OPTIMIZATION OF ECONOMIC ASPECT OF WATER HYACINTH UTILIZATION INTO LIQUID ORGANIC FERTILIZER USING WET TORREFACTION PROCESS

• Main Author: Rosita Hellena Hehanussa, Linda
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/70491
• Institution: Institut Teknologi Bandung

Water hyacinth is an aquatic plant that is considered a noxious weed due to its rapid growth. This plant can absorb nutrients and oxygen, affecting the surrounding organisms. Cirata Reservoir has an area of 6200 ha and 5.82% of its land was covered by water hyacinth in 2021. The solution carried out so far is removal with the amount of processing not proportional to the growth rate. This research aims to find a solution to the problem, namely by converting water hyacinth into liquid organic fertilizer by processing using a wet torrefaction process. The content of macro nutrients in the form of nitrogen (N), phosphorus (P2O5) and potassium (K2O) compounds is needed for plant growth productivity. The minimum technical requirements for organic fertilizer stipulated in the Decree of the Minister of Agriculture in 2019 state that the standard NPK content of liquid organic fertilizer is between 2-6%. Initial testing using a laboratory scale wet torrefaction reactor with a capacity of 2.5 L was carried out to determine the optimum temperature that produces liquid products with NPK content that meets the standards. The optimum reaction temperature at laboratory scale was used as a reference in testing other operating conditions. The test was then conducted with a pilot scale wet torrefaction reactor to analyse the NPK content of the liquid product. In addition, simpler operating conditions, namely using a pressure cooker and a pot, were carried out to see the trend of NPK content when compared to the use of a wet torrefaction reactor. On a laboratory scale, the process were carried out without the use of water because of the physical characteristics of water hyacinth which has a high water content. The reaction temperature variations were 120°C, 140°C, 160°C and 180°C and the holding time was set for 30 minutes. The optimum condition of the test occurred at a reaction temperature of 140°C with sample code WH 140-30 where the NPK content of 2.15% N, 2.05% P2O5 and 5.54% K2O reached the standard. Pilot scale wet torrefaction with optimum temperature showed that the N and K2O contents met the standard, while the P2O5 value did not meet the minimum standard. In the process of using pressure cooking with an operating pressure of 2 bar and holding time of 30 minutes, the results showed that the N value was less than 0.05% of the minimum limit and the P2O5 and K2O contents reached the standard. Based on the growth rate of water hyacinth in Cirata Reservoir is 11.33 m3/day, the reactor have to process water hyacinth into liquid organic fertilizer can be done with a reactor capacity of 3 m3. The operating parameters used in this process refer to the research pilot scale. Then the economic aspect can be done by calculating the total expenditure of the total energy needs of additional fuel in the process. While the total revenue is calculated from the total sales of liquid organic fertilizer. The optimum amount of profit from the difference between total income and total expenditure up to Rp 4.783.774 for a reactor per batch.