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.