In order to reduce consumed energy during woody biomass pulverization process and increase production rate of woody biomass powder, new pulverization pot for the vibration mill was developed. Multiple tube pot, arranged same small size tubes in parallel, was newly-designed, and various sizes of pulverization pot were also prepared for the pulverization experiment. In this experiment, effect of the pot size and the number of tubes of the pot on pulverization ability, such as pulverization particle size, crystallinity index of cellulose, consumed energy and productivity of woody powder, was evaluated. Pulverization ability in a large scale multiple tube vibration mill was also estimated in this paper. The number of tubes was completely unrelated with pulverization ability, when the size of tubes was same, in a multiple tube vibration mill. On the other hand, pulverization rate was significantly influenced by the pot diameter, and the pulverization rate of smaller pot was much faster than bigger diameter pot. Therefore, production of woody power was able to increase by using multiple small size tubes pot, and newly-developed multiple tube pot was also capable of reducing consumed energy per woody powder production significantly.
In this report, the yield of solid component undergoing the fast and slow pyrolysis in the packed bed of biomass particles has been compared with the analyzed one by the different three kinetic models (model-1: Thurner et.al, model-2: Mohan et.al, model-3: Miller et.al). From the results, the yield of solid component could be reproduced by the analysis using the model-3 even if the heating rate and the lignin content changed. Furthermore, the relationship between the volume reduction process in the packed bed and the chemical reaction undergoing pyrolysis was elucidated by the formularization. From the result, the volume in the packed bed of the biomass undergoing the pyrolysis can be estimated by using the model-3 and the dependence of gas volume in the bed on the temperature.
One way to reduce tar is by oxidative and thermal cracking by means of partial combustion of the producer gas in the gas reformer, an apparatus stage subsequent to the woody biomass gasifier. During the partial combustion process of the producer gas, inverse diffusion flame is formed as oxidizer is supplied to the hot producer gas. Cracking and polymerization of tar occur simultaneously at the proximity of the inverse diffusion flame. Polymerized tar grows into soot passing through polycyclic aromatic hydrocarbons (PAH). Several growth mechanisms of PAH have been proposed, which are common to the primary PAH growth followed by abstraction of a hydrogen-atom from the reacting hydrocarbon by a hydrogen radical. We can, therefore, point to the possibility of suppression of the soot formation by controlling the hydrogen concentration at the proximity of the inverse diffusion flame. In the present study, hydrogen concentration at the proximity of the inverse diffusion flame has been controlled by the small amount of hydrogen addition to the oxidizer. Soot formation is suppressed by the chemical effect of a small amount of additional hydrogen (approximately 0.5 % in the total enthalpy of the model producer gas), rather than by a slight change in oxygen concentration and the flow velocity of the oxidizer.
Recently, the microalgae that can produce fats and hydrocarbons attracts a lot of attention as means to solve the issue of global warming. The purposes of this study are to design microalgae-based biodiesel fuel (BDF) production system using exhaust gas from thermal power plants and considering regional characteristics, and to analysis potential of the microalgae from the viewpoint of energy balance, CO2 balance and fuel production cost. The system consists of five components: Culture, harvesting, extraction, transportation, conversion. In addition, the methodology of this study has three processes: Allocating microalgae culture plants and BDF production plants, optimizing transportation using Geographic Information System (GIS) with Network Analyst, and evaluating energy balance and CO2 reduction of the system. Besides, to minimize BDF production cost, we change the number of BDF production plants and consider trade-off between transportation cost and BDF production plants costs. The result shows that microalgae-based BDF production system has high potential for CO2 reduction and the possibility to competitive with the fossil fuel cost.
In our previous work, we presented a novel multi-time-stage input-output-based modeling framework for simulating the dynamics of nascent bioenergy supply chains. The production level within the supply chain at any given time interval is assumed to be dependent on the output surplus or deficit relative to targets in the previous interval or intervals. In our approach, the technology matrix, A, includes coefficients denoting flows of products (e.g., biofuels), intermediates (e.g., feedstock) and environmental goods (e.g., resources, pollutants), while the influence matrix, B, signifies the strength of the influence of flow surpluses and deficits on the supply chain. Introducing a feedback control term enables the system to suppress the undesirable dynamic behavior of the uncontrolled dynamic model such as oscillation or instability. In this paper, we apply our modeling framework to analyze the dynamic behavior of three nascent bioenergy supply chains competing for shared resources. Numerical simulations are used to assess the effects of key system parameters on the growth trajectories of the competing bioenergy systems and the effects of relative time lags in the development of one of the supply chains within the competing system. These numerical simulations show that policy interventions can be systematically imposed to suppress undesirable dynamic behavior in complex energy systems.
A direct saccharification process via hydrolysis of rice straw using a solid acid catalyst was developed and its feasibility was investigated. The effects of various reaction parameters and reuse of the catalyst on yields of monosaccharide and organic acid in saccharification of rice straw were evaluated. Saccharification was carried out using an 80 cm3 stainless autoclave. The main monosaccharides produced were xylose and glucose; and the main organic acids were acetic acid, formic acid and levulinic acid. The yields of monosaccharide and organic acid increased with increasing reaction temperature from 110 to 150 °C. The yields of organic acids increased with increasing reaction time from 1 to 6 h, while the yields of monosaccharides initially increased then decreased. It was observed that the particle size of rice straw and solid content of rice straw to water also affected saccharification. The maximum yield of monosaccharides was 148.7 g-sugar /kg-rice straw, obtained at 150 °C for 3 h with the 10 % solid content of rice straw to water. Based on composition analysis of rice straw before and after saccharification, it was found that most of the monosaccharide came from the decomposition of hemicelluloses.
On a bench scale, we successfully produced 16 L/d, equal to 0.1 BPD (barrel per day), of hydrocarbon liquid fuel from woody biomass throughout a proposed biomass-to-liquid (BTL) process, which consisted of gasification, wet and dry gas cleaning, water-gas shift reaction, gas compression, and Fischer-Tropsch (FT) synthesis reaction. In the oxygen-enriched air/CO2 gasification using a downdraft fixed-bed gasifier, the addition of CO2 to oxygen-enriched air as a gasifying agent led to an increase in both the conversion to gas on a carbon basis and the syngas content because of the enhancement of CO2 gasification (C + CO2 → 2CO). The CO and H2 contents increased to 40.8 vol%, 28.7 vol% and the N2 content decreased to 6.9 vol% monotonously with an increase in the pure oxygen flow rate. When a mixture of 19.1/63.4/17.5 vol% of N2/O2/CO2 was used as the gasifying agent, the conversion to gas on a carbon basis was 90.1 C-mol% and the product gas composition was 27.9 vol% H2, 40.4 vol% CO 21.2 vol% CO2, 4.0 vol% CH4, 1.0 vol% hydrocarbons with a carbon number greater than 2 (C2+H.C.) and 5.5 vol% N2. Feed gas with a H2/CO ratio appropriate for the FT synthesis reaction (57.4 vol% H2, 28.5 vol% CO, 0.9 vol% CO2, 5.0 vol% CH4, 1.3 vol% C2+H.C., and 6.9 vol% N2) was prepared through the water-gas shift reaction, desulfurization, CO2 removal. In the FT synthesis reaction at 4 MPa and 290-320 °C using a Ru/Mn/Al2O3 catalyst, the CO and H2 conversions were 73.5% and 83.9%, respectively, and the chain growth probability was 0.82; further, the selectivity and space time yield of hydrocarbons with a carbon number greater than 5 as a liquid fuel were 81.4% and 1.793 kg/(kg-cat. h), respectively.
This paper provided an analysis of the commodity chain from coconutproduction as feedstock for biodiesel production (called Coco Methyl Ester or CME) as well as the value addition from its production and processing. The value-added for the industry included the summation of all the value-added in each enterprise, which includes personnel remuneration or the wages paid, taxes and duties earned by the government from the enterprises, depreciation and interest on investments, and the entrepreneur's net profit. Total value added (including the profits generated out of the by-products) of biodiesel production amounted to PhP66,199.56 (US$1,504.54)/ha production of mature nut processed into CME. Biodieselproduction showed optimistic results in terms of employment created and government income through taxes. The whole conversion process from mature coconut to CME required a total of 53man-day/ha/year while tax revenues/hawere estimated at PhP9,033.67(US$ 205.31) annually. The biodiesel industry has great potential of contributing to the reduction of the country's dependence on imported fuels with due regard to the protection of public health and the environment, at the same time providing opportunities for livelihood for poverty alleviation and sustainable economic development and energy security.
Sustainable Integrated Bio-cycle Farming System (IBFS) is a good approach to integrate a multi-sector (Agriculture, Horticulture, Plantation, Forestry, Animal Husbandry, Fishery etc) to produce food, feed, fuel, fertilizer, pharmacy, edu-tainment, eco-tourism etc. Through technological strategy of 7R (Reuse, Reduce, Recycle, Refill, Replace, Repair and Replant) with added value in economic, environment and socio-culture aspect, this method can be approached as a characteristic of Education for Sustainable Development (EfSD). Tunnel digester for anaerobic digestion of organic materials produced organic fertilizer and bio-gas energy. The design of GAMA DIGESTER has been optimized to improve the methane (CH4) content in the biogas. The purity of methane in biogas increased to be 80% by the first generation of GAMA PURIFICATION unit. GAMA COMPRESSING unit, which is still under study for design improvement, is targeted to produce Compressed Methane Gas (CMG) in the near future. The GAMA DIGESTER, GAMA PURIFICATION and GAMA COMPRESSING could product sustainable bio-energy in the total system of IBFS.
The saccharification of the Sasa senanensis waste using hot compressed water treatment for enzymatic hydrolysis was investigated. Hot compressed water treatment of the Sasa senanensis waste was conducted at 180-260 °C and followed by enzymatic saccharification. After the enzymatic saccharification treatment, the highest total sugar yield (52 % on the feedstock base) was obtained from the Sasa senanensis waste pretreated at a temperature of 200 °C and holding time of 5 min. Glucose enzymatically produced was rapidly converted to ethanol within 8 h without any fermentation inhibitor. Approximately 100 % of theoretical yield of ethanol was obtained from glucose. The Sasa senanensis waste may be suitable for the feedstock of ethanol production from fermentable sugars because no inhibition was observed during the enzymatic saccharification and ethanol fermentation.