PEMBUATAN ASAM OKSALAT DARI SEKAM PADI

Rice husk is one of the agricultural waste containing cellulose. The oxalic acid can be produced from this material through 4 steps: reaction, precipitation, acidification and crystallization. Rice husk contain 52,5% of cellulose and 12,03% of water, could be converted into oxalic acid by alkalin process. Experiments were carried out in a three necks glass equipped with a thermometer, mixer, heater and water cooler. Cooking solution were varied 0,5 1,0 1,5 2,5 3,5 4,5 and 5,5N of NaOH solution and cooking time were 30, 45, 60, 75, 90 and 105 minutes. A maximum oxalic acid conversion at about 0,8417 or 44,19% mass of rice husk was obtained from cooking of 25 gram rice husk in 250 ml of 3,5N NaOH solution at a solution boiling temperature for 75 minutes and 225 rpm mixer. Oxalic acid conversion increased at 30 to 75 minutes and at 0,5 to 3,5N of NaOH solution. Key word:rice husk, cellulose, alkaline process, oxalic acid