The aim of this paper is to investigate boron species in coals in order to research partitioning of boron in pulverized coal-fired process. Some extracted coal samples using specific gravity separation and these LTA (Low Temperature Ash) samples were treated with leaching of pure water. Solid-state MAS 11B-NMR spectra of these coals and LTA samples were obtained. Chemical shift of boron species in coal was observed both trigonal and tetrahedral coordinated boron and existent ratio was different with kinds of coal. It was estimated that a part of boron in coal was existed as water-soluble compounds and its chemical form was boric acid and its anhydride, borate of alkaline and alkaline earth metals, and then these compounds minutely dispersed in organic matter of coal.
Biomass is a carbon neutral material and the development of processes for the use of the bioethanol is being accelerated worldwidely, as its demand for an alternate transportation fuel is increasing. The bioethanol has advantages such as low environmental impacts and high octane number. However, its heat of combustion per unit volume is about 70% of that of gasoline. Even an expected cost by a future NREL process is ¥30/kg-ethanol, it is much higher than an assumed production cost of gasoline of ¥25/l (crude oil, $30/bbl). In order to make the production cost of bioethanol competitive to that of gasoline, the bioethanol process should be rationalized. We reported on the rationalization of the refinement process of the bioethanol in the former report and also the rationalization of the fermentation process using corn stover as biomass resource. Herein, we report on the rationalization of the pretreatment process which uses hot water without sulfuric acid. The cost reduction by the rationalization of the pretreatment process is ¥1.5/kg-ethanol. The production cost of bioethanol is decreased by ¥3.5/kg-ethanol by whole process improvements and calculated to be ¥26.3/kg-ethanol.
Biomass is a carbon neutral material and the development of processes for the use of the bioethanol is being accelerated worldwidely, as its demand for an alternate transportation fuel is increasing. In order to make the production cost of bioethanol competitive to that of gasoline, the bioethanol process should be rationalized. We reported on rationalized process using corn stover as biomass resources. The production cost of bioethanol was decreased by 3.5¥/kg-ethanol by whole process improvements and calculated to be ¥26.3/kg-ethanol. Here, the results of rationalized process design and cost estimation of ethanol using cassava pulp instead of corn stover as biomass resource are reported. Cassava pulp is cheaper than corn stover based on unit ethanol production, however its composition is characterized as low cellulose and hemicellulose, and high starch and water contents compared to those of corn stover. The rationalized process was proposed under the consideration of those complex characteristics of cassava pulp. The production cost of bioethanol could be decreased to ¥22.2/kg-ethanol due to the rationalization in the pretreatment process and the saccharification process. The cost reduction of about ¥8/kg-ethanol or 26% compared to by the future NREL process was obtained.
Carbonization of model garbage under hydrothermal condition was examined, and then compared with dry condition. The char yields obtained from the model garbage using hydrothermal condition were equal to those using dry condition. The yield and its carbon content at 573K, 0h under hydrothermal condition are 43wt% and 68wt% respectively. The heating value of the char was 30MJ/kg at 573K under hydrothermal condition. As it is higher than the obtained char (25MJ/kg) under dry condition, it is suitable for use as a fuel.