1
Q
Explain Petroleum
A
- Also called crude oil
- A naturally mixture of hydrocarbons, generally in the liquid state, that may also include compounds of sulfur, nitrogen, oxygen, and metals and other elements (ASTM D-4175)
- Inorganic sediment and water may also be present
- Made up of hydrocarbons & non-hydrocarbons
- Elementary composition :
Carbon 84-87%
Hydrogen 11-14%
Sulfur 0-3%
Nitrogen 0-0.6%
2
Q
What are the hydrocarbons
A
- ALIPHATICS ( 25 % ) - C1 - C60
- AROMATICS ( 17% ) - (C6H5)n
- NAPHTHENES ( 50% ) - CYCLOALKANES
3
Q
What are the non-hydrocarbons
A
- SULFURS ( <8% )
- NITROGENS ( <1% )
- OXYGENS ( <3% )
- METALLICS ( <100PPM )
4
Q
Explain Paraffin
A
Refer to alkanes such as methane, ethane, propane, n and iso butane, n and iso pentane. These compounds are primarily obtained as a gas fraction from the crude distillation unit
5
Q
Explain Olefins
A
- Alkenes such as ethylene, propylene and butylenes are highly chemically reactive
- They are not found in mentionable quantities in crude oil but are encountered in some refinery processes such as alkylation
6
Q
Explain Naphthenes
A
- Naphthenes or cycloalkanes such as cyclopropane, methyl cyclohexane are also present in the crude oil
- These compounds are not aromatic and hence do not contribute much to the octane number
- Therefore, in the reforming reaction, these compounds are targeted to generate aromatics which have higher octane numbers than the naphthenes
- Polynuclear aromatics such as naphthalenes consist of two or three or more aromatic rings.
- Their molecular weight is usually between 150– 500
7
Q
Explain Aromatics
A
- Aromatics such as benzene, toluene o/m/p-xylene are also available in the crude oil
- These contribute towards higher octane number products and the target is to maximize their quantity in a refinery
process
8
Q
Explain Organic sulphur compounds
A
- Such as thiophene, pyridine also exist in the crude oil
- The basic difficulty of these organic sulphur compounds is the additional hydrogen requirements in the hydrotreaters to meet the EURO 5 standard
9
Q
Explain Oxygen containing compounds
A
- These compounds do not exist 2 % by weight in the crude oil
- Typical examples are acetic and benzoic acids
- These compounds cause corrosion and therefore needs to be effectively handled
10
Q
Explain Asphaltenes
A
- Are polynuclear aromatic structures consisting of 20 or more aromatic rings along with paraffinic and naphthenic chains
- A crude with high quantities of resins and asphaltenes (heavy crude) is usually targeted for coke production
11
Q
Explain Resins
A
- Are polynuclear aromatic structures supported with side chains of paraffins and small ring aromatics
- Their molecular weights vary between 500– 1500. These compounds also contain sulphur, nitrogen, oxygen, vanadium and nickel
12
Q
What is Natural Gas
A
- Is created naturally over the course of hundreds of millions of years
- It is formed when layers of decomposing plants and animals are subject to intense heat from the Earth and pressure from rocks
- All this pressure, heat and millions of years turned the natural material into coal, petroleum and natural gas
13
Q
Where does natural gas come from
A
- Is found in rock formations deep below the surface of the Earth
- Petroleum, or oil, is often found in the same areas. Humans have been using natural gas for cooking for hundreds of years
- The first industrial extraction of natural gas was in New York State in 1825
- Large drills are used to bore into the Earth and unlock natural gas from underground reservoirs
- Pipelines then transport
14
Q
Explain Production and Delivery of Natural gas
A
- Is collected from within the Earth’s crust, processed, and delivered to power plants, where it is converted into electricity
Step 1: Extract Step 2: Convert Step 3: Power
15
Q
Advantages of Natural Gas
A
- Natural gas is abundant and a major source of energy
- Infrastructure already in place
- Natural gas can be easily transported
- Natural gas produces less overall pollution
16
Q
Disadvantages of Natural Gas
A
- Natural gas is a non-renewable resource
- Storage
- Natural Gas Emits Carbon Dioxide
- Natural gas can be difficult to harness
17
Q
Summarise natural gases
A
- Mainly used as fuel for generating electricity and heat
- Natural gas in compressed form is used as fuel for vehicles which is known as CNG
- It is used as fuel for boilers and air conditioners worldwide
- This is used for making fertilizers also, mainly ammonia
18
Q
Explain Coal
A
- Is a “combustible mineral consisting of carbonized vegetable matter, used as a fuel ”
- The energy from coal comes from the breaking of carbon bonds
- During the Carboniferous Period, swamps and peat bogs were buried deep below ground
- Extreme pressure and temperature exerted on the vegetation within these swamps created peat
- Over time peat transforms into lignite
- Pressure and high temperature makes lignite into sub-bituminous coal which is converted into bituminous coal or “hard coal.
19
Q
What is Carbon Dioxide
A
- Is a covalent compound made of carbon and oxygen
- In simpler terms, it’s a kind of gas that forms when carbon atoms bond closely with two oxygen atoms. This bonding happens in a special way called covalent bonding, where the atoms share electrons with each other
- You can’t see or smell carbon dioxide, but it’s a big part of the air around us and plays a crucial role in life on Earth
- Plants use CO₂ to make food through a process called photosynthesis, turning CO₂ and sunlight into energy
- However, too much CO₂ in the atmosphere can lead to climate change, making it an important substance to understand in chemistry and environmental science
20
Q
What are uses if CO2
A
- Beverages - Carbonate soft drinks to give fizz and enhance taste
- Fire Extinguisher - Effective against electrical fires and flammable liquids as CO2 displaces o2 to smother fire
- Plant growth - CO2 accelerate growth
- Refridgeration - CO2 in the form of dry ice for cooling
- Medicals - Minimal invasive surgeries as it is non-toxic and dissolves in the body without trace
21
Q
What are the Health Effects of CO2
A
- Breathing Problems - High levels of CO₂ can make it hard to breathe, especially for people with asthma or lung conditions
- Dizziness - Being in an area with too much CO₂ can make you feel dizzy or light-headed.
- Headaches - Excessive CO₂ levels can cause headaches and fatigue, making it hard to concentrate
- Increased Heart Rate - Your heart may beat faster as it tries to supply enough oxygen to your body in high CO₂ conditions
22
Q
Environmental Effects of CO2
A
- Global Warming - CO₂ is a greenhouse gas that traps heat in the atmosphere, leading to global warming and climate change
- Ocean Acidification - CO₂ absorbed by oceans makes them more acidic, harming marine life and coral reefs
- Altered Plant Growth - High CO₂ levels can change how plants grow, affecting food crops and ecosystems
- Weather Changes - Increased CO₂ contributes to more extreme weather patterns, including hotter temperatures, storms, and droughts
23
Q
How is hydrogen produced
A
- Biomass - Gasification ; Bio-hydrogen
- Wind - Electrolysis
- Solar - Electrolysis
- Natural Gas - Reforming; Partial Oxidation
- Petroleum Coke / Residue - Gasification icl CO2 sequenstration
24
Q
What do the methods of producing hydrogen involve
A
- The splitting water (H2O) into its component parts of hydrogen (H2) and oxygen (O2)
- The most common method involves steam reforming of methane (from natural gas), although there are several other methods
25
Explain Steam reforming
Converts methane (and other hydrocarbons in natural gas) into hydrogen and carbon monoxide by reaction with steam over a nickel catalyst
26
Explain Electrolysis
Uses electrical current to split water into hydrogen at the cathode (+) and oxygen at the anode (-)
27
Explain Steam electrolysis
( A variation on conventional electrolysis) uses heat, instead of electricity, to provide some of the energy needed to split water, making the process more energy efficient
28
Explain Thermochemical water splitting
Uses chemicals and heat in multiple steps to split water into its component parts
29
Explain Photoelectrochemical
Systems use semi-conducting materials (like photovoltaics) to split water using only sunlight
30
Explain Photo-biological
Systems use microorganisms to split water using sunlight. Biological systems use microbes to break down a variety of biomass feed stocks into hydrogen
31
Explain Thermal water splitting
Uses a very high temperature (approximately 1000°C) to split wate
32
Explain Gasification
Uses heat to break down biomass or coal into a gas from which pure hydrogen can be generated
33
Explain the electrolysis of water in Hydrogen Production
- By providing energy from a battery, water (H2O) can be dissociated into the diatomic molecules of hydrogen (H2) and oxygen (O2)
- This process is a good example of the the application of the four
thermodynamic potentials (internal energy, U, Helmoltz free energy, F = U-TS; Enthalpy, H = U+pv and Gibbs free energy, G =U+pv-TS
- The electrolysis of one mole of water produces a mole of hydrogen gas and a half a mole of oxygen gas in their normal diatomic forms
- A detailed analysis of this process makes use of the thermodynamic potentials and the first law of thermodynamics
- This process is presumed to be at 298K and atmospheric pressure
34
What are the Main Energy Storage Market Applications for hydrogen storage
- Utility/industrial applications ( grid reinforcement, renewables integration and uninterruptible power supply (UPS) Applications )
- Transport / mobile applications ( on-board power for vehicles, new drive trains (electric and hybrid electric vehicles) and leisure applications (caravanning) )
- Portable applications ( computing, cell-phones and cameras (the 3 ‘C’s’) )
35
Expalin Generic Storage Systems for hydrogen storage
- Electrochemical systems ( batteries and flow cells )
- Mechanical systems ( fly-wheels and compressed air energy storage (CAES) )
- Electrical systems ( super-capacitors and superconducting magnetic energy storage (SMES) )
- Chemical systems ( hydrogen cycle (electrolysis -> storage -> power conversion) )
- Thermal systems ( sensible heat (storage heaters) and phase change )
36
Explain a fuel cell
An electrochemical device that produces electricity without combustion by combining hydrogen and oxygen to produce water and heat
37
Advantages of a fuel cell over conventional energy sources
- They produce zero or very low emissions, especially Green House Gases
(GHGs) depending on the fuel used
- Have few moving parts and thus require minimal maintenance, reducing lifecycle costs of energy production
- Modular in design, offering flexibility in size and efficiencies in
manufacturing
- Can be utilized for combined heat and power purposes, further increasing the efficiency of energy production
38
How do fuel cells work
1. Hydrogen atoms enter at the anode
2. The atoms are stripped of their electrons in the anode
3. The positively charged protons pass through the membrane to the cathode and the negatively charged electrons are forced through a circuit, generating electricity
4. After passing through the circuit the electrons combine with the protons and oxygen from the air to generate the fuel cells byproducts which are water and heat
39
What is the Classification of Fuel Cell
1. Based on the type of electrolyte
2. Based on Types of Fuel and oxidant
40
Explain the fuel cell classification based on the type of electrolyte
1. Alkaline Fuel cell (AFC)
2. Phosphoric Acid Fuel cell (PAFC)
3. Polymer Electrolytic Membrane Fuel Cell (PEMFC); Solid Polymer Fuel Cell (SPFC) and Proton Exchange Membrane Fuel cell (PEMFC)
4. Molten Carbonate Fuel Cell (MCFC)
5. Solid Oxide Fuel Cell (SOFC)
41
Explain the fuel cell classification based on Types of Fuel and oxidant
1.Hydrogen (pure)-Oxygen (pure) fuel cell
2. Hydrogen rich gas-air fuel cell
3. Ammonia–air fuel cell
4. Synthesis gas- air fuel cell
5. Hydro carbon (gas)- air fuel cell
42
Explain Electrocatalysis
- Is a specialized area in electrochemistry focused on the use of catalysts to modify the rates of electrochemical reactions
- Electrocatalysts have been established for several electrocatalysis reactions, such as oxygen reduction and fuel oxidation
43
Explain the Sabatier principle
- States that “an ideal catalyst must bind to the reactant at an intermediate strength which is neither too weak nor too strong
- ” This concept is based on the notion that if the bond is too weak, the catalyst and the reactant will hardly interact with each other, whereas if the bond is too
strong, the reactant will not desorb from the catalyst surface, effectively inhibiting further reactions
- This principle was first proposed in 1913 by the Nobel laureate, Paul Sabatier, based on empirical observations
44
How is hydrigen stored
1. Physical based = compressed gas; cold / cryogenic compressed; liquid H2
2. Material Base = Adsorbent; liquid organic; interstitial hydride; chemical hydrogen
CHM 221 - Inorganic
flashcards
Decks in class (12)
# Cards
-
Lecture 1 - Catalysis44
-
Lecture 2 Health and Nutrition69
-
Lecture 4 - Green Chemistry35
-
Lecture 5 - Crystal Structure30
-
Lecture 3 - Reactors18
-
Lecture 4b - Green Chemistry24
-
Lecture 2 test stuff39
-
Leecture 3 - Test 1 stuff20
-
Chapter 6 - Group Theory ( Test )31
-
Chapter 5 - Test ( Crystal structure )38
-
Extra for chapter 5&610
-
Test 2 Memo answers15
