Energy efficiency is crucial for many developing countries, including Indonesia. One of the solutions is to shift fossil fuels to an alternative source of energy, like biomass which is also available abundantly. Biomass conversion technique like gasification using palm empty fruit bunch is essential considering its potential in Indonesia. Advanced technology with a cost-effective and highly efficient gasification process is required to promote this method, especially in a rural area. Computational analysis for design and initial study is mandatory because gasification involves complicated chemical reactions. Biomass gasification characteristic was investigated using Computational Fluid Dynamic (CFD) program STAR CCM+. The Eulerian-Lagrangian concept was employed to model the gaseous phase (air) and solid phase (biomass particles) of biomass gasifier accordingly. Each of the gasification syngas formation - i.e., CO, N2, CH4, and H2 respectively - were analyzed. The objective of this paper is to characterize biomass gasification steps started with drying, thermal decomposition/pyrolysis, partial combustion of gases, vapor, and char, and finished with the gasification of decomposed products.

The paddlewheel aerator is one of the supporting facilities in the intensive aquaculture pond system. Assuming all the land uses an intensive cultivation system, more than two million paddlewheels worth more than 10 trillion will be needed by 2024. Currently, all paddlewheels are produced abroad or imported. This is very unfortunate considering the vast market potential. This paper discussed a preliminary study of developing paddlewheel aeration for shrimp ponds using an integrated intelligent aquaculture system to support intensification. Two paddlewheel aerators with modifications in the gearbox have been successfully installed. Based on the observation and user’s testimony, the newly installed paddlewheel was quite good, the sound of the motor was smooth, then the flow range was longer, the coverage area was more expansive than the existing waterwheel. This research would be a foundation for intelligent paddlewheel aeration design that can be developed domestically to support local industry in Indonesia.

Torrefaksi saat ini menjadi salah satu metode konversi biomassa yang menarik karena kemampuannya sebagaisalah satu pilihan energi terbarukan. Bahan bakar campuran batu bara dengan biomassa yang telah mengalamiproses torrefaksi dipandang sebagai bahan bakar yang paling murah saat ini dan merupakan metode yangmenjanjikan. Pemilihan bahan bakar biomassa berdasarkan karakteristiknya sangat diperlukan untukmemastikan agar proses pembakaran dapat tercapai dengan baik. Dua tipe residu biomassa dari hutan (tandansawit kosong dan bambu) telah diteliti dengan berbagai suhu penahanan torrefaksi dan waktu penahanantorrefaksi yang berbeda. Hasil penelitian menunjukkan hubungan positif antara suhu dan waktu torrefaksidengan kenaikan nilai kalor. Kadar air juga menurun bersamaan dengan semakin tingginya suhu dan makinlamanya waktu torrefaksi. Mass yield dan energy yield biomassa hasil proses torrefaksi juga telah dianalisis.Residu biomassa dari hutan yang telah melalui proses torrefaksi terbukti dapat menggantikan batu bara sebagaibahan bakar energi terbarukan.

The selection of the hull shape below the waterline becomes very important to improve performance and minimize emission during the design stage of the fast boat hull. To understand the performance comparison between the monohull and twin-hull of the same length and width, an analysis was carried out on an 8 m fiberglass ship with Maxsurf. Performance analysis was carried out with Hydromax for hydrostatic performance and ship stability and Hullspeed to analyze the performance of ship resistance and power. Hydrostatic Wetted Surface Area and transverse metacenter radius for the monohull were 13.883 m2 and 1.486 m, while a catamaran shows 12% to 24% higher WSA and 2% to 3% higher BMt compared to a monohull. The resistance and power of the ship at 40 knots for monohull were 24267.07 N and 1116.09 HP. In contrast, the catamaran shows up to 74% increase. Stability arm and radius of gyration show as follow: 0.297 m and 0.631 m for a monohull, while a catamaran shows up to 140% higher max GZ and 222% GMt. The results of this study can be used as a reference for determining the use of a monohull or catamaran hull in the early stages of a fast boat design.