## Waste treatment, Recycling

## Environmental Sciences

## Continuous Sub-Critical Water Plant - Organic wastes convert to resource and energy -

Keyword: Organics, Decomposition / extraction, Generation of resources and new energy

Dr. Yoshida Hiroyuki, Professor, College of Engineering Osaka Prefecture University

Organizations Involved

☐ Shiraishi Teruho, President, MITSUBISHI NAGASAKI MACHINERY

☐ Tanaka Masatoshi, President, Kinki Environmental Industry Co., LTD.

☐ 16 other corporations (previous 5 years)

Prof. Dr. Yoshida

Pres. Shiraishi

Pres. Tanaka

## 【Abstract】

The 21st COE program in Osaka Prefecture University (Dr. H. Yoshida Chemical Engineering) succeeded in converting organic wastes into valuable materials, such as organic acids, sugars, amino acids, and peptides using Sub-Critical Water. Sub-Critical Water extract DHA and EPA from fish waste, neutralize the prions that cause bovine spongiform encephalopathy (BSE). Also, methane gas from organics pretreated by Sub-Critical Water was produced efficiently and with high speed. The university built a continuous Sub-Critical Water plant in March, 2004.

## 【Summary of the technology transfer】Technological Impact

Organic wastes convert to valuable materials using Sub-Critical Water as it loads the material cycling. Also, residue converts to energy by fermentation.

We developed a vertical type continuous Sub-Critical Water plant (4 t/d) which was the first in the world. Our plant has attracted attention not only in Japan but also overseas. Sub-Critical Water decomposed organic wastes in 1-10 min and extracted oil completely and instantly. After separation of valuable products, residues were able to generate methane with high efficiency by methane fermentation. Methane was used to produce electricity and to drive a methane-driven motorcycle.

## ●Social Impact

Existing processes that convert raw materials directly to energy are expensive to run and seem to fail sooner or later. The concept of our processes is quite different from these. It is possible to develop new processes that bring benefits, create employment, and contribute also to the establishment of regional industries.

## ●Special Features of the Collaboration

From this field of science we find a germ, enhance this germ by engineering, and nurture it through a strong partnership among industries, governments, and academia. Finally, industries, governments, and academia make a collective effort to grow this valuable germ as a practical application worldwide.

## Project Background

Industrial waste of Japan amounts to 450,000,000 tons a year, 75% of which are organic wastes. To make organic wastes recyclable could be a solution to problems of industrial waste in Japan as well as in the world.

## Funding History

1. 21st COE Program

2. JST

3. Joint research with private companies

4. Research Institute on Material Cycling Engineering, Osaka Prefecture University

## I ntellectual property protection

Patent acquisition: Domestic 1

「PRODUCTION METHOD OF ORGANIC ACIDS FROM ORGANIC WASTES」

Patent application: Domestic 34, Overseas 3

「METHOD OF AND APPARATUS FOR PRODUCING SUBCRITICAL WATER DECOMPOSITION PRODUCTS」etc.

## Continuous Sub-Critical Water Plant (Osaka Prefecture University)

Sub-critical water hydrolysis plant constructed on 2003 (4 t/d)

Separation and recovery process of valuable substances constructed on 2006

Methane 60%

CO2 40%

Gas power plant constructed on 2004

Adsorption tank of generated biogas constructed on 2004

High speed and efficient methane fermentation plant constructed on 2004

"New Energy"

Methane gas station for motorcycle and running system of bio methane gas constructed on 2005

## Turning point in the Project

O'Needs for geographically distributed Sub-Critical Water plants (production facilities) are booming.

OBusiness models should be developed around technological research sections, plant developers, users, plant management, and buyers of valuable materials. OCooperation between the bureaucracy and private sectors is essential.