Haryono, S.T., M.T. Dosen Pembimbing 2 Yeni Komalasari / 142002012 Penulis Deviyanti Septina / 142002031 Penulis 2 Carlina D.A, Ir., M.T. Dosen Pembimbing 1

In the process of making tempe, it always produce waste in the form of washing liquid and the soybean skin. In this case the soybean skin which is thrown a way as a soaking result and washing of soybean hasn't been used optimally. Until now it is only has been used as a mixture of stock feed. The soybean skin is composed of polysacharide and ±40% are cellulose. The substantial cellulose has a economic value if it is processed to be oxalic acid. Oxalic acid is a chemical compound that has many applications. Oxalic acid can be used as a cleaner for automotive radiators, bleaching agent in the textile and wood industry, as a pH modifier in leather tanning, rust remover for metal treatment, removing calcium in water for waste water tratment and for neutralizes excess alkalinity in laundries. In this research oxalic acid is produced by reacting the soybean skin with the fusion using alkali (NaOH). The skin is fusioned with strong base until it produce oxalic acid. In the process of making oxalic acid there are four steps that must be done which are fusion, precipitation and filtration and acidification. In this research has been done some variation, they are ratio of concentration of NaOH which are 45%, 50%, 55%, 60% and also fusioning time which are 60, 90, 120 and 150 minutes. From the result of this research we find the optimum condition at concentration of NaOH 50% and fusioning time at 90 minutes. At optimum condition the yield of oxalic acid is 12,735 gram (25 ,74%).In the process of making tempe, it always produce waste in the form of washing liquid and the soybean skin. In this case the soybean skin which is thrown a way as a soaking result and washing of soybean hasn't been used optimally. Until now it is only has been used as a mixture of stock feed. The soybean skin is composed of polysacharide and ±40% are cellulose. The substantial cellulose has a economic value if it is processed to be oxalic acid. Oxalic acid is a chemical compound that has many applications. Oxalic acid can be used as a cleaner for automotive radiators, bleaching agent in the textile and wood industry, as a pH modifier in leather tanning, rust remover for metal treatment, removing calcium in water for waste water tratment and for neutralizes excess alkalinity in laundries. In this research oxalic acid is produced by reacting the soybean skin with the fusion using alkali (NaOH). The skin is fusioned with strong base until it produce oxalic acid. In the process of making oxalic acid there are four steps that must be done which are fusion, precipitation and filtration and acidification. In this research has been done some variation, they are ratio of concentration of NaOH which are 45%, 50%, 55%, 60% and also fusioning time which are 60, 90, 120 and 150 minutes. From the result of this research we find the optimum condition at concentration of NaOH 50% and fusioning time at 90 minutes. At optimum condition the yield of oxalic acid is 12,735 gram (25 ,74%).