Geoscience Reference
In-Depth Information
Figure 10.92 Influence of earth
ceramics on the room temperature
and relative humidity
[418]
.
100
Test room
Reference
80
60
40
20
0
5
15
Room temperature (ºC)
25
35
technology. The decomposition of the night soil was defined by a ratio of Chemical
oxygen demand (COD) Mn before and after the reaction. The reaction time was just
10 min. The decomposition ratio increased with increasing temperature, and oxygen
pressure over 2 MPa accelerated the decomposition. Night soil was over 90%
decomposed when the reaction temperature of the hydrothermal treatment was at
300
C for 10 min. Under these conditions, hydrothermal decomposition of night soil
occurred with an offensive smelling gas.
Figure 10.90
shows the conversion of
organic wastes to bioresource and energy. Furthermore, CO
2
gas is not discharged to
atmosphere in this system and it is possible to change CH
3
OH for the Cl chemical
industry. In the future, a closed system such as this type must be attained in all
industrial fields for the survival of modern civilization and for earth ecology. To
quote an example of such a system, at IAx Corp., Japan, a new closed system for the
collection of waste, separation, and recycling has been introduced, and achieved a
reduction in waste output by 85% without increasing the intake (
Figure 10.91
). In
order to achieve the objective of a waste zero system, the corporation is working out
new technology based on the closed manufacturing system. Soil, solidified hydro-
thermally, is a new material born from the development of a closed production sys-
tem
[418]
. The strength of the hydrothermally processed soil is equal to or greater
than that of concrete building materials (flexural strength
6 MPa). Its heat
capacity is greater than that of wood flooring (1090 kJ/m
3
, K), tatami mat (430 kJ/
m
3
, K), and carpet (330 kJ/m
3
, K). It also exhibits high humidity absorption and
desorption ability, similar to wood because of its pore sizes, which are extremely
small (10
4
5
20 nm) when compared to concrete blocks or conventional chinaware.
Figure 10.92
shows the influence of earth ceramics on the room temperature and rel-
ative humidity (temperature and relative humidity were measured for 1 month in
winter)
[418]
. The extremely small pores are the result of the pores in the raw mate-
rial (soil) itself and the pores that are formed during hydrothermal solidification.
This hydrothermally treated soil product, with a trade name Earth Ceramics, is being
