APES Video Notes: Energy from Biomass (Topic 6.7)

Key Objectives

• Describe the environmental effects of using biomass as an energy source.
• Practice describing responses or solutions to environmental issues.

Biomass vs. Biofuels

Biomass

• Definition: Organic matter used for energy, e.g., wood, charcoal, dried animal waste, dry grass.
• Usage: Primarily in developing nations for heating and cooking due to ease and low cost.
• Electricity Production: Rare due to low energy density; time-intensive compared to fossil fuels.

Biofuels

• Definition: Liquid fuels like ethanol or biodiesel, derived from biomass such as corn, sugar cane, or palm plants.
• Usage: Supplement or replacement for gasoline in transportation.

Modern vs. Fossil Carbon

• Biomass: Releases modern carbon, recently part of the atmospheric cycle, hence considered more carbon-neutral.
• Fossil Fuels: Release fossil carbon, adding new carbon to the atmosphere, which was previously stored underground.
• Analogy: Spending a found dollar (modern carbon) vs. savings (fossil carbon).

Environmental and Health Impacts of Biomass

• Pollutants Released: Carbon monoxide (CO), NOx, particulate matter, volatile organic compounds (VOCs).
• Health Effects: Respiratory irritants, exacerbating asthma, bronchitis, COPD, emphysema, and eye irritation.
• Indoor Cooking: Traps pollutants, worsening health effects.
• Deforestation and Habitat Loss: Driven by energy needs, especially in developing nations lacking environmental laws.
• Soil Erosion & Carbon Sequestration Loss: Less forest cover reduces soil stability and carbon absorption.
• Smog Formation: NOx and VOCs contribute to smog, affecting photosynthesis.

Biofuels Production and Environmental Impacts

Ethanol

• Sources: Primarily corn and sugar cane.
• Production Process: Harvested, broken down, fermented by yeast to produce ethanol, mixed with gasoline (E85/Flex Fuel).
• Environmental Concerns: Soil erosion, habitat loss, greenhouse gas emissions, water consumption.
• Ethanol Drawbacks: Less energy-dense than petroleum, affecting vehicle efficiency.

Algae as Biofuel Source

• Benefits: Potentially more sustainable, requires less land, can be cultivated and harvested efficiently.
• Uses: Bioethanol and biodiesel production.

Biodiesel

• Source: Primarily from plant oils, especially palm.
• Environmental Impact: Clearing land for palm plantations can increase greenhouse gas emissions.
• Graph Insight: Increasing share of emissions from palm cultivation.

Sustainability Considerations

• Renewability vs. Sustainability: Renewable by definition but not always sustainable due to agricultural practices.
• Impact on Food Supply: Competes with food uses, affecting prices.

Practice FRQ 6.7

Skills to Practice

1. Explain how biodiesel affects atmospheric carbon differently than fossil fuels.
2. Describe two environmental benefits of using algae for biofuel production over other crops like corn or palm oil.