Energi yang bersumber dari bahan bakar fosil merupakan komoditas penting bagi pembangunan ekonomi dan berkelanjutan. Namun, peningkatan populasi dan industrialisasi telah memberikan kontribusi yang signifikan terhadap inflasi permintaan energi secara global yang mengarah pada konsumsi sumber daya energi yang tidak terkendali. Oleh karena itu dibutuhkan alternatif pengganti bahan bakar fosil yang terbarukan dan berkelanjutan. Sumber bahan bakar alternatif salah satunya adalah biomassa seperti makroalga Ulva Lactuca yang memiliki kandungan utama protein, karbohidrat dan triasilgliserol dimana melalui teknik pirolisis dapat diproses menjadi bio-oil. Pada penelitian ini telah dilakukan pengujian proses pirolisis makroalga Ulva Lactuca dengan tujuan mengetahui laju kinetika dan besaran energi aktivasinya. Instrumen pada pengujian ini menggunakan Thermogravimetric Analysis (TGA). Ulva Lactuca yang sudah kering dicacah menjadi butiran-butiran halus dengan ukuran mesh 60, selanjutnya dikeringkan dalam oven listrik pada temperatur 1100C selama 4 jam kemudian dilakukan pengujian pada TGA pada heating rate berbeda: 10, 20 dan 30 K.menit-1 dengan temperatur maksimum 1224 K. Hasil penelitian menunjukkan dengan metode laju kinetika menggunakan alat uji TGA dapat menentukan besarnya energi aktivasi. Pada pirolisis makroalga Ulva Lactuca menunjukkan energi aktivasi terendah dicapai pada heating rate 20 K.menit-1 dengan nilai 5.508,607 [KJ.mol-1]. Energy sourced from fossil fuels is an important commodity for economic and sustainable development. However, increasing population and industrialization have contributed significantly to global energy demand inflation leading to uncontrolled consumption of energy resources. Therefore, an alternative to renewable and sustainable fossil fuels is needed. One of the alternative fuel sources is the Ulva Lactuca macroalgae biomass which has the main protein content, carbohydrates and triacylglycerol which through pyrolysis techniques such as bio-oil. In this study, the pyrolysis process of Ulva Lactuca was tested with the aim of knowing the kinetics rate and the amount of activation energy. The instrument in this test uses Thermogravimetric Analysis (TGA). Ulva Lactuca was chopped into fine granules with a mesh size of 60, then dried in an oven at 1100C for 4 hours then tested on TGA at different heating rates: 10, 20 and 30 K.min-1 with maximum temperature 1224 K. The results showed the rate kinetics method using the TGA test could determine the amount of activation energy. In the pyrolysis of Ulva Lactuca, the lowest activation energy was achieved at a heating rate of 20 K.min-1 with a value of 5.508.607 [KJ.mol-1].

Pandemi Covid-19 menyebabkan meningkatnya penggunaan layanan kesehatan yang sangat signifikan sehingga jumlah limbah medis yang dihasilkan akibat kegiatan ini cukup tinggi. Limbah medis termasuk ke dalam kategori limbah B3 yang harus ditangani dan dikelola dengan baik. Salah satu teknologi yang mampu mereduksi limbah tersebut yaitu insenerator jenis Fluidized Bed Combustion (FBC). Teknologi FBC ini menggunakan media pengaduk berupa pasir yang akan bercampur dengan bahan bakar dan dalam proses pembakarannya menggunakan temperature yang tinggi, namun dalam pembakaran tipe FBC ini memungkinkan terjadinya suatu aglomerasi di dalam reaktor. Salah satu yang menyebabkan terjadinya aglomerasi tersebut adalah pergerakan bed material dalam proses fluidisasi ini kurang maksimal. Oleh sebab itu, pada penelitian ini melakukan pengujian secara permodelan untuk mengetahui proses fluidisasi terhadap lonjakan bed material menggunakan software Circulating Particle Fluids Dynamic (CPFD) Barracuda Virtual Reactor. Dalam penelitian ini adapun variasi bed material yang digunakan adalah pasir silika dengan variasi diameter DA (0,2 mm), DB (0,5 mm), DC (0,8 mm), DD (1,1 mm). Kecepatan aliran udara fluidisasi ditetapkan sebesar 4 m/s dan tekanannya diberikan sebesar 1 atm. Menurut hasil simulasi, proses fluidisasi yang terbaik ditunjukkan oleh variasi pasir silika DA dengan tinggi lonjakan 80 cm dari permukaan reaktor. Sedangkan variasi diameter lainnya seperti DB, DC, DD berturut-turut tercatat hanya mencapai ketinggian 65 cm; 40 cm; 25 cm dari dasar rekator. The Covid-19 pandemic has caused the utilization of health services to be very significant so that the amount of medical waste generated from this activity is quite high. Medical waste is included in the category of B3 waste that must be handled and managed properly. One technology that can reduce this waste is the Fluidized Bed Combustion (FBC) type incinerator. This technology uses a mixture of sand mixed with fuel and in a high temperature combustion process, but in this type of FBC combustion it is possible for agglomeration to occur in the reactor. One of the causes of agglomeration is the movement of bed material in the fluidization process that is not optimal. Therefore, in this research, a modeling test was conducted to determine the basic material fluidization process using the Barracuda Virtual Reactor's Circulating Particle Fluids Dynamic (CPFD) software. Variations of bed material used are silica sand with a diameter of  DA (0,2 mm), DB (0,5 mm), DC (0,8 mm), DD (1,1 mm). The fluidization air flow velocity is set at 4 m/s and the applied pressure is 1 atm. Based on the simulation results, the best fluidization process is indicated by the variation of silica sand with a diameter of DA and a height of 80 cm from the reactor surface. While other diameter variations such as DB, DC, DD each recorded reaching a height of only 65 cm; 40 cm; 25 cm from the bottom of the reactor.

One of the main issues using biomass as fuel in air gasification is the dilution of its product gas by the nitrogen in the air. A dual reactor fluidized bed (DRFB) overcomes this problem in which the gasification and combustion reactions are decoupled and conducted in two separate fluidized bed reactors connected by circulating bed material. The DFRB unit made of 304 stainless steel pipe with a height of 100 and 150 cm, and inner diameters (i.d.) of 15.2 and 5.1 cm for gasifier and combustor respectively. The rice husk as fuel and quartz sand as bed material having the same size of 0.4 - 0.6 mm were applied in this investigation. Since the gasification process is an endothermic reaction, gasification temperatures are varied at 600°C to 700°C while combustion reactor were kept at 600°C using the electric heaters enclosed in ceramic cover. The superficial gas velocity in this study was kept constant at 17 m/s using the external air volumetric flux of the blower flow entering the DRFB loop. Gas gasification samples are then examined by gas chromatography to determine syngas content (CO, CH4 and H2). The test results showed that by the increasing temperature of the gasification reactor there was an increase in syngas especially CO gas conentration. The temperature increases in the gasification reactor (600°C, 650°C, 700°C) is able to increase the endothermic reaction in the gasification process which is dominated by CO gas production. The syngas efficiency was found to increase from 40.95% to 43.77%.as the temperature of the gasification reactor increased.

Terjadinya krisis energi mendorong pemerintah untuk melakukan upaya pengembangan bahan bakar alternatif, yang berasal dari sumber daya energi terbarukan, salah satunya adalah biomassa. Pada penelitian ini proses konversi energi biomassa dilakukan menggunakan teknologi dual reactor fluidized bed. Bahan bakar biomassa yang digunakan adalah sekam padi dan pasir silika digunakan sebagai material bed nya. Temperatur pada reaktor gasifikasi diatur antara 600-7000C dan temperatur pada reaktor pembakaran konstan pada 7000C. Hasil penelitian menunjukkan peningkatan temperatur pada reaktor gasifikasi berpengaruh terhadap meningkatnya fuel conversion rate pada proses gasifikasi. The occurrence of an energy crisis encourages the government to make efforts to develop alternative fuels, which come from renewable energy resources, one of which is biomass. In this study the biomass energy conversion process was carried out using dual reactor fluidized bed technology. The biomass fuel used is rice husk and silica sand is used as a bed material. The temperature in the gasification reactor is set between 600-7000C and the temperature in the combustion reactor is constant at 7000C. The results showed that the increase in temperature in the gasification reactor had an effect on increasing carbon efficiency in the gasification process.