Fossil energy resources that are available in the world are exhaustible. Therefore, the renewable biomass resource has attracted a lot of attention as the future energy resource. In addition, it is an advantage that the biomass grows while absorbing CO 2 , contributing to the prevention of global warming. Biomass utilization technologies are classified as pyrolysis and gasification, fermentation, and combustion. Fuel gases and synthesis gases produced by the pyrolysis and gasification is used as power generation, heating, chemical products, etc. However, pyrolysis and gasification processes also generated condensable organic compounds, so-called "tar". Most tar contents are present as the gases at high temperature. However, when the temperature is cooled down lower than their boiling point, causing a black oily liquid lead to the equipment failure, the appropriate processing is required. As the processing method, using the catalytic tar decomposition has been widely studied.In the present study, we have carried out the thermal decomposition of cellulose, in the experimental apparatus modeling a fluidized bed gasifier. The thermal decomposition of cellulose, tar and gas is generated, tar is collected and cooled, and the gases were measured by a gas-chromatograph with a flame ionization detector (GC-FID) and with a thermal conductivity detector (GC-TCD). Then, K and Ca are selected as the catalysts of alkali metals and alkaline earth metals contained in the waste biomass. They are present in the state of oxide or carbonate during pyrolysis and gasification. We conducted a similar experiment. The amount of condensable products and heavy tar were decreased by installing K 2 CO 3 and Ca(OH) 2 . Additionally, they brought further gas production. It can be concluded that alkali metal compound (K 2 CO 3 ) and alkaline earth compound (CaO) have a catalytic effect to decompose tar contents, to enhance gaseous production.

Large amounts of waste fine coals are produced, which are difficult to be treated because of high ash content and inorganic sulfuric compounds. In order to make efficient use of waste fine coal, a retrieval technique is necessary for the recovery of coal combustible content from fine waste coals. Nowadays, the floatation process can be used, but it is impractical for developing countries due to high costs, then the oil agglomeration process can deal with these problems. In this study, we investigated the affecting factors of coal cleaning efficiency of oil agglomeration on the element content and chemical structure of three different grade coals because there are many grades of coals around the world. For determination of chemical content in three different grade coals, the help of proximate and ultimate analysis was used, and then for investigation of their chemical structure differences of carbonaceous content, a Fourier transforminfrared spectrometry (FT-IR) was applied. Furthermore, for the oil agglomeration experiments, kerosene and vegetable oil which differ in structure were used as aggregating agents. We used ash free coals or their mixed samples which were conditioned to the ratios of carbonaceous and ash content in order to make it the same contained amounts. From the results of the oil agglomeration experiments, it was concluded that the characteristics of agglomerate and the coal cleaning efficiency of oil agglomeration are not only influenced by the oil types, but also affected by the oxygenic content, aromatic and aliphatic chemical structures in different grade coals. Oxygenic function groups of carbonaceous content in coal samples ,

Recently, large amounts of waste fine coals have been produced which are difficult to treat because of the high ash content and inorganic sulfuric compounds. In order to make efficient use of waste fine coal, the retrieval technique is necessary for recovery of coal combustible content from fine waste coals. Nowadays a floatation process is able to operate, but it is impractical for developing countries due to high costs. An oil agglomeration process can deal with these problems. In this study, we investigate the mechanism of the solution interface reaction on oil agglomeration in order to separate pyrite sulfur effectively from waste fine coal. For this purpose, we adjusted the pH of the solution of oil agglomeration experiments to the basic condition, which changed the surface characteristics to hydrophilicity from hydrophobicity. Furthermore, pH and dissolved oxygen changes of the solution were continually monitored and free ferric ions of the waste liquid were measured by flame atomic absorption spectrometry. These factors have a relationship with the oxidation and surface reaction of pyrite sulfur in the solution. Under high basic conditions, pyrite sulfur reduction indicated high values since the pyrite surface became hydrophilic due to covering of the surface of the pyrite sulfur by ferric hydroxide. As a result, the pyrite content did not recover together with hydrophobic carbonaceous content especially under high basic conditions.