In this article, we will discuss the production process of semi-refined carrageenan (SRC). This article is written by a team of academics from the Chemical Engineering Department of Sepuluh November Institute of Technology in 2023.
Carrageenan is a linear polysaccharide with galactose as its monomers, extracted from seaweed of the class Rhodophyceae. Carrageenan is available in semi-refined and refined grades, where the semi-refined grade still contains cellulose, while the refined grade does not contain cellulose.
The production process of semi-refined carrageenan consists of 3 stages, namely pre-treatment, extraction, and advanced processing unit. In the pre-treatment, a screw conveyor is used with a flow of clean water from top to bottom and a flow of seaweed from bottom to top, along with a crusher or rotary knife granulator to cut the clean seaweed. The next stage is extraction. In the extraction process, the seaweed is boiled in an alkaline solution, specifically 12% KOH with a KOH:seaweed ratio of 30:1, at a temperature of 90°C for 30 minutes. The further processing unit consists of a washing process. Washing is done twice with pressing using a water volume 30 times greater to lower the pH to 8-10. The pressing is done using a hydraulic press. Then, the wet carrageenan is dried using a tray dryer at a temperature of 87.5°C and a pressure of 1 atm. Next, the intermediate product is transferred to a ball mill to turn it into flour with an 80 mesh size. To inform about the safety of KOH, we attach its MSDS here.
According to this article, to produce 1500 tons of semi-refined carrageenan (SRC) per year, with 330 working days per year and 24 working hours per day, 10.3 tons of dried seaweed, 299 kg of KOH, 1.4 million liters of water, and 57.4 tons of steam per day are needed. The total investment required for the SRC plant is approximately USD 27 million, consisting of CAPEX of USD 19.5 million and OPEX of USD 7.5 million. The author recommends the establishment of the SRC factory in Takalar Regency, South Sulawesi. The economic parameters are an IRR of 18.31%, a payback time of 7.48 years, and a BEP of 38.2%.