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Demand for liquid cryogenic products is constantly growing. The creators of cryogenic liquid air separation plants (ASP) aim at further reduction of energy consumption when producing liquid oxygen, its extracting from the air and liquation. The analysis of various ASP schemes allows finding an effective solution of this problem for further introduction into small-tonnage plants. Applying the medium-pressure of expander-compressor unit in the ASP makes it possible to reduce energy consumption from 1.10 to 1.04 kWh per kg of produced liquid oxygen without using additional source of cold. Modernization of the investigated ASP will yield energy savings up to 216.000 kWh per year, and also will increase liquid oxygen output by 56 t compared with conventional plant.

This paper presents experimental results of the performance and exhaust pollution of spark ignition engines using gasoline-ethanol blended fuels at the rates of ethanol 0, 10, 15, 20 and 25% by volume. The experiment was conducted on the Daewoo A16DMS experimental engine at the internal combustion engine laboratory of the Danang University of Science and Technology. Experimental conditions were established to characterize the engine speed at the throttle position of 50% for the speed range from 1250 to 4500 rpm. Results show an improvement in torque, power, fuel consumption and engine emissions when using E10, E15, compared to gasoline (E0) at 50% throttle valve opening at speed range from 2000 to 4500 rpm; The E20 and E25 are at a disadvantage at all speeds. The presence of the ethanol in gasoline remarkably reduces the emission of CO and HC but increases NOX simultaneously.

The object of research is wells with a low temperature gradient of less than 2–2.5 °С per 100 m (regions of Tataria, Bashkiria, Udmurtia, etc.). In studying the layout of a device for utilizing geothermal energy, a system analysis method was used. And in the course of the study of the sucker rod pumping unit (SRPU) and the electric centrifugal pumping unit (ECPU), the comparative analysis method is used.The paper discusses the possibility of energy savings in the exploitation of oil fields located in regions with low geothermal potential of development facilities. A method for solving the problem is considered as an option for the integrated use of not only the petrothermal energy of the subsoil, but also the hydrokinetic energy of the formation water. It is shown that the utilization of low-temperature geothermal energy due to its combination with the utilization of the hydrokinetic energy of the water pumped through the RPM system (maintaining reservoir pressure) is economically beneficial. This is due to the fact that the method proposed in the work has a number of features, in particular, production (reactive) wells are equipped at the wellhead with thermoelectric generators that convert the thermal energy of the formation fluid into electrical energy. The use of such devices will reduce the cost of electricity to power the electric drive DPE (deep pumping equipment) and other consumers of electricity in the well. Electricity generated by thermoelectric DC modules is summed from all thermoelectric converters. The received energy is sent along the line to the power supply system of the ACS-TP (automated process control system). Thanks to this, it is possible to obtain electrical energy from low temperature wells. Compared with similar known classical methods, when the gas factor of the produced products is sufficiently high (³80–100 m3/t), the use of associated gas is used to power electric gas and turbine generators that generate power for DPE directly at the production well. However, this method of utilization of associated gas at a late stage of development is not economically feasible, since in this case it is extremely low for its implementation.

The article is dedicated to the effective management of the project activity of the energy service of a company and the management of a system of planned-prophylactic maintenance of electricity equipment.To solve this problem we have constructed a tree graph of the objectives of the project of development of power systems. We have determined the goal, sub-goal and the functions of management of energy services and the management of a system of planned-prophylactic maintenance of electricity equipment of a company.The target model of management of the project activity of the energy services of a company and the management of a system of planned-prophylactic maintenance of electricity equipment describes the goals of management of project activity of the energy service of a company and the management of a system of planned-prophylactic maintenance of electricity equipment, taking into account the decomposition into sub-goals.The functional model of project activity of the energy service of a company and the management of a system of planned-prophylactic maintenance of electricity equipment describes the functions of management of project activity of the energy service of a company and the management of a system of planned-prophylactic maintenance of electricity equipment, taking into account the decomposition into the elements to achieve the global goals of the object.

Despite a sufficient energy supply, harvesting energy from rainfall is essential for intelligent water management. A significant part is still untapped or little exploited, which is the renewable energy produced from rainwater. This paper proposes a portable gutter of the rainwater energy harvesting system to provide electricity that may be sufficient for powering lights and charging cell phones in rainy locations with limited electricity. A prototype is designed and tested to determine the feasibility of rainwater as a source of renewable energy. The aim is to minimize and respectively suspend the use of fossil energy sources, as well as decrease the percentage of pollution as it is a cause of global warming. The system prototype consisted of a gutter assembly that collected and funneled water from the roof to a downspout. The turbine was connected through a gearbox to a DC motor serving as the generator. The device is optimal during high rainfall intensities that produce larger flow rates. A smart algorithm has been applied, which is salutary to keep the system working and has the ability to control the flow of collected rainfall water. Also, this system is useful to install and use in the rural area where the national grids are not common and the level of rainfall is high. The applied system utilized and installed in more than one hundred premises can produce more than 4 kWh for one rain. In some countries such as Malaysia, the average number of rainy days is 250 days a year, so the use of this system in 100 premises can help to provide 80 MWh to the national grid yearly. The system is characterized by simplicity of design and lack of complexity in addition to ease of installation and cheapness, which is the basis for the availability of this system for use by everyone

Currently Indonesia is still heavily dependent on fossil fuels as an energy source. To reduce dependence on oil and meet global enviromental requirements, one way is with the development of enviromentally friendly fuel that is and alternative energy derived from plant oil called biodiesel. This study uses a Completely Randomized Design (CRD) with five treatments, S1 (Reaction transesterification 1 hour), S2 (transesterification 2 hours), S3 (transesterification 3 hours), S4 (transesterification 4 hours), and S5 (transesterification 5 hours) with three replications. The data were analyzed using ANOVA, continued by DNMRT at 5 % level. The results showed that the transesterification reaction time significantly (P0.05) on influenced the acid number, total glycerol, flash point, saponfication. The analysis has been carried obtained the best treatment is S5 with the results said saponfication (103.52 mg KOH/g), the acid value (1.29 mg KOH/g), total glycerol (0.19 %), viscosity (2.21 cSt), water content (0.02 %), flash point (115°C ), and the level of methyl ester (99.32 %).

This study was performed to evaluate the input-otput energy for oil palm production and to identify the possibility to save energy consumption for activities related to oil palm production. Observation was conducted at PTPN VII Farm Unit of Rejosari, South Lampung. The energy inputs included human power, fuel and electricity as well as indirect energy resulted from the use of farm machinery, fertilizer, and pesticide. Energy outputs to be considered were resulted from full fruit bunch (FFB) consisted of crude palm oil (CPO), palm kernel oil (PKO), fiber, shell, empty fruit bunch, and trunk. The study revealed that total energy input of 57,63 GJ.ha-1 was required in oil palm production. Maintenance of productive plant consumed the highest energy, that was 33,06 GJ.ha-1 or 57,37 % of the total energy input. Based on energy sources, fertilizer was the most important input for oil palm production, accounted for 31,22 GJ.ha-1 (51,18 % of total energy input). The study also concluded that oil palm production generated energy output of 339,14 GJ.ha-1 with energy rasio of 5,88, energy productivity of 0.258 kg FFB per MJ, energy intensity of 3,87 MJ per kg FFB, and net energy gain of 281,51 GJ.ha-1. Penelitian ini bertujuan untuk menganalisis energi masukan-keluaran dan mengidentifikasi kemungkinan penghematan energi pada proses budidaya kelapa sawit. Penelitian dilakukan di PTPN VII Unit Usaha Rejosari, Lampung Selatan dengan mengamati semua energi yang digunakan dan dihasilkan. Energi masukan terdiri dari tenaga manusia, bahan bakar, energi tidak langsung dari pupuk, pestisida, dan alat-mesin pertanian. Energi keluaran berasal dari tandan buah segar (TBS) dengan komponen minyak sawit, minyak inti sawit, serat, cangkang, dan tandan kosong, serta pelepah. Hasil penelitian menunjukkan bahwa budidaya kelapa sawit memerlukan energi masukan sebesar 57,63 GJ.ha-1 dan menghasilkan energi 339,14 GJ.ha-1. Sebagian besar energi masukan adalah penggunaan pupuk yang mencapai 31,22 GJ.ha-1 (54,18 % dari total energi masukan). Berdasarkan tahapan budidaya, maka pemeliharaan tanaman produktif memerlukan energi yang paling besar yaitu 33,06 GJ.ha-1 (57,37 %). Budidaya kelapa sawit menghasilkan energi neto 281,51 GJ.ha-1 dengan rasio energi 5,88, produktivitas energi 0,258 kg TBS/MJ, dan intensitas energi 3,87 MJ/kg TBS.

Production of biodiesel comes from trans-esterification reaction of fatty acid which produces methyl ester. Vegetables, animals and microalgae can be used for fatty acid sources by their oil, but microalgae have a more beneficial prospect compared to vegetables and animals. Microalgae have fast grow-rate, high oil productivity, low production cost and not having a competition with food industries. Among microalgae, Botryococcus braunii is the one with high oil quantity inside their cells (25 – 75 %). The wastewater of tofu industries is liquid residual from soybean processing becomes tofu which having a nuisance for the environment. This wastewater, usually called whey, is still containing organic materials such as water (99,34 %), protein (1,73 %), fat (0,63 %), nitrogen content (0,05%) and ash (0,11 %) and COD. Organic materials have effect to stimulate microalgae's growing. Objectives of this experiment are the influence of tofu whey addition at different concentrations toward biomass and lipid produced. This experiment provided the result which optimal cultivation of Botryococcus braunii reaches when using 10% concentration tofu whey with optimal optical density (OD) at day 9 (0,802), 2,4101 gram/litre of gained biomass and 0,8716 gram/litre of lipid production.,better than cultivation of Botryoccus braunii using syntetic nutrient. Maximum COD reduction was gained at 15% tofu whey addition with 88,51% efficiency. COD reduction at optimal tofu whey addition (10%) is 83,33%.

Under conditions of limited organic resources, polluted external environment, excessive emission of carbon in the atmosphere and as a result of global warming the use of renewed energy sources may become one of ways of solving problems of energy saving, energy efficiency, environment protection, energy independence from import raw materials. The active use of renewed energy sources will favor the increase of economic efficiency and competitiveness of components of the national AIC. The article indicates that during the last 20 years the world underwent worsening of natural-climatic and living conditions, climate change, strengthening of negative natural phenomena and so on. The aforesaid problems of the world scale were discussed at the International climatic conferences (Brazil – 1992; Japan – 1997; SAR – 2002; Paris – 2015; Germany – 2017), while considering the complex of questions as to improving the natural-climatic and living environment in the world, saving use of natural resources, acceleration of using renewable energy sources (RES), especially solar one. It was elucidated, that during the last years the power of solar energy stations (SPS) grew essentially. For the end of 2015 the leaders if setting SPS were the following countries: China, Germany, Japan, USA. In Ukraine the plan of development of the Combined energetic system for 2016–2025 years of SE «NEC «Ukrenergo»» provided the association of SPS power with electric nets of energy system with volume 1641.2 MW. There was realized the grouping of Ukrainian regions by the level of the technically achievable potential of solar energy. There was realized the assessment of the economic efficiency of products at using solar energy in the agroindustrial business in different regional conditions of Ukraine.

Potency of Agrriculture Sector as the Producer and the User of Renewble EnergyDevelopment of a dynamic world energy consumption within the limitation of fossil energy reserve as well as the awareness on the environmental conservation evoke the increase of interest on a renewable energy, especially a renewable energy resources from agriculture sector such as food crops, horticulture, estate commodities and animal husbandry. To be more specific, the main commodities are paddy, maize, cassava, coconut, palm oil, sugarcane, Jatropha curcas, sago, and large livestock (Cow/Cow waste). The potency of bio-energy derived from plant biomass residue of agriculture sector (without wood industry, maize) is around 441.1 GJ. At the same condition, in 2000, it is estimated roughly 430 million GJ or just about 470 million GJ if the residue of wood industry is included. Estimated that if the availability of bio-energy derived from the main production of agriculture commodity is calculated, so that Indonesia could provide bio-energy potentially amounted to 360.99 million GJ, therefore, the total amount would be around 802.09 million GJ. In contrast, the value is approximately equal to the continuous operating of more than 25 thousand units of electric power of renewable energy power for middle scale of 10 MW which is now being campaign. Agriculture sector is not only plays the role as the producer of a renewable energy, but also forms as a potential user. Alongside technology development of energy and agriculture sectors, the equivalent estimation between the production and the USAge of renewable energy in agricultural sector need to be studied continuously. This evaluation is useful to analyze the efficiency of agribusiness activities in Indonesia based on the improvement of national agriculture productivity and environmental conservation through renewable energy. RINGKASANPerkembangan kebutuhan energi dunia yang dinamis di tengah semakin terbatasnya cadangan energi fosil serta kepedulian terhadap kelestarian lingkungan hidup, menyebabkan perhatian terhadap energi terbarukan semakin meningkat, terutama pada sumber-sumber energi terbarukan di sektor pertanian seperti komoditi tanaman pangan, hortikultura, perkebunan dan peternakan. Secara lebih sempit lagi, diungkapkan komoditas-komoditas utamanya, yaitu padi, jagung, ubikayu, kelapa, kelapa sawit, tebu, jarak pagar, sagu serta ternak besar (sapi/kotoran sapi). Potensi bioenergi asal residu biomassa tanaman dari sektor pertanian (tanpa industri kayu kehutanan, jagung) adalah sekitar 441,1 juta GJ. Pada kondisi sama pada tahun 2000 diperhitungan sekitar 430 juta GJ, atau sekitar 470 juta GJ jika residu industri kayu dimasukkan. Jika diperhitungkan tersedianya bio-energi dari hasil pokok komoditas pertanian (nira, gula, minyaknya dll), maka diperkirakan Indonesia dapat menyediakan bioenergi secara potensial sejumlah 360,99 juta GJ, sehingga jumlah totalnya sekitar 802,09 juta GJ. Sebagai perbandingan, nilai tersebut kira-kira setara dengan pengoperasian terus menerus lebih dari 25 ribu unit pembangkit listrik tenaga energi terbarukan skala menengah ukuran 10 MW yang saat ini sedang dikampanyekan. Sektor pertanian selain sebagai penghasil energi terbarukan sekaligus merupakan pengguna potensial. Perhitungan keseimbangan antara produksi dan penggunaan energi terbarukan di sektor pertanian, perlu dikaji secara terus menerus, seiring dengan perkembangan teknologi di bidang energi dan pertanian. Evaluasi ini akan bermanfaat untuk menilai efisiensi kegiatan agribisnis di Indonesia dari segi peningkatan produktivitas pertanian nasional dan pelestarian lingkungan melalui energi terbarukan.