Biodiesel Production: Processes and Technologies

Introduction

Over the past few decades, fossil fuels from underground carbon resources such as coal, oil, and gas continue to play a crucial role in global energy systems. Fossil energy is an underlying driver of the commercial revolution and thus of technological, social, economic and developmental progress. Energy has played a hugely positive role in global change. However, these non-renewable energy sources (fossil fuels) even have a negative impact as they negatively affect human health, produce emissions like carbon monoxide, carbon dioxide, unburned hydrocarbons, oxides of nitrogen and other ozone-depleting substances. The earth should thus reconcile the role of energy in social and economic development with the need to decarbonize, reduce our dependence on fossil fuels and move towards lower-carbon energy sources (Hannah & Max, 2018).

The fossil fuel production and use began with coal. Its original exploitation dates back to 4000 B.C. in China, where burning occurred out of brown coal (one of the few types of coal). Be that as it may, considerable coal ignition was usually associated with the beginning of the industrial revolution (Golas & Needham, 1999). Figure 1 shows the global use of non-renewable energy sources like coal, oil, and gas from 1800 onwards. By and large, one could see that the worldwide use of fossil energy has expanded more than 1300-overlap. From Figure 1 it is observed that coal was the only fossil source until 1860s. The use of crude oil and natural gas production began two or three decades later. Also, Figure 1 shows that twentieth century saw an improvement in the use of fossil fuels, with coal falling from 96 percent of overall production in 1900 to about 30 percent in 2000. After 2000, crude oil is the most significant source of energy with around 39 percent of fossil fuels, followed by coal and natural gas with 33 and 28 percent, respectively.

Figure 1.

Global primary energy consumption by fossil fuel, measured in terawatt-hours (TWh)

Source: Vaclav, 2017

Crude oil is a blend of hydrocarbons formed from prehistoric plants and animals buried in the primal mud of swamps, lakes, and oceans. Crude oil is a non-renewable energy source, and it exists in liquid form underground pools or reservoirs, in tiny spaces within sedimentary rocks and near the surface in tar (or oil) sands (World Health Organization, 1989). About 100 countries worldwide produce crude oil. According to 2017 statistics (U.S. EIA, 2018a), 48 percent of the world's total crude oil production came from the top five countries (Russia-13%, Saudi Arabia-13%, United States-12%, Iraq-6% and Iran-5%) as shown in Figure 2.

Figure 2.

Top five crude oil producing countries, 1980-2017 (millions barrels per day)

Source: U.S. EIA, 2018a

The crude oil production and import scenarios reported in BP Energy Outlook 2030 (2012) are as follows:

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  The U.S. imports about 68 percent of its crude oil needs from other countries, while India imports 79 percent of its crude oil needs.

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  The Middle East and African generation do not fully meet Asia's energy needs, but the re-balancing of global energy exchange due to the improved net position in America is also a key factor.

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  India will increasingly depend on imports of oil, coal and natural gas to meet its growing energy needs.

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  European net imports and imports as an offer of use are increasing mainly due to declining local oil and gas production and increasing gas use. The development of net imports is primarily attributable to natural gas.

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  Import reliance, estimated as the share of demand met by net imports, is increasing for most major energy importers except the U.S.

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  In the year 2030, current energy importers are expected to import 40 percent more energy than today, with deficits in Europe and the Asia-Pacific region being offset by supply developments in the Middle East, the former Soviet Union, Africa, South and Central America.