Lignite coal is a natural resource which is readily available. It is generally dark brown or rarely black coal that formed from peat at shallow depths and temperature lower than 100°C. The calorific value of Lignite coal ranges from 8000 KJ/kg to 15000 KJ/Kg. It also has a high moisture content in the range of 45% to 55%. Due to its High Moisture content and low calorific value, it is mostly used in generating electricity. Lignite-Generated Electricity is generally low in cost and environmentally acceptable.
Uses of Lignite:
79% of the total lignite coal is used to generate electricity.
5% of the coal is used to generate synthetic natural gas.
5% of lignite coal is used to produce various fertilizer products.
Issues related to Environment:
The calorific value of lignite is low due to which, the quantity of coal needed is high.
This has a higher CO2 emission due to high moisture content and lower carbon content as compared to black coals.
Lignite mining involves the removal of a huge portion of water. Depending on the quality of the water, it could create agriculture or an environmental issue.
Lignite storage shed is the best possible solution to these problem related to the environment. Lignite storage sheds are often built over operating stockpiles since construction can proceed without interrupting operations.
Advantages of Lignite Storage Shed:
Protect environmental degradation in nearby areas.
Lesser Operation and Maintenance cost
For achieving adequate prevention and control of potential fugitive emission
Adhere to the current environmental guidelines by CPCB (Central Pollution control board)
About Hindustan Alcox
As a leading Lignite storage shed manufacturer, Hindustan Alcox Limited provides the complete & unique lignite storage shed ensuring best quality at every stage of its construction.
Coal is a fossil fuel just like oil and natural gas. In thermal power plants, coal storageorpetcoke storage (as the most exploited solid fuel) at large scale is preferred for the production of electric energy. A good preparation of coal before its combustion increases the homogeneity and efficiency of the fuel, reduces transportation costs and its displacement inside the plant produces less dust and reduces the emission of sulphur oxides. Besides, Preventive measures should be taken at every stage during the transport and bulk storage, in order to reduce any environmental impact, so that it became easier to maximize plant efficiency without any interference of any outside or environmental effects.
Performance Requirements for Maximum efficiency:
The large investment in a thermal power plant should be protected in best possible way by maintaining the quality of resources (like coal, petcoke, lignite etc) and by uplifting the performance of their handling system. The coal handling system and equipment should perform satisfactorily to meet the guaranteed performance for maximum efficiency as stated here under:
Efficient operation in thermal power plants means the careful use of fuels and other consumables resources including in-house consumption of electricity. High availability requires strong focus on maintenance, which in turns contribute as one of the factors in producing maximum efficiency.
Stacker or reclaimer should be stable under a specified design condition and meet all the specified requirements. During unfavorable environmental conditions, the stacker or reclaimer should reclaim the coal in a way to avoid generation of well compacted, damp and sticky coal.
Sulphur content in fuel always had an adverse effect on overall plant efficiency. ‘Corrosive acids formation’ and ‘heat loss in boiler’ can be evaded by properly supervising and removing the sulphur content in coal.
Condition based maintenance uses intelligent measurements and assessments. These can include oil quality, differential pressure measurements, vibration readings and many more. By such applications, maintenance and renewal of plant components can be done exactly when needed.
Fuel quality of coal, which is generally quoted in terms of its gross calorific value (GCV) along with its moisture and ash content impacts on whole plant operational efficiency. Assessing fuel quality and choosing fuel of maximum gross calorific value and less moisture & ash content improves combustion and power generation as well.
Variation in the ambient temperature tends to affect plant performance and load capability of gas turbines along with the performance of cooling system. Hence, it is better to maintain the ambient temperature near a specific threshold during plant operation for maximum power output.
Using long-time experience of 30 years, It has been challenge for Hindustan Alcox Limited to identify and eliminate unnecessary energy losses from the processes by providing the best choice for covering coal stockpiles under Coal storage shed. Alternatively, Coal Storage and handling can be done under dome structuresheds (like Coal dome,petcoke dome).
Introduction to Coal Gasification / IGCC technology:
IGCC stands for “Integrated Gasification combined cycle”. The preliminary conversion into a gaseous fuel originated is named as SynGas / Synthesis Gas. Synthetic gas is an intermediate source for generation of hydrogen, ammonia, methanol, & other synthetic hydrocarbon fuels. For electricity generation, synthetic gas is not only used as fuel of internal combustion engines due to its combustible nature, but also plays an important role in keeping the plant eco- friendly.
During Coal storage at a large scale, for harnessing coal’s energy more cleanly and efficiently, a number of different ways attempted in order to motivate environmental concerns. Among them, the technology comes out to be most successful is coal gasification, where instead of burning the fossil fuel, it is chemically transformed into synthetic natural gas or syngas.
What is the Need:
Till now, the main objective of Conventional Thermal Power Plant was to increase the efficiency by means of increased temperature and pressure in the steam, which in turn generate an efficient power outcome. But today the need is to get more efficient power production along with keeping the outside eco friendly. With the technical advancement in working methodology, the upgraded thermal power plants are now capable to generate power using Coal Gasifiers in purpose to increase efficiency of the plant.
Coal Storage
Advantages of using the Coal Gasifiers:
Clean Energy Conversion: From an economic and energy security perspective, coal gasification is proved the most successful process to dealt with clean energy conversion, since instead of opening the intermediate poisonous gases up to exploitation, coal gasification helps to access these resources cleanly.
Environment Friendly: Addressing the atmospheric problems resulting from burning coal and getting least affected by these poisonous gases is one of the top priority objectives of coal gasification. This Environment friendly feature of coal gasification is also the key to achieve near-zero emissions from gasification-based power generation.
Enhanced Power Generation & Reduced Resource Consumption:In coal based thermal power plants, synthetic gas collected during the coal gasification is used as fuel of internal combustion engines due to its combustible nature, which in turn not only participate in enhancing power generation but also reduces the resource consumption.
Easy Installation and Maintenance: Coal Gasifiers, which are the main source to carry out coal gasification are installed in conjunction with coal bunkers. As far as their fixing and maintenance is concerned, these coal gasifiers are very simple to install and to maintain for the long term.
Coal Storage Shed
To supplement the eco friendly nature of the energy, Hindustan Alcox Limited provides world-class structures to cover spans up to 150m and any length. These sheds provide economical solution for such storage needs.
Nowadays, Intermediate coal storage or lignite storage is common practice with indirect coal preparation systems. A constant feed from coal mines either to the coal mill or to the burners of a kiln system is a prerequisite for safer coal operations. The captive thermal power plants where coal is kept before burning also emit large quantities of carbon dioxide (CO2 ), the “greenhouse gas” which are largely responsible for climate change. Depending on different factors like geology, demographics & climate, the public health and environmental effects caused by power plant may also vary from place to place. Followings are the major impacts on public & environment by coal storage & handling:
Respiratory Effects: Inhalation effect from coal storage & handling is the biggest concern, which causes breathing problems not only to the people at the site but also to people living nearby the coal-based power plants.
Impact on water bodies: At the coal-based thermal power plant, screening of coal is done to remove the impurities from the coal and the waste is placed in waste piles. If rain comes, rain percolates through these waste piles containing harmful soluble components and elevates Total Dissolved Solids (TDS) in local water bodies. This runoff is also acidic and contains heavy metals. In this way, Coal storage harms land, surface waters, groundwater and even air.
Impact to the land: Affect to the land from coal storage and handling cause drastic changes in the local area nearby by deteriorating land fertility and inculcating harmful chemicals. Damage to plants, animals and humans occurs from the destruction and removal of habitat & environmental contamination.
Using coal storage sheds over open stockpiles will be very much beneficial in reducing the above mentioned impacts on public & environment by coal storage & handling. We at Hindustan Alcox Limited specializes in manufacturing coal storage sheds with long span steel structure having span of up to 150 m & height of up to 40 m. Along with these longitudinal sheds, we also built dome type structural storage sheds. These coal dome and lignite dome, engineered by Hindustan Alcox Limited is one of the best choices to cover stockpile for the purpose to benefit the environment.
Dome structure is a hemi-spherical hollow structure, used as roofing/ ceiling. Earlier Domes were only used in constructing Architectural buildings, but with the passage of time their importance to endure under adverse climatic conditions is understood and now domes can be seen in almost every sphere of construction industry. In other words, a semi-spherical structure with the curvature on top, when usually created to cover a sufficient room for bulk storage like cement, limestone, coal, lignite, gypsum, additives and many more. Depending upon the material used for storage, followings are the storage domes with their usage in industry:
a) Slag Dome:
Slag is metal-separated stony waste material in form of their metal oxides mixed with silicon di-oxides. Industrially, its storage in Slag dome is generally carried for Metal ore smelting process to serve some useful purpose like ‘temperature control in Smelting’, ‘preventing re-oxidation of molten metal’, ‘removing waste from smelting process’.
Usages:
Slag dome is useful in sustenance of its compaction characteristics of slag.
Slag dome is also useful in keeping low risk of breakability and maintenance of maximum strength.
b) Additive Dome:
Additives are organic material added to subject material in purpose to improve its inherit properties, performance, efficiency and reduce cost. Industrially, Additive storage covers a wide range of additives like antifoams, organic additives and other performance enhancement additives. Some well-known examples of additives are ‘fly ash’, ‘GGBFS’, and ‘silica fume’.
Usages:
Additive dome covers large span to facilitate the storage of various additives under same shed.
Storing Additives under domes facilitates maximum utilization of space in plant which may be used for other industrial purpose too.
Ventilation facility and prevention from adverse conditions of environment under additive dome will eliminate the problem of oxidation, which causes clinical effects in labor.
c) Gypsum Dome:
Gypsum storage
Gypsum is fine-grained calcium sulphate (CuSo4) material industrially used as fertilizer/enhancer in subject material to improve its inherit qualities, performance, efficiency and reduce cost.
Usages:
Gypsum storage is very useful in controlling fugitive emission of gypsum.
Storing Gypsum under domes facilitates maximum utilization of space in plant.
Gypsum dome also helpful in prevention from vulnerability caused by adverse environmental conditions and rainfall.
d) Clinker Dome:
At sintering stage in cement manufacturing process, a nodular material is formed known as Clinker. In the Cement plant, Clinker is prepared by fusing various clays and limestone with additives by melting them below to the point of liquidation. ‘Silica fume cement clinker’, ’pozzolana cement clinker’, ‘ground granulated blast furnace slag cement clinker’ are most commonly formed Clinkers.
Usages:
Clinker dome has a benefit of facilitating no spillage and zero dust pollution. This will not only prevent wastage of resources but also create health friendly environment for labor.
Clinker storage under dome also help in prevention from heat which further facilitates setting up hot clinker to its favorable temperature before being converted into its grinded form, known as cement.
Clinker storage protects clinker from being affected by Rainfall or heavy thunderstorms, which can harm the quality of clinker.
e) Cement Dome:
Bulk Storage Dome
The grinded form of clinker is cement. Cement is used as binding material that combines with water and other additives and sets to bind two other materials together. That is why it also called as Hydraulic binder. White cement, pozzolana cement, acid resistant cement, blast furnace cement, sulphate resistant cement, rapid hardening cement, quick-setting cement, high alumina cement, colored cement are some common types of cements in construction industry.
Usages:
Cement dome are highly non-vulnerable to maintain moisture and water resistance in heavy rainfall areas.
Maintenance of temperature and adequate ventilation system is recommended for large scale storage, which can be fulfilled under cement dome.
Cement storageare useful in providing maximum utilization of space in plant, which fulfills need of efficient loading and unloading of cement in order to feed power stations continuously.
f) Limestone dome:
Limestone is composition of calcium carbonate, CaCo3 with other minerals, generally found in organic sedimentary rocks formed from accumulation of shell, forms, coral etc. In clinker/cement formation, limestone is used as one of the major component. Moreover, In precious Architectural works, limestone is also used neutralize the effect of acidity caused by acid rain.
Usages:
Limestone storage costs less as compared to reinforced concrete silo for storage. Therefore limestone dome gives you economical storage solution.
Limestone dome provide best protection against moisture and rainy weather, as limestone is highly susceptible to moisture.
f) Coal/Lignite dome:
Extracted from the ground by coal mining, coal is the biggest source of energy for the worldwide electricity generation. In simple terms, there exist four types of coal – peat, lignite (brown coal), bituminous, and anthracite(highest quality coal). Coal/Lignite storage is done in large quantities and requires stacking in open areas. ‘Production in mild climatic condition and market it in winter season’, ‘Feed the thermal power stations continuously’ are some of the key reasons for coal storage, which we understand the most.
Usages:
Coal/lignite dome are made in such way to prevail cross ventilation at very corner inside it which can be done to prevent heat accumulation.
Coal domeprovide best protection against moisture and rainy weather since coal is vulnerable to moisture.
Now-a-days, Being the biggest source of energy the share of coal for electricity generation is raised. Coal storage plays crucial role in producing global energy, especially for power generation, but there is need to use it efficiently. An efficient thermal power plant consumes less coal and discharges less poisonous gases like Carbon-di-oxide, Carbon monoxide etc.
The following points will ensure how quality coal storage responsible for potential power generation:
Coal Storage Shed
Coal storage and handling should be managed in such way to prevail cross ventilation at very corner inside it to prevent heat accumulation as well as reduce the chances of spontaneous combustion of coal. This enhances potential power generation and reduces the coal consumption.
Since coal is highly susceptible to moisture, coal storage inside Coal dome provide best protection against moisture and rainy weather. This maintains the efficiency of coal to produce power.
By proper rotation of coal under storage shed, we can keep coal effective to feed to boiler and in turn maximize power generation. In an ability to cater maximum Space for storing coal, our team also has expertise in making hemi-spherical hollow structure, used as roofing, known as Dome structure.
Use of automatic fire extinguishers systems and dust proof electrical wiring systems will add additional security to the power plant, if there occur any chance of coal combustion.
In a coal based captive thermal power plant, coal is received from coal blocks/Mines by means of railcars or barges. Then the Coal is dropped in a coal yard and usually stored in stockpiles. Reclaiming of coal from stockpile is done using an automatic reclaimer/stacker consisting of reclaim tunnel hoppers and feeders. After that Coal is conveyed to the crusher house for coal crushing and transferred to belt feeders from where it is fed to the boiler.
Although many handling issues encountered in bulk storage but in case of coal storageorlignite storage, followings are the major handling issues to be faced while operating the boiler:
Bulk Storage Dome
The most common problem in operating coal undercoal storage sheds is flow blockage. It largely depends upon bulk density, particle size and moisture content in the coal.
Sometimes while handling, coal remains stagnant outside the feeding channel which has the tendency to combust spontaneously. Such Stagnant material may pose threat to fire.
When material discharge from conveyor belt to the chutes for a long time, the friction of material with chute surface increases and thereby reduces the velocity of steam coming from the boiler.
Boiler efficiency is mainly depended on presence of fuel properties in coal like hydrogen, moisture, and various other fire supporting elements in coal. To sustain excellent boiler efficiency, we have to keep losses (due to absence of such fuel properties in coal) to their minimum extent.
Few other factors responsible for sustaining maximum boiler efficiency are ‘keeping optimal air level’, ‘keeping the fineness of coal to required level’, ‘proper rotation of coal in power plant to avoid combustion’ and more.
Coal storage is done in large quantities and requires stacking in open areas. ‘Production in mild climatic condition and market it in winter season’, ‘Feed the thermal power stations continuously’ are some of the key reasons for coal storage, which we understand the most. Although many issues encountered in bulk storage but in case of storing coal, combustibility comes as a special case and need cautious treatment.
The Spontaneous Combustion of coal in the coal storage is serious issue now a days due to global warming and other exothermic processes such as microbial metabolism, oxidation at low temperature, absorption & desorption of water by virtue of differences between real and equilibrium moisture content in coal and air. These above processes largely contribute to spontaneous combustion of coal.
How coal storage sheds helpful in solving the problem of Spontaneous Combustion?
The Following points will clarify the importance of our sheds in solving the above-discussed issue:
Our Coal storagesheds are made in such way to prevail cross ventilation at very corner inside it. Good cross ventilation of air across the storage sheds helps in the prevention of heat accumulation and thereby helpful in keeping self-heating of coal away from the plant.
The covering keeps the environment of the Captive thermal power plantinside shed cool not only to avoid spontaneous combustion of coal but also create suitable temperature for efficient working of staff.
Coal combustion can also be avoided by proper rotation of coal in power plant which needs maximum storage space. In an ability to cater maximum Space for storing coal, our team also has expertise in making hemi-spherical hollow structure, used as roofing, known as Dome structuresince dome shape provides us more space than any other structural shape per unit area by 30%.
Moreover, use of automatic fire extinguishers systems and dust proof electrical wiring systems will add additional security to the power plant, if there occur any chance of coal combustion.
We at Hindustan Alcox Limited pay special attention towards adhering to the highest standards of quality. We offer complete solutions right from the design to the erection phase to ensure creation of coal storage sheds that are not only compatible with client needs but also offer the assurance of long life and great functionality.
Coal, a non-renewable combustible black sedimentary rock composed of carbon and hydrocarbons, whose combustible quality can be used for electricity generation. Peat, Lignite, black coal and anthracite are four most common forms of coal. Coal based captive thermal power plants are plants, which makes the use of coal for combustion and generate electricity by virtue of heat generated in combustion of coal. Coal Handling in Coal handling Plants/Unittakes place in following three steps:
Bunkering of coal
Unloading of coal
Stacking of coal
Bunkering and Unloading of coal is done whenever coal mines are far away from power plant. The Transportation mode for coal will be purely dependent on the power plant location, location of coal mines and available methods of transportation. Coal handling including bunkering and unloading, now called as ‘Out-plant Coal Handling’ and handling excluding bunkering and unloading known as ‘In-plant Coal Handling’. During out-plant coal handling, coal quality may get affected as it tends to absorb moisture and oxygen of air. This problem losing coal quality can be eliminated by coal storage.
Stacker/Reclaimer under storage Sheds
A large machine known as Stacker or Reclaimer mainly used for bulk storageand insidebulk storage shedfacility. As the name suggests, the two main functions of stacker are:
Stacking
Reclaiming
In Stacking Process, coal stock travel on conveyor rail in horizontal as well as in vertical direction. Stackers may be used to form two different patterns- ‘cone’ , ‘chevron’ either on one or both sides of stacker. Main motive of coal stacking is to produce efficient industrial outcome from coal by avoiding problems faced in coal stacking like oxidation of coal, spontaneous combustion, self-heating of coal, increase in moisture and many more.
In Reclaiming process, the two modes of operations are performed by stacker.
On/Off mode: In this mode of operation, Material to be reclaimed are not only easy to handle but also it maintains reclaimer efficiency. The material is carried on the belt driven by the constant speed and then discharged to the discharged/feed bin.
Direct mode: In direct mode of operation, it is difficult to handle the material to be reclaimed but this mode gives benefit to eliminate the need of intermediate bins.
Earlier, Stacker/Reclaimer run manually by operators but now due to advancement in technology, their operations are made to run on PLC-based automation, which not only make the operations cost effective but also saves the time to complete operations. This Coal Storage and handling can be done under bulk storage dome (like Coal dome, lignite dome) and horizontal semi circular storage sheds We, at Hindustan Alcox Limited, satisfy our clients the best available solution in storage and handling of any type of bulk storage.
– Coal storage shed Manufacturer in India (Hindustan Alcox Limited)
Coal Storage, Handling & Transport (Today’s Need )
Coal is used as one of the fossil fuel which is combustible black/ brown hard rock usually found in coal beds. Coal is composed of 65-95% carbon, with quantities of other elements such as hydrogen, nitrogen, sulphur and oxygen. Extracted from the ground by coal mining, coal is the biggest source of energy for the worldwide electricity generation. In simple terms, there exist four types of coal – peat, lignite (brown coal), bituminous, and anthracite (highest quality coal). Coke is one of the important and useful type of coal carrying less impurities and high carbon content. Coke (also called petroleum coke) is naturally occurred as well as man-made.
Coal Storage Shed
Few Facts about coal storage
Near about 70% of world steel production done through coal burning.
Coal-fired power stations produce environment-friendly electricity.
About 94% of the fossil fuel energy reserve in United States employ coal.
Need of Coal storage sheds
Industrially coal is stored in large quantities and needs stacking in open areas. ‘Meeting the customer demands’, ‘Production in mild climatic condition and market it in winter season’, ‘Feed the thermal power stations continuously’ are some of the key reasons for coal storage.
Main motive of coal storage sheds is to produce efficient industrial outcome from coal by avoiding problems faced in coal stacking like oxidation of coal, spontaneous combustion, self-heating of coal, increase in moisture and many more. These storage sheds are also used for Limestone storage, Additive storage, Clinker storage, Gypsum storage, lignite storage or any other Bulk Storage
Keeping various factors into account such as storage area design, dimensions, climate conditions and required machinery for procurement, some stacking techniques are employed which are helpful in discharging operations economically and potentially.
–Coal storage shed Manufacturer in India (Hindustan Alcox Limited)
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