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Abstract.A study has been conducted about the quality of young coal (brown coal ) briquettes from North Kolaka to determine the effect of varied adhesive on the proximate characteristics and calorific value. The young coal briquettes were made by using adhesives of starch, cassava starch and Castor oil plant starch at a concentration of 5 to 15% of the total mass. The grain size of young coal and the adhesive used were 60 mesh and 100 mesh, respectively. The samples were molded in a cylindrical mold with a diameter of 2.5 cm and a high of 6 cm, and with a pressure of 100 kg/cm 2 . After having been compacted, the young coal samples were then analyzed proximately i.e. moisture content, volatile matter, ash content and fixed carbon, as well as their calorific values calculation. The results showed that the increase of the adhesive could tend to increased the water content and volatile matter, but reduced the ash content, and the fixed carbon tend to constant except coal briquettes using starch adhesive it were increased. The calorific value of the young coal briquettes increased for all kinds of adhesives when the adhesive increased. The calorific value per one gram ranged from 3162.7 cal/g to 4678.7 cal/g. The highest calorific value, 4678.7 cal/g, was observed at the adhesive of 15 % of starch. The characteristics of young coal can be used as a raw material for making high-calorie hybrid briquettes.

The research area is located in Asera District, North Konawe Regency, Southeast Sulawesi Province which has ultramafic rock lithology. The purpose of this study is to determine the characteristics of ultramafic igneous rocks using petrographic and geochemical analysis. Petrographic analysis aims to determine the types and abundance of minerals present so that rock types can be determined based on the classification of Travis (1955) and Streckeisen (1976). The geochemical analysis aims to determine the oxide/major element so that it can determine the type of magma based on the AFM classification according to Irvine and Baragar  (1971) and the origin of the magma / original rock formation environment based on Pearce (1977).  Petrographic analysis results showed that ultramafic rocks in the study area consisted of 2 types of rocks namely peridotite consisting of wherlit and lherzoite and serpentinite.  The results of geochemical analysis indicate that the type of magma in the study area is thoellitic series and the origin of the magma/rock formation environment comes from the expansion of the oceanic floor or mid oceanig ridge (MOR) which is ultramafic.

Penelitian ini bertujuan untuk mengetahui pengaruh temperatur pirolisis terhadap kualitas fuel-oil dari limbah Polipropilena. Metode yang digunakan  adalah pirolisis cepat (fast-pirolisis) tanpa menggunakan katalis. Analisis fisis yang dilakukan meliputi: densitas, viskositas, dan nilai kalor. Limbah plastik Polipropilena dipirolisis dengan temperatur 450 oC, 500 oC dan 550 oC. Hasil analisis menunjukkan bahwa semua profil temperatur memenuhi standar bbm konvensional yang menyerupai BBM konvensional jenis bensin. Pada masing-masing temperatur pirolisis 450, 500 dan 550 °C diperoleh berturut-turut: rendemen 16; 64 ; 70 %; viskositas 0,76; 0,92; 1,12 cP, densitas 0,750; 0,764; 0.756 gr/ml dan nilai kalornya  11.388; 11.316; 11.356 kkal/kg. Berdasarkan analisis yang telah dilakukan bahan bakar minyak hasil pirolisis limbah plastik polipropilena dapat digunakan sebagai pengganti bahan bakar konvensional karena sudah memenuhi standar karakteristik bahan bakar sesuai American Standard and Testing Material (ASTM).

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