Research and development of biomass technology was briefly discussed in terms of modern sciences. Application of new sciences such as molecular biology, computer science and environmental science to the R & D of biomass was emphasized.
Biomass is a renewable and carbon neutral resource, because it fixes CO2 from the atmosphere by photosynthesis. Recently, it is focused on as an alternative fuel from the viewpoint of global warming mitigation and fossil resource saving. In Japan, biomass is, however, small and dispersive energy in terms of potential and collection, and therefore, R & D is required to convert biomass into energy at higher efficiency. Biomass Technology Research Center (BTRC) studied the technical development and social system for biomass utilization to establish a sustainable society. In BTRC, main research projects are as follows; 1) Ethanol production from woody biomass, 2) Biomass to Liquids (BTL), and 3) Study on biomass total system. In addition, Biomass-Asia projects are also included in R & D of BTRC.
Grazing in forestall mountain is a new harvest method from a steep mountain forest. However, a grown-up wood is often unfavorable for forage, because old wood is very hard to digest. But steam explosion process is hopeful to provide us new digestibles from woods.
As data for recycling of construction waste wood, we examined the chemical treatment to wood and the chemical substances used for them. Although the chemical substances contained in the chemicals differ with the change of the times, the chemicals containing halogen, sulfur, nitrogen, or harmful heavy metals have been used up to this day. Therefore, in case of thermal recycling about waste wood containing these chemical substances, cautions must be paid to air pollution, corrosion, processing of ashes, etc.
Hemp (Cannabis Sativa. L) is crops that grow and came well for about 10,000 years in Japan. The kind of this plant has the fiber type and the medicinal use type. Especially, the kind without the pharmacologic action is called an "Industrial Hemp" by the fiber type. Hemp is sold to clothes, food, cosmetics, paper, construction materials; the car interior material, the fertilizer, and horse's bed, etc. in EU nations, and the market has expanded. This plant decreased sharply by the restriction of Cannabis Control Law and the spread of the artificial fiber in Japan after World War II. It is being used only for a special usage for the divine service etc. now. Recently, the possibility of Hemp is expected as a resource crops in Hokkaido and Nagano Prefecture, etc. where the cultivation license was new and permitted for the first time after the war. However, a detailed examination of the economy of the use model has not been done. As for Hemp, I can harvest a dry stalk for each 1ha of 8t on the average and the seed of 1000kg. I can be larger than other farm products amount for each unit, and use the cascade with one crops. This research set three case studies, and compared the economies.
Forest resource, slope, public and forest road layers of Geographic Information System (GIS) were obtained from a prefecture, where a model area was located, in order to calculate harvesting costs of forest biomass resources. Future forest resources at each stand were predicted using Richard's growth curves. Then, stand harvesting schedules were planned by balancing harvesting volumes of forest biomass resources using random search while minimizing harvesting costs. Balanced harvesting forest biomass resources will be sufficient to supply electricity to 24.8% of houses in the model area. According to harvesting volumes, logging residues and thinned trees were harvested based on the schedule. If the forest biomass resources are not sufficient, broad-leaved forests are harvested to meet sufficient volumes. According to harvesting costs, logging residues were the cheapest, 5,000yen/ton, followed by broad-leaved forests, 11,000yen/ton; thinned trees were the most costly, 15,000yen/ton. Fuel cost of electricity, 19.45yen/kWh, was much higher by comparing with electricity price in Japan, 18.17yen/kWh. In order to use forest biomass resources as energy, it is necessary to reduce harvesting costs remarkably by developing forest road network and machines for harvesting and transporting forest biomass resources efficiently.
The Fuji Electric group has been developing the high speed methane fermentation system for food waste since 2001. Here, we present about the good point of the high speed methane fermentation system of Fuji Electric group and 0.4t/d pilot scale field test result at Hino city between 2003 to 2005.
Because of the need for development of alternative sources of liquid fuels, ethanol production from renewable resources has become important. Although yeast are used commercially in the traditional methods for ethanol production, Zymomonas mobilis and Zymobacter palmae are now being studied because of their potential for being used in fuel ethanol production. Zm. mobilis and Zb. palame are facultative anaerobic, gram-negative bacteria, and produce about 1.9 mol of ethanol from 1 mol of glucose, similar to industrial yeasts. As the advantages of these bacteria are their high growth rate and specific ethanol production, we focused on the production of fuel ethanol from cellulosic wastes by these bacteria. We therefore developed the unique host-vector systems for Zm. mobilis and Zb. palmae, respectively, and used the systems to expand the range of carbohydrate substrates utilized by these bacteria to include xylose, mannose, and cellooligosaccharides, which are hydrolysis products from cellulosic materials with an enzymatic-or acidic treatment. The recombinant strains exhibited efficient expression of genes encoding fermentation abilities of components of cellulose and hemicellulose, and produced ethanol from xylose, mannose, and cellooligosaccharides with a theoretical yield.
The heating rate of feedstock in supercritical water gasification is known to affect the gasification efficiency, but so far, no quantitative study has been made. In this study, the rate of production of 5-HMF, key compound of the tarry material was measured along with other products, and the effect of feedstock heating rate on this compound was investigated. It was found that the 5-HMF yield was high for slower heating rate and higher concentration of the feedstock, and agreed with the observed tar production affected by the feedstock heating rate.
We had found that calcium-oxide is as active as alkali-hydroxide in a transesterification of soybean oil, which indicated a heterogeneous catalytic process for biodiesel production utilizing solid-base. In this paper, the biodiesel production with calcium-oxide catalyst was studied for the used cooking oil. An increase in the acid value and an accumulation of the nitrogen compounds were obvious for the used restaurant oil. The oil degradation provided the induction period for the transesterification in the experimental biodiesel production, although the transesterification was completed at 2h independent of the oil degradation. Solution of the catalyst was the serious problem for the processing of the used restaurant oil.
Woody biomass is an abundant resource, and pyrolysis gasification to recover energy from it as a typical type of dry biomass has been studied and demonstrated actively in various regions. However, although woody biomass is dry, it is not dry enough to be ideal for energy recovery in most cases. Biomass with higher water content increases the energy consumed by water evaporation in the pyrolysis process, which results in less energy recovered from biomass. Especially when wood chips from raw trees such as thinned woods are used as the raw materials, a process to dry them is often required as an essential pretreatment for the pyrolysis gasification. The use of waste heat from gasification facilities for drying raw materials would lead to more effective use of biomass energy and also improve the energy efficiency in the facilities as a whole. We are comparatively examining methods to dry different existing types of woody chips and conducting various drying tests with woody chips to achieve a drying system specializing in woody chips. We have eventually conducted research aimed at establishing a low-cost, high-efficiency drying system by developing a drying system integrated with a pyrolysis gasification furnace.
R & D of advanced upgrading & gaisification system for biomass with high moisture are described in the paper. A dewatering technology in oil and a low temperature gasification technology are employed in the system. Results show that the dewatering process achieves 90% of thermal efficiency dealing with coffee grounds which include 65% moisture. In addition, upgraded biomass which includes highly dispersed Ca catalyst for gasification reactions is obtained by the dewatering process blending with 40g/kg-biomass CaOH. The upgraded biomass is fed into a gasifier named "the pyrolytic gasifier", which has a bubbling fluidized bed gasifier and a pneumatic transported bed char combustor. The syngas can be separated from the exthost gas of the char combustion, because heat from the combustion for endothermic gasification reaction is provided via circulating sand for fluidization medium. A design of the gasifier is examined by a reacting flow numerical simulation. The gasification process achieves 83% of cold gas efficiency and 2,500 to 3,500kcal/m^3N of syngas is obtained. A result of a thermal efficiency analysis of the whole system shows more than 75% of total cold gas efficinecy can be achieved and validity of the present system is confirmed.
To establish an efficient biomass gasification process a circulating fluidized bed system with a low temperature steam gasifier for wood chips and a regenerator has been provided. By using this apparatus, clay-derived porous catalysts having a capacity to capture volatiles are tested for steam gasification of wood biomass. The gasification experiments were carried out under condition of around 650℃ in riser temperature and around 3m/s of superficial velocity in riser. Influence of reactor temperature, superficial velocities and particle hold up at first and second gasifiers and riser were discussed to elucidate appropriate condition for low tar formation and high efficiency gasification.
A detailed survey were made on the demand and supply of ethanol fuel in Asian countries such as Japan, China, India, Thailand, Korea, Philippine, and Pakistan. As a result, it was clarified that ethanol market has been developed and commercialized already in China and Thailand. In Japan, however, utilization of ethanol fuel is under consideration through the empirical car testing, while in Korea, a progress is only for testing production of ethanol from the imported grains. In India, Philippine, and Pakistan, ethanol fuel production program has just initiated recently. On the other hand, the demand of ethanol fuel in these areas is increasing. In the near future, therefore, a large-scale ethanol production is expected to be developed in these Asian countries.
In this study, BTL (Biomass to Liquid) process in which the steam gasification and the Fischer-Tropsch synthesis reaction were combined was studied in order to produce diesel fuel for vehicle. For the process, a process design and simulations were performed using a process simulator. It is indicated that woody biomass of 100t/d could be converted to the liquid fuel of 13.9t/d. From the viewpoint of environmental load such as a CO_2 emission, the effective utilizations of heat and electricity were considered and it was found that an optimum operation condition was present. Consequently, the combustion of a part of biomass as heat source let CO_2 emission decrease in this condition. The biomass power generation was not usefully.
As now widely recognized, biomass utilization to contribute global warming requires substantial utilization which tends to be uneconomical within the present business structures. A variety of attempts have been made to cope with the above limitation but many of them face dilemma between convenience/value addition and positive energy economy/LCA. In this article I am discussing several principles that I believe necessary to put in biomass technology and utilization system development to make the outcome of our effort more effective. Importance of cultural reorganization for wood utilization as basic materials and potential of charcoal based network, Stirling engine and microgrids for really small villages are discussed.
"Biomass Japan Strategy Policy" anticipates quantity of annual waste biomass as 68 million ton (dry weight) in Japan, and aims for effective utilization of 80% of them. A reliable quantity of waste biomass in the world is not shown till now. Agricultural residues are estimated as 4.5 billion ton in Asia, because agriculture is the base sector in developing countries in Asia (about 10 billion ton in the World). Some part of such wastes (around 30-40%) are utilized as fuel, feedstuff, fertilizer, paper making and so on, but huge amount of them are still left without utilization. The physical and chemical properties of these residues are quite diverse, the effective utilization of these residues should be developed with consideration of such properties (right materials). In addition, the consideration of the harvesting season and transportation of them (the right position) is also important for the effective utilization. It would be essential to establish systematic industrial complex for the effective utilization of biomass ("biomass industrial complex") from the preservation of regional and global environment and production cost efficiency of view. Some designs of such system in Southeast Asia as a target are discussed.
In Japan, we used be use many kinds of wood fuel (e.g. firewood, charcoal, ogalite, wood pellet). About wood pellet, 30 pellet manufacturing plants had been installed in five years since 1982 because of oil crises. Unfortunately, demand of wood pellet was decreased in 1985. Many of pellet producers couldn't continue their production. As of 2000, only three were survived in the market. From 2002 to 2005, nearly 30 new pellet plants were built. In my survey in 2004, total production capacity was five times as demand in 2003. In this study, I would like define similarities and differences between challenge of densified wood fuel industry in 1980's and 2000's.
Investigation was made on direction of utilizing Japanese forest within the development of local economy. Possibility of recycle economy society was discussed by studying the concept of local economy, which is presently being sought, and problems were confirmed through reviewing the attempts of its introduction so far made. Based on the results, barriers to implement utilization of Japanese forest were reviewed in order from the viewpoints of social system, policy and law, advantage for the citizens, and citizen's participation, and possible measures were proposed.
In this paper we discussed the potentials of woody biomass production by growing willow short-rotation coppice in the southern part of Tohoku area. In addition, we described a collection of willow taxa suitable for willow biomass production in this area and a preliminary result of their growth characterization.
The strategy of biomass utilization of Japan is going to become widespread in the regional advancement, which is to say, from headquarter to the action fronts. The actual situation of the biomass utilization is estimated in Miyagi Prefecture as typical local governmental unit, and the possibility of regional advancement concerning food industry is also examined.
Major wood production in Vietnam are sawn timber (2,950,000m^3) and wood chip/particles (1,683,000m^3), mainly from plantations goes to overseas, which may results shortage of raw materials for domestic use for coming several years. 5 Million hectare reforestation program planned from 1998 to 2010 will establish 3 million ha of production forest in 2010 and enhanced plantation resources will help wood industries, in terms of raw material security. Small diameter logs produced from plantation in rotation of several years may reduce the recovery rate, and generates huge amount of industrial residues. So development of cost effective technologies to utilize these industrial residues in combination with value-added main products are an essential issue for fostering biomass industries in Vietnam.
We investigated the current situation of woody biomass resources and their utilization in Indonesia, especially in Java Island. For residue from the wood industry, it is consumed as other wood-derived materials in wood processing factory and fuelwood by the local people. For forest residue, it is also utilized as fuelwood by local people. Thus, for above two residues, the available wood resources may be quite limited compared to the original quantity of wood. For tree crop residue, the most promising one is from oil palm, which comprises about 39 million tons (dry base) and has not been well used; they have big potential to be utilized for material and energy productions.
Semi-carbonization is one of the most powerful way to enhance the energy density of woody fuels. Charcoal is also a candidate for high energy density fuel, but the total energy yield is too low to be a good fuel in enrgy system. Tar-impregnated semi-char is recommended.
The inventory and usable amount of biomass has been examined from various perspectives. Based on the statistical data acquired, the estimated "total amount of domestic inventory" was obtained. However, other information such as the regional characteristic of biomass, extensively available over the landscape, has not yet been placed into an organized form. In order to promote the use of biomass energy as a countermeasure against global warming, and to further promote the merits of a recycling society, the New Energy and Industrial Technology Development Organization (NEDO), has developed a series of maps and data detailing various biomass reserves. To increase the awareness of biomass as an energy source, NEDO has made this data available through the Internet.
Short-culm rice cultivars have been widely cultivated to get high yields because of their high lodging resistance and good light intercepting characteristics of the canopy. However, the potential for biomass production and yield is higher in long-culm cultivars than in short-culm cultivars. To breed high biomass producing cultivars using the beneficial characteristics of the long-culm rices, lodging resistance should be introduced. We bred a new long-culm rice cultivar with superior lodging resistance for forage use, 'Leaf star'. Shoot biomass in Leaf star was 12.6t/ha and 40% higher than that in Koshihikari. Leaf star had a very high breaking strength of the basal internode due to the large section modulus and the large bending stress. Long-culm rice cultivars with heavy biomass and superior lodging resistance can be utilized as biomass resources.
Carbonized material was prepared for the purpose of making use of chicken excrements as an environmental remediation by the carbonization treatment. The specific surface area of the carbonized chicken excrement was determined with a gas adsorption apparatus. Furthermore, decrease effects of iodine and atrazine in the aqueous solution were confirmed. The specific surfaces of the chicken excrement carbonized at 800□ or above were small. However, decreases in the concentration of iodine and atrazine in the aqueous solution were observed with addition of the carbonized chicken excrement.
For the production of highly concentrated bioethanol as an alternative fossil fuel, pevaporation, a membrane separation technique based on the use of an ethanol-selective membrane, has been a focus of research interest. In order to produce highly concentrated ethanol from a low-concentration ethanol solution containing succinic acid by pervaporation using an ethanol-permselective silicalite membrane, pervaporation performance was investigated. When supplying an ethanol solution containing succinic acid adjusted to pH>5, the pervaporation using a silicalite membrane double-coated with two types of silicone rubber exhibited no decrease in the performance. Also, using a silicalite membrane entirely covered with a silicone rubber sheet to prevent direct contact with succinic acid. No decrease in the ethanol concentration through the silicone rubber sheet-covered membrane was caused when supplying an ethanol solution containing succinic acid, not adjusted the pH.
In the present study, enzymatic saccharification of sawdust-based culture wastes of some edible mushrooms were performed with using several commercial cellulases. The highest saccharification rate (37%) could be obtained by the enzymatic treatment of Quercus serrata wood meal-based culture waste for cultivation of Lentinula edodes with Cellulase Onozuka R10 or RS.
The simultaneous saccharification and fermentation (SSF) is an essential process for bioethanol production using a cellulase. The enzymatic saccharification in the SSF is operated at a temperature that is required for the fermentation process. The temperature is lower than the enzymatic optimal condition. In this study, a column reactor process that is separated saccharification and fermentation was investigated. The saccharification was carried out at 50℃ in the column reactor, and the ethanol production was operated at 28℃ in the fermenter in which the immobilized yeast beads were packed. The efficacy of the column reactor was compared with that of the batch process.
Hydrothermal pretreatment and cellulase hydrolysis have been conducted using cabbage as a biomass model material. The results were analyzed based on reaction kinetics and determination of optimized condition for hydrothermal pretreatment has been presented.
Elution behavior of lignin and metals for hydrothermal treatment of lignocellulosic biomass was investigated using a percolator type reactor at a temperature of 200℃ (3.0MPa, 10mL/min). In case of barley straw, elution ratio of lignin reached to 80%. While, that of Japanese cedar was only 35%. It turned out a large amount of metal eluted from agricultural waste (rice hull and barley straw) in which the metals were contained originally. Especially, in case of rice hull, the eluted amount reached to 115.2mg/g in this experimental condition.
Hydrogen production from biomass in hot-compressed water was attempted at a lower temperature (300℃). It was found that ZnO was effective for production of H_2 from glucose, however, H_2 yield (=the produced amount of H_2/(the number of 2H molecule in the reactant) was only a few percent. Partial oxidation was attempted to increase the yield of H_2 via CO production because ZnO is an effective catalyst also for water-gas shift reaction. As a result, an addition of H_2O_2 to the reaction of glucose and sugarcane bagasse in hot-compressed water brought about the increase of yields of CO_2, CO, and H_2. The amount of added H_2O_2 affected the yield of all the gaseous products (CO_2, CO, and H_2): CO_2 and CO yields proportionally increased with increasing the amount of H_2O_2, whereas, H_2 yield decreased above a certain amount of H_2O_2. The fact that CO_2 yield was quite high and H_2 yield was still low indicates the increase of controllability of partial oxidation would be demanded.
The effect of TiO_2 and ZrO_2 on glucose reactions in hot-compressed water was examined by a batch type reactor. Anatase TiO_2 (a-TiO_2) was found to be an acid catalyst that promoted the formation of 5-hydroxymethyl-furaldehyde (HMF), on the other hand, rutile TiO_2 (r-TiO_2) was inactive.. Zirconia (m/c-ZrO_2: monoclic and tetragonal mixture) was a base catalyst to promote the isomerization of glucose. The TPD spectra showed us that the strength of the acidity and basicity is of importance on the glucose reaction
Gasification of lignin over supported metal catalysts in supercritical water was conducted at 400℃. The gasification proceeded in supercritical water through two steps; i) decomposition of lignin to low-molecular compounds and ii) gasification of the low-molecular compounds over metal catalysts. The first step (decomposition to low-molecular compounds) in the gasification was enhanced by increasing of water density.
Effect of chemical reaction on the heat transfer characteristics for turbulent flow of supercritical water was studied experimentally using oxidation reaction of the glucoso in aqueous solution. As a result, increase in heat transfer coefficient was observed at subctitical temperature up to near the critical point. These high values should be due to the disturbance of the flow caused by generation of the gas. Experimental results were compared with calculation from the equation of boiling flow. As a result, it was confirmed that the effect of the disturbance caused by generation of the gas is larger for supercritical pressure than that of a usual boiling phenomenon.
Livestock excreta requires proper treatment by Law on Promoting Proper Management and Use of Livestock Excreta, because livestock excreta causes odor problems and eutrophications problems, if it is released in environment. Compost production has been utilized for the treatment of livestock excreta, but new livestock excreta treating process is desired, because the amount of fertilizer that can be supplied to a specific farmyard area limitations. Methane fermentation process that is expected as energy recovery technology of livestock excreta has not been widely used because this process requires energy-and cost-consuming treatment of fermentation sludge and wastewater. On the other hand, supercritical water gasification process doesn't circumvents these problems by thermochemical conversion at high temperature. Thus, it is expected to be one of the new livestock excreta treating process. This paper presents our project of conducting experimental study of supercritical water gasification process by treatment of livestock excreta in a demonstration plant.