Niigata University and TERI collaborated in developing a biomass gas turbine system with an enhanced fuel applicability for rural villages in south Asia. This paper describes a mixed and standard type gas turbine system for this purpose. The mixed type gas turbine employs a regenerated Brayton cycle with a secondary combustor to burn various fuels. The thermodynamic analysis revealed that the mixed type gas turbine system has a capability to achieve the thermal efficiency between a regenerated Brayton cycle and a complete external fired system. An experimental test was done using mixtures of bio diesel fuel and kerosene. It demonstrated that the engine performance changed only slightly with regard to the mixture ratio. In the experiment, a prototype biomass gas turbine was able to achieve the 600 W power generation. The mixed fuel with the mixture ratio of bio fuel up to 60 % was confirmed to be applicable to the current gas turbine system.
Forced deactivation examinations using biomass combustion ash and KCl, CaCl2 aerosol have been carried out to clarify deactivation mechanism of the V2O5-WO3/TiO2 type DeNOX catalyst for the exhaust gas from coal and biomass co-fired boilers. Commercial honeycomb-type catalysts were used for their examinations. Characterizations were performed by SEM/EDS and NH3-TPD for both fresh and deactivated catalysts. As a result of wet impregnation examinations by using water slurry of biomass combustion ash, DeNOX performance decrease with increasing ash concentration of slurry. Under the liquid water coexists, alkali metals move to a catalyst from biomass combustion ash and cause the chemical deactivation by poisoning of the active sites. In case of the KCl aerosol exposure examination, K component causes the chemical deactivation with time while diffusing in the catalyst inside. As for the CaCl2 aerosol exposure examination under the SO2 coexistence, CaSO4 is deposited in catalyst surface and promotes physical deactivation by clogging catalyst pore that cause the gas diffusion inhibition. As shortly described here, Alkali metals and alkaline earth metals cause the different deactivation mechanism each. The findings will contribute to develop DeNOX catalyst which can maintain good performance even in exhaust gas from biomass co-firing coal boilers.
Kalina cycle is a power generation system for waste heat source of low temperature. This cycle is mainly used to a single heat source. By the way, there are extremely large potential of waste heat having different temperature region simultaneously. There for, it is researched how to give the heat for raising the power output of system to the heat source of two or more heat sources. As the result, the power output of system which warming the separator former and latter part of a cycle directly by an exhaust gas, when evaluate for waste water (70°C) and exhaust gas (300°C) as heat source.
The purpose of this study is to investigate conventional photovoltaic (PV) and concentrator photovoltaic (CPV) system performance. The CPV system is operational in Okayama, Japan. The impact of different climates conditions on the system is studied. The system has been collecting data since 2011. The relationship between CPV performance and the environment is more complex than that of the conventional flat-plate PV. It is important to define the primary factors leading to these differences and accelerate installation as a clean energy generation. One of the factors is spectral distribution. Furthermore, the relationship between the I-V characteristics of the system and the environment parameter is discussed.
Effect of addition of CaO and ZrO2 to MgO/SiO2 catalyst, which is effective for synthesis of High Quality BioDiesel (HiBD) was investigated using atmospheric agitated reactor at 430°C and LHSV = 0.3 h-1. Binary MgOCaO/SiO2 and MgO-ZrO2/SiO2 catalysts and ternary MgO-CaO-ZrO2/SiO2 catalyst were prepared by the incipient wetness impregnation method. Physical properties of these catalysts were characterized by XRD and BET methods. Both the fatty acids and the triglycerides in waste cooking oil were converted into hydrocarbon gases, CO, CO2, water and hydrocarbon oil. CaO- and/or ZrO2-added catalysts gave higher CO2 yields than MgO/SiO2 alone, and showed lower acid values. These observation indicates that the added oxides promote the decarboxylation reactions. Iodine values also decreased to some extent by the addition of these oxides.
The present study develops a renewable energy-focused input-output table (REFIO) for the year 2013, which can quantitatively and objectively assess environmental and socio-economic impacts of renewable power generation technologies and policies. The REFIO was built on the latest input-output table for Japan, by disaggregating the original sectors and adding new sectors related to 12 different renewable power generation technologies, namely, four types of solar photovoltaic, wind, two types of geothermal, small-scale hydro, wood biomass, and three types of biogas. The new 41 sectors are created for the construction and operation of the above power generation facilities, using both open data such as government statistics and published industry information, and confidential data collected from companies, associations and non-profit organizations, etc. To demonstrate an advantage of the REFIO developed, output multipliers are estimated for the construction and operation sectors of different renewable power generation technologies. The output multipliers vary from 2.51 to 3.13 for the construction sectors and from 1.05 to 2.62 for the operation sectors, depending on the types of technology. The more important finding is that there are distinct differences among different technologies in terms of sectors where the greater production is indirectly generated.
Wet-biomass such as sewage-sludge is very large resources of renewable energy and carbon material. However, since such wet-biomass contains much moisture, it is necessary to be dried before energy utilization as fuel. Therefore, we have developed a carbonization process combined with drying by fermentation. This process consists of two steps; drying by aerobic fermentation without additional energy to vaporize the moisture, and carbonizing by heat generated from burning of only volatile-matter derived from the sludge. In this paper, we focus on the drying step. In drying step, wet-sludge received was immediately mixed with wood-chips of about 2 times by volume to make a heap for fermentation. The temperature in the heap increased rapidly up-to ca.80°C for several days, then decreased gradually. The moisture of the sludge decreased gradually with temperature from ca.80wt% to below 30 wt% for 40 ～60 days. During fermentation, the heap was re-built every 7～10 days. The dried sludge was fed to carbonization step after removing the wood-chips by sieving. We discussed the changes of the sludge properties by drying, and the effects of the heap size and air-flow-rate blown into the heap on the changes of temperature and moisture during fermentation.
A carbonization process combined with drying by fermentation has been developed to utilize effectively wet-biomass such as sewage-sludge. This process consists of two steps; drying by aerobic fermentation and carbonizing without fossil fuel for heating. In this paper, we focus on the carbonization step because we reported the drying step in the previous paper. We designed and constructed a carbonization plant to treat 1.0 t/h dried-sludge of lower 30wt% moisture. It consists of a rotary kiln heated externally and a combustor burning only volatile-matter from the sludge during stable operation of the plant. At a start of the plant operation, A-fuel is burned in the combustor to heat the kiln up to over 400 °C. Then the dried sewage-sludge of ca.30 wt% moisture is gradually fed into the kiln. These operations provided that the stable carbonization condition without A-fuel was temperature of 410 - 430 °C at the sludge feeding rate of 1.0 t/h. Under this condition, char yield was ca.50wt%, and its heating value and carbon content were ca.3,500 kcal/kg and 35 - 38 wt%, respectively. At present, the plant is continuously operated for around 3 weeks at once without fossil fuels except at start up.
Studies on palm oil cogeneration systems, and design and analysis to further improve the energy efficiency have been done based on process integration technology. The products during cogeneration are crude palm oil (CPO) and solid wastes which come from empty fruit bunches, fibers and nutshells. However, factors affecting the production of biomass and biofuel from solid wastes and crude palm oil from oil palm fruit bunches for the boiler-based and combustion-based cogeneration can be further explored. This study hence aims to determine these factors, and then expound further in forecasting the production volume of biomass fuel and biofuel produced during cogeneration. For this purpose, the multiple regression (MR) technique is employed, and the results based on the mathematical modelling concept are thus compared. Mathematical models on the production of oil palm fruit bunches are developed via the model-building processes. Data variables are transformed using the ladder-power transformation method from a data set of 31 observations. Two models are developed, namely, Model I is for the production volume on biomass fuel from fresh oil palm fruit bunches, while Model II is the production volume on liquid biofuel from crude palm oil (CPO). There are five independent variables in Model I, and four independent variables in Model II. The four-phase in multiple regression model-building are carried out to change the non-normal data to normality. The best model obtained by the model transformation method in Model I is M72.2.5 where the main factor is the total workers employed during last pay period, and interaction factors up to the second order are: harvested area interact with yield per hectare, harvested area interact with local delivery average price, harvested area interact with total workers employed during last pay period, yield per hectare interact with local delivery average price, harvested area interact with local delivery average price interact with total workers employed during last pay period and yield per hectare interact with local delivery average price interact with total workers employed during last pay period. The significant factors on the biomass production are the yield per hectare and the harvested area of the oil palm fruit bunches. The mean absolute prediction error (MAPE) value for the best model on model transformation Model II is 2.62 %. Thus, the best model using the model transformation method is said to be excellent and acceptable to forecast for the production volume of biomass fuel and biofuel during cogeneration.