Production of Biodiesel from Non-Edible Sources: Technological Updates

Production of Biodiesel from Non-Edible Sources: Technological Updates offers a step-by-step guide to the production of biodiesel, providing comparisons of existing methods, new and state-of-the-art technologies, and real-world examples of implementation. The book discusses all potential non-edible feedstocks for biodiesel production, providing their properties, availability, and processing, including deeper insights into kinetic models and simulation of biodiesel fermentation. Readers will gain knowledge of existing parameters and methods for biodiesel production, optimization, scale-up, and sustainability, along with guidance on the practical implementation of these methods and techniques.

Finally, environmental sustainability, techno-economic analysis, and policymaking aspects are considered and put into the context of future prospects. This book offers a step-by-step guide for researchers and industry practitioners involved in bioenergy, renewable energy, biofuels production and bioconversion processes.

• Provides step-by-step guidance on key processes and procedures
• Reviews all the available non-edible feedstocks for biodiesel production and presents their properties, pros and cons
• Presents pilot and industry-scale case studies on the implementation of biodiesel production from non-edible feedstocks
• Addresses optimization, environmental sustainability, economic viability and policy issues to support commercialization

• Language: English
• Publisher: Elsevier Science
• Release date: Feb 10, 2022
• ISBN: 9780323858977

Book preview

Chapter 1

Introduction

Shangeetha Ganesan¹, Hao Sen Siow¹, Akintomiwa O. Esan¹, ², Sivajothi Nadarajah¹ and Nur Liyana Abdul Manaff¹,    ¹School of Chemical Sciences, Universiti Sains Malaysia, Penang, Malaysia,    ²Department of Pure and Applied Chemistry, Ladoke Akintola University of Technology, Ogbomoso, Nigeria

Abstract

Currently, the largest contributors to greenhouse gas emission are the transportation sector followed closely by the electricity and industrial sector. Both the transportation and industrial sectors contribute to greenhouses gases due to the burning of fossil fuel. The best way to mitigate this problem is by switching to alternative fuels namely biodiesel. Biodiesel is an excellent alternative to fossil fuel. It is a renewable fuel comprising fatty acid chains of monoalkyl esters derived animal fats or vegetable oils. However, biodiesel is plagued with the food-for-fuel controversy as the raw materials are mainly sourced from edible oils. This raises valid food security concerns. Therefore researchers worldwide are clamoring to produce biodiesel from non-edible sources. In this chapter, we will discuss in detail worldwide energy resources and consumption, production rate and demands for diesel fuel, biodiesel as renewable energy source, and the use of non-edible seed oils as biodiesel feedstock.

Keywords

Biodiesel; renewable energy; energy; non-edible feedstock

1.1 Overview of energy resources and consumption

1.1.1 Energy and economy

Over the years, energy has been regarded as a measure of the capacity and capability to perform work. It has also been referred to kinetically as a measure of the ability to convert the inherent capacity and capability into motion. The relationship existing presently between energy and the economy of nations is a very determining factor in the status of each nation (Martinás, 2005).

According to the modern economic concept, energy is regarded as a fuel, a substance employed as a source of energy. Energy, in the form of fuel, is a significant factor that has been associated with human civilization and economic power. The discovery of fossil fuels in some nations has triggered the economic potential of such nations (Islam et al., 2019).

The increasing energy demand globally has resulted in the increasing economic power of nations involved in its production. The economy of countries like the United States, China, and Russia are boosted by the primary energy resources they provide globally, which constitute about 38%. Nations with sole economic dependency on such energy resources have suffered dire consequences whenever there is a drop in international market price. Policies are also being put in place by the majority of these nations to emphasize the sustainability of the energy resources without detriment to the environment and future generations. The development of a nation in terms of energy resources has also been found to exhibit correlations with excellent energy policies (Nematchoua et al., 2014).

The global energy demand is expected to rise to about 35%–60% in 2030 when compared to the energy demand values of the year 2010. The European Union (EU) is projected to account for about a 15%–20% rise in global energy demand (Tvaronavičienė et al., 2019). The ASEAN countries, India, China, and other Asia Pacific countries show progressive growth in energy demand up to 2040 with the ASEAN countries alone accounting for 14% of the global increment of primary energy demand (Lu et al., 2017).

Recently, nations of the world have put into consideration a balanced approach regarding energy. This involves placing into proper perspective a way of meeting the rising energy demand and environmental sustainability in terms of safety. The rising energy demands and depletion of fossil reserves means proactive measures need to be carried to meet the demands. But it is also important that in meeting these objectives, future sustainability regarding the safety of the environment is also of paramount concern (Ben-Salha et al., 2018).

1.1.2 Global energy resources

Energy resources that have made a tremendous contribution to the wealth and sustainability of nations are classified into conventional and non-conventional resources. Conventional resources are further divided into renewable and non-renewable sources. Non-renewable conventional energy sources that are limited and have the capability of being depleted include crude oil, natural gas, nuclear, and coal. This is mainly because of the long period of years required for them to be formed in nature. On the other hand, renewable energy sources such as hydropower, bioenergy, marine, solar, and wind are produced continuously in a short time. Despite the great demand and importance of conventional energy sources, the challenge associated with depletion of these sources and environmental factors has aided the usage of non-conventional energy sources, such as carbon capture, carbon storage, and energy efficiency. According to the International Energy Outlook of 2019, conventional energy resources are the most abundantly utilized globally with the renewable sources having the best projection in terms of demand of 3% increment per year until 2050 (EIA, 2019).

1.1.2.1 Coal

Coal is regarded as the second most crucial energy source formed from prehistoric vegetation accumulated in swamps and peat bogs when subjected to high temperature and pressure. The formation of coal began about 290–360 million years ago in the carboniferous age, which is also called the first coal age. The quality of each coal deposit depends on the degree of applied temperature and pressure and the duration of time it takes to be formed. Coals are generally classified into two types depending on the degree of change experienced by the coal during maturation (coalification). Low-rank coals have low energy content with low carbon content and high moisture content. Physically, they are soft and dull with an earthy appearance. Examples include lignite and sub-bituminous coals. High-rank coals, on the other hand, produce high energy and are characterized by high carbon content and low moisture content. They are generally stronger and more rigid than the low-rank coals and have a black luster appearance. A typical example is anthracite coal (WCA, 2005; WEC, 2016). An estimation of about 984 billion tonnes of coal reserves has been proven to be available globally. The distribution of the coal reserves across major continents for the years 1998, 2008, and 2018 is shown in Fig. 1.1.

Figure 1.1 Distribution of coal-proved reserves in 1998, 2008, and 2018 in different continents (BP p.l.c., 2019a, 2019b). Data from BP p.l.c. (2019a), https://www.bp.com/content/dam/bp/business-sites/en/global/corporate/pdfs/energy-economics/statistical-review/bp-stats-review-2019-full-report.pdf; BP p.l.c. (2019b), BP Energy Outlook 2019. https://www.bp.com/content/dam/bp/business-sites/en/global/corporate/pdfs/news-and-insights/press-releases/bp-energy-outlook-2019.pdf.

Coal makes up about 30% of the global energy consumed, and the global consumption of coal increased by 64% between 2000 and 2014. It has also been revealed that 40% of the power generated globally comes from hard coal and lignite. This is evident in countries with large coal deposits like Poland, South Africa, China, and Australia that depend on coal for 94%, 92%, 77%, and 76% of total electricity, respectively. Consumption of hard coal and lignite is expected to increase yearly by 1.5% and 1%, respectively, until the year 2030. Asia has the largest market for coal consumption estimated at 54%, with China having the largest share as a result of its large population. Globally, there is a shift towards clean coal technologies involving carbon capture and storage (CCS) technologies. This allows for continued utilization of coal power plants operating at higher efficiencies and low-carbon emissions without having a significant effect on global climate change. There is also a decline in the use of coal in Western Europe due to climate change policies, while India’s coal consumption is expected to be on the increase, and China is adopting the clean coal technology approach. The Coal industry has also experienced a downward shift due to the overabundance and price of natural gas; a typical example is in the United States where coal is being replaced with gas in power plants (WCA, 2005; WEC, 2016).

1.1.2.2 Crude oil

Crude oil is regarded as the world’s leading fuel. It is a non-renewable energy source that is made up of a liquid mixture of hydrocarbon deposits and other organic constituents. These hydrocarbon mixtures are formed from organic-rich sediments. It accounts for about 33% of the total energy consumed globally, which implies crude oil is the world’s leading fuel. The consumption of oil is expected to continue to rise especially in the transportation sector. This is because a significant change is not expected via biofuel utilization or electric cars in the next two decades. It undergoes a refining process producing useful products like gasoline, diesel, kerosene, and other petrochemicals. The quality of crude oil is dependent on the amount of sulfur contained in crude oil. Sulfur exhibits corrosive tendencies, which lead to the production of toxic hydrogen sulfide gas. The price of crude oil is also dependent on the density and sulfur content. Crude oil with lower density and sulfur content is more expensive than high-density crude oil with greater sulfur content. This is due to the use of less-expensive refinery processes for low-density crude oil (WCA, 2005; WEC, 2016).

The total crude oil–proven reserves were estimated at 1730 thousand million barrels as of 2018. The distribution of the crude oil reserves across major continents for the years 1998, 2008, and 2018 is shown in Fig. 1.2. Global oil production was also found to increase by about 2.2–80 million barrels day−1 in 2018 and is projected to increase to about 100 million barrels day−1 in 2050 (BP p.l.c., 2019a; 2019b; WEC, 2016).

Figure 1.2 Distribution of crude oil–proved reserves in 1998, 2008, and 2018 in different continents (BP p.l.c., 2019a, 2019b). CIS, Commonwealth of Independent State. Data from BP p.l.c. (2019a), https://www.bp.com/content/dam/bp/business-sites/en/global/corporate/pdfs/energy-economics/statistical-review/bp-stats-review-2019-full-report.pdf; BP p.l.c. (2019b), BP Energy Outlook 2019. https://www.bp.com/content/dam/bp/business-sites/en/global/corporate/pdfs/news-and-insights/press-releases/bp-energy-outlook-2019.pdf.

1.1.2.3 Natural gas

Natural gas is regarded as the only fossil fuel with the possible expectation of potential growth and a unique role as the transition of the globe into a cleaner, safer, and sustainable future occurs. It is a mixture of gaseous hydrocarbon comprising majorly about 80% methane and other gases like ethane, propane, butane, helium, and nitrogen in minute quantities. It is regarded as the third most important fuel accounting for 24% of the total energy globally. It is also the second-largest energy source for power generation with a share of 22%. It is also the fastest-growing fuel in the world because of its greater yearly increase of 1.1% in comparison to 0.6% for oil and 0.4% for coal. Natural gas reserves are majorly discovered in sedimentary rocks situated close to other solid and liquid hydrocarbon beds. Natural gas represents about 24% of the world’s primary energy and is regarded as the second energy source for generating power. Advanced recovery methods are now being employed in the enhanced recovery of gases from abandoned and newly discovered reservoirs (Islam et al., 2019).

Natural gas can be used in the raw form and also in other forms as compressed natural gas (CNG) and liquefied natural gas (LNG). CNG is stored in cylindrical cylinders after being subjected to compression of less than 1% of its volume at standard temperature and pressure. LNG is produced when natural gas is condensed to about 1/600th of its original volume at standard temperature and pressure. The proven reserve for natural gas is expected to be above 200 trillion m³ by 2030. The distribution of the natural gas reserves across major continents for the years 1998, 2008, and 2018 is shown in Fig. 1.3 (BP p.l.c., 2019a, 2019b; WEC, 2016).

Figure 1.3 Distribution of natural gas–proved reserves in 1998, 2008, and 2018 in different continents (BP p.l.c., 2019a, 2019b). CIS, Commonwealth of Independent State. Data from BP p.l.c. (2019a), https://www.bp.com/content/dam/bp/business-sites/en/global/corporate/pdfs/energy-economics/statistical-review/bp-stats-review-2019-full-report.pdf; BP p.l.c. (2019b), BP Energy Outlook 2019. https://www.bp.com/content/dam/bp/business-sites/en/global/corporate/pdfs/news-and-insights/press-releases/bp-energy-outlook-2019.pdf.

1.1.2.4 Nuclear energy

Nuclear energy is a form of heat energy that can be released via reactions involving nuclear fusion or fission taking place between neutrons and protons in the nucleus of an atom. Electricity can be produced when a large amount of heat energy released is applied to generate steam from turbines (Fig. 1.4). Uranium-235, an isotope of uranium, is the most commonly used element in industrial nuclear power generators. The development of nuclear energy is majorly found in few countries like the United States, China, Russia, and Australia (WCA, 2005; WEC, 2016). Fig. 1.5 shows the distribution of uranium in different countries.

Figure 1.4 A nuclear power plant (Rypkema, 2018). Image courtesy Stefan Kühn. From Rypkema, H. A. (2018). Green chemistry: An inclusive approach. In Environmental chemistry, renewable energy, and global policy (pp. 19–47). https://doi.org/10.1016/B978-0-12-809270-5.00002-9.

Figure 1.5 Distribution of uranium resources in different countries (World Nuclear Association, 2019). From World Nuclear Association. (2019). The nuclear fuel report: Expanded summary-global scenarios for demand and supply availability 2019–2040 (Report No. 2020/005). https://www.world-nuclear.org/getmedia/b488c502-baf9-4142-8d12-42bab97593c3/nuclear-fuel-report-2019-expanded-summary-final.pdf.aspx.

Nuclear energy plays a vital role in the world’s electricity production by contributing about 10% of the total production. The obvious benefits associated with nuclear energy include near-zero greenhouse gas (GHG) emissions, secured source of power, long-term cost-competitiveness, and industrial and human capital benefits. A typical example of the environmental benefits of nuclear energy was recorded in 2018 when the emission of about 2.2 billion tonnes of carbon dioxide (CO2) was avoided through the 2563 TWh of electricity generated by the world’s nuclear power plants. The United States and EU have been able to provide 55% and 53% carbon-free electricity, respectively, from nuclear energy. One major fear associated with nuclear plants for generating electricity is the production of radioactive waste, but this has been found to be in negligible amounts and can easily be disposed of safely. Future predictions are in favor of increased use of nuclear energy for power due to increased electricity demand and changes in consumption of energy. The transportation sector with the rise in the development of electric cars is also expected to place a strong demand for electricity, which would lead to the use of other sources of energy like nuclear energy. Apart from electricity generation, nuclear energy is expected to be applied as an eco-friendly low-carbon source of heat in different applications like hydrogen production, oil refining, water desalination, and district heating (World Nuclear Association, 2019).

1.1.2.5 Hydropower

Hydropower, also known as hydroelectricity, is a form of energy generated from the natural water cycle through the force initiated from fast-moving or falling water (Fig. 1.6). It is a cheap renewable source of electricity and water management that is clean, reliable, and also sustainable. It is rated among the cleanest sources of electricity and the replacement of coal with hydropower is curbing the emission of 4 billion tonnes of GHGs into the global atmosphere annually. Despite the huge amount of GHG emission prevention associated with the use of hydropower, it has been observed not to be totally void of emissions from GHGs. Hydropower emissions are generally lower than fossil-generated emissions by one or two orders of magnitude. Ecosystem burdens and adverse socioeconomic impacts are also problems encountered due to hydropower utilization. It is also regarded as the leading source of generating renewable electricity with a supply of 71% globally. The growth rate obtained for total installed capacity between 2005 and 2015 was about 40%, and this is expected to increase at an annual rate of about 4% due to the interest being generated globally. The major development relating to hydroelectricity is situated in China, Latin America, and Africa. The future market for hydroelectricity development is expected to be Asia due to the huge amount of unused potential estimated to be about 7195 TWh year−1. The leading nations with the highest installed hydroelectricity in 2019 are China (356.4 GW), Brazil (109.1 GW), United States (102.8 GW), Canada (81.4 GW), India (50.1 GW), and Japan (49.91 GW) (Islam et al., 2019; WEC, 2016).

Figure 1.6 The hydropower plant at the Hoover Dam, located on the Nevada–Arizona border ( El Bassam et al., 2013). Photo courtesy U.S. Bureau of Reclamation. From El Bassam, N., Maegaard, P., & Schlichting, M. L. (2013). Distributed renewable energies for off-grid communities. In Hydropower (pp. 167–174). https://doi.org/10.1016/B978-0-12-397178-4.00010-4.

Hydropower has contributed more towards renewable energy in comparison to other renewable energy sources. It has helped in decarbonizing the global economy by reducing dependence on fossil fuels. An estimation of about 800 GW of hydropower is needed in the next 20 years to accomplish the energy-related goals of the Sustainable Development Goals and the Paris Agreement on climate change. According to the International Hydropower Association (IHA), the total capacity of hydropower installed in 2019 was 1308 gigawatts (GW), which represents an increment of about 15 GW in comparison to 2018. This indicates that more efforts are needed to improve hydropower generation annually to meet the set target in the next two decades. Fig. 1.7 shows the new installed hydropower capacity by region in 2019 (BP p.l.c., 2019a, 2019b). Sustainability assessments of hydropower are also being carried out to assist governmental authorities with the provision of comprehensive information in deciding the construction of facilities. This assessment also ensures the evaluation of existing hydropower projects in order to understand the future directions. It also helps in the proper knowledge of the impacts of hydropower projects on the economy, environment, and society (Zhang et al., 2021).

Figure 1.7 Distribution of installed hydropower in different regions in 2019 ( IHA, 2020). From IHA. (2020). Hydropower status report 2020. https://www.hydropower.org/publications/2020-hydropower-status-report.

1.1.2.6 Bioenergy

Bioenergy can be described as the utilization of biological substances or biomass for the generation of energy. It is also described as a versatile energy source that involves the transformation of biomass into solid, liquid, or gaseous fuels. These fuels are applicable in all areas of the society for electricity generation, transportation, heat transfer purpose, and in industries. Bioenergy application involves the use of bioenergy crops, agricultural residues, postconsumer wastes, animal manure, and forest products in the generation of heat and electricity as well as transport fuels. It is regarded as the largest source of renewable energy presently. The utilization of biomass as a source of electrical energy has grown consistently in recent years. It has played a vital role in decarbonizing electricity systems through the use of low-carbon baseload electricity. Heat generation from biomass, on the other hand, has received limited policy support, thereby growing at a slower rate. Transport fuels have also suffered some challenges due to the debate on appropriate sustainability criteria and structural challenges. Increased efforts are therefore needed to amplify the use of bioenergy because of the great potential attached to it, which will support the United Nations Sustainable Development Goals and the Paris Agreement on limiting the global mean temperature (IEA & FAO, 2017; IRENA, 2014). The rate of consumption of different bioenergy varies depending on geographical location. Bioethanol and biodiesel are consumed in large amounts as replacements for transportation fuels in most developed countries. Developing countries employ the use of bioenergy for domestic, industrial, and economic development. Traditional biomass is employed as the dominant domestic fuel in the least developed countries without access to electricity or another energy source (Islam et al., 2019; WEC, 2016).

The future of the use of biomass is regarded as auspicious. It is estimated that in the next two decades, biomass would be responsible for 60% of the total renewable energy use. The global biomass demand is expected to increase to 108 exajoules (EJ) provided favorable policies are implemented (IEA & FAO, 2017; IRENA, 2014).

1.1.2.7 Solar

Solar energy is the primary source of the different types of energy found on the Earth. It is of great importance and potential because of the vast amount of energy that can be derived from it. The amount of solar energy available at a specific period is subject to variations in time, geographic and weather conditions. Availability of land is also an important factor when it comes to large-scale solar energy production. The total amount of solar energy absorbed and reflected is about 70% and 30%, respectively. The Earth absorbs about 51%, while the remaining 19% is absorbed by the clouds and atmosphere. The solar energy reflection of about 30% takes place from the air, clouds, and surface of the Earth. The solar energy absorbed by the atmosphere has a direct effect on the climatic processes of the Earth’s surface. This affects photosynthesis, wind and ocean currents, the water movement cycle, and land and ocean surface heating by 0.023%, 1%, 23%, and 46%, respectively. The total energy consumed globally is far lesser than the annual global potential solar energy, which is in the range of 1575–49,837 EJ subject to seasonal and geographic variations. Solar photovoltaic (PV) modules, solar thermal collectors (STCs), and PV thermal are part of the technologies employed to harness solar energy in useable forms. The solar PV modules are developed specifically for the conversion of sunlight to electricity using a photoelectric effect that employs the use of a semiconductor material like silicon (Fig. 1.8). Countries that are involved in large installations of solar PV include Germany, China, Japan, and United States. Countries in Africa and the Middle East with a great amount of solar energy have not tapped significantly into the abundance of available resources. The STC is explicitly designed for harnessing heat from the Sun, while the PV thermal is designed for heat and electricity generation (WEC, 2016; United Nations Development, 2000).

Figure 1.8 A solar power plant ( El Bassam, 2021). From El Bassam, N. (2021). Solar energy: Technologies and options. In Distributed renewable energies for off-grid communities (pp. 123–147). https://doi.org/10.1016/B978-0-12-821605-7.00015-5.

The importance of solar-powered electricity has been linked to the exponential increases experienced annually in terms of the installed capacity. The global installed capacity as of the end of 2015 was 227 GW representing 1% of the total electricity used globally. This increased to 480 GW at the end of 2018, and future projections of 2840 GW and 8519 GW are expected in 2030 and 2050, respectively. Favorable government policies are positively affecting the solar energy market, and this has led to a drop in prices of solar power with new emerging markets in developing nations. These projections, if actualized, will help in supporting the Sustainable Development Goals of the United Nations (IRENA, 2019).

1.1.2.8 Wind energy

Wind energy is a reliable and promising source of renewable energy that is formed when unequal heating of the atmosphere by the Sun or surface Earth irregularities leads to induced kinetic energy. The kinetic energy of wind, which is an inexhaustible resource, is generally converted to mechanical energy and can be applied to various technological processes. Wind turbines are employed in generating electricity called wind power from the wind (Fig. 1.9). The wind power generated is categorized as large wind onshore, small wind onshore, and offshore turbines. The main parameters involved in the determination of wind power include mean annual wind speed, instantaneous wind speed, and probability that a particular wind speed, wind power, and wind energy will occur. The speed of wind is subject to seasonal changes with winter months having higher wind speed than summer months. The change in wind speed is also dependent on height, that is, altitude and wind speed have a direct proportionality relationship (Islam et al., 2019; WEC,