1.1 Benefit of Biomass

1.1.1 What is biomass?

Generally biomass is the matter that can be derived directly or indirectly from plant which is utilized as energy or materials in a substantial amount. “Indirectly” refers to the products available via animal husbandry and the food industry. Biomass is called as “phytomass” and is often translated bioresource or bio-derived-resource. The resource base includes hundreds of thousands of plant species, terrestrial and aquatic, various agricultural, forestry and industrial residues and process waste, sewage and animal wastes. Energy crops, which make the large scale energy plantation, will be one of the most promising biomass, though it is not yet commercialized at the present moment. Specifically biomass means wood, Napier grass, rape seed, water hyacinth, giant kelp, chlorella, sawdust, wood chip, rice straw, rice husk, kitchen garbage, pulp sludge, animal dung etc. As plantation type biomass, eucalyptus, hybrid poplar, oil palm, sugar cane, switch grass etc. are included in this category.

According to Oxford English Dictionary, it was in 1934 that the term ”biomass” appeared first in the literature. In Journal of Marine Biology Association, Russian scientist Bogorov used biomass as nomenclature. He measured the weight of marine plankton (Calanus finmarchicus) after drying which he collected in order to investigate the seasonal growth change of plankton. He named this dried plankton biomass.

Biomass is very various and the classification will be reviewed in 2.(1). Biomass specifically means agricultural wastes such as rice straw and rice husk, forestry wastes such as sawdust and saw mill dust, MSW, excrement, animal dung, kitchen garbage, sewage sludge, etc. In the category of plantation type, biomass includes wood such as eucalyptus, hybrid poplar, palm tree, sugar cane, switch grass, kelp etc.

Biomass is renewable resource and the energy derived from biomass is called renewable energy. However, biomass is designated as new energy in Japan and this naming is a legal term peculiar to our country. Law concerning promotion of the use of new energy was enforced in April of 1997. Though biomass was not approved as one of new energies at this moment,

biomass was legally approved when the law was amended in January of 2002.

According to the Law, power generation by photovoltaics, wind energy, fuel cell, wastes, and biomass as well as thermal use of waste are designated as new energy. Legally new energy is provided by the law what should be the production, generation, and utilization of petroleum alternatives, what is insufficiently infiltrated by the economic restriction, and what is specially prescribed in order to promote the use of new energy by the government ordinance. In foreign countries, biomass is usually called and designated as one of renewable energies.

Many studies have suggested that biomass-derived energy will provide a greater share of the overall energy supply as the price of fossil fuels increase over the next several decades. The use of biomass a source of energy is very attractive, since it can be a zero net CO2 energy source, and therefore does not contribute to increased greenhouse gas emission. It is carbon neutrality of biomass, which is precisely described in 1.(2). The combustion of biomass energy results in the emission of CO2, however, since nearly all of the carbon in the fuel is converted to CO2, just as it is during the consumption of fossil fuels. The zero net CO2 argument relies on the assumption that new trees, or other plants, will be replanted to the extent that they will fix any CO2 released during the consumption of biomass energy. This may well be true for the properly managed energy plantations, but is not likely to pertain in many developing countries where most of the biomass energy is obtained from forests which are not being replanted, at least not to the same degree that they are being harvested.

The widespread expansion of biomass energy use may result in significant concerns about availability of land, which may otherwise be used for food production, or other commercial use such as timber production. Recent reports showed that a wide range of estimates of future biomass energy potential, ranging from the current level of approximately 42 EJ to nearly 350 EJ close to the current level of total energy production by the year 2100. Consequently, it is desired that biomass energy should be wisely utilized in accordance with the food or valuable material production as well as environmental preservation.

Biomass is quite various and different in its chemical property, physical property, moisture content, mechanical strength etc. and the conversion technologies to materials and energy are also diversified. Researches which make it possible to develop cost effective and environmentally friendly conversion technologies have been done to reduce the dependence on fossil fuels, to suppress CO2 emission, and to activate rural economies.