizer Fluidized fertilizer Fig. (14) The biogas plant main components and flow diagram
Nenaiea factory biogas project : Second stage project o How we go to 2 nd stage: The biogas plant main components and flow diagram: The 1700 m3 digester design concept (has Fixed bed & Fluidized bed sectors) The digester 3D design (GLS tank) Fig. (15) 2 phase 1700 m3 digester design concept and 3D design (GLS tank) The biogas plant have a Fixed bed & Fluidized bed digester
Nenaiea factory biogas project : Second stage project o How we go to 2 nd stage: GLS tank construction on site : Fig. (16) GLS tank construction on site
Conclusions: o Lessons learnt indicate considerable rationale for El Nenaiea project potential replication in Egypt as well as the African countries among which are the following : Agricultural (crop & animal) residues can be considered the most important traditional fuel not only in the Egyptian rural areas but also in Africa. As international pressures to reduce carbon dioxide emissions grow, humanity s oldest fuel, biomass, is gaining a new lease of life. Biomass fuels fall into two main categories: energy crops and residues where residues in Africa in considerable quantities. Biomass fuels can either be burned directly, converted to refusederived fuel (RDF) or digested to yield gas.
Conclusions: o Lessons learnt indicate considerable rationale for El Nenaiea project potential replication in Egypt as well as the African countries among which are the following : The technologies, which may be employed to produce power from biomass, range from the simple and inefficient to leading edge technologies allowing wide spectrum use in Africa. Improved technology may be the key to the economic deployment of biomass. More than half of the world population use wood and agriculture residues as a primary energy source for household purposes by burned in primitive mud stoves and ovens, or burned immediately in the fields after harvesting which leads to great energy and economic losses as well as environmental hazards.
Conclusions: o Lessons learnt indicate considerable rationale for El Nenaiea project potential replication in Egypt as well as the African countries among which are the following : Its total amount in Egypt is estimated to be 35-40 million tons of dry-matter/ year, where 60 % of this quantity can be used for energy purposes. In the context of Biomass Technologies, it should be noted that Egypt, as well as many African countries, is party to the United Nation Framework Convention on Climate Change (UNFCCC) that demands stabilization and reduction of CO 2 emissions as well as other greenhouse gases, such as methane, according to Paris treaty of 2015. Biomass resources are CO 2 neutral fuels, and increasing its utilization for energy purposes will imply fewer emissions of CO 2 and methane.