H. Kurokawa

Liquefaction Processes And Characterization Of Liquefied Products From Waste Woody Materials In Different Acidic Catalysts

The liquefaction process is one of the promising techniques for effective utilization of woody biomass, for the lignocelluloses can be converted to liquid reactive material, as eco-polymeric materials. Japanese cedar (Cryptomeria Japonica), as an abundant waste softwood material, was selected and used in our wood liquefaction experiment. In order to investigate the basic characteristics and potentially harmful metal contents, the composition and metal elements of waste woody samples had been determined, and based on the methods of Japanese Industrial Standard (JIS) and by an ICP-AES, separately. Then the waste woody samples were liquefied by a phenol wood liquefaction according to the orthogonal test L9 (3 4 ), in order to obtain relatively less residue by different reaction conditions. It is thought that sulfuric acid plays an important role in retarding the condensation reaction during the acid-catalyzed phenol liquefaction because of the dehydration, and it can be summarized that the most influential factors of the wood liquefaction conditions were obtained within the setting ranges on four factors and three levels by using the orthogonal tests. In the acidic catalyst comparison experiment, as a result, when using concentrated sulfuric acid as the strong acidic catalyst, the minimum of residual content had reached 9.71%. According to these experimental results, the new liquefied samples

Characterization of suspended particulate matter emitted from waste rice husk as biomass fuel under different combustion conditions

There are large quantities of waste rice husk, e.g. around 3 million tons are estimated as biomass waste every year in Japan. Air pollutants emitted from exhaust gases of rice husk incineration lead to very important environmental damage, not only because of the influence on global environment and climate, when released into the atmosphere, but also on human health due to local air pollution. Therefore, it is necessary to effectively utilize waste rice husk and to reduce air pollutants. In recent years, there is an increasing demand on the utilization of unused biomass instead of fossil oil fuel in combustors for farminggreenhouses heating during the winter season. This increase in the demand will increase the running costs. In general, since these combustors are small in size, there is lack of regulations or laws (e.g. the air pollution control act and the waste disposal and public cleaning law) in operation for their air pollution control. So far, small size combustors are characterized by their simplicity of structure and the low costs; therefore, they emit visible black carbon (elemental carbon) due to their poor combustion performance. In this study, we investigated if fossil fuel can be substituted by waste rice husk in laboratory model combustion experiments. We evaluated the emission behavior of harmful air pollutants emitted from rice husk combustion by measuring carbonaceous and ionic composition of suspended particulate matter in the exhaust gases. From the analytical results we found that particulate mass concentrations can be reduced substantially at high temperature combustion. Fine particle size distribution is different with combustion conditions (e.g. smoldering combustion, flaming combustion). Ionic composition is mainly

Investigation of condensation reaction during phenol liquefaction of waste woody materials

The liquefaction of waste woody materials in the presence of phenol and acid catalyst is a promising method for converting waste woody materials into phenolic resin. The condensation reaction during the liquefaction process is a major problem for its practical application. The effects of various reaction conditions on the extent of the condensation reaction were investigated. The residue content, molecular weight distributions and phenol concentration were measured to investigate the condensation reaction. As a result, it was observed that the intense reaction conditions caused fast liquefaction and led to a remarkable condensation reaction. It was also found that the residue content began to increase at an earlier reaction time when a more remarkable condensation reaction occurred. These results indicated that the condensation reaction was one of the causes for too much degradation of liquefi ed wood molecules under intense liquefaction. The phenol concentrations in the liquefaction products were measured to investigate their effect on the condensation reaction. It was shown that the phenol concentration was 8% lower at the end of the reaction when the condensation reaction was high. It was indicated that the drop in phenol concentration suppressed the liquefaction and promoted the condensation reaction. The addition of methanol during the liquefaction process suppressed the condensation reaction. The residue content was 11% when 50% methanol was added, while it reached 66% when methanol was not added. This can be because methanol reduced the bound phenol, which could be a reaction site of condensation

Reactivity for pyrolysis and Co2 gasification of alkali metal loaded waste wood char.

In this study, different carbonization processes were performed for thinning wood waste as organic industrial waste and forestry waste biomass to produce waste wood char, which is used as solid and gaseous fuel. Waste biomass samples were added to Na + (NaOH) using thermogravimetry with a differential thermal analyser (TG/DTA), where the behaviour of thermal decomposition and the effect of additive amount of alkali metal were investigated. Waste wood char yields were increased at the peak temperature and weight loss was decreased with the increment of Na + (NaOH) loaded value. The fi xed carbon amount of waste wood char was also increased with the maximum Na + (NaOH) loaded value at 100:1, and then it was decreased. Furthermore, in order to evaluate the effect of Na + (NaOH) loaded value on char reactivity, an isothermal CO 2 gasifi cation experiment was performed at temperatures between 700°C and 900°C for chars obtained by pyrolysis at 900°C. It was shown that the reaction rate was increased with increasing temperature and the reaction rate of raw char was markedly slower than Na + (NaOH) loaded char. The activation energies of char were in decreasing trend with increasing Na loaded value. However, the activation energies of CO 2 gasifi cation of char samples were conversely increased when Na + loaded on char sample was more than 50:1. If too large amounts of Na + (NaOH) were loaded on char sample, the rate of gasifi cation reaction and the activation energy will be decreased as Na + reacts with the char surface covering the gasifying agent.

Suppression method of the condensation reaction during phenol liquefaction of woody material

The liquefaction of woody materials in the presence of phenol and acid catalyst is a promising method to utilize the waste woody materials into phenolic resin. However, the condensation reaction is a major problem for its practical applications. In order to suppress condensation reactions, methanol was added to the liquefaction medium. Even the intense condensation reactions were suppressed by the addition of 50% methanol (mol% to phenol). The effect of methanol was further confirmed by the measurement of molecular weight distribution. In the case of mild condensation, addition of 5% methanol suppressed the production of the residues. At the same time, the liquefaction rates overall were faster than the case without methanol. It was inferred that the existence of methanol lowered the amount of combined phenol which could be the reaction site of the condensation reaction. On the other hand, larger amounts of methanol (100%) retarded the liquefaction rate and the consumption rate of phenol. The actual reaction temperature in the reactor was lower than the setup temperature of the oil bath when the methanol was added. The investigation of the IR spectra showed that there were almost no differences between the functional groups of the liquefied products obtained with and without methanol. The addition of small amounts of methanol could be applicable because the disadvantages of methanol addition could be reduced.

Process analysis of waste bamboo materials using solvent liquefaction

Bamboo is one of the significant biomass resources; it has been used in houses, flooring, construction of scaffolding and bridges, among others. The solvent liquefaction process is one of the promising techniques for effective utilization of waste bamboo materials for the lignocelluloses which can be converted to liquid reactive materials as biomass-based materials. Bamboo has the advantage of providing the liquefied products with a small range of variances. The components of bamboo have high acidity in the presence of mineral acid catalysts and possess the constituents which can react with polyethylene glycol 400 (PEG 400). In this study, waste bamboo materials have been used in liquefaction experiments. The liquefaction process and liquefied residue have been monitored according to the liquefied conditions and surface changes of waste bamboo samples observed by a scanning electron microscope. The changes in the functional groups have been analysed by a Fourier transform infrared spectrometer and behavior of the crystalline structures of liquefied bamboo has been determined by X-ray diffraction. Other experiments, such as degree of polymerization have also been carried out for confirming the results. Regarding the results, it was found that an increment of the temperature and the amount of the acid catalysts improved the efficiency of liquefaction. At the same time, the dissolution time of lignin was significantly shorter than the one of cellulose in the solvent liquefaction process of PEG 400.

Characterization of liquefied products from model woody components in the presence of mineral acid catalysts

Cellulose and lignin are the main structural polymers in the plant cell wall. Cellulose is the structural component of the primary cell wall of green plants, many forms of algae and the oomycetes. About 40–50% of woody matter is cellulose. Lignin is a highly cross-linked polymer created by the polymerization of substituted phenolic compounds, known as monolignols, such as coniferyl, pcoumaryl, and synapyl alcohol. Liquefaction process is one of the promising techniques for effective utilization of woody biomass for the lignocelluloses can be converted to liquid reactive materials as the bio-based materials. Cellulose would have an advantage of providing liquefied product with small range of variance. The phenolated woody components have high acidity in the presence of mineral acid catalysts and possess the constituents which can react with formaldehyde. In addition, lignin, one of the major woody components including the hydroxyl-benzyl structure, has the potential to react with formaldehyde. However, as its complexity in structure, the liquefaction mechanism and the liquefied products with phenol should be found out to solve some problems such as the reaction efficiency and low molecular weight products, and it will be useful to preparation of bio-based materials thought the liquefaction processes. In our study, two model woody components have been used under the different liquefaction conditions with phenol. In our experiments, the model cellulose component is specially used in the experiment to test the characteristics of the

Characterization Of Liquefied Waste Bamboo And White-rotted Wood

Due to the depletion of fossil fuel resources, the utilization of sustainable and renewable biomass is studied in various fields. Wood liquefaction is one of the applicable methods for material utilization of waste biomass. In this study, valueless waste bamboo and white-rotted wood were liquefied for reuse as an alternative plastic material. The waste bamboo samples were liquefied in polyethylene glycol (PEG) with sulfuric acid as a catalyst. Then, the molecular weight distribution of the contents of the liquefied bamboo samples was analyzed using gel permeation chromatography (GPC) and the residue mass was also measured in order to investigate the residue contents. At the same time, the white-rotted woody samples were liquefied in phenol with sulfuric acid as a catalyst. Rotted woody samples and liquefied contents were analyzed with X-ray diffraction (XRD) and determined by GPC, and the residue contents were also compared with the results of non-rotted woody samples. The waste bamboo samples were liquefied effectively under the reaction conditions of a temperature of 150°C, the acidic catalyst of 12% H₂SO₄ and 1/4 proportion of bamboo samples to solvent, respectively. The residue contents were the lowest at a reaction time of 30 minutes, and after that they were increased a reaction progressed. With the help of GPC analysis, it was found that the peaks of the contents of the liquefied bamboo samples at the initial reaction stage appeared at a high molecular weight distribution, which disappeared when the reaction progressed. When the white-rotted woody samples were liquefied, due to the low powder density, the samples did not perform well at the initial reaction stage. From GPC analysis of the liquefied contents, the liquefied tendency and the residue contents of the white-rotted woody samples seemed to be almost the same as those of the non-rotted original woody samples.

Process Analysis Of Waste Bamboo Materials Using Solvent Liquefaction

Bamboo is one of the significant biomass resources; it has been used in houses, flooring, construction of scaffolding and bridges, among others. The solvent liquefaction process is one of the promising techniques for effective utilization of waste bamboo materials for the lignocelluloses which can be converted to liquid reactive materials as biomass-based materials. Bamboo has the advantage of providing the liquefied products with a small range of variances. The components of bamboo have high acidity in the presence of mineral acid catalysts and possess the constituents which can react with polyethylene glycol 400 (PEG 400). In this study, waste bamboo materials have been used in liquefaction experiments. The liquefaction process and liquefied residue have been monitored according to the liquefied conditions and surface changes of waste bamboo samples observed by a scanning electron microscope. The changes in the functional groups have been analysed by a Fourier transform infrared spectrometer and behavior of the crystalline structures of liquefied bamboo has been determined by X-ray diffraction. Other experiments, such as degree of polymerization have also been carried out for confirming the results. Regarding the results, it was found that an increment of the temperature and the amount of the acid catalysts improved the efficiency of liquefaction. At the same time, the dissolution time of lignin was significantly shorter than the one of cellulose in the solvent liquefaction process of PEG 400.

OIL AGGREGATED BEHAVIOR FOR COAL RECOVERY AND COMBUSTION CHARACTERISTICS OF THEIR AGGREGATES FROM DIFFERENT GRADE COALS

Large amounts of waste fi ne coals are very diffi cult to be treated due to the presence of ash and inorganic sulphur compounds. In order to use waste fi ne coal effi ciently, a retrieval technique is necessary for the recovery of combustible contents of coal from fi ne waste coals. Nowadays, a fl otation process has been used for the treatment, but it is impractical for developing countries due to its higher costs. Therefore, oil agglomeration process has been used to deal with these problems. In this study, the factors affecting the coal cleaning effi ciency of the oil agglomeration process were investigated with the element contents and chemical structure of three different grade coals. Chemical contents in three different grade coals were determined by proximate and ultimate analyses and the differences in chemical structure of carbonaceous contents of different grade coals were investigated by a Fourier transform-infrared spectrometry. In free coals or their mixed samples, the ratio of ash and carbonaceous contents were maintained to make it homogeneous. From the results of oil agglomeration experiments, it was concluded that the characteristics of agglomerate and the coal cleaning effi ciency of oil agglomeration were not only infl uenced by the type of oils but also by the oxygen contents and the aromatic and aliphatic chemical structures in different grade coals. The oxygenic functional groups of carbonaceous contents in coal samples prevented oil from attaching the carbonaceous surface and form the bulky aggregate. This depressed the combustible matter recovery, but this was resolved by changing the oil types. Oxygen contents in oils such as vegetable oil played a role in bridging material to the oxygenic functional groups of carbonaceous contents in coal samples. Meanwhile, it was observed that aromatic functional groups in carbonaceous contents interacted badly with the aliphatic functional groups in oil due to the resonance inspection of delocalized π electrons. Comparatively carbonaceous contents consisting of more aliphatic series or graphite-reinforced structures were tended to form aggregates easily. Even when different types of coals were used in the oil agglomeration, it was possible to achieve a better effi ciency by taking these factors into account. Moreover, by thermogravimetric-derivative thermogravimetric (TG-DTG) analyses, it was found that the combustion characteristics of carbonaceous contents were improved due to oil attachment.