Prarancangan Pabrik Asam Humat dari Batubara Kualitas Rendah dengan Kapasitas 100.000 Ton/Tahun
THEODORA NATHANIA EVA PUSPITASARI, Prof. Himawan Tri Bayu Murti Petrus, S.T., M.E., D.Eng.
2024 | Skripsi | TEKNIK KIMIA
Humic acid is a complex organic compound that is produced through the breakdown of organic matter, such as lignite, a type of low-quality coal. It is essential for improving soil fertility and water retention, and the construction of a humic acid plant in Indonesia utilizing low-quality coal is motivated by the abundant reserves, primarily of medium and low quality. The humic acid that is produced serves a variety of purposes, including soil conditioning, increasing agricultural productivity, and acting as an adsorbent to bind heavy metals and other hazardous substances, thus meeting the demands of the country's agricultural sector. Utilizing low-quality coal for humic acid production not only reduces negative environmental impacts but also supports sustainable industry, which is planned to be implemented by 2031.
The preliminary design of a humic acid plant from low-quality coal with a design capacity of 100,000 tons annually was motivated by the growing market demand for the product. The plant will operate around 24 hours a day, 330 days a year. The process of extracting humic acid from coal involves three main stages: initial extraction, oxidation, and secondary extraction. The process runs at a pressure of 1 atm, with an extraction temperature of 60°C using potassium hydroxide (KOH) and an oxidation temperature of 50°C using hydrogen peroxide (H2O2).
After that, the extracted humic acid is precipitated at 35°C and 1 atm of pressure using an acid solution, in this instance hydrochloric acid (HCl). To get a more concentrated and purer solid-phase humic acid product, the extracted humic acid must be precipitated to separate it from the extraction solution. On a two-hectare area of land in the Lawang Kidul Subdistrict of Muara Enim Regency, South Sumatra Province, the plant is expected to be developed and employ 255 people in total. Utility units at the plant support the production process. These units include a 4,825 kg/h water supply unit, a 965 kg/h fire water supply unit, a 907.89 kW electricity supply unit, a process air supply unit, and an instrumentation and combustion air supply unit.
This plant needs $48,917,940.91 in working capital and $20,697,018.77 in fixed capital to complete the production process. Given its low risk and 64.73% pre-tax and 48.54% post-tax ROIs, this plant is deemed to be well-managed. 1.36 years prior to taxes and 1.74 years following taxes is the payback period (POT). At 41.99% of production capacity, the break-even point (BEP) is reached, and the discounted cash flow rate of return (DCFRR) is 22.88%. The plant is economically favorable and deserving of more investigation based on these economic evaluation characteristics.
Kata Kunci : batubara, kualitas rendah, asam humat