Feasibility of Biogas Utilization in Developing Countries: Egypt a Case Study

Research Article

Austin Chem Eng. 2015;2(2): 1017.

# Feasibility of Biogas Utilization in Developing Countries: Egypt a Case Study

Mohamed El Zayat¹*, Mohamed G Hassan², Christopher l Taylor³ and Salah El Haggar4

¹Environmental Engineering PhD Program, American University in Cairo, Egypt

²Energy and Petroleum Engineering, American University in Cairo, Egypt

³Chemical Engineering Department, Loughborough University, UK

4Department of Mechanical Engineering, American University in Cairo, Egypt

*Corresponding author: Mohamed El Zayat, Member (ASCE/EWRI), Environmental Engineering PhD Program, The American University in Cairo, P.O. Box 74, New Cairo 11835, Egypt

Received: March 25, 2015; Accepted: July 02, 2015; Published: July 09, 2015

## Abstract

One of the main concerns of implementing Anaerobic Digesters (AD) that result in releasing biogas is the disposal of large quantities of organic wastes in an economically and sustainable manners. This paper evaluates the economic sustainability of implementing anaerobic digesters and capturing the released biogas for energy utilization in contained communities in rural areas in Egypt. The experimental data conducted from anaerobic digester on a pilot scale were scaled up and used to perform the economic viability of the proposed project. The reactor was fed by liquid cow manure with Chemical Oxygen Demand (COD) varies between 7500-8000 mg/l at 35°C for 6 days retention time. It was found that, the reactor is capable of producing 0.53 Nm³ of biogas per m³ reactor per day. The economic viability of a project extends beyond the initial financial analysis. It entails analyzing the data using shadow prices as to elimination price distortions, analyzing the indirect costs and benefits of the project, and looking at the overall effect of the project on the economy. The economic indicators are based on the Net Economic Present Value (NEPV) and Economic Rate of Return (ERR) that is resulted from optimal energy production and dig estate application. Through economic evaluation, the Egyptian government can determine which projects will be of benefit to the economy and which will be costly, decisions on which governments formulate their policies. The study concludes that the project will help contribute to the sustainable development of Egypt through its contribution to the environmental, economic, and social pillars. The highest NEPV and ERR were observed by earning carbon credits from reducing greenhouse gas emissions under Kyoto Protocol as a Clean Development Mechanism (CDM) project or Clean Development Mechanism of Program of Activities (CPA). The revenue from the CDM/CPA can overcome any financial barriers, encourage decision makers, and provide foreign exchange for the country. Moreover, the project has a positive value added and creates new jobs. Thus, it would be in the best interests of the economy as a whole for projects like this are implemented on a greater scale.

Keywords: Anaerobic Digesters; Biogas; Economic Indicators

## Abbreviations

AD: Anaerobic Digesters; CERs: Certified Emission Reductions; CDM: Clean development mechanism; CNG: Compressed Natural Gas; COD: Chemical Oxygen Demand; CPA: CDM Programme of activities; EB: Economic Benefit; EC: Economic Cost; ERR: Economic rate of return; FI: Lang Factor; Fic: Multiplication factors for indirect costs; Fdc: Multiplication Factor for direct costs; FD: Fixed Dome; HLR: Hydraulic Loading Rate; HRT: Hydraulic Retention Time; If: Complete plant cost; IMPEC: Costs of main equipment once installed; IPCC: Intergovernmental Panel on Climate Change; LR: Loading Rate; MBTU: Million British Thermal Unit; MPEC: Main Plant Equipment Cost; NCF: Net Cash Flow; NEPV: Net Economic Present Value; OFMSW: Organic Fraction of the Municipal Solid Waste; PBP: Payback Period; POA: Programme Of Activities; SDR: Social Discount Rate; UASB: Up-flow Anaerobic Sludge Blanket; UNFCCC: United Nations Convention on Climate Change; VFR: Volumetric Flow Rate; WACC: Weighted Average Cost of Capital

## Introduction

Biogas is produced from anaerobic degradation of organic substrates, such as animal manure, organic fraction from municipal solid waste, agricultural wastes and food processing by-products. Biogas is a naturally produced mixture of Methane (CH4), Carbon Dioxide (CO2), and other trace impurities like Hydrogen Sulphide (H2S), Water Vapor (H2O), Nitrogen (N2) and Oxygen (O2). The major constituents of biogas are CH4 and CO2 with a concentration varies from 55 to 65% and 40 to 45% respectively [1]. Biogas formation through fermentation of organic material has the potential of tackling contemporary challenges: the degradation of biomass, production of renewable as well as environmentally friendly energy and a fertilizer by-product. Biogas is a clean renewable energy that promises to be a good alternative for fossil fuels. As a consequence, biogas can be utilized in a variety of different applications including cooking, heating, generating electricity, and transport to supplement Compressed Natural Gas (CNG) usage [2]. Hence, biogas technology has been an attractive prospect across the world. Biogas is generated from an organic anaerobic digestion process which requires a symbiotic mixture of certain bacteria and organic material [3]. The biogas generation rate depends on various factors, such as pH, temperature, Hydraulic Retention Time (HRT), Carbon to Nitrogen (C/N) ratio…etc. [4]. In 2005, Laaber found that the median biogas productivity is 0.89 Nm³/m³ reactor/day after evaluating more than 35 plants. In this study, the physical experiments were conducted in the Egyptian climatic conditions so that the biogas productivity could improve the reliability of the economic evaluation.

In contained rural areas in Egypt, tons of biomass is available for production of biogas. By installing biogas units in the households, the animal manure which is currently disposed of in an unsustainable way will be fermented in biogas digesters and a significant amount of methane emission can be avoided which has twenty one times the global warming potential of carbon dioxide. The potential utilization of the digestate as fertilizers can also reduce dependence on energy intensive mineral fertilizers [5]. Accordingly, proper functioning for anaerobic digesters in rural areas can provide multiple economic benefits to the users. Biogas projects can also get the finance from the certified emission reductions as a Clean Development Mechanism (CDM) project or Program of Activity (PoA CDM). In 2009, the UNEP stated that the number of biogas projects that are under validation, requesting registration or registered is 516, or 11.6% of the CDM projects [6]. The CERs or carbon finance will make such projects more economically viable in Egypt either as a CDM project or PoA.

Biogas plants in households have many positive environmental impacts. It is very important to specify such environmental benefits in order to optimize them. Biogas installations reduce the emission of greenhouse gases by substituting conventional fuels and synthetic fertilizers. Biogas utilization leads to reduced dependence on nonrenewable fuel sources, and hence preserves nature resources. Improved manure management practices result in reducing ground and surface water pollution and odor. One of the main significant positive effects relies on improving human wellbeing due to the reduction of pathogens from untreated organic wastes. Besides biogas, the digestate application to land is the most attractive option in terms of environmental issues, because it allows nutrients to be recovered and reduces loss of organic matter suffered by soils under agricultural exploitation [7].

The aim of this research project was to ascertain the economic feasibility in developing a small scale biogas system which would be built in contained rural areas in Egypt. The anaerobic digester would treat all organic food, incorporate biogas scrubbing/drying equipment to purify the methane to allow its use as a source of energy supply, and produce a by-product fertilizer which would generate another source of income. The study assesses the socio-economic impacts on households in rural areas.

## Biogas formation

Figure 1 illustrates the four step process which converts organic matter into Biogas. The bacteria form a symbiotic relationship with each other as the intermediate products, such as Acetate, are required by the methanogenic bacteria to create the methane in biogas. The acetogenic bacteria prefer acidic conditions, pH less than 6.8, and are easier to cultivate than the methanogenic bacteria, which prefer pH conditions of 6.8-7.5 [3].