Utilization of BIOMASS as a fuel

What’s Biomass

An organic substance of plants on the earth is made through the reaction of sun beam, water and carbon dioxide in the air, so called Carbon Dioxide Assimilation. The main composition of such substance is aldehyde, sugar contents, starch, cellulose, lignin, vegetable fat and protein, etc.

Even herbivorous animal also get solar energy indirectly by eating plants. Thus, creatures that store solar energy in themselves are generally called “Biomass”.

Fossil fuel such as coal or oil was formed by the fossilization of trees and algae buried in the underground for a long time, and even natural gas was also formed and stored in the derground by the same process. Though the fossil fuel is no doubt a sort of biomass accordingly, it shall be referred as a fossil fuel and defined separately from biomass in this page. Biomass shall be defined basically as the materials originated in the vegetation to be reproducible in one year or dozens of years including the body wastes of herbivorous.

Possible utilization of biomass fuel

Total deposit of fossil fuel on this planet is estimated to be one trillion tons or so. It is also estimated to have taken from tens of million years to hundreds of million years for the formation. Nevertheless, we, human race are going to exhaust the resource in the period as short as one hundred or two hundred years. Furthermore, increase of carbon dioxide(CO₂) is enormous being accelerated by excessive deforestation etc. This unexpected rapid increase of CO₂has now been a realistic problem to us. It has already brought us an abnormal weather condition such as greenhouse effect following the decrease of land area due to rise of sea level, etc.

Figure 1 shows producible years of each fossil fuel:

Name of resource	Coal	Oil	Natural Gas
Producible year(Y)	529	50	68

Figure 1

In order to maintain the quantity of CO₂ suitable for human race to live, well-balanced utilization of biomass with fossil fuel is quite necessary. This means that we should consume biomass energy (including fossil fuel) less than the quantity of CO₂ to be actually fixed on the earth in a year. It is said that except cold region and desert district, quantity of CO₂ to be fixed yearly reaches more than 200 g/m2 averagely on the ground, and 100 to 200 g/m² even in the water. Total quantity of fixed CO₂ is estimated to be 50 billion tons yearly on the ground and 25 billion tons in the water. If we convert it into calorific value, 6 x 10¹⁹ kcal of energy is produced every year, which is equivalent almost nine times the total energy to be consumed in the world yearly. It can be theoretically said if we utilize biomass as much as reproducible yearly, total energy demand of the world can be covered by biomass without depending on fossil fuels.

Problem of biomass as a fuel

Typical biomass fuels are agricultural derivation products such as rice husk and straw, and forestry waste like wood thinned out. Though they can be dried and just used, they involve some disadvantages compared with oil and natural gas, such as high nominal volume, limited handling efficiency, lower calorific value, unsteady supply, a little more ash content，etc. Every effort is necessary to solve these disadvantages. The following are the examples for easier utilization of biomass:

Corn

Rice husk