Water Hyacinth Pyrolysis For Electricity And Charcoal Production

 

Map of distribution of global water hyacinth infestation

Water hyacinth has become a global concern as the most disturbing and invasive aquatic weed. The impact of water hyacinth losses covers the environment, economy and even social conditions experienced by many countries as a result of the water hyacinth attack. Economically, the losses due to water hyacinth are also very large, reaching hundreds to thousands of millions of dollars. Pyrolysis of water hyacinth for electricity and charcoal production is one solution to overcome the water hyacinth attack. In this way, it is hoped that the growth of water hyacinth can be controlled and reduce the environmental impact significantly. This is because the speed of attack from the fast growth of water hyacinth can be balanced with the speed of the biomass requirement for the pyrolysis process that produces electricity and charcoal.

The electricity generated in addition to operate or running the pyrolysis unit can also be used for various needs of the surrounding community. Meanwhile, the charcoal produced can be used for energy and agricultural applications, or in general the motivation for charcoal (biochar) production is as shown in the scheme below. And to facilitate handling both storage, transportation and use, the charcoal can be compressed / densified into pellets or briquettes. The need for energy or fuel for the surrounding community for cooking and so on, can use the charcoal that has been compressed into the pellets or briquette. If the community previously used firewood obtained from the forest illegally, then the charcoal pellet or briquette is also a solution to the problem of forest destruction.

 

The use of water hyacinth as a bioenergy is the best option and is most recommended by prominent experts and researchers around the world. Pyrolysis is one way or method of bioenergy production. It is true that water hyacinth also provides environmental benefits, namely phytoremediation, but with uncontrolled development, the aspects of the losses incurred are far greater than the benefits obtained. This requires good management so as to produce optimal benefits. In a number of cases even the water hyacinth creates silting which causes the volume and discharge of water, even though the water is used for hydroelectric power plants. This causes the hydropower plant to have less water supply and disrupt its operation. So that the use of water hyacinth for electricity production with pyrolysis will again increase the supply of electricity produced and at the same time overcome the volume and discharge of water for the hydropower plant. Basically, maintaining a balance between the environment and economic aspects must be made in such a way as to become a sustainable activity so that it is in line with the bioeconomic era. Bioeconomics is defined as knowledge-based production and using biological resources or living things to produce products, processes and services in the economic sector within the framework of a sustainable economic system.

Dessicated Coconut Factory and Continuous Pyrolysis

There are about 20 dessicated coconut factories operating in Indonesia or estimated to be more than 100 units worldwide. With an average capacity of 2 tons / hour, this dessicated coconut factory requires approximately 16,200 coconuts every hour. The byproducts produced are coconut shell and coconut water. Coconut shells produced are around 6 tons / hour and coconut water 4.2 tons / hour. The dessicated coconut plant needs electricity and heat to sterilize the coconut meat and drying the dessicated coconut. Energy in the form of electricity and heat can be met from the utilization of the coconut shell.

There are several technologies for utilizing these coconut shells so that products in the form of electricity and heat are obtained. The popular technology today is with a steam turbine boiler, with this technology the coconut shell is burned in a furnace and heats water in the boiler so that it produces steam to drive the turbine and then generate electricity through a generator. This technology is the same as in palm oil mills. In palm oil mill the fiber and part of the palm kernel shell (PKS) is used as fuel to produce electricity and steam is also used to sterilize fresh fruit bunches (FFB) before being processed into oil.

Another better technology is continuous pyrolysis. This in addition to producing electricity and heat also produces charcoal product. Coconut shell charcoal is high-quality charcoal and is much needed by a number of industries such as the briquette charcoal industry and activated carbon. In the pyrolysis technology the coconut shell is not burned directly, but is heated in a vacuum condition (absence of oxygen). Pyrolysis products such as syngas and biooil are used for electricity production and can also be heat, heat energy is also produced from the pyrolysis process itself which is exothermic, while charcoal is the main product of the pyrolysis process.

Only With Continuous Pyrolysis, Charcoal Briquette Industry Will Get a Supply Of High Quality Raw Materials

Charcoal briquette plant with a large capacity can only be supplied charcoal produced from continuous pyrolysis technology. The quality of products are standard and stable as well as the quantity of large quantities can only be met when using continuous pyrolysis technology in the process of charcoal production. Charcoal of satisfactory market quality can be made in kilns of any size or type when suitable coaling temperature and time conditions are present. It is perhaps more difficult to produce charcoal of consistently high quality in uninsulated metal kilns because of rapid and large heat loss.

The growing popularity of charcoal briquette has spurred great interest recently because its benefit on specific fuel application. Some information on plant equipment, manufacturing detail and the practicability of briquette production with contionous pyrolysis system to provide a few items of special interest.

Equipment : The equipment required for briquette manufacture is highly specialized. Powered units are required for grinding and mixing dry and wet charcoal, wet forming the briquettes, moving material in the process, and continous drying. Production rates are 1 to 3.5 tons of briquettes per hour. The equipment for both capacities is basically the same, but somewhat larger and heavier machines are needed for 3.5 ton output. Standard equipment for a 1-ton-per-hour briquetting plant includes the following :

-Briquette press with paddle feeder

-Hammer mill

-Charcoal feeder with surge hopper

-Paddle mixer

-Vertical fluxer

-Starch feeder or pump

-Briquette drier

-Boiler, 30 horsepower - - 15 pounds per square inch gage pressure

-Conveyors

-Bagging machine

-Building, 60 feet by 120 feet, with 20 feet clear height.

The labor requirements per shift are eight men, including a foreman, a machine operator, a night-shift maintenance man, a bagger and three men for warehouse and miscellaneous jobs.

Plant processing :-In general , charcoal lump and fines as received or from plant storage are fed by screw conveyor to hammer mill or crusher for feed material of 1/8-inch and smaller screen size. The ground charcoal is moved mechanically or by air to a surge bin for metered flows to the mixer, metered amounts of about 5 percent of binder (potato, corn or cassava starch) with water are added. After agiataion in a paddle mixer, the mixture is run through the fluxer for more throrough working of the mass before it is transferred to the press feeder for regulated flow to the forming press.

From the press, the wet or green briquettes are moved by belt conveyor to a special device for uniform loading and continous passage through the drier. The conditions for the drying are usually a 3-to 4-hour period at a temperature of about 275 F. The processing steps are carried out as shown in figure below.

Because of the large daily charcoal requirements and the investment necessary for even the smallest commercial briquette operation, it is not practical for the smaller kiln operator to undertake such manufacture. Operating the smallest commercial plant at a production rate of about 10 tons of briquette per day would require at least 250 tons of charcoal monthly.  Briquetting plants usually operate on two or three shifts per day for most economical production.

 

Only charcoal plant with level of production above 10 tons/day adequate for charcoal briquette plants need.  JFE project can provide charcoal plant (continous pyrolysis technology)  to meet that needs include high specification (quality) of charcoal requirement if it’s needed.