Refuse Paper & Plastic Fuel (RPF) production factory of long standing

(Industrial Waste Close-up 2010.10)

Ichikawa Kankyo Engineering Co., Ltd. Gyotoku Factory

Outline of Ichikawa Kankyo Engineering Co., Ltd., Gyotoku factory

Operation start : March, 1978
Location : 212 Katoshinden, Ichikawa city, 272-0124
History : Apr.1986. Start of operation of RPF production plant
May, 2003. Completion of renewal of the RPF production plant
Licensed waste : Industrial waste and general waste
Treatment method : 1. Intermediate treatment by means of shredding/separation/pelletizing
2. Intermediate treatment by means of melting (for polystyrene foam)
Plant capacity : 1. Shredder:120 t/day Separator: 120 t/day Pelletizer: 80t/day
2. Melting furnace: 0.8 t/day (for polystyrene foam)
URL : http://www.ike.co.jp/about_plant.php#gyotoku

Introduction

Mr. Masayoshi Shitano, General Manager of Environmental Recycling Business Division (Photo 1) and Ms. Miki Akashi, staff of Corporate Planning Office kindly made the explanation and the tour guiding of the factory of long standing.

Mr. Masayoshi Shitano, General Manager of Environmental Recycling Business Division
Photo 1. Mr. Masayoshi Shitano, General Manager of Environmental Recycling Business Division

A flow of RPF production is shown in Figure 1 and a view of the production line is shown in Photo 2. The basic production process includes the following sub-processes:

  1. Primary shredding of carrying-in waste (2-stage)
  2. Separation by “Ballistic separator” consisting of vibrating screen and air blow unit.Primarily shredded waste material is separated into light material (film, sheet, paper, etc.), heavy material (rigid plastic, metal, etc.) and others of which diameter are under 30mm.
  3. Removal of foreign matters by a magnetic separator and "Multi-sorter" consisting of near infrared ray plastic identification unit and physical removing unit. Metal and chlorine-based plastic are removed out of sorted waste material.
  4. Secondary shredding of sorted waste material of increased purity and  supplemental material.
  5. Solidification of secondarily shredded waste material into RPF by a pelletizer.

RPF production flow of Gyotoku factory
Figure 1. RPF production flow of Gyotoku factory

A view of RPF production line of Gytoku factory
Photo 2. A view of RPF production line of Gytoku factory

RPF is produced according to a criterion for calorific value and chlorine content set up by ourselves. For the purpose of the adjustment of chlorine content and calorific value, supplemental material is added. In this case, the rough target is set in-between 6000 and 7000 kcal/kg. Benefitting from the past experiences, three kinds of RPF with different chlorine content are produced by adequate mixing of yard A and yard B materials. Yard A material of very low chlorine content and yard B material of relatively high chlorine content are prepared by dividing carrying-in waste. The process control is carried out by measuring the chlorine content of RPF regularly. RPF is sold to paper-making and biomass power generation businesses at several yen/kg. There it is used as fuel for a boiler by mixing with other fuel such as wood chips. Meanwhile, RPF of excessively high chlorine content is taken by cement companies on inverse onerous basis.

Feature of RPF production

Features of the RPF production in Gyotoku factory are as follows:

RPF production from general waste and industrial waste

Wastes subject to treatment are paper, plastic and others which are categorized as general waste or industrial waste and the ratio thereof is roughly 1:1. The seasonal variation of carrying-in waste is small.

Thorough management of carrying-in waste and efficient removal of foreign matters

Careful segmentation of carrying-in waste by the content of chlorine-based plastic enables to skip manual separation and to simplify foreign matters removing as well. Also, the configuration of shredded waste treatment line is designed so as to enhance the removing efficiency of chlorine-based plastic by the multi-sorter.

Strengthening of environmental measure

To take measures against the emission of dust and odor, and noise, the plant is installed in a building, and to keep working atmosphere in good conditions, local ventilators are equipped. Particulate materials in the air suctioned by ventilators are removed by a bug-filter and the odor of exhaust steam from a pelletizer is masked with deodorizer.

RPF production in the future

Technical problems related to RPF production have almost been solved at Gyotoku factory. However, economical problems such as lower capacity utilization due to the decline trend of the amount of carrying-in waste and higher cost burden including electricity expense, and maintenance and repair expense of the plant still remain unsolved.

Use of the waste plastic containers and packaging for solid fuel was approved as a recycling method with conditions from 2007. Furthermore, Japanese Industrial Standards Z7311 “Refuse paper & plastic fuel (RPF)” was established in 2010 to secure reliability of RPF as a fuel and to build a kind of promotion base for further use of RPF. Thus, public interest in the thermal recovery from waste plastic with the form of PRF is increasing.

Rich experience and know-how on RPF production obtained at Gyotoku factory may be quite useful for future environmentally-conscious RPF production and the use of its energy potential. Such information is expected to be disclosed.

(Reported by Tanikawa, JW)