Indonesia produces a large amount of oil palm empty fruit bunch (EFB) that has potency used as media for mushroom cultivation. The research emphasized the use of EFB to grow oyster mushrooms as an alternative for delignification without chemicals. This research aimed to study the growth of oyster mushroom (Pleurotus ostreatus) at EFB based growing media treatments. The media consisted of a mixture of EFB and sawdust at the composition of 0%, 25%, 50%, 75%, and 100%. The media were also supplemented with rice bran, CaCO3, and TSP fertilizer. The data were collected on the mycelium growth and the mushroom weight. During cultivation in baglog, there was no difference in mycelium growth rate. The EFB composition of 25% showed faster growth among the other compositions, followed by the EFB composition of 50%, 75%, and 0%. The highest Biological Efficiency Ratio (BER) at 56.25% was obtained at media composition of 50%. The EFB contained in baglog also showed biodelignification process. Biodelignification has the benefit which can reduce the use of chemicals in the delignification process to convert EFB into cellulose. The highest lignin reduction (40.12%) occurred in 75% of EFB media composition, while hemicellulose (49.56%) occurred in 100% EFB media composition.

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Peningkatan kapasitas produksi biodiesel menyebabkan meningkatnya produksi gliserol. Salah satu cara alternatif untuk meningkatkan nilai ekonomi gliserol adalah melalui esterifikasi gliserol menjadi surfaktan, yaitu gliserol ester (GE). Penelitian ini bertujuan melakukan sintesis GE berbasis asam oleat sawit dengan waktu reaksi 180 menit menggunakan katalis p-toluenesulfonic acid (PTSA). Suhu sintesis yang digunakan, yaitu:140, 160, 180, dan 240°C. Hasil uji ANOVA dan Duncan (α = 0,05) menunjukkan bahwa suhu sintesis berpengaruh nyata pada rendemen, angka asam, dan viskositas. Proses sintesis GE optimum diperoleh pada suhu sintesis 160°C dengan nilai rendemen GE sebesar 95,66%, pH 7, nilai angka asam 11,28 mg KOH/g sampel, viskositas kinematis 75,76 cst, dan densitas 0,944 g cm-3. Suhu sintesis 160°C, 180°C, dan 240°C menghasilkan rendemen yang tinggi, berkisar 95,66-97,07% dan tidak berbeda nyata antara ketiganya. Analisis menggunakan metode Analytical Hierarchy Process(AHP) juga menghasilkan suhu terbaik untuk sintesis GE adalah 160°C. Produk GE yang terbentuk mengandung gugus ester, asam karboksilat, dan alkohol yang muncul pada 1240,41-1739,62 cm-1.[Kata kunci: biodiesel, esterifikasi, katalis PTSA, surfaktan]

Biodiesel saat ini menjadi bahan bakar terbarukan yang banyak diaplikasikan di beberapa negara, salah satunya Indonesia. Biodiesel dapat disintesis dari berbagai macam minyak nabati seperti minyak kelapa, kelapa sawit, biji bunga matahari, biji jarak, dan biji karet. Biodiesel memiliki kelebihan dibandingkan bahan bakar berbasis fosil karena tidak beracun, memiliki emisi gas buang yang lebih bersih, dan dapat digunakan murni maupun sebagai campuran dengan bahan bakar diesel petroleum. Teknologi produksi biodiesel biasanya menggunakan bahan baku minyak nabati dengan menggunakan teknik transesterifikasi yang merupakan salah satu teknik yang paling sering digunakan dalam produksi biodiesel. Proses yang terjadi berupa proses konversi asam lemak dari minyak dan methanol menjadi biodiesel dengan bantuan katalis homogen yaitu katalis asam atau basa. Penelitian ini menggunakan minyak nabati berasal dari minyak kelapa sawit dan minyak jarak pagar yang disintesis menjadi biodiesel dengan katalis KOH 1% (b/v). Hasil karakteristik biodiesel minyak sawit dan jarak pagar secara keseluruhan tidak berbeda dan masuk standar SNI 7182-2015. Kadar metil ester sebesar 97,66%; angka asam 0,25 mg KOH/g sampel; angka penyabunan 184,93; gliserol total 0,22; densitas 0,878 g/cm3.

Biodiesel in Indonesia is a mixture of Fatty Acid Methyl Ester (FAME) and diesel oil. Mixing FAME and diesel oil is challenging since FAME is separated from diesel oil at low temperatures. Changes in the physico-chemical properties of biodiesel during storage decrease biodiesel quality due to dissolved oxygen, potentially damaging the engine. Using glycerol ester (GE) as an additive can be an alternative solution to tackle that problem. This research examined the stability of GE-added biodiesel. As a comparison, commercial diethyl ether (DEE) additive was used. The concentration of additive added to biodiesel varied at 1000, 2000, and 3000 ppm while the storage temperature varied at 12, 25, and 42℃. The stability of biodiesel was evaluated for three months by measuring the acid value, viscosity, corrosion rate, and water content. The acid values ​​​​of the various types and concentrations of additives still meet the SNI 7182-2015 standard (0.5 mg KOH g-1 sample) with a value range of 0.148-  0.392 mg KOH g-1 sample. Kinematic viscosity had a value range of 3.12-3.58 cst, which also meets the SNI 7182-2015 standard (2.3-6 cst). The highest corrosion rate for GE and DEE was in the first week, with values of 0.447 and 0.261 mpy, respectively. Both B50 biodiesel control and the addition of 1000 ppm GE had the same water content value on the 18th day, which was 0.046%, and this value was considered the highest water content. This means adding an additive can maintain the water content in B50 biodiesel. Overall, GE additives in B50 biodiesel with various concentrations comply with SNI 7182-2015 standard.