Surface Chemistry of Carbon Capture

Climate Change Aspects

K. S. Birdi

• Publisher: CRC Press
• Year: 2019
• Print ISBN: 9780815361251
• eBook ISBN: 9781351116442
• Edition: 1
• Topic: Physical Sciences
• Subtopic: Chemistry
• Index: Chemistry

Surface Chemistry of Carbon Capture: Climate Change Aspects provides comprehensive and up-to-date literature on carbon capture and storage (CCS) technology and delineates the surface chemistry of this process.

Mankind is dependent on energy from gas, oil, coal, atomic energy, and various other sources. In all fossil fuel combustion processes, carbon dioxide (CO2) is produced (ca. 25 Gt/year). In the past few decades, we have observed a constant increase in CO2 content in the air (currently ca. 400 ppm [0.04%]). This book discusses the technology related to carbon (i.e., CO2) capture and sequestration (CCS) from fossil fuel energy plants, which is considered an important means of CO2 control. It also covers the adsorption/absorption processes of CO2 on solids and similar procedures to help address growing climate change concerns.

CHAPTER 1

Introduction to Surface Chemistry of Carbon Capture

1.1 Introduction to Surface Chemistry of Carbon Capture

The Earth is surrounded by atmosphere (air), and water is found in great oceans (covering almost 75% of the surface of the Earth):

• ATMOSPHERE
• … … … … … … … … … … .
• … … … … … … … … … … .
• … … … … … … … … … … .
• EARTH—OCEANS

Furthermore, the Earth—atmosphere—sun system

• SUN—ATMOSPHERE—EARTH

composes a configuration that mankind has admired and studied for many centuries. Ancient religions and civilizations have worshipped certain specific natural elements for thousands of years, and some religions still worship them. These elements were

• Air (atmosphere, wind)
• Water (rivers, oceans)
• Sun (light, heat, radiation)
• Fire (flame, combustion)

COMPOSITION OF AIR (ATMOSPHERE)

The composition of air (or the atmosphere), as known today, is a mixture of different gases (near the surface of Earth):

• nitrogen (N₂: 28 gm/mol) (78%);
• oxygen (O₂: 32 gm/mol) (21%);
• argon (Ar: 40 gm/mol) (0.9%);
• carbon dioxide (CO₂: 44 gm/mol) (0.04%);
• water (H₂O: 18 gm/mol) (vapor) (traces);
• other gases (hydrogen, etc.) (traces).

The global average temperature of the Earth is primarily regulated by the heat received from the Sun (Appendix C). Furthermore, the energy (heat, radiation) reaching the Earth from the Sun has to pass through the atmosphere surrounding the Earth. This means that the sun’s energy (radiation) has to interact with

• gas molecules (and dust particles) in the air (atmosphere)
• reflection by air/clouds
• reflection from Earth, trees, and ocean surface

The heat from the Sun (the surface temperature of the Sun is 5500°C) is transmitted by the infrared wave length of the radiation. The infrared is absorbed by some gases found in the atmosphere (e.g., carbon dioxide, methane, etc.). These gases are called greenhouse gases (GHGs). The absorbed infrared energy is reflected in all directions, which increases the temperature of the planet Earth. In the present text, there is only interest in carbon dioxide and its interactions with the temperature balance of the Earth.

The concentration of carbon dioxide (CO₂) in air is reported to be increasing over the past century (ca. 2 ppm/year) (IPCC, 1995, 2005a, b, 2007, 2019; IEA (International Energy Agency) 2011, 2012, 2013, 2014a, b, c, 2015a, b, c, d, 2016e; EPA Handbook, 2011; Dubey et al., 2002; Sanz-Pérez, 2016; Rackley, 2010; Dennis, 2014; CSIRO, 2013; Albo et al., 2010; Oh, 2010; Hinkov et al., 2016). This has been attributed to fossil fuel burning (combustion) (anthropogenic CO₂) (Leung et al., 2014; McDonald et al., 2015). Furthermore, the increase in population and increased energy demand leads to increase in anthropogenic CO₂.

This book relates to the carbon (i.e., CO₂) capture and surface chemistry properties of carbon dioxide (CO₂), especially its connections to the change in temperature (average temperature) of Earth. However, it is useful to describe some general remarks about the atmosphere (air) and its characteristics.

The composition (and temperature and pressure) of air varies with height over Earth. In other words, when one considers the composition of air, the height has to be considered. The gradient of composition of air (i.e., variation of composition with height) might be dependent on time scale (and space). Similarly, water (e.g., oceans, rivers, lakes, drinking water) contains different salts (sodium, calcium, chlorides, sulfates, etc.) that are known to interact with some components of air (for example, carbon dioxide, oxygen). Mankind has been aware of the essential role played by these elements for the existence of life on Earth. Even though millions of miles away, the Sun provides heat to the Earth. Besides heat, the Sun also emits other kinds of energy to Earth, for example, radiation, ultraviolet light, and so on. The atmosphere surrounding the Earth has four distinct layers (Saha, 2008; Lang, 2006):

• 0 to 10 miles (0 to 16 km: temperature range, ca. 20°C to −50°C) TROPOSPHERE: This is the region of human activities.
• 10 to 30 miles (16 to 50 km: temperature range, ca. −50°C to 0°C) STRATOSPHERE: The ozone gas (O₃) layer, which absorbs the ultraviolet (UV) radiation from the sun, is found in this region. The temperature is higher at higher altitude, owing to the absorbance of ultraviolet radiation from the Sun.
• 31 to 53 miles (50 to 80 km: temperature range from ca. 0°C to 90°C) MESOSPHERE: In the mesosphere, the temperature decreases as altitude increases.
• 53 to 75 miles (80 to 200 km: temperature from ca. >90°C) THERMOSPHERE: In this region temperature increases with altitude, owing to absorption of highly energetic solar radiation.

This clearly shows the complex sun—atmosphere system and the interactions relating to temperature on the Earth.

Further, mankind has used fire (with respect to food, combustion processes, energy (electricity, mechanical), transportation) in many different applications and technologies (both directly and indirectly) for many hundreds of years. It is also recognized that all these elements are essential for the existence of life on Earth. Fire or combustion of fossil fuels in the modern age is described as

• COMBUSTION: FOSSIL FUELS + OXYGEN (FROM AIR) = FIRE (heat, electricity, mechanical energy, etc.) (CO₂ produced)

This process (i.e., the production of carbon oxide) is anthropogenic and is currently related to the world population (e.g., food and energy demands). It is thus seen that the above process of combustion adds CO₂ to the air. At the same time, it must be stressed that carbon dioxide in air is essential for the existence of life on Earth.

PHOTOSYNTHESIS AND CARBON DIOXIDE CYCLE

The most significant process with regard to life and all kinds of living species on the Earth is the supply/production of food. The latter is singularly provided by the complex system that is dependent on the photosynthesis process (Paoletti et al., 2002; Raschi et al., 2000):

• CARBON DIOXIDE (CO₂) + SUN SHINE + WATER < PHOTOSYNTHESIS > ALL KINDS OF PLANTS/FOODS/CARBOHYDRATES

Each gas component in air is known to have a specific role in the life cycle on Earth. For example, even though the concentration of carbon dioxide (CO₂) in air is at present only 400 ppm (0.04%), it provides all carbonaceous food to life. Food is obviously the most necessary product for the existence of life on Earth. Actually, the photosynthesis process is the opposite of fossil fuel combustion, and CO₂ is captured in plants and so on. It is important to mention that all the carbon atoms in plants on Earth are supplied by the CO₂ in air (via photosynthesis). Furthermore, the food is digested by all living species on Earth by the metabolism process (Appendix C):

• The CO₂—food—metabolism cycle:
  • CO₂ in air (photosynthesis) >>>> Food >>>> Metabolism (exhale CO₂)

This shows that in the life cycle on Earth all the carbonaceous components are solely provided by CO₂ in the air (EPA Handbook, 2011). Actually, it is clear now that all these natural elements are interrelated and are basic necessities for life on Earth. The characteristics of the different gases in air (atmosphere) for example:

• Oxygen (O₂: 21% in air) is essential for all living species (as a source of metabolic and other reactions, for example, oxidation)....

Table of contents

• Cover
• Half Title
• Title
• Copyright
• Contents
• Author
• Chapter 1 ■ Introduction to Surface Chemistry of Carbon Capture
• Chapter 2 ■ Adsorption (on Solids) and Absorption (in Fluids) of Gases (CCS Procedures) (Surface Chemistry Aspects)
• Chapter 3 ■ Surface Chemistry of Solids
• Chapter 4 ■ Carbon Capture and Sequestration (CCS) Technology (Basic Remarks)
• Chapter 5 ■ A Short Review of Different Carbon Dioxide (CO2) Capture Processes (Adsorption on Solids and Absorption in Fluids)
• Appendix A: Surface Chemistry Essentials
• Appendix B
• Appendix C
• Bibliography
• Index