Showing posts with label Fluidised bed combustion. Show all posts
Showing posts with label Fluidised bed combustion. Show all posts

Tuesday, December 3, 2019

Conversion of Industrial Furnaces and Boilers with Biomass Fuels

 

The use of biomass fuels especially palm kernel shells (PKS) has been increasing lately. This was mainly due to the high price of natural gas and non-subsidized industrial LPG. Viewed from the environmental aspect it is a progress because there is a reduction in fossil fuels (carbon positive) which causes climate change and global warming. Industries that initially used furnaces and gas-fired boilers needed to replace them into biomass, especially palm kernel shells which are solid fuels. The availability of palm kernel shells is  also very abundant inline with CPO products or palm oil plantations in Indonesia. Biomass such as wood chips, wood pellets and so on can basically be used as fuel for the furnace, but economic considerations and continuity of supplies are the main considerations. The quality of the palm kernel shell is also almost equal to the wood pellet and in the international market indeed the palm kernel shell is the main competitor of wood pellet. And when compared to other agricultural waste biomass such as rice husks, palm kernel shells  are also far superior both in terms of calories and bulk density, so palm kernel shells are increasingly becoming a favorite fuel.
 

At present the palm kernel shell has also become an export commodity especially for the Japanese and Korean markets. The two countries are the biggest consumers of the palm kernel shells, especially in Asia but with the main motivation due to the implementation of environmental programs in the country. Large incentives are given by the states to companies, especially power plants, when using biomass fuels, especially palm kernel shells because they are a renewable energy group. This is very encouraging the use of palm kernel shells in the two countries. While the main suppliers of palm kernel shells are from Indonesia and Malaysia as the world's largest CPO producer as well as the owner of the largest palm oil plantation in the world today. This condition will certainly create competition especially when the demand for palm kernel shells is equally large. When these conditions occur, special strategies are needed to react to them, thus providing a large added value for Indonesia and Malaysia, or the pks sources. 

 Palm kernel shells are biomass fuels that have almost no processing and can be used directly, while for wood pellets an industry is needed for processing. Based on the fact above, palm kernel shells should be prioritized for the domestic market and wood pellets for the export market. When the production of wood pellets currently still relies on sawdust and wood wastes which are limited in quantity, then in addition to the the environmental aspects of sustainability recognition are also difficult to be obtained. When wood pellet production is made from energy plantations by growing energy crops such as calliandra and gliricidae, although the availability of raw materials can be guaranteed and capable of large capacities and environmental aspects of sustainability can be obtained, but in general producers are still not interested because the process route is long and need mastering the aspects of energy plantation cultivation. EFB pellet production can be a solution for  this. EFB or palm oil empty fruit bunches like palm kernel shells are an abundant amount of solid palm oil mill waste and are currently largely untapped, for more details, please read here.


If the use of biomass fuels, especially palm kernel shells in Indonesia is getting bigger, it means that it is comparable to efforts to reduce greenhouse gases or CO2 derived from fossil fuels. An achievement in the environmental field that can be proud of course. At present, there are not a few palm oil mills which have not yet sold their palm kernel shells, especially those in remote areas. The effort to take the palm kernel shells at the palm oil mills is also a challenge, but with users in the country it is also easier. If the palm kernel shells for the export market, especially Japan, require a large minimum quantity of an average of 10,000 tons per shipment and the quality of a tight palm kernel shell (especially aspects of cleanliness anddryness), the domestic market in addition to the volume of each shipment is smaller, the quality requirements are also not so tight. The transportation of palm kernel shells to Japan with such quantities requires large bulk vessels, while for the domestic market it is sufficient by barges.
 


Conversion from natural gas to solid fuels especially palm kernel shell biomass does require different equipment and operational aspects. Biomass fuels, especially palm kernel shells, require a larger space for storage, the combustion process is not as easy as gas fuel, and solid ash is also produced. The industrial users of palm kernel shell fuel usually have to replace their furnaces or boilers with furnaces or industrial boilers with biomass fuel, especially palm kernel shells. Basically there are 3 groups of combustion technologies that can be used namely grate, fluidized bed and pulverized combustion. The aspect of mixing air with fuel is an important aspect in the combustion process. Solid fuels have low mixing qualities with air compared to liquid fuels moreover in the gas fuel. In liquid fuels and especially gas, fuels can be atomized so that they are close to the molecular size of air, whereas solid fuels cannot. Grate combustion has the lowest air-fuel mixing rate, fluidized bed has a better homogenisation air-fuel mixture and pulverized combustion has the best homogenisation air-fuel mixture level that can be obtained from combustion of solid fuels. The choice of combustion technology is mainly based on the heat capacity needed and economic aspects including the price of the equipment, operational and maintenance costs. 

Sunday, July 6, 2014

Sectors of Pellet Fuel Usage

As a source of energy or wood pellet fuel or pellet fuel can be used in small-scale such as the household to large-scale on power plants. Both quantity and quality pellet are the parameters in its use in relation to equipment that is used. Basically from small-scale to large scale on the use pellet fuel especially related to efficiency factor, easy in operation, safety and gas emission impact (eventhough wood pellet include as renewable fuel that enter the category as carbon neutral) while the use on large-scale the qualityfactor of pellet got a serious attention. Technology that was used to utilize the wood pellet is almost all use combustion technology (direct combustion) to get output in form of heat or electricity.






In small-scale the use pellet fuel for mainly in the four season countries for room/space heating, even for this sector needs premium quality of wood pellet for pellet stove. Pellet stove has not yet been familiar in Indonesia because the wood pellet also still very difficult to get. Other equipment that are to be used in small-scale is boiler and burner. Boiler system will produce steam to source of steam and hot water. While burner can be used for various source of heat.



On the medium-large scale, users mainly for industries and coal-fired power plants. Grate combustor and stoker are equipments that general used in the industry. Pulverized technology system and fluidized bed commonly used in power plant. The percentage of wood pellets this time is still less than 5 percent on the use of cofiring in the coal powerplant. Wood pellet for pulverized while biomass pellet for fluidized bed. The characteristics of both pellet cause of the difference.


Tuesday, January 21, 2014

Fluidized Bed Combustion System Best Match For Agroindustrial Waste Biomass



Fluidized bed combustion (FBC) systems are widely used for power generation. FBC systems can be modified to be circulating FBC (CFBC), where the material is circulated back into the combustion chamber for burning up.  FBC systems are generally limited to a size of less than 300 MW, but there is powerplant  in Lagisza, Poland who designed it to 460 MW and hopes can be scaled up to 600-800 MW in the future. FBC and CFBC system is important because coal power plant that has long operated can be repowered, opening the possibility of cofiring with biomass on a wider scale conditions. The advantages of FBC systems include:  

-Ability to burn fuels with a wide range in moisture content, particle size, and density. And the potential for this type of fuel coal, biomass, tire-derivated-fuel, agricultural residues, and urban wood wastes.
-Heat transfer from combustion  more efficient so that the combustion temperature is lower, which in turn will reduce NOx emissions.
-Lower costs for SO2 capture because limestone can be added directly to the medium fluidization at a lower cost than installing scrubbers after combustion.


Coal power plant to install FBC  the system as part of a retrofit or new plant construction will be very open to the use of biomass (even if without biomass at first). FBC system has many advantages associated with the ability of fuel flexibility. Transport of biomass from feedstock sources to power plants efficiently if compacted (densification) is made to be like pellets. Wood pellets made ​​from woody biomass is increasingly limited its availability unless intensively pursued as create energy plantations, while the agro-industry wastes such as oil palm biomass is widely available and has not been utilized so that the potential for densification as fuel in FBC systems. Aspects of the environment, climate change and globalwarming is  major factors is the use of biomass fuels.

Production of Bark Briquettes from Wood Pellet Factory Waste

To reduce the ash content of wood pellets and thereby improve their quality, a process known as "debarking" (removing the tree bar...