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:
- Suitable for all types of Indian bituminous coals
- Cold and Clean Gas with High NCV > 1350 Kcal/Nm³
- Pollution free Zero Discharge System
- Complete Automation for easy operation and safety
- Up to 90% Energy Conversion efficiency
- High CV Clean Tar as by product returning ~ 15 % cost of coal
- Turnkey Solution with O&M
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
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.
