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Transcript of Gasification Presentation
The extraction process The conversion process The coke/asphaltene can be used as feedstock in the gasification process to produces Hydrogen and electricity
The end products Steam Hydrogen Organic Chemicals?! Electricity Market Requirements Amount of Asphaltene In Athabasica 350,000 b/d mined Stockpiles of oil sand coke may well exceed 30 million tons 6000 t/day Represent almost 1000 MW of electricity if utilized in IGCC Plant Why Gasification?? Gasification via IGCC is unmatched by competing means of dealing with the leftover coke/asphaltene
Gaseous emissions from an IGCC plant approach those from the natural gas burning boiler
Solid waste from IGCC represents only a fraction of that from the competing technologies The pressurized fluid bed combustion (PFBC) technology may emerge as a competitor for IGCC.
In this case, sulfur content of the feedstock is the determining parameter. IGCC technology is preferred for high sulfur feedstocks such as oil sand coke Shell's Project The Long Lake project in Alberta, Canada, is a joint venture between energy company Nexen and OPTI Canada
Extracting 72,000 bbl/d of bitumen from the Athabasca oil sands.
OPTI’s OrCrude™ primary upgrading process converts the raw bitumen into a partially upgraded product and a heavy asphaltene by-product.
A distillate hydrocracking unit upgrades the product further into a premium-quality synthetic crude.
The heavy asphaltene by-product feeds a 3,600-t/d Shell gasification unit, which generates hydrogen for the hydrocracker and process steam. Excess syngas is used to generate steam and power for bitumen extraction.
Shell's Gasifier The Shell gasifier consists of a vertical vessel equipped with a water-cooled membrane wall covered with a protective refractory and a layer of the frozen slag.
The membrane wall serves as a radiant cooler, generating high pressure steam.
Hot gaseous products exit the gasifier and enter the syngas cooler for the additional production of the high pressure steam.
Shell's Gasification Process The Shell gasification process can be combined with other upgrading and treating technologies to convert a wide range of low-value heavy residues and asphaltenes into synthesis gas (syngas).
After treating, this gas can be used as clean fuel for the IGCC, as a hydrogen source for hydrocrackers or it can be converted into high-value products such as synthetic hydrocarbons.
Outlook The Shell gasification process offers several technical advantages. It helps provide a high syngas yield, which is provided by special burner and reactor designs that enable operation at low oxygen consumption and low soot formation. Key features include:
feed: high ash, sulphur content and viscosity;
typically >2,600 Nm³ (CO + H2)/(t feedstock); and
Shell’s gasification technology is highly flexible and can be tuned to a variety of configurations, depending on customers’ needs. The use of gasification can help in:
improving product quality while simultaneously reducing plant emissions;
producing sufficient hydrogen for producing today’s clean fuels;
adapting processing facilities as demand for fuel oil diminishes;
reducing demand for natural gas; and
converting low-value products into high-value products.
Reducing the toxicity of waste asphaltene <1 mg soot/Nm³ in raw syngas. It also helps enhance thermal efficiency through the syngas cooling process. Coal Gasification Projects Shell (SCGP) The Process once-through, dry-feed, oxygen-blown, entrained flow slagging process that converts coal into clean, medium-calorific-value syngas Since 1956
40 syngas projects
100 Shell gasifiers
27 licences (China, India, Vietnam, UK, Australia, the Netherlands…) Energy Efficiency Dry Feed vs. Slurry Feed The Shell Gasifier Refractory-lined reactor vessel, equipped with an inner membrane wall consisting of circulating water/steam-filled tubes.
During operation, ash is converted into molten slag. The molten slag, cooled by the membrane wall, vitrifies to form a protective layer against slag erosion of the refractory.
Inner reactor wall temperature is controlled by circulating water through the membrane wall, producing steam. Produced slag flows down the reactor into a water bath, where it solidifies and is removed through a lock hopper as slurry.
Shell Coal Gasificatioon Process Manufacturing the membrane wall SCGP–-IGCC Gasification process:
burn syngas in a turbine to produce electricity. Excess heat is captured and used to power a second turbine to produce more electricity.
Benefits of the SCGP-–IGCC process
High net energy efficiency
Low oxygen-to-coal consumption ratio
Lower carbon dioxide emissions than traditional coal plants
CO2 captured ready for use
At its giant synfuels complex at Secunda in South Africa, Sasol converts more than 40-million metric tons of coal a year into liquid fuels, industrial pipeline gas and a range of chemical feedstock, including the building blocks for industrial solvents and polymers. The Secunda site comprises two giant factories with a combined capacity equivalent to about 150 000 barrels a day. The leader in UCG technology across the world
A publicly listed company in Australia
Committed to UCG for cleaner power and fuels
Underground Coal Gasification gasify coal where it lies under the ground
eliminate mining and surface gasification facilities
25% less CO2 emissions
Injection Gasification Transportation
The coal seam is ignited and air or oxygen is pumped into a well to drive coal combustion and gasification.
Through partial combustion and a series of subsequent reactions controlled by heat, pressure and water influx, the coal is converted to syngas.
Syngas flows from the gasification chamber through the horizontal connection in the coal seam and flows to the surface through another well.
Vertical wells are drilled into the coal seam. These are linked together horizontally by drilling or combustion links. Yerostigaz (located in Uzbekistan)
Started in 1961
the only commercial UCG operation in the world
In 2007, Linc Energy took control
now it produces 1,000,000 m3/day of syngas, piped to the nearby Angren Power Station
UCG For Future Energy key competitive advantage:
avoids capital and operating costs of mining
avoids most aboveground gasification costs
CO2 capture ready
no surface disturbance
create a new energy class
What is Gasification? Conversion of any carbonaceous fuel to a gaseous product with a useable heating value by reacting the raw material at high temperatures with a controlled amount of oxygen.
It requires a feedstock Coal, petroleum, biofuel, biomass or wastes.
Product Synthesis gas (a mixture of H2, CO, CO2 and H20). The Process Chemistry of Gasification Moving Bed Gasifiers Feedstock and fluxes are loaded from the top into the refractory lined vessel and are allowed to move down as they are heated in contact with a high oxygen content gas flowing in the gasifier.
Moving-bed gasifiers offer simplicity, feedstock flexibility, low gas exit temperatures, and high equipment efficiency.
The disadvantages include dangerous explosive situations if not carefully monitored and the effort to clean the produced gas if it is used for applications other than direct heating.
Fluid Bed Gasifiers
Fluidized-bed gasifiers suspend feedstock particles in an oxygen rich gas so the resulting bed within the gasifier acts as a fluid.
Fluidized bed gasifiers offer load flexibility and high heat transfer rates, however, lower temperature operation limits feedstock to reactive and low rank coals.
Entrained Flow Gasifiers Feedstock and steam, oxygen or air are introduced in the top of the gasifier. Within the gasifier, high temperature and pressure—and extremely turbulent flow—causes the conversion to gas to occur very rapidly, achieving a high throughput.
The high temperatures involved in this type of gasification shorten the life of system components.
Also, it may be necessary to add fluxes or blend feedstock parameters to achieve good slagging characteristics.
Applications The Economics The Feedstock Just about anything Flexibilty Gasification processes, final products, ancillary systems are also adjustable to market price swings Regulations CO2 emissions regulations The near-zero CO2 emission of gasification makes it a lucrative investment The Product Syngas is a cheap alternative feedstock for industries The future trend Environmental Issues CO2 Capture Techniques for CO2 capture and storage Very low emission of sulfur and nitrous oxides Water Consumption Reduced reliance on steam Not the primary means of transferring the energy from the coal to rotational energy only used to recover the heat from the gas turbine exhaust Low Emissions Used for geological storage
OR Sale as by-product The Advantages Use of materials that aren't typically used as fuel Any organics EVEN plastic can be feedstock High-temperature combustion refines out corrosive ash elements such as chloride and potassium Clean gas production from otherwise problematic fuels Neither emits nor traps CO2 The End products are also felxible Near Zero emissions Energy Security Syngas is potentially more efficient than direct combustion of the original fuel The Disadvantages The Future Power Consumption Higher initial costs R&D and engineering costs are high Initial setup costs are high Practice is not Widely available A concern for investors No Industry track-record Solution Integration with current plants can reduce costs Economies of Scale Each plant built benefits from the knowledge of previous plants Poor Public Perception Using coal for energy is not favorable Awareness?? Syngas must be cleaned and purified A complex multistage process Oil Prices are increasing Gasification could be an alternative?? The 1990s Saw the first commercial application of Gasification (IGCC) A little History The Polk Power Station near Mulberry, Florida, in the early 1990s 2008 144 IGCC plants Worldwide 21st Century Motorworks developed gasification technology in a prototype pickup truck that could use any biomass materials for fuel. Power used in gasification and syngas conversion is significant The vehicle was displayed at the 2009 Boston Greenfest Use in other industries Conclusion Strong dependance on fossil fuels Future alternative?! Environmentally-friendly Thank You :) Presented by: Sebastian Saavedra
Mohammad Mahfooz Refrences Shell Global Solutions,2006
C.Higman, M. Burgt, 2007
Shell Coal Gasification Technology, I. Graaf, 2008
Sasol Synfuels International，2005
Cost and Performance Baseline for Fossil Energy Plants, Vol. 1, DOE/NETL-2007/1281, May 2007.B_IG_GEE_012908
Justyn Peters, 2011
Highman, Christopher, van der Burght, Maarten. Gasification. Elsevier: 2008. (pp 10-20, 101-110).
The Energy Lab. Type of gasifiers. http://www.netl.doe.gov/technologies/coalpower/gasification/gasifipedia/4-gasifiers/4-1_types.html. 2011
Texaco. Gasification Process. http://www.gasification.org/Docs/Workshops/2001/Speakers/Texaco.pdf. 2011.