Anaerobic Digestion Plant in Tripoli, Libya- A Case Study

CHAPTER 1

Introduction

Background

Cumulative scarcity of energy resources around the globe is leading to the growing demand for alternate energy resources. Understanding the importance of sustainable development, the waste-to-energy market is also going through a resurgence. Since electricity generation using fossil fuel produces a non-renewable form of energy with harmful effects on the environment, recycling trash to generate electricity is gaining popularity due to its significant advantages over traditional fossil fuel energy methods.

Anaerobic Digestion Technology

In developed nations, structures have been set up into the Anaerobic Digestion Process, widely practised to generate heat and energy. However, developing nations have not been quick to adopt this method to increase their national grid power. Anaerobic Digestion (AD) is described as a biological process, which has the capability to break down biodegradable organic matter through microorganisms’ activities (Khoiyangbam, Gupta & Kumar, 2014). Oxygen has to be absent for this biodegradable organic matter to be converted biogas, which comprises of methane (CH4), carbon dioxide (CO2), as well as an insignificant amount of other gases (Ekström, 2014). The biggest advantage of AD is that it provides a sustainable energy solution. The reduced amount of emissions of harmful gases is another advantage of the AD plant. Solid nutrients obtained after the breakdown of organic food matter are the by-products of the plant and can improve soil fertility. As cited in several reports, for many years, anaerobic digestion has been preferred in the management of waste produced from industries and municipals. Using an AD process presents the option to produce energy that could be sold in electricity, heat, or steam (Richards, Cummings & Jewell, 2010).

Several European Union member countries such as the UK, Denmark, Germany and France have been leaders in managing organic waste, with the application of the AD technology (Gupta, 2006). The AD technology produces biogas estimated at 60% methane (CH4), lower levels of CO2, and traces of ammonia. The methane could be vital in fueling a Combined Heat and Power (CHP) system, which helps in the production of electricity and heat. It is estimated that methane has 21 times the effect of green gas emissions of CO2 (Kalia, 2016). As food wastes decompose in the open air, it contributes methane to the atmosphere. For this reason, the AD process is useful in displacing conventional generation, as well as helping in reducing greenhouse emissions. The AD process leads to nutrient-rich solid production, which could be applied to the soil to enhance its fertility. This is beneficial to horticultural farming and several other agricultural practices. In the city suburbs of Tripoli, the solid nutrients could be used in farms. In fact, the full utilisation of AD technology is combining waste management and adequate use of the by-products (Khoiyangbam, Gupta & Kumar, 2014).

Sustainable Energy Solution

By definition, sustainable energy means the provision of energy such that it meets the present energy demand without compromising the ability of future generations to meet their own needs. Two key components of sustainable energy are energy efficiency and renewable energy. The main source of electricity generation around the world, by far, is either water reservoirs or fossil fuels. Scarcity of natural resources with time is an inevitable condition. Sustainability demands utilisation methods that are alternative to the use of natural reservoirs to generate electricity. The use of sustainable energy saves natural resources for the next generations and is environmentally friendly. Burning of coal or emits emit carbon

dioxide, carbon monoxide, lead oxides, and other harmful gases into the atmosphere that contaminates the environment and affects the residents’ health. The utilisation of sustainable solutions like waste to energy conversion provides a solution for proper waste management and produces energy to meet the electricity needs.

The production of sustainable energy is taking on increasing importance in dwindling resources and the increase of energy consumption around the world. Biogas technology is considered one of the options for deploying organic residues (including food wastes) to renewable energy and valuable fertilisers. Many organisations and government agencies generally judge anaerobic digestion technology and biogas to be a sustainable method for reducing the strengths and environmental impacts of wastes and a way for producing the sustainable form of energy.

Anaerobic digestion technology is one of the established technologies for the sustainable processing of residues and wastes worldwide. AD process is useful for treating biodegradable waste such as food waste and produces saleable products such as methane. Anaerobic digestion is moreover considered of the most efficient biomass-to-energy routes. This technology saves over 90% of resources most resources categories and maximises organic wastes valorisation is an environmentally sustainable strategy (Priadi et al. 2015). It has been obvious that anaerobic digestion technology will take an important place in the human’s resource supply for the coming decades. It is also clear that transitions towards more sustainable sources of materials and energy are necessary. The technology of biomass is such an alternative resource that has a large potential in the application ranges and mitigating climate change issues.

Significance of Establishing AD Plant in Tripoli-Libya

Energy has been instrumental in realising economic development. The increased economic growth has contributed to overreliance on energy, leading to enormous pressure, as demand for fossil energy keeps soaring (Richards et al., 2010). This is because fossil energy is a non-renewable form of energy, and fossil energy resources have diminished. It is difficult to meet the increased demand for fossil fuel (Dosta et al., 2007). The increased use of fossil energy contributes to detrimental effects on the environment. For this reason, it is imperative to seek alternative energy sources, which are friendly to the environment. As a result, greener, renewable, and clean energy have seen increased demand. A set of fundamental considerations is essential in finding a suitable location for establishing the proposed Anaerobic Digestion plant for food wastes; some of these aspects will be highlighted in chapter two. The proposed AD plant’s location should be selected such that it maintains a suitable distance from the residential area in Tripoli. Other considerations for location choice include choosing a site that is accessible for the transportation of food waste and feasible enough for the distribution and transmission of the electricity produced.

Sustainable development and economic growth heavily rely on energy, which cannot be avoided (Ekström, 2014). Like several African nations, Libya has exhibited its immense potential for growth, driven by population growth. The growing Libyan population has led to increased dumping of wastes into the environment (Ekström, 2014; Otman & Karlberg, 2007). As a result, Libya has seen an influx of social, environmental, and economic problems, which has called for urgent intervention. In major cities such as Tripoli, the preferred waste management technique is the use of Collection-Transportation-Dumping, landfills, and out of city boundaries (Hamad et al., 2014). In Tripoli, land scarcity has been a major concern,

resulting from increased urbanisation and geographical location. In this sense, creating landfills and dumping sites is problematic. Tripoli residents have claimed that waste disposal is expensive and have been restricted to one option of waste disposal (Otman & Karlberg, 2007).