PROVIDE HEATING BOILERS BY COAL GAS AND AIR POLLUTION REDUCTION
Project objectives
In the scope of the project, 3.5km long gas pipeline was installed from the Coal Gas Plant of the Grand power LLC, to the end-user location to supply heating boilers by product gas.
Project objectives:
- To reduce emissions from heating boilers, and increase thermal efficiency of the boilers.
- To supply heating boiler by cheap coal gas and prove its reduction amount of air pollution.
- To learn lessons and experience during gas pipeline distribution.
Project rationale
According to the research of National Committee of Air Pollution Reduction, 50% of the total pollution is caused by the raw coal usage of ger district consumers, and the combustion flue gas of enterprises ‘low-pressure boilers’ causes 10% of pollution. While combustion of raw coal, not only flue gas but also coal dust, fly ashes and other particulate matters increase air pollution. UB city residents’ sickness rate of congenital acromicria and respiratory disease is increasing gradually due to the air pollution.
The best solution of the air pollution problems is shifting solid fuel of Ger Districts into gas fuel and building a gas pipeline distribution system. However, the residents are not confident that gas could be safe and reliable fuel for the domestic heating. There is necessity to introduce gas advantages to the residents by implementing small gas supply system and to learn from the real experience for us.
Project Benefits
The project has termendous social and environmental benefits. In the frame of the project, 3 enterprises of Unit 0151 of Border Troops, Workshops of Grand Power LLC, and Precast Concrete Plant of Grand Baishin LLC is supplied by coal gas and is reduced toxic emissions from their heating boiler combustion. Also the project has folllowing objectives:
- To introduce advantages of gas application to reduce an air pollution of the raw coal combustion in UB city.
- To solve an enterprises’s heating only boilers by coal gas, and save the investment of conventional heating pipeline system.
- To reduce solid wastes of coal combustion, accordingly enable convenient environment to the residents.
- To reduce sickness rate of residents , which caused by air pollution.
The results of emission analyse that is conducted by Monitoring and Controlling Department of the Capital Air Quality Bureau in 13th of December 2014 is shown below.
Parameters g/kg |
MNS 5216-1:2011
Standard limits
|
For coal gas fuel of Grand Power |
In comparison with the standard |
NOₓ emission |
no standards |
|
|
CO emission |
10g/MJ |
0,23g/MJ |
43 times lower |
SO₂ and H₂S emissions |
Up to 2g/kg |
1,78g/kg |
1,1 times lower |
Table 1. The toxic gas contents in the flue gas that produced from coal gas combustion
From the above table, CO emissions in flue gas during coal gas combustion is 43 times lower and sulfuric oxide emission is 1.1 times lower than the standard limits. In the UB city, heating only boilers and ger district’s stoves produce much more emissions than standards.
Project Location
The pipeline starts from territory of 32nd khoroo of Songinokhairkhan District and continues at 22nd khoroo of same district. The figure below shows location of the project.
In the scope of the project, enterprises that marked yellow on the figure would be supplied by coal gas, and enterprises that marked green are available to be supplied easily, if the capacity of Coal Gas Plant was extended. Gas pipeline is installed across to the flood protection dam. It crosses central paved road one time and railway 2 times.
Strengths of the project
The Coal Gas Plant has an annual capacity of 20 million cubic meters of gas. Currently, the plant is providing gas to only heat only boilers of Grand baishin LLC. It means that it’s using 25% of production amount. There are no customers that have constant operations around the plant area. A Clean Air foundation has supported private sectors that work to reduce UB air pollution and has assisted to put 3.5km long gas transmission pipeline until public enterprises with constant operations during heating seasons. It is contributed a lot to introduce advantages of gas fuel, to increase the gas consumption and so forth to reduce an air pollution. The Coal Gas Plant enables following advantages for the project.
- Lower investment
- Experienced and skillful labors
- Steady operation
Project legal environment and safety issues
There are several laws, standards and norms on gas application and supply. In example:
- Law on Crude Oil Products
- Law on Energy
- Law on Construction
- “Gas Supply” Construction Code 42-01-04
- “ Erection of Gas Supply” Construction Code 42-02-04
- Regulation of technical applications for Gas Enterprises
- Safety Codes for Gas Enterprises
- “General Planning of Industrial building” Construction Code 30-02-07
In terms of the project safety, a project owner has to develop an Operation Manual on gas distribution, Safety Codes and Manual on gas application as well as on Monitoring and Controlling progress of pipeline system. Product Sales Contract should be made with customers.
Technology Description
Coal gas plant has a two-stage coal gasifier from China. The gasifier has flexible operation to gasify all kind of coal; flexible feed coal consumption, 5% more productivity than one stage gasifier and hasn’t got any phenol waste. Its producer gas has a heating value more than 5800kJ/m³. The gasifier type is fixed-bed, air and steam mixture blown. It has an ash discharger and a steam jacket.
Parameters |
Unit |
Amount |
Diameter of furnace |
mm |
2000 |
Particle size of combustion material |
mm |
20–40, 25–50, 30-60 |
Consumption of combustion material |
kg/hr |
800-900 |
Coal gas production |
m3/hr |
2500-2800 |
Coal heating value (minimum) |
HHV |
kJ/m³ |
7000 |
LHV |
kJ/m³ |
5300 |
Mixed |
kJ/m³ |
6400 |
Output temperature of furnace |
Upper stage |
°С |
90-150 |
Lower stage |
°С |
400-550 |
Output pressure of furnace |
Upper stage |
Pa |
2000-3700 |
Lower stage |
Pa |
2000-4000 |
Lower aeration pressure of furnace |
Па |
6000 |
Air-steam mixture temperature |
°С |
50-60 |
Heating area of steam jacket |
m² |
13.9 |
Steam pressure of water jacket |
MPa |
0.3 |
Steam amount of water jacket |
kg/hr |
300 |
Type of combustion materials |
Lignite, sticky or non-sticky bituminous coal |
Table 2. Technical specifications of coal gasifier
The “mixed gas gasifier” is manufactured under the patent of the Shanxi Institute of China. The average coal gas content is that СО: 20-25%, Н₂: 9-14%, СН₄: 1-4%, СО₂: 5-10%, О₂<0.8%.
The plant has 1 set of gasifier, dust cyclone, air cooler, 2 sets of electric filters of coal tar, 2 sets of dryers, and 3000m³ gas container.
In the frame of the project, 2 sets of HDSR200 type gas root blowers with capacity of 35kPa each are installed to transfer gas by pipeline. Gas sensor, automatic safety valve, and gas flowmeter is installed for protection of consumer.