It is consumed much energy in fossil fuels to production crops in greenhouses in Japan. And fl ue gas as CO2 fertilization is used for growing crops in modern greenhouses. If biomass as renewable energy can use for production vegetables in greenhouses, more than 800,000 kl of energy a year (in crude oil equivalent) will be saved. In this study, at fi rst, we made the biomass combustion equipment, and performed fundamental examination for various pellet fuel. We performed the examination that considered an application to a real greenhouse next. We considered biomass as both a source of energy and CO2 gas for greenhouses, and the following fi ndings were obtained: 1) Based on the standard of CO2 gas fertilization to greenhouses, it is diffi cult to apply biomass as a CO2 fertilizer, so that biomass should be applied to energy use only, at least for the time being. 2) Practical biomass energy machinery for economy, high reliability and greenhouses satisfying the conservatism that it is easy is necessary. 3) It is necessary to develop crop varieties and cultivation systems requiring less strict environmental control. 4) Disposal of combustion ash occurring abundantly, effective practical use is necessary.
The purpose of this study is to investigate experimentally the characteristics of a pyrolytic gasifier. Two facilities were used. One is a 1⁄5 scale plastic model of the 6t⁄d pilot plant. With this model the relative solid circulation rate was measured. The second facility was used the lab-scale bubbling fluidized bed gasifier coupled with a pneumatically transported char bed combustor. Here, the gasification characteristics were investigated for a two-stage bubbling fluidized bed gasifier.The results revealed that a relative solid circulation rate above 20 could be achieved by control of fluidized bed height and pressure in the gasifier, therefore allowing self-sustaining operation. The combustor inlet showed severe wear; hence, for this part abrasion-resistant material must be used. Concerning gasification characteristics, the two-stage bubbling fluidized bed gasifier showed a remarkable increase in gasification efficiency and tar suppression. When gasifying Ca-impregnated fuel, however, no remarkable change in tar contents was observed. This result is interpreted such that tar can easily be reformed/destructed by a Ca-catalyst. A cold gas efficiency about 83.5 %, which is feasible for self-sustained operation, was still achieved at somewhat lower temperatures in the gasifier for Ca-impregnated fuel. Consequently, the operation of the pyrolytic gasifier is easy. However, for the lower temperature tar increased. Therefore, gas reforming at a subsequent stage of the gasifier is important.
Biomass utilities for high water content have very important signifi cance close future in Japan. Especially, London treaty for ocean disposal of wastes in 2007-6 has big problems to keep of sustainability provisions supply for our lives. We could calculate to exist total caloric thermal energy 124TJ⁄y (340GJ⁄dZ) in Pig wastes as domestic biomass energy. This study is doing fundamental experimental by thermal decomposition and combustion for Pig wastes. Thermal decomposition analysis investigates for gasifi cation and fi xed carbon combustion characteristics. Fundamental combustion experiment shows time dependent combustion process, ignition process, fl ame process and char combustion process.
Sugi thinnings with small diameter that are not suitable for lumber can be considered as important domestic energy resources. To utilize Sugi thinnings as alternative fuel of coal cokes, properties of compressive strength and heating value of compressed semi-carbonized wood fuel are investigated. To enhance the heating value, "semi-carbonization", that is the pyrolysis in the temperature range between 200 and 400 degree, is conducted. From the variation of heating value and energy yield of char with pyrolysis temperature, the semi-carbonization pyrolysis is found to be the upgrading technology to convert the woody biomass into the high energy density fuel at high energy yield. To increase the compressive strength, "Cold Isostatic Pressing" method is adopted. The compressive strength of the compressed wood fuel decreases with pyrolysis temperature, while the heating value increases. The drastic decrease in the compressive strength is observed at temperature of 250 degree. The increase in the hydrostatic compression pressure improves the compressive strength for an entire range of semi-carbonization pyrolysis. The alternative fuel with high heating value and high compressive strength can be produced by the semi-carbonization processing at temperature of 280 degree for wood fuel compressed at hydrostatic pressure of 200MPa.
Biomass pellet utilities are popular in North European as a pellet stove and boiler et al. But, we have a lot of problem on wood biomass utilities in social situations and geography conditions. Especially, to move of biomass from mountain area to user side transportation coast rises. Therefore, we have to improve for thermal energy characteristics in biomass based on moving. This technology is new carbonized technology for improvement of biomass thermal energy characteristics. This technology controls heated temperature and pressed force by hot-press method. Fundamental properties of biomass show thermal decomposition and ultimate analysis. In these results, we suggest to occur a half carbonized phenomena for improvement of thermal energy. Half carbonized phenomena begin approximately 540K in sawdust and 580K in cellulose. And, total calorifi c value suddenly increases in these heated temperatures. Sawdust could suggest occurring lower 40K to compare cellulose.
Based on un-use biomass utilities, Carbonized technology is noticed as material utilities and solid fuel. Therefore, this technology is tackling by national project as large-scale utilities. But, this technology is dehydrated volatiles matter during carbonized from biomass. Especially, Woody tar into one of volatile matter has vicious handling to get into trouble in carbonized equipment. In this study, we propose to get fundamental knowledge for effective thermal utility through thermal decompositions and fundamental combustion properties on experimental results. Woody tar has high caloric value (approximately 30MJ/kg) and high carbon ration. On the other hand, a woody vinegar liquid has thermal decomposition property close to water property with heat absorption as evaporation latent heat of water. In fundamental combustion experimental result, a woody tar has fl ammable combustion and surface combustion. Especially, a total combustion and ignition time properties has hyperbola relation to environment temperatures in furnace.