Carbon Capture and Clean Fossil Fuels

Difference between an OCGT and a CCGT???

An Open Cycle Gas Turbine (OCGT) is a type of gas turbine that generates electricity directly from the combustion of natural gas in a single cycle, while a Combined Cycle Gas Turbine (CCGT) uses both a gas turbine and a steam turbine in a combined cycle to improve overall efficiency by utilizing the waste heat from the gas turbine.

How many plants are responsive for about half of global man-made CO2 emissions?

About 8000 worldwide

Different types of CCS?

Post-combustion capture, pre-combustion capture, and oxy-combustion capture

CO2 Emission Scenarios

CO2 per kWh for coal, natural gas combustion turbine (NGCT), wind and nuclear

Coal: 870
NGCT: 674
Wind: 14
Nuclear: 12

What is an integrated assessment model (IAM?)

An integrated assessment model (IAM) is a quantitative framework that combines knowledge from various disciplines to assess the interactions between human systems and the environment, particularly related to climate change and policy impacts.

What was the IEA’s landmark roadmap publish?

Net Zero Emissions by 20500 Scenario (NZE1), published in May 2021

What is tight oil

Oil trapped in shale rocks. Forms much the same as conventional oil, but is not mobile within the rocks and needs to be hydraulically fractured to get the oil out

What is Oil Shale

Rocks that contain kerogen but have not been heated in the past and have not matured to produce oil. Pyrolysis of the oil shale produces synthetic crude oil

What are oil sands (tar sands)

A mixture of extremely heavy oil (bitumen) with sands, with huge deposits in Canada and Venezuela. Questionable environmental credentials.

How do you remove unconventional gas?

Hydraulic fracturing with water under high pressure (with added sand and other materials), forces fissures into the shale and allows the gas out.

What is conventional coal?

Coal mines from deep mines or open cast mining

What is unconventional coal?

Digging a hole down into an unmineable coal seam, drill another hole a little way away in the seam. Drill through the seam and link the hole. Pump down air or oxygen to the first hole and set the seam on fire. The hot combustion products pass through and gasify the remained of the coal, and produce syngas at the other end of the hole.

What is the difference between a reserve and a resource

Reserve: profitability using today’s resources and current prices
Resources: how much is actually out there

What is pulverised coal combustion?

Technology for the large scale utilisation of coal (or other solid fuels) for generation of power and heat.
A mixture of pulverised fuel and air is injected into the combustion chamber. Combustion takes place while the fuel is in suspension. The flue gas is cleaned.

What is a circulating fluidised bed (CFB)

A bed of fine inert matieral with an air / oxygen stream. Fuel is fed in from the side and suspended, combusting and providing heat. Water is passed through creating steam. The mixture of gas and particles are separated using a cyclone with material returned to the base of the combustor. Operates at temperatures below 900C to avoid ash melting and sticking. Long residence time of the fuel in the bed and good heat and mass transfer allows for the burning of poor quality fuels. Chemical looping agents can be used in the bed.

CCGT block diagram?

OCGT Block diagram?

What is a Combined Heat and Power Plant, and how does the energy wasted different to a conventional power plant?

Exhaust gases from thermal power station used to heat water which can then be piped to homes. CPP (60-70% wasted), CHP (20% wasted)

Natural Gas wt%

Methane 70-90 wt%

Ethane 5-15 wt%

Propane + butane <5 wt%

Gas in place meaning?

All the gas that is there

How much LNG do Australia and Qatar produce?

Roughly 110 bn m3 per year

Quantity of natural gas hydrates?

20 quadrillion m3 of methane

Four ranks of coal?

Lignite - highly reactive, lowest carbon content
Sub bituminous - black, dull surface. High heating value
Bituminous - Hard black rock
Anthracite - highest carbon content, slightly lower heating value than bituminous

What is the reserves to production ratio (R/P)

Number of years a resource will last if production rates stay the same

Dry basis?

Not including moisture content

Dry, ash free basis?

Not including moisture and ash

Ultimate analysis?

Procedure to determine CHNS in the sample

Lower Heating Value (LHV)

The energy released from combustion of coal, not including the energy from condensing steam (from the combustion of H content in coal)

Higher Heating value

The energy released from the combustion of coal, including the energy from condensing steam

Steam cycle?

Power station heats and evaporates high pressure water to form steam (superheated steam), which is then expanded through a turbine (HP)

The exhaust from the turbine is then passed back to the boiler, and expanded again through an intermediate pressure turbine.
Finally, the steam is passed back to the furnace one final time, then expanded in the low pressure turbine (may be two turbines in parallel))
Pressurised water in the inlet may be heated up using the exhaust gas near the end of the furnace, this is done via an economiser.

Coal fired power plant boiler schematic?

When did the UK stop power production from coal?

21st April 2017

South & Central America R/P Ratio?

150

What is an oil reserve?

The amount of oil that can be recovered financially feasibly at the current price of oil

Highest and lowest carbon intensities of oil production by country 2019?

Canada - 45
Kuwait - 6 kgco2/boe

Initial Stages in Oil Drilling?

1. Survey

2. Environmental impact Studies

3. Preparation of landscape

4. Rig construction

5. Hole Digging

Two types of well?

Wildcat (exploratory)
Production (drilling where known hydrocarbon deposits exist)

Equipment and materials required for oil drilling?

Drill Bit

Drill Pipe
Bottom Hole Assembly
Drilling Mud

What is drilling mud used for?

Cooling and lubricating
Conveyance of cuttings to surface
Maintenance of well integrity

Prevent fluid ingress into the well

What is a kick

Where hydrocarbons overcome the hydrostatic pressure of the mud and enter the well. (very dangerous)

What is the purpose of cementing an oil well?

Sealing off wellbore from fresh water, and prevention of contamination of aquifers.

What is the use of a christmas tree?

Collection of valves used to produce oil or gas. Controls the flow out of the well. Use d in both above and below sea installations.