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Coal Gasification- A Sustainable & Innovative Heating Solution

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A Sustainable & Innovative Heating Solution

Coal gasification is a process captures thermal & chemical energy of coal into gaseous components methane (CH4), Hydrogen (H2) and Carbon monoxide (CO) which can be used for Industrial heating applications. This process offers several advantages over traditional coal combustion which involve handling of solid coal, residual ash and unburnt carbon. The direct exposure to the coal is not possible in many production processes.

The Coal Gas produced from air-fed gasifiers delivers clean gaseous fuel with the ash of coal, tar and unburnt carbon remaining in the gasifier as residue.

The cost of fuel per unit of energy varies from coal being cheapest then moving higher to furnace oil, High speed diesel, Natural Gas, Propane & LPG. In the last 25 years, the average cost of energy from coal has been 50 – 70% lower than these fuels.

Coal Gasification therefore offers Indian Coal as a suitable replacement for all industrial heating applications like steel, ceramics, glass etc. as an alternate technically feasible, proven technology and cheaper solution than traditionally expensive fuels like furnace oil, natural gas and Propane.

In the Steel Industry all heating applications like Reheating furnace, Annealing furnaces, Iron ore dryers and pelletisation require large amount of heat which can be sourced from Coal Gasification at almost half lower cost of fuel for economic and competitive solution of steel making.

Why coal Gasification For Pellet Plants ?

Pelletisation need a large amount of heat energy for drying of the wet Iron ore pellets. Since, in India most of these pellet plants are designed on expensive fuels like furnace oil or natural gas the cost of manufacturing Iron ore pellets becomes very high which makes Indian pellets less competitive in the global market.

Global Pelletization Fuel Usage Treands:

In China, Iron ore palletisation plants are designed with coal gas or mixed gas as fuel which results in their cost of manufacturing being very low. Similarly, Brazil based Iron ore pelletisation plants are designed for natural gas as Brazil has large natural gas reserves making the cost very low. But, in India pellet plants are designed for furnace oil or Pulverised coal injection. Both these fuels are import based and expensive which makes Indian Pellets manufacturing process systematically expensive and less competitive in the global market.

The coal is available in India in abundance and at a cheaper cost the alternative fuels. Therefore, in order to use the domestic coal for efficiently producing Iron ore pellets, Coal gasification is the most suitable method.

From over twenty-three years Dev Energy has worked in arena of Coal Gasification and now there are many pellet plants are operational with Coal Gasification. Some of these are 2 MTPA Pellet Plant near Raipur, 0.4 MTPA pellet plant near Bilaspur, 0.6 MTPA plant in Orrisa, 0.6 MTPA plant near Durgapur and 0.6 MTPA pellet plant near Hospet in Karnataka.

Key Feature Of Dev Energy Solution:

Pelletisation - Successfull Case study:

MTPA STRAIGHT GRATE PELLET

Design Gas output: 17000 Nm³/ hr
System Configuration: 2 x 4.0 DSCG
Furnace oil replaced: 54 KL / day

Dev Energy provided a Turnkey solution to Minera Steel and Power, Bellary where furnace oil was used as a fuel in their pellet plant. Dev Energy took the challenge and replaced 100% of Furnace Oil with Coal Gas. This resulted in the “World’s First Straight Grate Pellet Plant on 100% Coal Gas”.

Technology Advantages:

The technology uses seven stages of cleaning and cooling of gas with three stages of closed cycle indirect cooling including air cooler and indirect water cooler are used to cool the gas. The two stages of electrostatics precipitation are used to clean the gas of tar. Dust is removed by cyclone. The seventh stage of sulphur removal is done using desulphurisation tower.

The need for water scrubbing is eliminated and all cooling is done without direct contact with water. This eliminates generation fresh water in to phenolic water. A specially designed heat exchanger is used to vaporise the condensate moisture and phenols which are injected back to the gasifier. This technology of reusing the phenolic water helps save energy and uses the phenolic water back in to the system.

The tar produced by the process of dry electrostatic precipitation is at low temperature and free of moisture. This tar is a high-quality tar with CV > 8500 Kcal / Kg.

The technology complies with the norms of pollution control board. The process uses indirect cooling and cleaning which results in no fresh phenolic water generation. The condensate phenolic water is reused in the gasification system. The system is designed for 100% water and steam reuse and no water of any type is discharged outside the system limit making it a zero-discharge system. The system is designed to capture the harmful fumes generated during process. 

Process Flow Diagram

The technology has positive impact on health and safety of the operating team because of its non-contact nature making it much safer to operate. It is also very user friendly for and provides consistent performance.

The automation helps to continuously monitor the quality and quantity of gas which feed the Algorithmic based programming to increases the overall efficiency of the system. The clean gas improves the life of the furnaces and the burning systems.

The safety of the system is ensured with a combination of fast cut off valves with high speed vents for gas release and a highly responsive signal interlocking system programmed into the PLC system.

Dev Energy provided a Turnkey solution to Minera Steel and Power, Bellary where furnace oil was used as a fuel in their pellet plant. Dev Energy took the challenge and replaced 100% of Furnace Oil with Coal Gas. This resulted in the “World’s First Straight Grate Pellet Plant on 100% Coal Gas”.

STEEL REHEATING FURNACE, JSPL
Design Gas output: 80000 Nm³/ hr
System Configuration: 10 x 3.6 DSCG
Furnace oil replaced: 250 KL / day

AGI GLASSPAC is a project where innovative solution for regenerative furnaces was implemented. Here the gas is used alternatively in two different chambers and thus in this furnace the gas is required to switch alternatively in the chambers without stopping the flow.  Dev Energy designed a proprietary automatic switch valve to overcome this challange. The valve was integrated with the furnace and gasifier automation system. This system was installed near Hyderabad.

Conclusion

Dev Energy with coal gasification as sustainable solution not only gives efficient and economical heating applications in various stages of steel making but also delivers decarbonisation by replacing the highly polluting GHGs generated from conventional e.g. furnace oil especially reducing carbon di-oxide (CO2).

The system, processes and the equipment are designed and engineered by experienced and professional engineer from India and China. All the manufacturing of equipment is in house in the modern production facilities. This ensures that the demanding quality standards are maintained without any compromise

Dev Energy believes that the success of coal gasification project lies not only in supply of the right technology and equipment, but also in providing right operational training to the team. In order to ensure the system is operated by trained people. Dev Energy provides onsite training to the operational and maintenance teams and if required also take up contracts for operating the system to ensure project’s success. The team of project managers, engineers, trained operators and specialised contractors to provide end to end turnkey solution to the industry.

Present geopolitical environment is pointing in the direction that India needs to use internal resources and reduce dependence on imports. For India, with its huge coal reserves, Coal gasification is a best alternative to reduce country’s dependency on imported fossil fuels.

Today, with many of the India’s and the World’s first innovations in the field of Coal Gasification Dev Energy is in a position to take up any challenge to convert conventional fossil fuels to coal gas for the iron and steel industry.

Circulating Fluidised Bed Coal Gasification Technology for High Ash Indian Coal – Fuel & Dri Syn Gas

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National Coal Gasification Mission

“We have set a target to gasify around 100 million ton of domestic coal by the year 2030. Coal Gas will be used in transport & cooking while urea and steel from gasification will promote manufacturing. Latest technology can be introduced to make gas from coal and environment will be protected with coal gasification” – SHRI NARENDRA MODIHon. Prime Minister of India.

What is Gasification?

Gasification is a robust, proven, and versatile technology that produces syn gas (carbon monoxide (CO) + Hydrogen (H2)) from reaction between carbon, oxygen and steam air at low to high pressure (atmospheric to 30 bar g) and temperature ranging from 1000oC to 1600oC.

Gasification not only captures heat but also Chemical value of feedstock like Coal.

However, Indian coal has challenges of high ash (>35%) thermal non-coking coal and high moisture (48% – 54%) lignite which calls for need most applicable technology.

Ash is removed by gravity from the gasifier and is discharged into a system for depressurization and disposal. The gasifier maintains a low level of carbon in the bottom ash discharge stream and achieves overall carbon conversions that can exceed 99%. Cold gas efficiencies of over 80% and carbon conversion of up to 99% have been repeatedly demonstrated on a commercial scale in CFB operating plants.

CFB is more fuel-flexible, utilizing low-rank and other high-ash coals, and offers higher efficiency than competing gasification technologies, due to the fluidized bed design and resulting long residence times of the reacting particles.

Fines carried over from the fluidized bed are separated from the syngas prior to heat recovery and syngas cleanup. The product syngas is essentially free of tars and oils due to the temperature and residence time of the gases in the fluidized bed, simplifying downstream heat recovery and gas cleaning operations.

CFB gasification adopts three-stage waste heat recovery process, which can recover the heat of high temperature syngas to produce high temperature and high pressure steam along with air/oxygen preheating resulting in overall high thermal efficiency.

Technology Overview

Our Partners

JINAN HUANGTAI GAS FURANCE CO. LTD.

Normal Pressure – Air Fed – Fuel

  • In Operation Since 2009
  • > 22 Operational plants
  • Higher calorific value fuel : 1250 kcal/Nm3
  • Continuous 21 month gasifier campaign

Ease of Operation & Maintenance

Shanghai Zepu Engineering Technology Co. Ltd.

HIGH PRESSURE – OXYGEN FED – DRI SYN GAS

  • Patented and improvised CFB technology
  • High Pressure – 3 bar to 40 bar
  • Proven commercial scale plants from basic engineering, detailed engineering, and EPC solutions for clean syn gas
  • Customised solution for various end-use applications such as clean DRI Syn Gas, Methanol, DME, Ammonia, Urea and SNG
  • Strong R&D in line to handle low-rank coals of high ash and moisture

Technical & Economic Advantages

Government of India Incentives

CFB is the only proven commercial-scale technology for high ash Indian coal gasification projects to benefit from all Government of India incentive schemes:

  • Viability Gap Funding (₹ 8500 cr)
  • Dedicated Coal linkages assurance
  • Notified Coal Pricing (Lower coal price than auction rates)
  • 50% rebate on captive mine dedicated to surface coal gasification
  • Coal Price GST waive off (~ 400 Rs/ton)

National Steel Mission – Guarantee off-take for steel makers

As India’s major contributing GDP National mission to grow to 300 million ton per annum steel production by 2030 from 127 million ton per annum as of 2024 to support strong infrastructure growth, steel producers will also be served by the proven commercial-scale CFB technology clean DRI syn gas from high ash Indian coal gasification projects. These projects will also be 100% Green Hydrogen compatible for coming decades as against Blast Furnace route which depends on high price of coking coal imports.

CFB Coal Gasification – “IN India FOR India”

Technology Selection – Why CFB?

   Commercial scale three technologies which are Fixed Bed, Entrained Flow and Fluidised Bed technologies below pros and cons:

Based on various interactions organised by the Ministry of Coal for the implementation of the National Coal Gasification mission it is evident that all major technology developers such as Thermax, BHEL and CSIR-CIMFR have chosen CFB starting with pilot scale as the most suitable technology for Indian high ash coal.

CFB Technology – How it Works?

Grinding, sorting, shredding, and/or drying may be required to bring the feedstock up to the gasifier feed system’s standards of <10 mm particulate size.

The prepared feedstock is pneumatically supplied to the CFB gasifier vessel, which is a bubbling in circulating fluidized bed reactor. The feedstock combines with air/oxygen and steam as gasification in the fluidized bed, uniform temperature of 1000 oC is maintained to provide high carbon conversion and non-slagging conditions for the feedstock’s ash. The CFB gasification process is carried out as partial oxidations as gasification of feedstock with agglomeration and separation of ash.

Technology Features & Advantages

Adaptability of CFB Syn Gas

The syngas is subsequently processed for use in a variety of applications, including direct reduced iron (DRI) steel production, methanol, fertilizers like ammonia, Urea, further ammonium nitrate, substitute natural gas (SNG) and di-methyl ether. Pre-combustion carbon capture CFB Gasification in syngas cleaning systems downstream of the gasification process makes it useful for CO2 removal as raw material for downstream products and potential to make it carbon neutral technology solution.

Compatibility with downstream DRI Licensors

   CFB technology has full flexibility of H2/CO ratio, CO2 removal adjustment as required by all global DRI technology providers offering wide adaptability for the complete technical and commercial optimisation for steel makers.

Flexibility of CFB offering

CFB gasification adopts oxygen-enriched gasification, and the N2 content in syngas can be effectively controlled below 5% or lower. CFB gasification pressure is high avoiding any downstream compression requirement, and the CH4 content in the syngas can be up to Controlled ideal for DRI steel-making feedstock.

Compatibility with downstream DRI Licensors

CFB technology has fully aligned requirement of H2/CO ratio, and CO2 removal adjustment as required by all global DRI technology providers offering wide adaptability for the complete technical and commercial optimisation for steel makers.

Optimized process configuration

Commercial DRI Plant – Ready for offering

0.5 MTPA DRI – Vertical Shaft Kiln

Clean DRI Syn Gas Process

CFB offers the flexibility of a partial water shift gas process unit for the downstream vertical shaft kiln. Also, this technology is capable for using wide range of O2 purity from Air Separation unit and CO2 removal unit required levels.

Conclusion

    DEV ENERGY with its successful Turnkey project design and implementation proven solution provider has delivered > 23 years and is committed to taking National Gasification mission on a fast implementation model with low capital cost using a Circulating Fluidised Bed Technology with commercial scale projects. We are also well aligned with the “Make in India” model even with China Partners as maximizing local manufacturing and minimum proprietary scope (<5%) with no technology transfer fee requirement due to Dev Energy exclusive partnerships already in place. With experienced & qualified EPC solution provider not only can coal gasification projects on fast track but also provide after sales service and operational success for sustainability of high ash Indian coal gasification with CFB.

References

  1. https://pib.gov.in/PressReleasePage.aspx?PRID=1999220
  2. https://coal.gov.in/sites/default/files/ncgm/ncgm21-09-21.pdf
  3. https://www.netl.doe.gov/carbon-management/gasification#:~:text=Gasification%20enables%20remediation%20of%20wastes,net%2Dzero%20energy%20system%20basis.
  4. https://pib.gov.in/PressReleasePage.aspx?PRID=1944388

Achieving Cost Reduction through Enhanced Efficiency in Scrap-based Steel Melting Shop

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Importance Of Secondary Steel Sector

Secondary steel provides a convincing answer for sustainable practices. Recycling and rerolling methods not only reduce environmental impact they also ensures high-quality goods that fulfil industrial requirements. As the construction industry prioritizes sustainability, using secondary steel is critical for a greener future. That is where secondary Steel Melting Shop (SMS) becomes critical to achieve this.

Steel is one of the most competitive sectors. The makers must be efficient and cost-competitive with main producers that create steel from iron ore. To manufacture molten steel, the secondary steelmaking process must employ electric arc or induction furnaces. In India, approximately 45% of steel is manufactured utilising induction furnaces with two major raw materials – Sponge iron and Scrap steel. The primary expense of producing steel is melting, hence the cost efficiency of the SMS becomes critical.

Heart Of An Efficient Sms Process

  • High Power Density 
  • High Melt Rate 
  • High Yield l Low Heat time 
  • Low Power Consumption Per Ton 
  • Less Pollution 
  • Longer Life of Equipmen

SMS that uses scrap as their primary raw material face significant challenges since scrap is never constant and processing.

Steel Technology 

Scrap can be treated using three basic methods: shearing, baling, and shredding. The process identification is determined by the kind of raw steel scrap, its density, size, cleanliness level, furnace size, furnace power density, and other factors. There are numerous types and sizes of equipment available to process scrap from 1 to 100 tonnes per hour.

The majority of the cost of producing steel is power. Dev Energy has been actively focusing on power reduction, including its dynamics and its relationship to scrap processing. The time required for melting is determined by the scrap’s form, density, and size. Improper input scrap leads to longer melting times and increased power usage.

The aim is to process the scrap in the right settings with technology that matches the type of scrap.

Shredder- Hammer Mill

The Hammer Mill Shredders have output density of almost 1.4 ton/m3 with metal recovery of up to 98%. The operation cost of ~ INR 700 /t makes it savings super star for steel scrap melters.

Steel Technology

Innovative solutions in fumes extraction system from the house of Dev Energy results in high dust removal efficiency and clean gas dust concentration is achieved with minimum work zone emissions.

DEV ENERGY developed and deployed a Dog House based fumes extraction system for induction furnaces, collecting more than 95% of the fumes and total power usage is ~10kwh/t.

Scrap steel has a large amount of galvanised and painted material that is high in zinc, and the dust recovered typically contains up to ~ 40% of this zinc. This dust can be sold on the market. This converts the DEV ENERGY provided pollution control system into a revenue-generating system rather than an expenditure.

The key performance parameter in compliance of PCB Norms is for the Dog House to suck > 95% fumes and the Bag House f iltration to remove the SPM and exhaust through chimney only under norms.

Scrap Pusher compliments the Dog House system to help SMS furnaces achieve the required melting rate. It has hydraulic operation and rotation on Slew bearing. The telescopic boom on hydraulic motor makes it first choice for users.

parameters cannot be defined, therefore the technologies need to adapt to this variable environment. 

The entire process, from scrap purchasing to melting, must be linked with the desired outcome.

 Dev Energy has acquired competence in providing unique turnkey solutions for effective scrap separation, processing, and feeding into the furnace. This feeding system must also be connected with the pollution or flue control system used during the melting process.

Scrap Processing

 The scrap processing machines must be selected with reference to the type of scrap that the SMS can source. The machines must be complemented by appropriate scrap unloading and segregation systems. After the scrap is treated, the melt shop design and equipment should be able to feed it into the furnace. Dev Energy offers a full variety of turnkey solutions for scrap unloading, segregation, scrap processing and scrap handling and feeding.

 Box Shear

Box shears are ideal for processing a huge variety of scraps. The machine can take all the input scrap and convert it into output of density ~ 1 ton/m3.

The operational cost of ~ INR 250/t makes it the wisest choices for users.

 The perfect implementation of superior shredders and shears reduces the power consumption by up to ~ 8% and heat time by up to ~ 10% resulting in overall ~ 10% net cost savings.

 Fumes Extraction System (FES)

 The National Green Tribunal (NGT) rules and the more stringent Pollution Control Boards (PCBs) have compelled SMS retailers to investigate and reassess flue control system technology. The present devices can only absorb up to ~ 60% of emissions and cannot fulfil government standards. Because they are intended for exceptionally high working pressure, their operating costs are quite expensive.

 Scrap Charging Trolley which is remote controlled and runs at speed of ~ 30 MPM with VFD DRIVE helps feed the scrap to furnaces without the need for Dog House to be moved. Both back-front and side-travel option are available for versatile layout design.

 By achieving desired parameters at the outlet of fumes extraction system the workers can do work more efficiently. Higher Yeilds becomes possible once the above mentioned systems are installed and utilised regularly.

Conclusion

Dev Energy is a prominent and reliable provider of end-to-end operational cost reduction solutions for secondary steel melting plants, including scrap processing, scrap feeding and fume extraction systems. With a proven solution offering spanning more than two decades, we have lowered our clients’ production costs while increasing compliance with PCB standards in tighter emission specification limits. Overall, we are devoted to continuing to increase production efficiency in the secondary steel melting shops business.