Fossil Fuels Review
Chapter 19: Fossil Fuels
Lecture Objectives
Identify energy sources: Outline various energy sources utilized by humanity.
Discuss EROI concept: Explain the value of Energy Returned On Investment (EROI).
Describe fossil fuel processes: Detail the formation and extraction methodologies for major fossil fuels.
Concern over oil supply: Evaluate anxieties regarding the future decline of conventional oil reserves.
Environmental impacts: Investigate the environmental repercussions of fossil fuel usage and investigate potential solutions to minimize these effects.
Political, social, and economic aspects: Assess the socio-political and economic facets associated with fossil fuel utilization.
Energy conservation strategies: Explore methods for energy conservation and efficiency enhancement.
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Alberta’s Oil Sands and the Keystone XL Pipeline
Oil Sands Overview:
Also known as tar sands, these involve sand or clay layers that hold bitumen, a thick, tarry form of petroleum.
Numerous large tar sand deposits exist in Alberta, Canada, with significant ecological consequences arising from extraction and processing.
Extraction Process: Companies conduct the following to extract oil from oil sands:
Land clearing: Forests are cleared and land strip-mined to access oil sands.
Separation process: Sand deposits are mixed with hot water and chemicals to segregate bitumen.
Wastewater management: Toxic wastewater is stored in tailings lakes, posing environmental hazards.
U.S. Market Influence: The United States is a primary consumer of tar sands oil.
Extraction Methods of Oil Sands
Strip-mining Method:
Deposits are removed from the surface.
Combination of crushing and hot water application is utilized to separate bitumen.
Steam Extraction:
Steam and solvents are injected into underground deposits to liquefy bitumen for extraction.
After liquefaction, bitumen is pumped to the surface for further processing into synthetic crude.
Sources of Energy
Energy Harnessing: Various renewable and nonrenewable energy sources exist due to humanity's adaptation in utilizing natural energy forms.
Solar Energy Role: Most energy on Earth is derived from the sun, influencing wind patterns, photo-synthesis, and the water cycle.
Fossil Fuel Formation: When plants and organisms that utilize photosynthesis die, they can be transformed into fossil fuels (oil, coal, natural gas) by undergoing burial and anaerobic decomposition over millions of years.
Geothermal Energy: Additionally, geothermal energy is sourced from the Earth's core.
Fossil Fuels vs. Biomass: Since the Industrial Revolution, fossil fuels have become more prominent than biomass due to their high energy content, enhancing their efficiency for combustion, transport, and storage.
Fossil Fuel End Uses: Predominant applications include transportation, manufacturing, heating, cooking, and electricity generation.
Fossil Fuel Consumption Trends
Global Consumption Disparity: Developed nations typically consume more fossil fuels than developing nations, which mainly utilize energy for subsistence.
U.S. Energy Supply Breakdown: In the United States, fossil fuels (coal, oil, natural gas) account for 82% of total energy demand.
Fuel Consumption by Sector:
Detailed usage statistics for electricity generation and transportation across various sectors, highlighting losses encountered (waste heat).
Energy Investment Analysis
Energy Harvesting Costs: Extracting energy requires machinery, infrastructure, and various resources, constituting an energy investment.
Net Energy Concept:
Net Energy: Defined as the difference between energy returned from a source versus energy invested.
Calculation Formula: \text{Net Energy} = \text{Energy Returned} - \text{Energy Invested}
EROI Indicator: Energy sources are evaluated based on EROI, calculated as: \text{EROI} = \frac{\text{Energy Returned}}{\text{Energy Invested}}
Decreasing Ratios: EROI ratios decrease as extraction processes become more difficult and resource availability diminishes; conventional oil and natural gas EROI declined from 24:1 in the 1950s to 11:1 in recent years.
Formation and Characteristics of Fossil Fuels
Fossil Fuel Formation Overview: Fossil fuels are non-renewable energy sources formed from the remains of ancient photosynthetic organisms, which, after their demise, undergo conversion in anaerobic conditions through heat and pressure over millions of years into these energy-rich substances.
Coal Formation:
Described as a hard, blackish substance formed from compressed woody organic matter into dense carbon structures.
Extraction Methods: Primarily through strip mining, subsurface mining, and mountaintop removal techniques.
Crude Oil: Defined as unrefined oil from geological formations.
Natural Gas: Consists mainly of methane (CH_4) with other volatile hydrocarbons, usually referred to as petroleum when including both oil and natural gas.
Oil Shale: A type of sedimentary rock rich in organic content, convertible into shale oil through processing.
Methane Hydrate: Solid formations of methane within water molecule crystal structures found in oceanic and Arctic sediments.
Fuel Refining Processes
Refining Demystified: Crude oil is a composite of multiple hydrocarbons requiring refinement to separate based on molecular size, subsequently producing various specialized fuels for diverse uses, including heating, cooking, and transportation.
End Products: Refined fuels also contribute to making lubricants, asphalt, and other petrochemical products.
Electricity Generation using Coal
Coal-Fired Power Plant Process:
Coal Pulverization: Coal is finely ground and introduced into a furnace.
Combustion and Heating: Heat generated from combustion boils water, creating steam.
Turbine Mechanism: Steam drives a turbine, generating electricity via magnet and copper coil interactions.
Electricity Distribution: Generated electricity is transmitted to consumers.
Recycling Process: Steam is cooled and condensed back into water for reuse in the furnace.
Pollutant Management: Systems are integrated to filter pollutants from combustion processes.
Waste Management: Ash residue from the combustion process is taken to hazardous waste landfills.
Natural Gas and Petroleum Uses
Natural Gas Applications: Utilized primarily for electricity, heating, and culinary purposes.
Petroleum Products: Mobilized as vehicle fuel, with derivatives permeating through a variety of household items.
Depletion of Fossil Fuels
Nonrenewable Nature: As nonrenewable resources, fossil fuel availability diminishes with continued consumption.
Reserves-to-Production Ratio (R/P ratio): Calculated by dividing total reserves by the yearly production rate; current estimations:
Oil Reserves: 1.7 trillion barrels, production rate at 32 billion barrels/year ( \Rightarrow \frac{1.7 \text{ trillion}}{32 \text{ billion}} = 53 \text{ years remaining} )
Natural Gas Reserves: Estimated at 54 years.
Coal R/P ratio: Approximately 110 years.
Global Fossil Fuel Consumption
Daily Oil Extraction Rates:
Major producers: Saudi Arabia, Iran, United States, Germany, Japan.
Extending Fossil Fuel Access
Methods of Extraction Enhancement: Methods that increase fuel output but often lower EROI ratios and exacerbate pollution issues:
Mountaintop Mining: Involves the complete removal of mountaintops for coal access, leading to soil erosion.
Secondary Extraction: Up to two-thirds of fossil deposits often remain post-primary extraction, necessitating costly secondary processes to recover remaining resources via injected solvents or steam.
Hydraulic Fracturing (Fracking): High-pressure injection of chemically treated water into rocks, a contentious method primarily debated regions above geological formations like the Marcellus Shale.
Deep-water Drilling: Roughly 35% of U.S. oil and 10% of natural gas now stem from offshore resources.
Arctic Exploration: Climate change's impact on melting ice exposing Arctic regions to drilling, although significant challenges exist due to harsh weather and safety concerns.
Environmental and Health Impacts of Fossil Fuel Extraction
Extraction Effects: Notable damages to landscapes and habitats from various extraction methods.
Coal Mining Risks: Includes health hazards for subsurface miners, extensive erosion, acid mine drainage, and habitat destruction from mountaintop removal.
Oil Drilling Infrastructure: Damaging infrastructure effects such as access roads, pipelines, and worker housing contributing to environmental degradation and transport leakage.
Transport and Storage Risks:
Oil and coal transported by rail carries explosive derailment risks.
Approximately 2.7% of supplied natural gas escapes into the atmosphere, alongside methane releases during oil drilling due to inadequate collection systems.
Incident Case Study - Deepwater Horizon:
The 2010 catastrophic explosion resulted in extensive and prolonged oil leakage into the Gulf, affecting wildlife and habitats.
Health Risks from Fossil Fuel Emissions
Emission Complications:
Combustion processes result in various harmful pollutants:
Mercury Emissions: Released from coal combustion, bioaccumulates in food chains.
Cancer-Causing Hydrocarbons: Such as benzene and toluene from gasoline combustion.
Poisonous Emissions: E.g., hydrogen sulfide from crude oil.
Acid Precipitation Contributors: Sulfur dioxide and nitrogen oxides released from vehicles and power plants.
Study Objectives
Describe the formation of crude oil and list common petroleum products.
Discuss conventional crude oil, heavy oil, oil sands, and oil shale, including their relative advantages and disadvantages.
Define natural gas, its uses, occurrences, and the advantages and disadvantages of its energy applications.
Clarify hydraulic fracturing (fracking) and explore its controversies.
Examine coal, including its formation, distribution, uses, and associated pros and cons as a fuel source.