Silviase/jgov_v1.4_full_ann huggingface dataset:
waste-plastic gasification process, waste plastics are processed into intermediate formed products in a pretreatment process. The products are then put into a pressurizing two-stage gasification furnace (EUP system) involving the low and high temperature stages where they are thermally decomposed into hydrogen gas and carbon monoxide gas. The gases generated as a result are put into ammonia production equipment where they are synthesized with nitrogen in the air to make ammonia. With this technology, waste plastics can be recycled into ammonia of the same quality as the conventional product produced from naphtha and other substances used for such materials as nylon. (Fig. 2-30)

Fig. 2-30 Process of producing ammonia from waste plastics

Source: Showa Denko K.K.

A technology to make oils from waste plastics has also been put into practical use. Specifically, waste plastics are separated from foreign matter in a pretreatment process and then put in a recycled oil production apparatus where the plastics go through a demineralization process, a thermal decomposition process, and a oil production process into hydrocarbon oils (heavy, middle-weight, and light oils) as recycled commercial goods. For the uses of those hydrocarbon oils, light oils are accepted by oil refineries as petrochemical materials, and middle-weight and heavy oils are used as fuels for power generation.

Introducing these technologies required solving a number of difficult technical issues, such as the removal of chloride in waste plastics and forming processes.

## b) Recycling end-of-life vehicles

The automobile industry, which is also called a comprehensive industry, produces automobiles using various materials such as metals, glass, and plastics. End-of-life vehicles have conventionally been recycled or disposed of by companies specializing in dismantling or crushing. Nowadays they are recycled under the Law for the Recycling of End-of-Life Vehicles (End-of-Life Vehicle Recycling Law) with specified targets for reusing resources from shredder dust at 70% or higher, and airbags at 85% or higher by 2015.
An example of technologies to recycle end-of-life vehicles is collecting aluminum wheels for melting down and converting into suspension parts. This technology enables an automobile company to establish an intra-company recycling process where it collects used products of its own, melts them down, and makes them into new parts in its parts production factory. (Fig. 2-31)

Fig. 2-31 Recycling aluminum wheels

End-of-life vehicles after all reused or recyclable parts are collected are crushed and shredded into shredder dust. Until now, shredder dust has been buried, but is now being treated by means of recycling technologies because a target rate for reusing it as a resource has been set. For example, shredder dust is put into an indirectly heating rotary kiln shielded from the air and thermally decomposed at 450°C for one to two hours to obtain carbides (thermally decomposed carbon) that are used as materials and fuel for electric furnaces. This process also recovers valuable metals. (Fig. 2-32)

Fig. 2-32 Technology for carbonizing automobile shredder residue

Source: Mitsui Engineering & Shipbuilding Co., Ltd.

About 100 million tires, or one million by weight, are discarded every year. Typical examples of waste tire recycling include using them as a firing fuel in cement production, as a material for cement, and as a source of thermal energy. In addition, in steel plants, technology to convert them into a resource has been introduced. Specifically, pieces of cut up waste tires are put in a scrap melting process furnace, where the carbon components of
the rubber are used as materials and fuel for the production of pig iron, while the steel cords (the iron in string form that forms the skeleton of a tire to maintain its shape) are used as a source of iron. Another technology put into practice involves thermally decomposing waste tires in an externally heating rotary kiln to separate and produce gases, oils, and carbons by means of dry distillation and iron wires for use as materials and energy sources. Each of these technologies used in steel manufacturing processes has converted waste tires into resources at 60,000 tons annually. (Fig. 2-33)

Fig. 2-33 Flow of processing waste tires

Source: Nippon Steel Corporation

## c) Recycling of discarded home appliances

Since the Law for the Recycling of Specified Kinds of Home Appliances (the Home Appliance Recycling Law) became effective, home appliance producers are required to recycle four specified appliances into commercial goods at a rate (excluding thermal recycling) of at least 60% for home air conditioners, at least 55% for television sets, at least 50% for refrigerators and freezers, and at least 50% for washing machines. The steps for recycling home appliance products are shown in Fig. 2-34, where various technologies are used to ultimately recover metals, glass, and plastics. As an enhanced effort for recycling plastics, waste plastics recovered from used home appliance products are used again as components for new products. Recycling that substitutes and reduces the input of virgin materials has a higher value added (closed recycling). Such recycling has been made possible by meticulously separating the collection of waste plastic from used home appliances by means of manual dismantling and by developing technologies to make the properties and service lives of recycled plastics meet the requirements of the home appliance products to which they will be applied. (Fig. 2-35)
Fig. 2-34 Flow of recycling home appliances

Fig. 2-35 Case of closed recycling

Changes in the rates of recycling the four specified products in the Home Appliance Recycling Law into commercial goods according to their materials are shown in Fig. 2-36. As shown there, the recycling of non-metal materials such as plastics and glass has increased since the Law became effective.
Fig. 2-36 Change in volume for four specified materials recycled for reuse as a product

Source: Environmental Council Planning Committee on Sound Material Cycle Society

## Column

## I nternational resource cycle of used copying machines

A system is in operation for collecting used products such as copying machines, printers and related products, including cartridges, in nine countries and regions in the Asia Pacific region. The used products are delivered to a recycling factory in Thailand, where they are dismantled and sorted and then recycled into a useable resource. In constructing this international resource-cycle system, four principles were established: (1) preventing unlawful disposal of such machines, (2) producing no environmental impact on the import country, (3) importing no waste, and (4) returning some benefits to the import country. Collected used products are sent from each sales location to the plant together with a list of weights, where they are dismantled and sorted out into 68 categories. In 2005, about 20,000 units of used copiers and printers were collected, of which 99.2% were converted back into resources.

Areas covered by recycling system and routes for recovering used products

Source: Fuji Xerox Co., Ltd.
## d) Recycling of wastes from construction sites

Wastes coming out of construction sites include not only concrete and asphalt waste and sludge, but also mixed construction wastes. Mixed construction waste may include not only waste produced in the construction, remodeling, and dismantling of buildings, but also fractional pieces of construction materials, packing materials, and waste materials from provisional structures, which may be mixtures of waste plastic, wood, paper, metal, and so on. According to a survey on the state of by-products from construction by the Ministry of Land, Infrastructure and Transport of Japan, the quantity of construction waste produced in 2005 is about 77 million tons in weight, which represents a decrease from about 83 million tons reported by a similar survey in 2002.

In order to encourage the recycling of construction waste, the Construction Material Recycling Law was established in 2000. This law requires that those who have construction contracts under specific conditions dismantle and separate construction waste and convert them back into resources. It also provides that the rates of concrete blocks, wood products used in construction, and asphalt and concrete blocks recycled into resources will be increased to 95% by 2010.

To enable the recycling and making into resources of mixed construction waste, it is necessary to make them into products with stable properties and qualities. Technologies to sort such mixed construction waste involve sorting it by means of a sieve composed of a combination of rotary gears, removing oils attached on their surfaces with water, washing gravels and sand with water, which is crushed into recycled washed sand. The remaining silt and clay is dehydrated and dried and the material is then burned into recycled artificial aggregate.

Roller screen unit

Source: TAKEEI CO., LTD.

Gravity separator

Source: Takatoshi Co., Ltd.
Subbase course material

Source: Daiko Group

Washed recycled sand Source: Mud Recycling Association

## Column

## History of recycling gypsum

Sulfur dioxide $ \left(\mathrm{SO}_{2}\right) $ discharged in the burning of coal or oil is removed by a desulfurization device. A large-scale boiler, for example in a thermal power plant, is based on limestone slurry absorption desulfurization technology. This technology involves using limestone $ \left(\mathrm{CaCO}_{3}\right) $ or slacked lime $ \left(\mathrm{Ca}(\mathrm{OH})_{2}\right) $ to absorb $ SO_{2} $ to make the limestone or lime into gypsum (calcium sulfate: $ CaSO_{4} $ ) or calcium sulfate $ \left(\mathrm{CaSO}_{3}\right) $ . Gypsum produced in this process has been recycled into gypsum boards for use as a building material for interior walls and ceiling substrates.

In October 1999, however, there occurred an accident at a final stable disposal site in Fukuoka Prefecture where a worker died of suspected hydrogen-sulfide poison. Other similar cases occurred around the country. It was discovered that buried waste gypsum boards can be metabolized by sulfate-reducing microorganisms living in groundwater at the disposal site thus producing hydrogen sulfide.

In view of the above-mentioned fact, the involved parties have made efforts to recycle waste gypsum boards and reduce the quantity of such waste. A technology to recycle waste gypsum boards into boards has now been developed.

Recycling gypsum board

Source: Yoshino Gypsum Co., Ltd.
## e) Recycling food waste

Food waste is the residues derived from animals or plants leftover during the processes of production, distribution, and consumption. Specifically they are processing residues produced in the food production process, unsold and disposed food products, food leftover after consumption, and cooking garbage. The food waste produced by the food production industry is relatively easy to recycle because it is easier to acquire the quantity of waste required for recycling and because the composition of a food waste is uniform. Such waste is made into compost or fertilizers or oils or fats are extracted from them. As a result, 78% of the food waste produced in the food production industry is recycled. Food waste produced during distribution and at restaurants is also made into compost or fertilizers or oils or fats are extracted from them. As a result, 24% of them are recycled.

Composting technology involves putting food waste into a rotary-kiln fermentation tank and rotating it for two or three days while supplying air to accelerate fermentation. The fermentation tank heats to nearly 60°C because sugars and cellulose (fibers) in the food waste is oxidative-decomposed by microorganisms. Pathogenic bacteria and eggs of parasitic worms are killed so that sanitary compost is produced.

Technology for producing eco-feeds from food waste involves collecting separated food residues suitable for making livestock feed and putting them into a heating and drying process, a fermentation process (drying, liquefying, etc.), a dehydration process by means of deep-frying and depressurizing (a tempura process), or a liquefaction process for making feed, in order to produce livestock feed. (Fig. 2-37)

Fig. 2-37 Composting facilities

Source: JFE Environmental Solutions Corporation

Recently technology to make kitchen garbage or wood waste (residues in the agricultural process) into resources, such as fuels, by carbonizing, liquefying, and distilling has been put into practical use. (Fig. 2-38)
Fig. 2-38 Food and wood waste recycling project

Source: Kansai Saishigen Network Co., Ltd

## f) Recycling paper

In recent years used paper has been used in the paper-manufacturing industry at record-breaking rates. The quantity of used paper used in 2005 was about 18.59 million tons. The major area of use for used paper is board papers such as cardboards. In that area the ratio of used paper as materials has reached 90%. On the other hand, in the area of paper in paper manufacturing, the ratio of used paper as a material is less than 40%. For newspaper or sanitary paper products, the ratio has already reached more than 50%. While used paper is used as a material for paper manufacturing on the basis of its advantage in formability, it is also now being used to create other paper products.

The technology for producing used paper pulp for use as recycled paper involves (1) decomposing used paper into fiber in a mixer called a pulper, (2) screening out foreign matter such as sand and plastics, and (3) bleaching the fiber by means of a flotator (bubble-producing device) to make the ink attach to and float with bubbles. (See Fig. 2-39)

Fig. 2-39 Paper-recycled pulp production process

Source: Oji Paper Co., Ltd.
## g) Technologies to recycle non-burnable waste and large-size discarded articles

In 2006, the quantity of non-industrial non-burnable waste reached about 2.76 million tons and that the quantity of large-size discarded articles about 800,000 tons. Technology to crush and sort the waste and efficiently convert the valuable portions into resources has been introduced. The technology involves crushing waste and articles with a crushing machine first roughly and then finely into pieces of sizes and shapes that enable efficient sorting by sorting equipment, selecting crushed iron pieces by means of a magnetic separator, sorting crushed grains by means of rotary sieves on the basis of the different grain distributions according to substances to separate non-burnable components efficiently, and further separating non-ferrous components by means of a ferromagnetic drum rotating at high speed. The final residues are burnable. (Fig. 2-40)

Fig. 2-40 Facility for crushing and sorting large-size discarded articles

Source: Kubota Corporation

## h) Recycling incineration ash

Various waste such as garbage incineration ash or sewage sludge in urban areas are used as a main material (about 50% of the materials) in the production of eco-cement. Eco-cement was included in the Japan Industrial Standards (JIS) in July 2002. Materials for ordinary cement include limestone, clay, silica, and iron materials. In the case of eco-cement, garbage incineration ash, sludge, and so on produced in urban areas is used instead of limestone, clay, and silica. Garbage incineration ash contains all the components necessary for the production of cement and is effectively used as eco-cement. In the process of the production of eco-cement, some heavy metals contained in such ash are separated and recovered.

In the Tama area of the Tokyo Metropolitan Area, an eco-cement production plant that processes and recycles incineration residues and melting fly ash produced in municipal garbage incineration plants into eco-cement is in operation. (Fig. 2-41)
A picture of an eco-cement plant Source: the homepage of the Tokyo Tama Extended-area Resource Cycle Cooperative

Fig. 2-41 Eco-cement flow sheet

Source: Ichihara Ecocement Corporation
## (4) Waste into energy

When it is difficult to recycle waste into materials it must be processed by other means such as incineration. Thermal energy produced in such a process can be recovered in the form of power energy or water vapor, a process called thermal recycling. Technology to convert biomass waste such as food waste, livestock manure, and wood waste from construction into methane for use as energy is also being used with increasing frequency.

Today, the reduction of emission of greenhouse-effect gases such as $ CO_{2} $ is an important issue related to controlling global warming. Thermal recycling converts thermal energy produced by waste incineration into electric power and other forms of energy. Since it replaces fossil fuels it reduces $ CO_{2} $ emissions. In addition, in view of the fact that biomass contains $ CO_{2} $ that is fixed from the atmosphere, the $ CO_{2} $ produced by burning biomass is considered as reintroducing $ CO_{2} $ that originally existed in the air (the carbon neutral concept). Accordingly, these $ CO_{2} $ emissions are not included with artificial $ CO_{2} $ emissions, and substituting biomass for fossil fuel results in a reduction of $ CO_{2} $ emissions.

## a) Waste power generation

Waste power generation involves recovering high-temperature thermal energy produced by incinerating waste by means of a boiler and using the water vapor thus generate to rotate a power generation turbine. It is an effective means of using the heat produced by incinerating plants. The first waste power generation plant in Japan was probably the Nishiyodo Plant of Osaka City established in 1965. Since then, the national government has encouraged waste power generation, by, for example, granting subsidies to construct new incineration plants and equipment for the use of extra heat added to existing incineration plants. As a result, many waste power generation facilities have been constructed around the country. As of the end of fiscal 2004, of the waste incineration plants in operation or under construction, 281 plants are generating or will generate electric power. These power generation plants have a total capacity of 1,491 MW and account for about 20% of all waste incineration plants. (Fig. 2-42)

Fig. 2-42 Outline of waste power generation

Waste may contain plastics or vinyl chloride, which produce hydrogen chloride when incinerated. Along with hydrogen chloride, iron chloride and alkali iron sulfate is produced on the surface of metals, which decomposes with dust on the surface. The metal surfaces subsequently rapidly corrode when the surface temperature rise to $ 350^{\circ} $ C- $ 400^{\circ} $ C. As a result, waste incineration plants in Japan are designed so that the temperature of water vapor does not exceed $ 300^{\circ} $ C. As a result, the power generation efficiency of waste power generation plants is 10%-15% at the most. More recent plants, however, have an efficiency
exceeding 15%. Nevertheless, this rate is low compared to the 40% efficiency of thermal power plants.

“Super waste power generation” is a technique for improving the efficiency of waste power generation. This is a system where natural gas-turbine power generation equipment is constructed in a waste incineration plant. Water vapor produced in the waste incineration boiler is heated to high temperatures with the heat discharged from the gas turbine and used by a vapor turbine for power generation. This system improves power generation efficacy by 20%-25%.

Additionally, the use of gasification and melting furnaces are being increasingly used as incineration equipment. These furnaces thermally decompose waste to produce combustible gases and carbides, and burns them at high temperatures of $ 1200^{\circ} $ C and higher. The heat discharged is used for power generation. (Fig. 2-43)

Fig. 2-43 Example of super waste power generation

## b) Biomass power generation

Power generation using biomass such as wood chips or bagasse (residual pulp of sugar cane after the juice is extracted), among industrial wastes, has also been introduced. The biomass of such industrial waste can be acquired in large homogenous quantities. This type of power generation involves burning wood chips or bagasse in a stoker furnace or a fluidized bed furnace, absorbing burning heat in a boiler, and using it to power a steam turbine. It can supply heat at the same time. The issue of treating chlorine contained in biomass when water vapor is in a high temperature, high pressure state, and the issue of optimizing a series of processes including storage, pretreatment, transportation, supply, and burning of biomass to ensure stable power generation, had to be solved in order to put this technology into practical use.

## c) RDF (refuse derived fuel)

Small-scale garbage incineration plants cannot economically implement heat recovery individually. Thus, some small-scale garbage treatment plants process garbage into burn-
able solid fuel, and the fuel is collected at a dedicated power generation plant. This solid fuel is called RDF (refuse derived fuel). It is produced by crushing and drying burnable garbage, removing the non-burnable, iron, and aluminum portion, adding a preservative to it, and then compressing and forming it. (Fig. 2-44)

Fig. 2-44 Flow of RPF production

RDF has a heat capacity of about 4,000-5,000 kcal per kg, twice that of ordinary non-industrial waste. Moreover, harmful substances can be extracted in the processing stage, so discharge gases are easy to treat. Furthermore, it is easy to handle because it is a solid and can be transported by ordinary trucks. Additionally, this fuel is easy to make odor free and store because it is dry.

In August 2003, a storage tank exploded at an RDF power generation plant in Mie Prefecture. It was assumed that the RDF may have ignited due to heat generated by fermentation, or that the storage tank might have produced combustible gas. As a result, in December 2003 the Ministry of the Environment (MOE) reviewed RDF production, storage, and property control methods and developed guidelines for the safe production and use of RDF. In September 2004, the MOE revised the Regulations for Enforcement of the Wastes Disposal and Public Cleansing Law in terms of the safe production and use of RDF based on those guidelines in order to reinforce the regulation.