Telah dilakukan penelitian mengenai upaya peningkatan kadar etanol pati singkong karet dengan adsorpsi. Penelitian ini bertujuan untuk mengetahui peningkatan kadar etanol sebelum dan setelah adsorpsi pada berbagai variasi ukuran partikel adsorben CaO. Variasi ukuran partikel adsorben yang digunakan yaitu 60, 80, 100, dan 120 mesh. Penelitian dilakukan dengan tiga proses yaitu pembuatan serbuk CaO, pembuatan bioetanol dan upaya peningkatan kemurnian bioetanol. Serbuk CaO dibuat melalui kalsinasi batu kapur. Pembuatan bioetanol terdiri dari 4 tahap yaitu pretreatment, hidrolisis, fermentasi dan distilasi. Upaya peningkatan kemurnian bioetanol dilakukan dengan adsorpsi berbagai variasi ukuran serbuk CaO. Hasil penelitian menunjukkan kadar etanol pati singkong karet sebesar 33% mengalami peningkatan dan penurunan saat berinteraksi dengan serbuk CaO 60, 80, 100, dan 120 mesh berturut-turut sebesar 33,333%; 36,667%; 43,333% dan 25%. Data kadar etanol hasil adsorpsi dianalisis menggunakan Uji Kruskal Wallis, Uji Duncan dan Wilcoxon. Hasil Uji Kruskal Wallis menyatakan bahwa terdapat pengaruh nyata kadar etanol pada  variabel bebas ukuran partikel sebuk CaO; Uji Duncan menyatakan terdapat perbedaan bermakna kadar etanol pada interaksi 100 dan 120 mesh, sedangkan perbedaan tidak bermakna pada 60 dan 80 mesh; dan Wilcoxon menyatakan adanya perbedaan pH sebelum dan setelah adsorpsi. Bersadarkan uji tersebut peningkatan kadar etanol maksimum didapatkan saat berinteraksi dengan adsoben CaO 100 mesh.

Kata kunci: Kadar etanol pati singkong karet, adsorpsi, CaO, ukuran partikel adsorben, mesh.

            Research has been conducted on the efforts to increase rubber cassava starch levels with adsorption. This research aims to determine the increase in ethanol levels before and after adsorption in various sizes of CaO adsorbent particles. Variations of the adsorbent particle size used are 60, 80, 100, and 120 mesh. The research was conducted with three processes, produsction of CaO powder, bioethanol production and efforts to increase the levels of bioethanol. CaO powder is made through limestone calcination. Production of bioethanol consists of 4 stages that isi pretreatment, hydrolysis, fermentation and distillation. Efforts to improve the levels of bioethanol are carried out by adsorption of various sizes of CaO powder. The results showed a rubber cassava starch rate of 33% increased and decreased when interacting with the CaO 60, 80, 100 and 120 mesh in a row of 33.333%; 36.667%; 43.333% and 25%. Data was analyzed using statistics including test Kruskal Wallis, The Duncan Test and Wilcoxon. Results of the Kruskal Wallis test is that there is a noticeable influence on the levels of ethanol in particle size variables of the CaO; The Duncan test states there is a meaningful difference in ethanol levels in the interactions 100 and 120 mesh, while differences are meaningless at 60 and 80 mesh; and Wilcoxon expressed a pH difference before and after adsorption. According to the the test, increased maximum ethanol levels gained when interacting with the CaO 100 mesh adsorbent.

Keywords: Ethanol levels of cassava rubber starch, adsorption, CaO, particle size of adsorbent, mesh.