Features
Biogas and Biomass Energy
Takako Honjo

National Institute of Advanced Industry
Science and Technology (AIST)

In the recent years, the sources of biomass for energy are changing. Firewood and coal are age-old biomass energy. Fossil fuel is one precious source of such energy. The amount of fossil fuel being used can be lowered if biomass adsorbed CO2 by photosynthesis and is utilized as energy.
The biomass resources, having its roots in the solar energy, are renewable energy. Since carbon circulates [CO2→organic matter→CO2→・・], carbon dioxide (CO2) does not increase in the environment. Thus, this condition means ‘carbon-neutral’.
Biomass energy has various forms. The classification is as follows: a form of fuel, such as solid (chip, pellet, and charcoal), liquid (ethanol, methanol, and biodiesel), and gas (methane gas, gasified gas by heat treatment); a form of use, such as power generation, heat use, and fuel for cars; a form of manufacture; and a form of material, such as wastes and energy crops.
Forest biomass is the largest resources among others. However, advanced and innovative use is still immature because there are both technical and cost problems. It will take more time for development into full-scale use.
In this feature, the latest technology on biogas and biomass energy from waste biomasses is introduced.
Kenichi Sasauchi of ChugaiRo Co., Ltd. reported on ‘Gasification and power generation of woody biomass’, which is currently on the validation phase. In this study, methane is fermented to produce energy, which is generally the wet type of fermentation process. Masato Fujita of Takuma Co., Ltd. described ‘Biogasification of the biogenous waste, such as food waste, biodegradable fish trays, and newspapers using the dry anaerobic fermentation system’. Meanwhile, Yukimasa Ogawa of OBAYASHI CORPORATION presented a report on ‘Medium and high temperature fermentation using livestock waste and food waste’. To date, bio-ethanol is made from glucose, which is extracted from sugarcane, sweet corn, cassava, etc. Koji Miwa of Tsukishima Kikai Co., Ltd. reported on ‘Development of lignocellulosic biomass to ethanol using waste house wood’.
ASEAN countries lying in the tropical region are endowed with a rich source of biomass. A variety of tropical plants, like palm and banana, grow fast in abundance. The different parts of the mentioned plants are valuable residual biomass resources. These countries are considered reservoir of biomass resources.
If we can make a cooperative with the ASEAN countries, the abundant biomass resources can be utilized with the said technologies. In the long run, CO2 will be greatly reduced.
Extreme weather conditions around the world consistent with global warming due to the effect of greenhouse gases have been a problem. The "Kyoto Protocol", which established numerical targets of greenhouse gas emissions, came into force in February 2005. In order to implement it, the Kyoto Mechanism, called CDM, was composed of the following: 1) Joint Implementation; 2) International Emission Trading; and 3) Clean Development Mechanism. In order to achieve CO2 reduction target by 2012, utilizing these mechanisms is imposed in each of the industrialized nations.
The purpose of CDM is to achieve a joint reduction project (sustainable development) in the developing countries with the financial and technical help of industrialized countries. It also aims to calculate the produced amount of emissions reduction (verification required) as an amount of reduction of industrialized countries. It is a useful system for both industrialized and developing countries.
Therefore, in collaboration with the ASEAN member countries, the CDM project on biomass is considered to be one of the effective CO2 -reducing methods.
Currently, the practical use of CDM affects the market prices of CO2 international emission trading and carbon tax. This is an anticipated and foreseen effect.
In the future, for global warming prevention, the interaction with ASEAN member countries will deepen and the project on the effective use of biomass energy will develop greatly.


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1 Gasification and Power Generation of Woody Biomass