» Environmental & energy conservation and Pollution Control
Environmental & energy conservation and
Coal moisture Control System
Great concern is paid to the energy consumption
reduction in the coking process and environment improvement, and a large
amount of exploration has been made. Japan is credited for developing the
coal moisture control process. The heat transfer oil and thermal medium of
steam are respectively utilized in the 1st and 2nd generation to directly
and indirectly regulate moisture of coal material. This method indirectly
wasted external heat supply like steam with complicated equipment, large
investment and high operation cost. In order to improve granularity of coal
charge to make it more well-distributed, former Soviet Union developed
pneumatic separating technology. But it has this only effect and little
applications. The pretreatment technology of granularity classification and
moisture control to coking coal in coal preparation system is one of the
advanced technologies in coking industry.
MIPL & Jiangsu Zhongxian Group Co. Ltd., which is devoted to
environmental protection with independent intellectual property rights, has
been cooperating with international first-class R&D Institutions and
coking factories on areas of coal moisture control and classification &
separating technologies. The group owns advanced moisture control and
classification & separation technologies and equipments. We can set up
appropriate process flow and equipments of moisture control and
classification & separation technologies according to requirements of
clients to optimize economic, environmental and social benefits.
Technology and facilities:
1.1 Technology :
The coal moisture control and classification &
separating technologies are applied to deliver coking coal to moisture
classification apparatus through feeding system. The coal material is
fluidized by remaining heat of flue waste gas of 180°c220°c
in coke oven as heat source and power supply and then heat circulation to
control moisture is conducted. The coal material will be classified and
separated according to granularity grade. After moisture control and
separation, the coal material of fine granule less than 3mm will be conveyed
to coal tower through transportation system and coal material of coarse
granule more than 3mm will be feeded into pulverizer to be pulverized and
then conveyed to coal tower. The exhaust gas out of moist control will be
gathered at the main pipe and dust-removed by dust remover and then
discharged into the air. The coal dust collected from each dust remover will
be formed through forming machine and then conveyed to coal tower.
1.2 Major facilities :
Major facilities coal material transportation
system, feeding & discharging system, moisture control classification
apparatus, exhaust gas induced fan, dust removing system, coal dust forming
apparatus and system of monitoring, testing and controlling etc.
1.3 Characteristics :
1.4 Effect of the project :
- In the process, the waste flue gas in coke oven is taken as the heat
source for adjustment of coking coal moisture and power supply of coal
material classification & separation, that is, make full use of
plenty of low-heat complementary energy in the coke-oven plant without
the external heat supply, and cancel the external heat supply required
in the traditional process.
- The moisture control classification apparatus selected in the
process function as adjustment of coking coal moisture and its
classification and separation. In the same moisture control
classification apparatus, it meets the requirement of coking coal
moisture control and granularity classification.
- The process can realize the granularity classification of coking
coal and make granularity of coal material more well-distributed.
Therefore, the coking coal with coarse granule can be pulverized to make
inert constituents and high ash percentage components pulverized to
appropriate degree of fineness and avoid the over grinding of coking
coal of fine granule.
- Systematically set up technical and environmental dust removal
facilities for the dust purification in each dust-entrainment points,
thus there is no air and environment pollution. Then send the collected
coal dust after the forming treatment.
- Systematically apply the centralized operation and control model
with high automation, stable production and reliable operation, which
makes the unmanned site operation true. Optimize collecting control of
flue gas waste in coke oven to ensure no effect on the coke oven
- This simple system process integrates feeding, classification &
separation, drying and discharging. It occupies small area and has
reliable equipment with strong processing power and adaptation to
2. The condition needed for CMCC
The date provided by us:
- The implementation of CMCC technology boasts the distinct effect of
- Make full use of plenty of low-heat complementary energy of flue
gas in the coke oven in the coke-oven plant.
- Reduce the moisture content of coking coal so as to make the
energy consumption of heating coal gas in the coking process dropped
(about evaporation energy consumption of appropriate water in the
- Only make the coking coal with coarse granule grinded, thus the
workload of pulverizer in the coal preparation workshop is reduced
so as to save 30% electricity power consumption..
- The water content of coking coal can be reduced by 4% to 6%. It can
reduce the discharge rate of coking sewage. The relevant water needn't
to be put into treatment process for coking sewage. The control and
stabilization of moisture within coal material can lead to stable
operation of coke oven and prolonged useful life of it.
- The implementation of CMCC obviously improves the thermal stability
of coking coal, improves indices of coking coals quality and
increases coke strength and ash content of coking coal.
- With bulk density of coking coal increased and distillation period
shortened, the production capacity of coke oven can be improved by
- While the quality of coking coal is kept the same or improved
slightly, the weak-coking coal can be used more of 8%-10%.
- Technology of processing CMCC by waste flue gas in coke oven can
realize recycling of waste heat energy. This technology is an important
constitutes for coking industry to develop circular economy and reduces
greenhouse effect and 36kg carbon dioxide per ton will be less
- Engineering regional plan graph: 1:1000
- The existing graph of new or old one in recent years: 1:500;
- Designation graph in industrial area and the old plant
- The existing architecture and construction graph of coal blending
and pulverizer system, and the original dedusting engineering graph.
- Belt conveyor for going up to coal tower
- Coke oven chimney, plan and elevation graph of chimney flue, main
flue turning plate valve and its installation graph.
- Corollary coke oven specification, capacity, moist coal consumption
per year, coal preparation matching facilities, the number of pulverizer
and belt conveyer, their capacity, and so on.
- Moist coal data: the moisture content(%), granularity, blending coal
heap density (kg/m3), specific heat capacity of coal kJ/kg.
- Waste gas data: specific heat capacity kJ/kg. Temperature, humidity,
oxygen content, waste gas capacity of single chimney flue, main chimney
flue suction range in the base of chimney
- Dynamic medium contact of engineering water, electricity, compressed
air, nitrogen and the range of dedusting.
- Normal compressed air: pressure and fluctuation range, dew point,
dust content, surplus and connecting point position.
- Purified compressed air: pressure and fluctuation range, dew
point, dust content, surplus and connecting point position.
- Nitrogen: pressure and fluctuation range, purity degree, surplus
and connecting point position.
- Voltage grade: the requirement of selection type of low voltage
cabinet, computerized integrated protection, PLC, frequency
- Meteorology data in plant area
- Geological data in plant area
- Flood data in plant area
- Virescence data in plant area
- Requirement of control
Air Heating Blast Furnace
With the improvement in Iron smelting technology the
coke consumption in Blast furnace is decreasing year by year, resulting in
lower calorific value of Blast-furnace gas. If only Blast-furnace gas is
burnt in air heating furnace, the blast temperature can reach upto 1000 to
1050 ºC, which can not meet the requirement of high blast temperature.
In order to increase the blast temperature, lots of measures have been
taken in China, for example, mixed burn of some coke-oven gas of high
calorific value, pre-heat the air and gas by flue gas heat in the air
heating furnace. Due to general shortage of coke-oven gas with high
calorific value in most iron & steel plants and the low temperature of
waste gas in flue pipe, where even with a separate heat pipe heat exchanger,
the air and gas to be blasted into the hot air furnace can be reheated to
150 to 170 ºC only. Some other heat source should be developed to
pre-heat the air and gas to the required 250 to 450 ºC respectively if
we want to realize a high temperature at 1200 ºC to 1250 ºC with
only blast-furnace gas burned in air heating furnace. Under these
conditions, the technology of double pre-heating device (or sectional type)
with additional burning furnace has been developed.
The system is made of additional burning furnace, tube type air pre-heating
device, gas pre-heating device (sectional high temperature air
preheater), combustion fan, flue gas induced draft fan etc.
The pre-heating device is of tube-type heat exchanger that induces the flue
gas heat in Air heating furnace into the mixing box of burning furnace by
high temperature induced draft fan to mix with the high temperature flue gas
in the burning furnace. This helps to get mixed flue gas at 500 to 600 ºC
which further enters into the air and gas pre-heating devices separately.
After heat exchange, the air and gases are heated to 250-300º C. The
sectional pre-heating device is of tube-type heat exchanger that pre-heat
the air and gas to 150-170º C by flue gas in air heating furnace
firstly, then it induces the flue gas heat in air heating furnace into the
mixing box of burning furnace by high temperature induced draft fan to mix
with the high temperature flue gas in the burning furnace to get mixed flue
gas at 550-700º C, and then pre-heat the combustion air which has been
pre-heated to 150-170ºC to 450ºC again by such mixed flue gas, and
finally, the air and gases are heated to 450ºC and 170ºC
The pre-heated air and gas further enters into the air heating furnace for
burning. Due to the increased physical heat of air and gas, the hot blast
temperature can also be increased. It is analyzed according to the result of
thermodynamics that the adoption of double pre-heating systems with
additional burning device can guarantee increase in the hot blast
temperature by 180-200º C, so as to greatly reduce the Coke Ratio and
increase coal injection and output.
- It can be used to treat the dust in iron and steel plants, various
dust, sludge, iron oxide scale and pickling residue, etc. in
agglomeration plants, iron mills, steel works and rolling mills.
Valuable metals such as Zn and Pb, etc. can be collected in the process
for metal iron recovery.
- It can be used to directly produce iron via. reduction, produce
high-quality metallized pellets by the raw material of iron ore
concentrate or high-grade ore powder for blast furnace and electric
furnace or used as the cooling agent for rotary furnace.
- Optimized iron making operation
The rotary furnace as the recovery station is a relatively independent
flow in an iron and steel plant, it can be used to treat various dust by
a centralized mode and supply stable and uniformly composite products to
the blast furnace, the optimized operation in the iron making system has
totally realized the self-digestion of dust in the iron and steel plant.
- Zinc recovery
More than 90% Zn in the dust can be recovered and crude ZnO dust that
the ZnO content is 80% above can be obtained.
- No secondary pollution
The rotary furnace is a sealed system with clean flue gas and micro
negative pressure operation, and there is seldom discharge in the whole
- Interconnected to the existing flow
The technique of rotary furnace is highly independent and seldom
conflict against the existing flow.
Valuable metals can be recovered in dust treatment; iron can be
directly produced via reduction with the raw material of high-quality
iron ore concentrate powder
With the high development of iron and steel
industry, the techniques for coking, gas purification and recovery have also
been changed quickly, the large scale modernization of coke oven plants at
present has clearly shown that the techniques for coal coking and the
recovery of chemical products are still playing an important role in the
future production of iron and steel.
Technical flow for gas purification and recovery
Raw gas is brought up into the gas collecting pipe from the charging
chamber, circulatory ammonia water is used for spraying to cool down the gas
and separate the tar and ammonia water out; the gas is then brought via the
suction pipe to the primary cooler and then the air blower in the recovery
workshop, after the gas is cooled down and treated by various absorbents,
chemical products including tar, ammonia, crude benzol and so on are
extracted, and the purified gas from the coke oven is usually sent back to
the coke oven for heating or used as the fuel for other metallurgical
furnaces, or furthermore used as the raw gas for ammonia synthesis or the
civil urban gas.
Flow of traditional gas purification:
1 Primary cooling - 2 Gas supply - 3 Electric capture - 4 Pre-cooling
(preliminary naphthalene depriving) - 5 Desulphurization - 6 Thiamine - 7
Naphthalene final cool washing - 8 Debenzolization - 9 Gas purified
The air blower sends gas at 50°C~60°C,
which is cooled to 30°C~32°C after the cooling and naphthalene
removal made by remaining Ammonia and condensing in the pre-cooling tower,
after which the naphthalene content should be less than 300mg/m3.
Then it goes to the desulfurization section at the bottom of the primary
desulfurization regenerating tower to countercurrent contact the
desulfurization solution sprayed from the top tower; under the reaction of
catalyst, the sulfureted hydrogen and hydrogen cyanide in the gas get
absorbed in the desulfurization solution which is further pumped onto the
regeneration section of the tower by the recycle pump through the wet seal
in the bottom of the tower to contact with air by self-priming injector for
catalytic oxidation regeneration. The regenerated liquid flows into the
desulfurization section for rotative spray by means of the liquid level
regulator. And then the coke oven-gas after purification in the primary
sulfurization system will goes to the second and third class desulfurization
purification system (same class in the process), so that the sulfurated
hydrogen content in the gas becomes less than 20mg/m3. After the
desulfurization, the gas goes to the ammonium sulfate section. The sulfur
foam spills over the regeneration section of desulfurization tower
self-flows into the concentrating groove and the sulfur foam concentrate is
sent into the sulfur melting furnace by the sulfur foam pump. Then the
molten sulfur after smelting flows into the cooler pan and after natural
cooling, we get the product sulphur.
It describes those processes used to make water more acceptable for a
desired end-use. These can include use as drinking water, industrial
processes, medical and many other uses. The goal of all water treatment
process is to remove existing contaminants in the water, or reduce the
concentration of such contaminants so the water becomes fit for its desired
end-use. One such use is returning water that has been used back into the
natural environment without adverse ecological impact. The processes
involved in treating water for drinking purpose may be solids separation
using physical such as settling and filtration, chemical such as
disinfection and coagulation. We can provide full water treatment solution
Innovative Pyrolysis Process for Municipal Solid Waste (MSW) Treatment
Municipal solid waste (MSW) generation is a serious problem worldwide. Generation of such each year is around 10 billion tons, which is six times more than the world’s grain yield, and 14 times more than the world’s steel output. MSW not only occupies large pieces of land, pollutes the environment, but also poses health danger to human beings.
I. Current Technology
Common methods of MSW disposal include landfill, composting and incineration, among which landfill and composting are now in a difficult situation due to large land occupation, low level of resources utilization, etc. Incineration is the mainstream technology of MSW treatment, widely used in Japan, USA, and other similar developed countries. Though this technology features large processing scale, good incineration effect, mature off-gas treatment and environmental protection capabilities which can serve the purpose of volume reduction and resource utilisation, dioxin is surely to be generated as a secondary source of pollution due to oxygen firing in incineration. In addition, such treatment plants need high CAPEX and OPEX.
The pyrolysis technology for MSW disposal is recognized presently as a better alternative to the MSW incineration method.
Our pyrolysis process for MSW disposal is in an oxygen free atmosphere, and it features a high degree of cleanness. In addition, such value-added by products as clean gas and oil can also be extracted in the process from MSW. With a single unit treatment capacity of 50 - 1500TPD, both CAPEX and OPEX of such pyrolysis plants for MSW disposal are lower than those of a similar grate incineration plant widely adopted in the developed countries.
II. Our New Pyrolysis Process for MSW Disposal.
This new pyrolysis process for MSW disposal mainly consists of pre-treatment system, pyrolysis system(RHF), fluidized-bed gasification system (FBG), oil/gas separation/purification system ((OGSP), off-gas cleaning system, waste-water treatment system, etc.
2. Process Flow
MSW is transported into the plant, and unloaded into the trash storage pit after being weighed. The same is then conveyed into the pre-treatment unit for segregation. The segregated inorganic matters like rubble, concrete pieces, glass,etc. can be taken out for landfill, and the segregated metal objects are collected for sales on the market. Such organic matters segregated out and flammable materials as household wastes, plastic, rubber, waste paper, wood/bamboo chips, leather, etc. are crushed into small pieces before being charged into a rotating bed (rotary hearth furnace) for pyrolysis.
3. Possible Uses of the Pyrolysis Products
Products generated during the pyrolysis inside the RHF like oil, gas and carbon can be utilised in different processes depending on the practical requirements.
1) The pyrolysis oil/gas can be separated in the OGSP unit into clean gas that can be sold to the market. The pyrolysis carbon and the tar generated during the oil/gas separation can be used as raw materials for the FBG. The producer gas generated in the FBG in turn can be the fuel for combustion in the RHF, with the offgas being directly discharged into the atmosphere. Or,
2) The mixture of the pyrolysis oil/gas can used for power generation, and the pyrolysis carbon can be used in the FBG for producer gas generation. Or,
3) The gas from the OGSP is directly supplied as fuel to the RHF, and the remaining oil (tar) and the pyrolysis carbon can be sold to the market.
III. Features of New Pyrolysis Technology The new pyrolysis technology for MSW treatment is now the 3rd generation MSW treatment technology in the world, and the main features of this innovative process are as follows:
- No dioxin pollution.
- No generation of such hazardous wastes as fly ash.
- Effective Control of Stenchy Pollution.
- Harmless Treatment of the Waste Water.
- Highly Efficient Utilisation of MSW Resources.
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