JEA Northside Generating Station
Encyclopedia
JEA Northside Generating Station in Jacksonville, Florida
is a major power plant
, one of the three power plants owned and operated by JEA
, Jacksonville's municipal utilities service. It produces electricity by burning coal
and petroleum coke
at Units 1 and 2, the largest circulating fluidized-bed
combustors, (CFBs), in the world. These combustors, completed in 2002 and rated at 297.5 megawatts each, produce enough electricity to light more than 250,000 households. In addition, Unit ST3 produces 505 megawatts of electricity by burning residual fuel oil and/or natural gas
.
coastline, on the north bank of a back channel of the St. Johns River
, which is being used as a waterway
for fuel delivery as well as a source of cooling water.
The Northside Generating Station also borders Timucuan Ecological and Historic Preserve
that consists of North Florida wetland
s and contains historic sites of Timucua
peoples.
. This most recent upgrade was funded by JEA (234 million USD) and the U.S. Department of Energy (75 million USD).
Initial synchronization was achieved for Unit 2 on February 19, 2002, and for Unit 1 on May 29, 2002. As a result, the facility generates significantly more power now.
, high-ash coal
and petroleum coke
.
In a CFB combustor, coal or other fuels, air, and crushed limestone
or other sorbent
s are injected into the lower portion of the combustor for initial burning of the fuel. The combustion
actually occurs in a bed of fuel, sorbent, and ash particles that are fluidized by air nozzle
s in the bottom of the combustor. The air expands the bed, creates turbulence for enhanced mixing, and provides most of the oxygen
necessary for combustion of the fuel. As the fuel particles decrease in size through combustion and breakage, they are transported higher in the combustor where additional air is injected. As the particles continue to decrease in size, unreacted fuel, ash, and fine limestone particles are swept out of the combustor, collected in a particle separator (also called a cyclone), and recycled to the lower portion of the combustor. This is the "circulating" nature of the combustor. Drains in the bottom of the combustor remove a fraction of the bed composed primarily of ash while new fuel and sorbent are added. The combustion ash is suitable for beneficial uses such as road construction material, agricultural fertilizer
, and reclaiming surface mining
areas.
The limestone captures up to 98% of the sulfur impurities released from the fuel. When heated in the CFB combustor, the limestone, consisting primarily of calcium carbonate
(CaCO3), converts to calcium oxide
(CaO) and CO2 . The CaO reacts with the SO2 from the burning fuel to form calcium sulfate
(CaSO4), an inert material that is removed with the combustion ash. The combustion efficiency of the CFB combustor allows the fuel to be burned at a relatively low temperature of about 1650 °F (898.9 °C), thus reducing NOx formation by approximately 60% compared with conventional coal-fired technologies. Greater than 99% of particulate emissions in the flue gas
are removed downstream of the combustor by either an electrostatic precipitator or a fabric filter (baghouse).
The heated combustor converts water in tubes lining the combustor's walls to high pressure steam. The steam is then superheated in tube bundles placed in the solids circulating stream and the flue gas
stream. The superheated steam drives a steam turbine-generator to produce electricity in a conventional steam cycle.
from the back channel of the St. Johns River
to cool the station's condensers, after which the water is returned to the back channel. This cooling water does not mix with other liquid process streams while in contact with the condensers. Because Unit 2 has been out of service since 1983, the actual demand for cooling water by Northside Generating Station at full load since that time has been approximately 620 million U.S. gallons per day (Mgd), or 430700 gallons (1,630.4 m³) per minute
, to operate Units 1 and 3. Operation of the entire 3-unit plant occurred only from about 1978 until 1980. During that time, the demand for cooling water was approximately 827 Mgd (574000 gallons (2,172.8 m³) per minute): 24.5% for Unit 1, 24.5% for Unit 2, and 51% for Unit 3. This amount of surface water supplied to the station was approximately 10% of the average flow passing through the back channel of the St. Johns River.
Before passing through the condensers, noncontact cooling water at Northside Generating Station is treated intermittently with a biocide
to prevent biological growth on the heat exchanger tubes. Sodium hypochlorite (NaOCl) and occasionally sodium bromide
(NaBr) are used. Treatment occurs no more than 2 hours per day per operating unit. The St. Johns River
Power Park taps into the discharge side of the Northside Generating Station condensers to obtain cooling tower
makeup. The average surface water flow supplied to the Power Park heat rejection system is 50 Mgd (34400 gallons (130.2 m³) per minute). Approximately 25% of this surface water evaporates into the atmosphere
from the cooling towers. Cooling tower blowdown is routed back into Northside Generating Station's discharge collector basin. The daily average temperature of the cooling tower blowdown is limited to 96 °F (35.6 °C).
results from both units met all emission requirements for particulate, SO2, acid gases and heavy metals.
Florida
Florida is a state in the southeastern United States, located on the nation's Atlantic and Gulf coasts. It is bordered to the west by the Gulf of Mexico, to the north by Alabama and Georgia and to the east by the Atlantic Ocean. With a population of 18,801,310 as measured by the 2010 census, it...
is a major power plant
Power station
A power station is an industrial facility for the generation of electric energy....
, one of the three power plants owned and operated by JEA
JEA
JEA , located in Jacksonville, Florida, is the eighth largest community-owned electric utility company in the United States and largest in Florida. As of 2009, JEA serves more than 417,000 electric customers, 305,000 water customers and 230,000 sewer customers. Besides Jacksonville , JEA also has...
, Jacksonville's municipal utilities service. It produces electricity by burning coal
Coal
Coal is a combustible black or brownish-black sedimentary rock usually occurring in rock strata in layers or veins called coal beds or coal seams. The harder forms, such as anthracite coal, can be regarded as metamorphic rock because of later exposure to elevated temperature and pressure...
and petroleum coke
Petroleum coke
Petroleum coke is a carbonaceous solid derived from oil refinery coker units or other cracking processes. Other coke has traditionally been derived from coal....
at Units 1 and 2, the largest circulating fluidized-bed
Fluidized bed
A fluidized bed is formed when a quantity of a solid particulate substance is placed under appropriate conditions to cause the solid/fluid mixture to behave as a fluid. This is usually achieved by the introduction of pressurized fluid through the particulate medium...
combustors, (CFBs), in the world. These combustors, completed in 2002 and rated at 297.5 megawatts each, produce enough electricity to light more than 250,000 households. In addition, Unit ST3 produces 505 megawatts of electricity by burning residual fuel oil and/or natural gas
Natural gas
Natural gas is a naturally occurring gas mixture consisting primarily of methane, typically with 0–20% higher hydrocarbons . It is found associated with other hydrocarbon fuel, in coal beds, as methane clathrates, and is an important fuel source and a major feedstock for fertilizers.Most natural...
.
Location
The Northside Generating Station is located north-east of the intersection of Routes 9A and 105 in the city of Jacksonville, Florida. It is 8.5 miles (13.7 km) from the Atlantic OceanAtlantic Ocean
The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...
coastline, on the north bank of a back channel of the St. Johns River
St. Johns River
The St. Johns River is the longest river in the U.S. state of Florida and its most significant for commercial and recreational use. At long, it winds through or borders twelve counties, three of which are the state's largest. The drop in elevation from the headwaters to the mouth is less than ;...
, which is being used as a waterway
Waterway
A waterway is any navigable body of water. Waterways can include rivers, lakes, seas, oceans, and canals. In order for a waterway to be navigable, it must meet several criteria:...
for fuel delivery as well as a source of cooling water.
The Northside Generating Station also borders Timucuan Ecological and Historic Preserve
Timucuan Ecological and Historic Preserve
The Timucuan Ecological and Historic Preserve is located in the city of Jacksonville, Florida, in the United States. The park was established in 1988, and covers 46,000 acres...
that consists of North Florida wetland
Wetland
A wetland is an area of land whose soil is saturated with water either permanently or seasonally. Wetlands are categorised by their characteristic vegetation, which is adapted to these unique soil conditions....
s and contains historic sites of Timucua
Timucua
The Timucua were a Native American people who lived in Northeast and North Central Florida and southeast Georgia. They were the largest indigenous group in that area and consisted of about 35 chiefdoms, many leading thousands of people. The various groups of Timucua spoke several dialects of the...
peoples.
History
The Northside Generating Station began producing electricity for Jacksonville in March, 1966 with oil as its only fuel, when former Unit 1, rated at 275 megawatts, was installed. In June, 1972 a similar Unit 2 was launched, but had to be shut down in 1983 due to major boiler problems. A plant expansion in 1977 added a 564-megawatt Unit ST3, which is still in operation today. This expansion enabled the use of oil and natural gas fuels. In 1996, JEA committed to reduce certain pollutants from the Northside Station by at least 10% when it upgraded Unit 2 (non-functional at the time) and Unit 1 by introducing the new clean coal technologyClean coal technology
Clean coal technology is a collection of technologies being developed to reduce the environmental impact of coal energy generation. When coal is used as a fuel source, the gaseous emmissions generated by the thermal decomposition of the coal, include sulphur dioxide, nitrogen dioxide, carbon...
. This most recent upgrade was funded by JEA (234 million USD) and the U.S. Department of Energy (75 million USD).
Initial synchronization was achieved for Unit 2 on February 19, 2002, and for Unit 1 on May 29, 2002. As a result, the facility generates significantly more power now.
CFB Technology
CFB technology is an advanced method for burning coal and other fuels efficiently while removing air emissions inside the sophisticated combustor system. CFB technology provides flexibility in utility operations because a wide variety of solid fuels can be used, including high-sulfurSulfur
Sulfur or sulphur is the chemical element with atomic number 16. In the periodic table it is represented by the symbol S. It is an abundant, multivalent non-metal. Under normal conditions, sulfur atoms form cyclic octatomic molecules with chemical formula S8. Elemental sulfur is a bright yellow...
, high-ash coal
Coal
Coal is a combustible black or brownish-black sedimentary rock usually occurring in rock strata in layers or veins called coal beds or coal seams. The harder forms, such as anthracite coal, can be regarded as metamorphic rock because of later exposure to elevated temperature and pressure...
and petroleum coke
Petroleum coke
Petroleum coke is a carbonaceous solid derived from oil refinery coker units or other cracking processes. Other coke has traditionally been derived from coal....
.
In a CFB combustor, coal or other fuels, air, and crushed limestone
Limestone
Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera....
or other sorbent
Sorbent
A sorbent is a material used to absorb liquids or gases. Examples include:*A material similar to molecular sieve material. It has a large internal surface area and good thermal conductivity. It is typically supplied in pellets of 1 mm to 2 mm diameter and roughly 5 mm length or as...
s are injected into the lower portion of the combustor for initial burning of the fuel. The combustion
Combustion
Combustion or burning is the sequence of exothermic chemical reactions between a fuel and an oxidant accompanied by the production of heat and conversion of chemical species. The release of heat can result in the production of light in the form of either glowing or a flame...
actually occurs in a bed of fuel, sorbent, and ash particles that are fluidized by air nozzle
Nozzle
A nozzle is a device designed to control the direction or characteristics of a fluid flow as it exits an enclosed chamber or pipe via an orifice....
s in the bottom of the combustor. The air expands the bed, creates turbulence for enhanced mixing, and provides most of the oxygen
Oxygen
Oxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...
necessary for combustion of the fuel. As the fuel particles decrease in size through combustion and breakage, they are transported higher in the combustor where additional air is injected. As the particles continue to decrease in size, unreacted fuel, ash, and fine limestone particles are swept out of the combustor, collected in a particle separator (also called a cyclone), and recycled to the lower portion of the combustor. This is the "circulating" nature of the combustor. Drains in the bottom of the combustor remove a fraction of the bed composed primarily of ash while new fuel and sorbent are added. The combustion ash is suitable for beneficial uses such as road construction material, agricultural fertilizer
Fertilizer
Fertilizer is any organic or inorganic material of natural or synthetic origin that is added to a soil to supply one or more plant nutrients essential to the growth of plants. A recent assessment found that about 40 to 60% of crop yields are attributable to commercial fertilizer use...
, and reclaiming surface mining
Surface mining
Surface mining , is a type of mining in which soil and rock overlying the mineral deposit are removed...
areas.
The limestone captures up to 98% of the sulfur impurities released from the fuel. When heated in the CFB combustor, the limestone, consisting primarily of calcium carbonate
Calcium carbonate
Calcium carbonate is a chemical compound with the formula CaCO3. It is a common substance found in rocks in all parts of the world, and is the main component of shells of marine organisms, snails, coal balls, pearls, and eggshells. Calcium carbonate is the active ingredient in agricultural lime,...
(CaCO3), converts to calcium oxide
Calcium oxide
Calcium oxide , commonly known as quicklime or burnt lime, is a widely used chemical compound. It is a white, caustic, alkaline crystalline solid at room temperature....
(CaO) and CO2 . The CaO reacts with the SO2 from the burning fuel to form calcium sulfate
Calcium sulfate
Calcium sulfate is a common laboratory and industrial chemical. In the form of γ-anhydrite , it is used as a desiccant. It is also used as a coagulant in products like tofu. In the natural state, unrefined calcium sulfate is a translucent, crystalline white rock...
(CaSO4), an inert material that is removed with the combustion ash. The combustion efficiency of the CFB combustor allows the fuel to be burned at a relatively low temperature of about 1650 °F (898.9 °C), thus reducing NOx formation by approximately 60% compared with conventional coal-fired technologies. Greater than 99% of particulate emissions in the flue gas
Flue gas
Flue gas is the gas exiting to the atmosphere via a flue, which is a pipe or channel for conveying exhaust gases from a fireplace, oven, furnace, boiler or steam generator. Quite often, the flue gas refers to the combustion exhaust gas produced at power plants...
are removed downstream of the combustor by either an electrostatic precipitator or a fabric filter (baghouse).
The heated combustor converts water in tubes lining the combustor's walls to high pressure steam. The steam is then superheated in tube bundles placed in the solids circulating stream and the flue gas
Flue gas
Flue gas is the gas exiting to the atmosphere via a flue, which is a pipe or channel for conveying exhaust gases from a fireplace, oven, furnace, boiler or steam generator. Quite often, the flue gas refers to the combustion exhaust gas produced at power plants...
stream. The superheated steam drives a steam turbine-generator to produce electricity in a conventional steam cycle.
Fuel supply
The plant uses a continuous ship unloader, the only one of its type in the continental United States. The solid fuel is transferred from barges onto the fuel conveyor system, which in turn transports it to the two largest fuel storage domes in North America. Pet coke and coal travel from the ship to the domes in about twenty minutes, entirely inside a sealed system to prevent dust particles from escaping into the surrounding environment.Water use
Water is delivered by an elevated intake flumeFlume
A flume is an open artificial water channel, in the form of a gravity chute, that leads water from a diversion dam or weir completely aside a natural flow. Often, the flume is an elevated box structure that follows the natural contours of the land. These have been extensively used in hydraulic...
from the back channel of the St. Johns River
St. Johns River
The St. Johns River is the longest river in the U.S. state of Florida and its most significant for commercial and recreational use. At long, it winds through or borders twelve counties, three of which are the state's largest. The drop in elevation from the headwaters to the mouth is less than ;...
to cool the station's condensers, after which the water is returned to the back channel. This cooling water does not mix with other liquid process streams while in contact with the condensers. Because Unit 2 has been out of service since 1983, the actual demand for cooling water by Northside Generating Station at full load since that time has been approximately 620 million U.S. gallons per day (Mgd), or 430700 gallons (1,630.4 m³) per minute
Minute
A minute is a unit of measurement of time or of angle. The minute is a unit of time equal to 1/60th of an hour or 60 seconds. In the UTC time scale, a minute on rare occasions has 59 or 61 seconds; see leap second. The minute is not an SI unit; however, it is accepted for use with SI units...
, to operate Units 1 and 3. Operation of the entire 3-unit plant occurred only from about 1978 until 1980. During that time, the demand for cooling water was approximately 827 Mgd (574000 gallons (2,172.8 m³) per minute): 24.5% for Unit 1, 24.5% for Unit 2, and 51% for Unit 3. This amount of surface water supplied to the station was approximately 10% of the average flow passing through the back channel of the St. Johns River.
Before passing through the condensers, noncontact cooling water at Northside Generating Station is treated intermittently with a biocide
Biocide
A biocide is a chemical substance or microorganism which can deter, render harmless, or exert a controlling effect on any harmful organism by chemical or biological means. Biocides are commonly used in medicine, agriculture, forestry, and industry...
to prevent biological growth on the heat exchanger tubes. Sodium hypochlorite (NaOCl) and occasionally sodium bromide
Sodium bromide
Sodium bromide is an inorganic compound with the formula NaBr. It is a high-melting white, crystalline solid that resembles sodium chloride. It is a widely used source of the bromide ion and has many applications.-Synthesis, structure, reactions:...
(NaBr) are used. Treatment occurs no more than 2 hours per day per operating unit. The St. Johns River
St. Johns River
The St. Johns River is the longest river in the U.S. state of Florida and its most significant for commercial and recreational use. At long, it winds through or borders twelve counties, three of which are the state's largest. The drop in elevation from the headwaters to the mouth is less than ;...
Power Park taps into the discharge side of the Northside Generating Station condensers to obtain cooling tower
Cooling tower
Cooling towers are heat removal devices used to transfer process waste heat to the atmosphere. Cooling towers may either use the evaporation of water to remove process heat and cool the working fluid to near the wet-bulb air temperature or in the case of closed circuit dry cooling towers rely...
makeup. The average surface water flow supplied to the Power Park heat rejection system is 50 Mgd (34400 gallons (130.2 m³) per minute). Approximately 25% of this surface water evaporates into the atmosphere
Atmosphere
An atmosphere is a layer of gases that may surround a material body of sufficient mass, and that is held in place by the gravity of the body. An atmosphere may be retained for a longer duration, if the gravity is high and the atmosphere's temperature is low...
from the cooling towers. Cooling tower blowdown is routed back into Northside Generating Station's discharge collector basin. The daily average temperature of the cooling tower blowdown is limited to 96 °F (35.6 °C).
Emissions
Preliminary Emission Tests were conducted on Units 1 and 2 over the summer of 2002. Testing was conducted on both units burning coal and petroleum coke. Results are summarized in the table below. Emissionsresults from both units met all emission requirements for particulate, SO2, acid gases and heavy metals.
| Pollutant | Units | Emission Standard | Coal Coal Coal is a combustible black or brownish-black sedimentary rock usually occurring in rock strata in layers or veins called coal beds or coal seams. The harder forms, such as anthracite coal, can be regarded as metamorphic rock because of later exposure to elevated temperature and pressure... -fired | Petroleum Coke Petroleum coke Petroleum coke is a carbonaceous solid derived from oil refinery coker units or other cracking processes. Other coke has traditionally been derived from coal.... -fired |
|---|---|---|---|---|
| SO2 | lb/MMBTU | ≤ 0.15 | 0.0−0.04 | 0.03−0.13 |
| NOx | lb/MMBTU | ≤ 0.09 | 0.04−0.06 | 0.02 |
| Solid particulate | lb/MMBTU | ≤ 0.011 | 0.004 | 0.007 |
| PM10 | lb/MMBTU | ≤ 0.011 | 0.006 | 0.004 |
| SO3 | lb/hour Hour The hour is a unit of measurement of time. In modern usage, an hour comprises 60 minutes, or 3,600 seconds... |
≤ 1.1 | 0.43 | 0.0 |
| Fluoride Fluoride Fluoride is the anion F−, the reduced form of fluorine when as an ion and when bonded to another element. Both organofluorine compounds and inorganic fluorine containing compounds are called fluorides. Fluoride, like other halides, is a monovalent ion . Its compounds often have properties that are... |
lb/MMBTU | ≤ 1.57×10−4 | 1.06×10−4 | 0.95×10−4 |
| Lead Lead Lead is a main-group element in the carbon group with the symbol Pb and atomic number 82. Lead is a soft, malleable poor metal. It is also counted as one of the heavy metals. Metallic lead has a bluish-white color after being freshly cut, but it soon tarnishes to a dull grayish color when exposed... |
lb/MMBTU | ≤ 2.6×10−5 | 0.56×10−5 | 0.59×10−5 |
| Mercury Mercury (element) Mercury is a chemical element with the symbol Hg and atomic number 80. It is also known as quicksilver or hydrargyrum... |
lb/MMBTU | ≤ 1.05×10−5 | 0.095×10−5 | 0.028×10−5 |