ALTERNATIVE METHOD OF THE ACTIVATION PROCESS FOR BENTONITE MINERAL

Biodiesel manufacture usually applies liquid catalyst (homogenic catalyst) that deals with some obstacles, such as difficulty in catalyst product separation as they are in the same liquid phase, corrosive characters, excessive catalyst cannot be reused, and complicated to be handled. An alternative for a better process is solid catalyst as a heterogeneous system between raw material and product. Bentonite has layer structures and a potential to be used as solid catalyst by activation process. Three methods of activation process had been conducted,namely 60°C-heating; 60°C-heating followed by 1 week settling and 2 weeks settlement. Each method was performed in sulphuric acid and the chemical content of Al2O3 and SiO2 was observed. An activated bentonite has a molar ratio of SiO2 and Al2O3 between 6 - 9. All methods resulted in expected molar ratio, but the 2 weeks settlement process without heating provided more significant result which means it performed energy saving compared to other methods

PENINGKATAN KADAR BIJIH BAUKSIT KIJANG DAN TAYAN DENGAN METODE SCRUBBING

Untuk mengembangkan potensi bauksit di Tayan dan Kijang, Pusat Penelitian dan Pengembangan Teknologi Mineral dan Batubara (Puslitbang tekMIRA) telah bekerjasama dengan PT. Antam Tbk., mengkaji peningkatan mutu bijih bauksit. Bahan baku yang digunakan terdiri dari empat macam percontoh bijih bauksit yang diambil dari dua lokasi yaitu dari Kijang tiga percontoh, sedangkan dari Tayan satu percontoh. Percontoh dari Kijang memiliki kadar SiO2 total 18,36 - 29,16 %, SiO2  reaktif 7,54 - 9,84 %, Al2O3  40,12 - 48,36%,  Fe2O3  4,27- 5,13 %, TiO2  0,40 - 0,49% dan LOI 20,80 -23,45 %. Percontoh dari Tayan memiliki kadar SiO2 total 4,69 %, Al2O3 38,95%,  Fe2O3 19,67 %. Proses peningkatan mutu (upgrading) bauksit menggunakan scrubber (molen) dengan kondisi berubah waktu putar antara 0- 60 menit dan kondisi tetap 50 % padatan dan putaran 30 rpm. Tahapan proses scrubbing meliputi pencampuran dan pemercontohan, scrubbing, pengayakan, pengeringan, penimbangan, penggerusan, dan analisis kimia. Parameter mutu yang digunakan adalah persen kumulatif ukuran butiran +1,7 mm (+ 12 mesh), perolehan Al2O3, kadar SiO2  total, SiO2 reaktif , Al2O3, dan Fe2O3. Uji coba proses scrubbing ini telah memberikan hasil yang baik ditinjau dari peningkatan kadar, perolehan dan rasio konsentrasi. Kadar Al2O3 hasil uji coba berkisar antara 50,53-53,67% dengan perolehan berkisar 82,78-89,66% dan rasio konsentrasi 78,42-84,8%. Bauksit tercuci yang dihasilkan ini telah memenuhi syarat untuk dijadikan bahan baku pembuatan alumina melalui proses Bayer

ALTERATION OF MONTMORILLONITE CLAY TO SOLID ACID CATALYST BY HEATING AND ACID SOAKING

Commercial biodiesel production nowadays still uses sodium hydroxide solution as homogenous catalyst. This catalyst has some weaknesses, which cannot be reused and difficult on its separation from the product (methyl esther). Therefore, alternative catalyst is necessary to be sought to solve the problem and solid catalyst from clay has a possibility to be applied. Montmorilonite clay is widespread mineral in Indonesia and its layer structure is potential to be used as solid catalyst. The alteration processes consist of upgrading montmorillonite content followed by activation and esterification to review its performance. Previous activa- tion was carried out using aqueous sulphuric acid of 0.05; 0.5; 5 and 10 M and settled in each solution for two weeks. To obtain shorten activation time, modified method has been done with similar acid strength range but using preheating 60°C for 6 hours and settled within a week. Clay’s performance was observed by esterification reaction using Palm Fatty Acid Distillate (PFAD) of fried oil production waste as raw material. Its initial and final acid number were then reviewed. The conversion of PFAD to esther was measured from deviation of initial of final acid number. Previous method’s result of 2 weeks settlement showed maximum conversion of 91.6% at 5M acid strength of activation, while modified method reached maximum conversion only 67.63% at similar acid strength of activation. Both results were not yet resemble the 5M sulphuric acid solution as homogenous catalyst which is able to convert PFAD to esther as much as 98.73%. However, the method of 2 weeks settlement could be developed further to gain the optimum conversion

BENEFISIASI LEMPUNG BOGOR UNTUK KATALIS PADAT DALAM SINTESIS BIODIESEL

Dalam upaya mencari alternatif katalis padat untuk sintesis biodiesel, telah dilakukan benefisisasi lempung mengandung monmorilonit asal Nanggung, Bogor. Benefisiasi dilakukan melalui pengadukan kasar dan pemisahan monmorilonit dengan hidrosiklon. Monmorilonit keluar dari hidrosiklon sebagai aliran atas dan diaktifasi dengan asam sulfat melalui perendaman dengan konsentrasi 0,05; 0,5; 5 M selama dua minggu. Lempung aktif yang dihasilkan diuji angka asam dan kinerjanya dalam esterifikasi lemak nabati dengan pembanding katalis asam sulfat. Hasil pengujian menunjukkan, angka asam lempung dapat ditingkatkan dari asalnya 2,06 mmol H+/gram berturut-turut menjadi 2,46; 2,87; dan 2,98 mmol H+/gram, setelah diaktifasi dengan asam sulfat 0,05; 0,5; dan 5 M. Juga kemampuannya mengkonversi lemak nabati menjadi ester dapat ditingkatkan dari 50,36% berturut-turut mencapai 64,89; 67,11; dan 70,96 %. Kemampuan konversi lempung aktif tersebut dapat mencapai 72 % dari kemampuan konversi katalis asam sulfat