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Penelitian ini bertujuan untuk mengetahui kesesuaian lahan, penerapan dan pengembangan teknologi budidaya tambak sehingga potensi sumber daya yang tersedia dapat dimanfaatkan secara optimal dan lestari. Metode penelitian yang digunakan adalah metode survei yaitu mengumpulkan data dari sampel yang diambil secara acak terdiri dari 59 rumah tangga perikanan dan kesesuaian lahan tambak menggunakan Sistem Informasi Geografis. Hasil Penelitian menunjukkan bahwa Kelurahan Waetuo dengan luasan tambak 343,288 ha memiliki luasan tertinggi dengan rincian S1 = 297,303 ha dan S2 = 45,985 ha. Sementara itu, Kelurahan Bajoe memiliki luas tambak terendah yaitu 57,036 ha dengan rincian S1 = 35,958 ha dan S2 = 21,078 ha. Jika ditinjau dari penerapan teknologi, pada umumnya pembudidaya tambak yang ada di lokasi penelitian menggunakan sistem teknologi tradisional yaitu secara polikultur sekitar 88 % sedangkan monokultur hanya 12 %. Berdasarkan hasil penelitian disimpulkan bahwa lahan tambak di Kecamatan Tanete Riattang Timur sudah sangat sesuai dan pada umumnya menggunakan sistem teknologi tradisional secara polikultur.

Pada tahun 2018, 37,5 juta ton tandan kosong kelapa sawit (TKKS) diproduksi di Indonesia dan berpotensi untuk digunakan sebagai bahan bakar padat. Namun, ada dua masalah utama dalam penggunaan TKKS sebagai bahan bakar padat, yaitu nilai kalor yang rendah dan kandungan kalium yang tinggi. Oleh karena itu, EFB perlu melalui beberapa proses terlebih dahulu yaitu torrefaction dan washing. Namun, ketika torrefaksi dilakukan terlebih dahulu diperkirakan dapat mempengaruhi kinerja pelindian kalium. Metode studi literatur digunakan dalam penelitian ini untuk mengetahui pengaruh torrefaksi terhadap pelindian kalium TKKS. Penelitian diawali dengan pengumpulan data torrefaction dan leaching dengan perlakuan perendaman dan pengadukan yang dilakukan pada TKKS dari berbagai sumber. Data tersebut kemudian dianalisis dan disimpulkan menjadi 4 zona dekomposisi, yaitu zona rendah (100℃ ≤T200℃ ), zona sedang (200℃ ≤T≤250℃ ), zona tinggi (250℃ T≤330), dan zona ekstrem (T330℃ ). Berdasarkan hasil analisis, TKKS pada zona rendah dan zona sedang dipilih sebagai zona yang sesuai untuk dilakukan torrefaksi pada TKKS karena nilai kalor TKKS dapat mencapai nilai kalor batubara peringkat Lignite A, sedangkan untuk zona sedang telah setara dengan batubara peringkat C sub-bituminus. Berdasarkan nilai kalor yang dapat dicapai dengan mempertimbangkan proses leaching yang tepat untuk diterapkan, torrefaksi pada 200℃ dianggap dapat menghasilkan produk torrefaksi yang optimal untuk TKKS. Kemudian, untuk menurunkan kadar kalium pada zona rendah dan sedang hingga suhu bias 230℃ , perlakuan perendaman terbukti dapat menurunkan kadar kalium rata-rata 52,2%. Untuk mengoptimalkan penurunan kandungan kalium, TKKS perlu direndam pada suhu lingkungan dengan perbandingan air cucian terhadap biomassa 30:1 selama minimal 15 menit. ABSTRACT In 2018, 37.5 million tons of palm oil empty fruit bunches (EFB) were produced in Indonesia and have the potential to be used as solid fuel. However, there are two main problems in using EFB as a solid fuel, which are low heating value and high potassium content. Therefore, EFB needs to go through several processes first, namely torrefaction and washing. However, when torrefaction is carried out first is thought to be able to affect the potassium leaching performance. The literature study method was used in this study to investigate the influence of the torrefaction on the potassium leaching of EFB. The research is begun by gathering data of torrefaction and leaching by soaked and stirred treatment, carried out on EFB from various sources. Then, the data is analyzed and concluded into 4 decomposition zones, namely the low zone (100℃≤T200℃), the moderate zone (200℃≤T≤250℃), the high zone (250℃T≤330℃), and the extreme zone (T330℃). Based on the results of the analysis, TKKS in the low zone and the moderate zone are selected as the appropriate zone to do torrefaction on EFB because the heating value of EFB could achieve Lignite A rank coal heating value, while for the medium zone has been equivalent to sub-bituminous C rank coal. Based on the heating value that can be achieved while considering the right leaching process to be applied, torrefaction at 200℃ is considered could produce the optimal torrefaction products for EFB. Then, to reduce the potassium content in low and moderate zones to a refractive temperature of 230℃, the soaked treatment has been proven to reduce potassium content by an average of 52.2%. As for optimizing the reduction in the potassium content, EFB needs to be soaked at environmental temperatures with a ratio of washing water to the biomass of 30:1 for at least 15 minutes.

Pembakaran bersama batubara dan biomassa di pembangkit listrik tenaga batubara yang ada sedang dipertimbangkan sebagai alternatif yang layak untuk transisi pemanfaatan energi yang tidak terbarukan ke terbarukan. Dalam hal ini, berbagai penelitian telah dilakukan dalam dua puluh tahun terakhir, yang sebagian besar kesimpulan umum adalah bahwa efisiensi boiler menurun sehubungan dengan peningkatan persentase biomassa dalam co-firing, namun studi tambahan dianggap diperlukan, terutama untuk limbah biomassa yang melimpah di Indonesia. Biomassa limbah yang akan digunakan dalam penelitian ini adalah tandan kosong kelapa sawit (TKKS), sekam padi, dan wood pellet yang dihasilkan dari serbuk gergaji. Karakteristik termodinamika pembakaran co-firing yang akan digunakan dalam penelitian ini adalah air-to-fuel ratio (AFR), emisi CO2 pembakaran, dan temperatur nyala adiabatik. Sebuah open source Cool Prop formulasi sifat termodinamika diimplementasikan untuk mengevaluasi sifat termodinamika bahan yang sesuai yang terlibat dalam penelitian ini. Hasil penelitian menunjukkan bahwa AFR menurun dengan bertambahnya komposisi biomassa dalam bahan bakar, dimana laju perubahan masing-masing AFR per persen biomassa adalah -0,018, -0,0406, dan -0,026 untuk campuran batubara-TKKS, batubara-sekam padi, dan batubara-kayu. Adapun karakteristik AFR, emisi karbon dioksida menurun dengan meningkatnya persen massa biomassa dalam komposisi bahan bakar. Laju perubahan CO2 sehubungan dengan persen biomassa dalam komposisi bahan bakar adalah masing-masing -6.3x10-3, -1.12x10-2, dan -6.48x10-3 untuk campuran batubara-TKKS, batubara-sekam padi, dan batubara-kayu. Suhu nyala adiabatik juga menurun sehubungan dengan peningkatan persentase massa biomassa dalam komposisi bahan bakar. Laju perubahan suhu nyala adiabatik dalam K/%biomassa berturut-turut adalah -13,93, -10,70, dan -12,81 untuk campuran TKKS batubara, sekam padi, dan kayu batubara.Co-firing of coal and biomass in an existing coal fired power plant is being considered as a viable alternative to transition from non-renewable-to-renewable energy utilization. In this regard, various researches have been conducted in the last twenty years, in most of which the general conclusion is that the boiler efficiency decreases with respect to increasing biomass percentage in co-firing, nonetheless, additional study is deemed to be required, especially for waste biomass which are abundantly available in Indonesia. The waste biomass to be employed in this study are palm empty fruit bunch (EFB), rice husk, and wood pellet produced from sawdust. Co-firing combustion thermodynamic characteristics which are to be deployed in this study are air-to-fuel ratio (AFR), combustion CO2 emission, and adiabatic flame temperature. An open source CoolProp of thermodynamics properties formulations were implemented in order to evaluate thermodynamic properties of corresponding materials involved in this study. The results of the study show that AFR decreases with increasing biomass composition in the fuel, where the AFR rate of change per percent of biomassa are -0.018, -0.0406, and -0.026 for blend of coal-EFB, coal-rice husk, and coal-wood, respectively. As to the AFR characteristic, the emission of carbon dioxide is decreasing with increasing percent mass of biomass in the fuel composition. The CO2 rate of change with respect to percent biomass in fuel composition are -6.3x10-3, -1.12x10-2, and -6.48x10-3 for the blend of coal-EFB, coal-rice husk, and coal-wood, respectively. The adiabatic flame temperature is also decreasing with respect to increasing biomass mass percentage in fuel composition. The adiabatic flame temperature rate of change in K/%biomass are -13.93, -10.70, and -12.81 for the blend of coal-EFB, coal-rice husk, and coal-wood, respectively.

Dried coal typically had certain Particle Size Distribution (PSD) resulting from the size reduction process. Effect of PSD to the compaction phenomenon was investigated on the binary mixtures of In...

Some cultivators depend on the owners of capital, such as traders and entrepreneurs, so there is dependence on the owners of the capital. This study aims to determine the main factors that influence the development of seaweed cultivation; measure the contribution of these main factors to the development of seaweed cultivation, and determine the strategy for developing seaweed cultivation in Tanete Riattang District. East. Data were collected using observation, interview, and participatory rapid appraisal methods. Data were analyzed qualitatively. The results show that the main factors that influence the development of seaweed cultivation are the availability of 85.9% land with decent conditions, labor, business feasibility of 1.34 based on OI/Ratio analysis, access to capital, marketing results, post-harvest handling, and local government policies. Together and integrated, the main factors contribute to supporting and hindering the development of seaweed aquaculture. Possible development strategies These are land management and construction design of cultivation methods, application of long line and floating raft methods in offshore waters, activating extension of the "behavior" system (training and visits), setting planting schedules, technical guidance on cultivation and business management, forming Joint Business Groups (KUB), planning cultivation locations by involving stakeholders, zoning coastal and marine areas, forming partnerships between cultivators and entrepreneurs, and providing capital assistance with a revolving system and credit with interest subsidies.

Indonesia consumed 410,454 GWh of electricity in 2015, with the average electricity consumption of 918.6 kWh per-capita. This number is still below the national energy policy mandate that targeting of 2,500 kWh per-capita by 2025. To meet the target, it is necessary to increase the installed capacity of power plant by identifying and utilizing the potential of local energy, particularly from renewable energy resources. This gap between electricity supply and demand is one of the most common energy modeling research areas in developing countries. Proper and efficient execution of policy play a vital role in the implementation and adoption of innovations, such as: potency of energy diversity by using waste to energy (WtE) technologies to generate electricity over conventional power generation. Within this context, a system dynamic (SD) model was developed to identify the most suitable policy from the long term perspective to generate electricity from municipal solid waste (MSW). The methodology explains the feedback loop through causal diagram. Additionally, it also explains the involvement of various stakeholders and the variables necessary for the implementation of WtE in Indonesia. The policy instruments included in the model are: land availability, MSW management, WtE technology options, electricity generation and GHG emission reduction. Furthermore the model was exercised in the Bandung area. The results show that combinations of the above mentioned policy instruments significantly increase the supply of electricity, reduce the GHG emission, decrease the available land needed, and increase the share of renewable energy.

Municipal solid waste (MSW) has the great potential to be next generation of solid fuel. However, it has major drawbacks of low calorific value and low bulk density. Low calorific value results smaller energy and the low bulk density develop problems during the handling, transportation, and storage. Combination of torrefaction and briquetting offer solutions for those problems. Torrefaction is the thermochemical process in the inert condition used to produce high calorie solid fuel. Meanwhile, briquetting is a densification process used to increase the bulk density of the powder material. In this research, the process employs starch material contained in MSW as the binder to create agglomeration among the particles. In order to understand the role of starch as binder, this study was initiated by performing binderless briquetting at low pressure employing starch material, rice, as binder and torrefied orange peel as the representative of MSW. The experiment was varied in various parameter such as the rice composition in the briquette, briquetting temperature and rice torrefaction temperature. The products were then evaluated for its quality by comparing its briquette strength using drop shatter test method. The result showed that the optimum rice torrefaction temperature to produce durable briquette from torrefied MSW material was 175 ℃.

Municipal solid waste has the potential to become renewable energy resource. As solid fuel however, municipal solid waste has many problems caused by its low bulk density. Briquetting process is widely used to overcome the problem of low bulk density in solid fuel. Organic fraction of solid waste is benefited with lignin as one of its constituent which could be utilized as internal binder in hot briquetting process. To provide better understanding of lignin characteristic as internal binder, briquetting research was commenced in two stages using dry leaves as the representation of organic fraction in municipal solid waste, which contains 35.14% lignin. First stage was aimed to search the opportunity for evaluating lignin characteristic with variance of briquetting pressure. The second stage was used to investigate the binding characteristic of lignin as briquetting temperature increased in the range of lignin phase transition from glassy to liquid phase. The mechanical strength of produced briquette was measured using drop shatter test. Experiment results show that briquetting pressure of 500 bar could be utilized to evaluate the lignin characteristic in briquetting process. Highest performance of lignin as internal binder in briquetting was obtained at temperature 164 °C. In this temperature, briquette with DSI as high as 83% could be provided. The improved quality of lignin in green strength condition was probably caused by mechanical interlocking and adhesion effect that appeared during hot briquetting process.

A combination of wet torrefaction and binderless briquetting processes, namely torre-briquetting process, has been developed in Indonesia to treat the mixed municipal solid waste into a solid fuel. A mixture of organic and plastic waste was treated in a 2.5 L reactor using saturated steam in the temperature range of 175 to 225°C. Afterwards, the products were briquetted in varied pressure of 500 to 1000 bar. It was observed that the wet torrefaction process at the temperature of 225°C, residence time of 30 min and sample-to-water ratio of 1:2.5 was able to produce the solid product with heating value of up to 5923 kcal/kg, equivalent to that of bituminous coal. In the briquetting aspect, the briquetted product showed adequate drop test durability of 90% at 1000 bar briquetting pressure. The density of the briquette however, has not reached the standard of 1000 kg/m3, presumably due to the presence of large sized plastic in the briquette. The results suggest that by employing wet torrefaction, the organic fibers in the mixed waste are trapped into the plastic matrix, producing granules which are suitable for briquetting. Therefore, the torre-briquetting process can be a revolutionary solution to treat the MSW without any separation required to produce high caloric solid fuel.

Gas turbine for a power plant has 72 pieces of cone burner in its combustion chamber. High-speed diesel oil (HSD) is use as fuel to produce 130 MW of power at 3,000 rpm. The maximum temperature at the turbine inlet is estimated about 1087oC and at the outlet is between 400-540oC. Sixty percent of the cone burner failed repetitively at one side of the tip-end after 6,000 hours of service. The refurbished cone burner has to be replaced by a new one after 18,000 of service-hours. The cone burner material is cast Hastelloy-X (nickel based alloys). Metallurgical analyses by microstructural observation using optical and scanning electron microscopes, and energy dispersive spectroscope have been performed to observe the change in burner microstructure. Thermodynamics analysis has been performed to obtain temperature distribution around the failed section. Two failed cone burners have been examined; cone burner that has not been repaired, and that has been repaired twice. Thermodynamics analysis result shown that the temperature around the failed section is between 897 to 1087oC. Microstructure of the good part, far from the failed section, consists of cast structure of austenite matrix and fine carbide particles. Severe carbide precipitation and growth was observed on the failed section even the nominal carbon content in material is only 0.10% (max.). Severe carbide precipitation occurred because of carbon ingress from the environment (carburization) which combines with carbide forming elements in material (chromium, molybdenum, and tungsten). As a result, the corrosion and oxidation resistance of material decreased significantly after long time exposure at high temperature that led to oxidation, thinning, and failure of the cone burner tip. Failure only localized on one side of the tip-edge, therefore refurbishment by welding and coating can be performed to extend the life cycle of cone burner. The current examination results shows that the replacement cycle is not only limited to 18,000 hours but can also be extended to 48,000 hours.

Less utilized empty fruit bunch (EFB) is seldom used as solid biofuel due to its high alkali content that potentially cause ash deposit called slagging and fouling. This phenomenon could harm biomass-fired power plant equipment. Some pre-treatment of EFB is needed to reduce EFB ash deposit potential. The effect of wet torrefaction pre-treatment in laboratory scale was successfully proven in decreasing slagging and fouling potential while increasing EFB calorific value that could fulfill clean solid fuel criteria. This research focuses on wet torrefaction process that conducted on a pilot scale with the capacity of 250 liters. It was found that wet torrefaction process can improve the product's calorific value up to 9.41% while reduce its ash content down to 1.01% comparing to the raw EFB. The reduction of ash content also leads to the reduction of slagging and fouling tendency that presents in terms of alkali index. Alkali index is a quantitative method that can be calculated after obtaining metal oxides fraction on solid fuel. Metal oxides could be obtained by using energy dispersive x-ray spectroscopy.

The development of new practices in nuclear reactor safety aspects and optimization of recent nuclear reactors, including the APWR and the PHWR reactors, needs a knowledge on natural convective heat transfer within sub-channels formed among several nuclear fuel rods or heat exchanger tubes. Unfortunately, the currently available empirical correlation equations for such heat transfer modes are limited and researches on convective heat transfer within a bundle of vertical cylinders (especially within the natural convection modes) are scarcely done. Although boundary layers around the heat exchanger cylinders or fuel rods may be dominated by their entry regions, most of available convection correlation equations are for fully developed boundary layers. Recently, an experimental study on natural convective heat transfer in a subchannel formed by several heated parallel cylinders that arranged in a hexagonal configuration has been being done. The study seeks for a new convection correlation for the natural convective heat transfer in the sub-channel formed among the hexagonal vertical cylinders. A new convective heat transfer correlation equation has been obtained from the study and compared to several similar equations in literatures.

Gasification is a conversion process converting carbon-based solid fuel into gaseous products that have considerable amount of calorific value. One of the carbon-based solid fuel that serves as feed for gasification is coal. Gasification gaseous product is termed as syngas (synthetic gas) that is composed of several different gases. Syngas produced from gasification vary from one process to another, this is due to several factors which are: feed characteristics, operation condition, gasified fluid condition, and gasification method or technology. One of the utilization of syngas is for combined cycle power plant fuel. In order to meet the need to convert carbon-based solid fuel into gaseous fuel for combined cycle power plant, engineering adjustment for gasification was done using related software to create the syngas with characteristics of natural gas that serve as fuel for combined cycle power plant in Indonesia. Feed used for the gasification process in this paper was Indonesian Low Rank Coal and the method used to obtain syngas was Modified Fixed Bed Gasifier. From the engineering adjustment process, the yielded syngas possessed lower heating value as much as 31828.32 kJ/kg in gasification condition of 600°C, 3.5 bar, and steam to feed ratio was 1 kg/kg.Syngas characteristics obtained from the process was used as a reference for the adjustment of the fuel system modification in combined cycle power plant that will have the same capacity with the conversion of the system's fuel from natural gas to syngas.