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Yasumitsu Kondo
Bureau of construction, Kitakyushu city
14-18, Osayuki-nishi 5-choume, kokuraminami-ku, kitakyushu 803-8501 Japan
Yasumitsu_kondou01@mail2.city.kitakyushu.jp

Abstract: Now, Kitakyushu city has two recycling methods of sewage sludge. The first way is thatdried sludge is burned with refuse at incineration facility located by sewage treatment plant. The
heat energy generated by the burning is recycled as sources such as electric power source for theplant and the source for sludge drying. Secondly, we’ve been materializing sludge for cement since1997. Kitakyushu city is one of the first Japanese cities that introduced this new technology. Bothways are the largest scale ones in Japan. For the next utilization, we are now trying to use sludge as
an efficient fuel by further drying process.
Keywords: cement material, sludge incineration, dewatered sludge, fuelization, super
power generation
Introduction
In Japan sewage sludge tends to increase every year by the spread of sewers, advanced biologicaltreatment, and change of a lifestyle and so on. Along with it more and more difficulties are coming
up in finding appropriate sludge process measures and cost in the treatment. Among municipalities
having wastewater treatment plant (WWTP), there is a local body to have a cement company treat
dewatered sludge (DS) at its factory, far away 600 km from the city with cargo train transportation.
Kitakyushu city introduced Cement Materialization System (CMS) for DS in 1997 and Sludge
Incineration System with generally refuse (SIS) at incineration facilities in 1999 instead of sea
reclamation and sea dumping disposal. By this shift, we had achieved our objective to utilize thesludge for cement material and power generating to a certain extent. Circumstances surrounding
biosolids sludge, however, have been changing these days, as the central government proclaimed
biomass strategy for promotion of its utilization in various fields and “the renewable portfolio
standard” was enacted in 2003 in favour of sludge energy use in response to the Kyoto protocol
enforcement. In line with this movement we have started tackling for the further utilization of
sewage sludge as useful biomass resources with intention of reduction of environmental burden on
our city toward a recycling society. In this paper we introduce our present state of DS treatment andefforts for future biosolids utilization.

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Utilization of sewage sludge in Kitakyushu City of Japan

Figure1 shows transition of sewage sludge treatment and volume in Kitakyushu city

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Fig. 1

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㪪㪼㪸㩷㪻㫌㫄㫇㫀㫅㪾䇭㽶Transition of the amount of sewage sludge

The dewatered sludge treatment in Kitakyushu city
(1) Outline of present treatment
Kitakyushu city processes DS by two methods called CMS and SIS. The former is the recycling
method of the sewage sludge developed by joint team consisting of Kitakyushu city and a cementcompany and is utilized in other cities now. Incidentally Kitakyushu’s case serves as the greatest inquantity in Japan. As for the system of CMS, DS is received with a hopper for exclusive use, andthen thrown into a rotary kiln with cement materials, such as limestone, and calcinations process isperformed. Then, rapid cooling is carried out with the clinker cooler and it becomes powderedcement. On the other hand, the steam produced by the boilers of SIS is used as dry source for the
DS drier at WWTP. The SIS generates electricity, a fraction of which is supplied to the WWTP thatpumps up treated water for the incineration facility. In the process, incineration and wastewater
facilities synergistically work.
(2)Destination of DS for treatment
There are 5 WWTPs in this city, and they generate approximately 230 t/day of DS. About 60t out of
230t/day is generated from the Hiagari WWTP(HW) with digestion tanks, and the rest (170t/day) isfrom other WWTPs without digestion process. In addition, half of the daily sludge is turned into
cement materials, and the other half is disposed together with regular household refuse atincineration facilities. In order for the sludge to be transformed as cement material, the sludge istransferred to the Mitsubishi Material Corp.’s facilities both at Kurosaki and Kanda. On the other
hand, the remaining sludge is supplied to the sludge drier in HW. After drying, the sludge is carriedout to the Hiagari and Kougasaki incineration facilities. The destination of DS and its mount ofsludge processed are shown in Fig. 2.

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Utilization of sewage sludge in Kitakyushu City of Japan‫‒⁫⁓⁖‡⁦…†․‫‬‥‥„․•†‪⁦‡⁖⁓⁫‒••⁦‡⁫⁗⁓⁤‒„

3․†‪⁦‡⁖⁓⁫‒••⁦‡⁫⁗⁓⁤‒․․„‫‒⁤⁓⁗⁫‡⁦••‫‬
Hiagari

Kitaminato
treatment

treatmentᵏᵎᵌᵗᵩᶋᴾ

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Kurosaki facility

Kougasakiᵗᵌᵓᵩᶋᴾ

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treatment••⁦‡⁫⁗⁓⁤‒‣

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facility․‧†‣⁦‡⁖⁓⁫‒‣‪„․••⁦‡⁫⁗⁓⁤
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Cement Material
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Kanda facility
Incinalation with refuse

Fig. 2 Destination of DS and its mount of sludge processed(3) Sludge incineration system with generally refuse (SIS) and power generation
The flow of SIS and diagram of usage of power generated are shown in Figs.3 and 4. As mentioned
above, using the steam generated at the Hiagari Incineration facility (HIF) adjacent to HW, DS isdried in a drier currently installed within㩷 HW and dried pellets are burned by boilers in HIF and
KIF(Kougasaki Incineration Facility). The steam turbines in these facilities generate power using
steam attained, and the power generated is supplied to own facility and HW. The surplus of thepower is provided to a power company in trade. Thus Energy recycle system has been achieved.
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Fig. 3㪟 㫆 㫇㫇㪼㫉

Energy recycle system of SIS- 203 -

㪩㪼 㪽㫌 㫊㪼㫀㫅 㪺㫀㫅 㪸㫉㪸㫋㫀㫆㫅㪛㫉㫐㫊㫃㫌㪻㪾㪼㪩 㪼㪽㫌㫊㪼

4

Utilization of sewage sludge in Kitakyushu City of Japan㪮㪮 㪫㪧㪙 㫀㫆㫊㫆㫃㫀㪻 㫊㪛㫉㫐㩷㫊㫃㫌㪻 㪾㪼㪫 㫆㫋㪸㫃㩷㫀㫅 㪺㫀㫅 㪸㫉 㪸㫋㪼㪻 㩷㫍㫆 㫃㫌㫄 㪼㪈 㪎㪇㪃㪇㪇㪇㩷㫋㫆 㫅㩷㫇㪼㫉 㩷㫐㪼 㪸㫉㪈㪏 㪃㪇㪇 㪇㪤㪮㪿㩷㩷㩿㩷㪎 㪃㪇㪇 㪇㫋㪄㪚 㪦 㪉㪀㪩㪼 㪽㫌 㫊㪼 㩷㪾㪼 㫅 㪼㫉㪸 㫋㫀㫆㫅㩿㩷㪍㪃 㪇㪇 㪇 㫂㪮㩷㪀㪠㫅 㪺㫀㫅 㪸㫉㪸㫋㫀㫆㫅㩷㪽㪸㪺㪅㪍㪃㪌㪇 㪇㫋㩷㫀 㫅㪺㫃㫌㪻㪼㪻㪫㫆㫋 㪸㫃㩷㪼㫃㪼㪺㫋 㫉㫀㪺 㫀㫋 㫐㪋㪈㪃㪇㪇㪇㪤 㪮㪿㪉㪈 㪃㪇㪇 㪇㪤㪮㪿㪥 㫆㫅㪄㪹 㫀㫆 㫊㫆 㫃㫀㪻㫊㩿㫇㫃㪸㫊㫋㫀㪺㩷㪸㫅㪻㫆㫋㪿 㪼㫉㫊 㪀㩷㩷 㩷㩷㩷㩷㪪 㪸㫃㪼䇭 㪉㪃㪇 㪇㪇㪤㪮 㪿

Fig. 4 Hiagari incineration facility’s fuel for power and electricity distribution
The most significant point of SIS is that the sludge regarded as mere waste is actually power
generation resources. If we compare power generation efficiency of our facilities to 40% of athermal power plant, 26% at KIF or 10% at HIF is relatively low. However, we can produce thepower we need every day without having an electric generating system itself.
Dewatered sludge drier (DSD)
The drier(water evaporation 2㬍1,800 kg/hr) shown in Fig.5 consists of hopper, sludge feeder, mainpart of the drier, mixer, form making machine, etc.
㪪 㫃㫌 㪻 㪾 㪼 㩷 㪺 㪸 㫂 㪼㪪 㫃㫌 㪻 㪾 㪼 㩷 㪺 㪸 㫂 㪼㪚 㫆 㫅 㫊 㫋㪸 㫅 㫋㩷㪽㪼 㪼 㪻 㪼 㫉䇭 䋨 㫃㫆 㫎 㩷 㫄 㫆 㫀㫊 㫋 㫌 㫉 㪼 䋩㪚 㫆 㫅 㫊 㫋㪸 㫅 㫋㩷㪽㪼 㪼 㪻 㪼 㫉䋨 㪿 㫀㪾 㪿 㩷 㫄 㫆 㫀㫊 㫋 㫌 㫉 㪼 䋩

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㪝 㫆 㫉㫄 㩷㫄 㪸 㫂 㪼 㪻 㩷㪺 㪸 㫂 㪼 㩷㪿 㫆 㫇 㫇 㪼 㫉㪪 㫃㫌 㪻 㪾 㪼 㩷 㫇 㫌 㫄 㫇 㩷 㫋 㫆 㩷 㫄 㫀㫏 㪼 㫉䌐㪚 㫆 㫅 㫊 㫋㪸 㫅 㫋㩷㫍 㫆 㫃㫌 㫄 㪼 㩷㪽㪼 㪼 㪻 㪼 㫉㪪 㫃㫌 㪻 㪾 㪼 㩷 㪻 㫉 㫐 㪼 㫉㪠㫅 㪺 㫀㫅 㪸 㫃㪸 㫋 㫀㫆 㫅 㩷㪽 㪸 㪺 㫀㫃㫀㫋 㫐㪤 㫀㫏 㫀㫅 㪾 㩷 㪻 㪼 㫍 㫀㪺 㪼㪛 㫉 㫀㪼 㪻 㩷 㫊 㫃㫌 㪻 㪾 㪼 㩷 㪽 㪼 㪼 㪻 㪼 㫉㪝 㫆 㫉 㫄 㩷 㫄 㪸 㫂 㫀㫅 㪾 㩷㫄 㪸 㪺 㪿 㫀㫅 㪼㪪 㫋㪼 㪸 㫄 㩷㪿 㪼 㪸 㪻 㪼 㫉㪛 㪼 㫆 㪻 㫆 㫉 㫀㫑 㪼 㪻 㩷㪸 㫀㫉 㩷 㫇 㫉 㪼 㪿 㪼 㪸 㫋 㪼 㫉㪛 㫉 㫐 㩷 㪸 㫀㫉 㩷㫇 㫉㪼 㪿 㪼 㪸 㫋㪼 㫅㪫 㪿 㪼 㫉 㫄 㪸 㫃㩷㫊 㫋㫆 㫉㪸 㪾 㪼 㩷㪻 㪼 㫆 㪻 㫆 㫉 㫀㪄㫑 㪸 㫋 㫀㫆 㫅 㩷㪽㫌 㫉㫅 㪸 㪺 㪼㪪㫋㪸㪺㫂㩷

㪛㪼㪿㫌㫄㫀㪻㫀㪽㫀㪼㫉㩷㪛 㫀㫉 㪼 㪺 㫋 㫃㫐 㩷 㪹 㫌 㫉 㫅 㫅 㫀㫅 㪾 㩷㪽㫌 㫉㫅 㪸 㪺 㪼㪜 㪸 㪺 㪿 㩷 㪻 㪼 㫍 㫀㪺 㪼㪪 㫃㫌 㪻 㪾 㪼 㩷 㪽 㫃㫆 㫎㪞 㪸 㫊 㩷 㪽 㫃㫆 㫎㪪 㫋 㪼 㪸 㫄 㩷 㪽 㫃㫆 㫎㪮 㪸 㫋 㪼 㫉 㩷 㪽 㫃㫆 㫎㪚 㫆 㫅 㪻 㪼 㫅 㫊 㪸 㫋㪼 㩷㫋㪸㫅 㫂㪠㫅 㪺 㫀㫅 㪸 㫃㪸 㫋 㫀㫆 㫅 㩷㪽 㪸 㪺 㫀㫃㫀㫋 㫐

Fig. 5 The flow of sludge dryness facility at HW.
The steam (6t/h) used for drying, which is the surplus steam generated at the adjacent HIF,
dehydrates 75% moisture sludge to 40%. The dried pellet is 3cm in diameter and 10cm long. The
pellet burns efficiently at the incineration facilities and does not fall out of stoker. In this drying
process, original sludge in 75% moisture is mixed with 20% moisture sludge in the drier, and the
mixture then turns into 40% sludge. The offensive odour emitted from the sewage sludge is an issueof this drying process, so this plant has three resolutions for deodorization of sludge.
Refuse incineration and Super power generation system- 204 -

Utilization of sewage sludge in Kitakyushu City of Japan

5

Next, we describe super power generation system (SPGS) which is adopted at KIF. The SPGS uses
gas turbine together with steam turbine. As shown in Figure 6, 7 the steam of the refuse incineration
boilers is reheated by high temperature exhaust gas from gas turbine, which is placed in the former
steps of the steam turbine and consumes city gas as fuel. Reheated steam reaches the hightemperature at 370 degrees C and the high pressure at 38 atmospheres absolute. Thus, thiscombined system, steam turbine and gas turbine, achieves 26% power generation efficiency.
Through this system much more electricity can be obtained than conventional systems. This
combined system is a maximum scale in Japan.
㪩 㪼㪽㫌㫊㪼 㩷㪛 㫉㫐㩷㫊㫃㫌㪻 㪾㪼㪙 㫆㫀㫃㪼㫉㩷㪟 㫆 㫇 㫇 㪼㫉㩷㪙 㪸㪾㩷㪽㫀㫃㫋㪼㫉㪪㫋㪸㪺㫂㩷㪩 㪼㪽㫌㫊㪼 㩷㫇 㫀㫋㪨㫌㪼㫅㪺㪿㩷㫉㪼㪸㪺㫋㫆㫉㪪 㫋㪼 㪸㫄 㩷㫊㫌㫇 㪼㫉㩷㪿 㪼㪸㫋㪼㫉㪠㫅㪺 㫀㫅 㪼㫉㪸 㫋㫆 㫉㩷㪜㪺㫆㫅㫆㫄㫀㫑㪼㫉㩷 㪪㫌㫇㪼㫉㩷㪿㪼㪸㫋㪼㫉㪟 㫆 㫋㩷㫊㫇 㫉㫀㫅㪾㩷㪽㪸 㪺㫀㫃㫀㫋㫐㪚 㫀㫋㫐㩷㩷㪾㪸㫊㪞 㪼 㫅 㪼㫉㪸㫋㫆㫉㩷㪞 㪸㫊㩷㫋㫌 㫉㪹 㫀㫅㪼㩷㪪 㫋㪼 㪸㫄 㩷㫋㫌 㫉㪹 㫀㫅㪼㪠㫅 㪿㫆 㫌 㫊㪼 㩷㫊㫋㪼㪸 㫄㪞 㪼㫅 㪼 㫉㪸㫋㫆 㫉㩷㪚 㫆 㫅 㪻 㪼 㫅㫊㪼 㫉㩷㪚 㫆㫆 㫃㫀㫅 㪾㩷㩷㩷㫋㫆 㫎 㪼㫉㪪 㫋㪼㪸㫄 㩷㩷㪽㫃㫆 㫎㪠㫅㪺 㫀㫅㪸 㫃㪸㫋㫀㫆 㫅㩷㩷㪺㪸㫇 㪸㪺 㫀㫋㫐㩷㩷㩷㩷㪏㪈 㪇㩷㩷䌴㪆 ᣣ㪞 㪼 㫅㪼 㫉㪸㫋㫀㫆㫅 㩷㪺 㪸㫇 㪸㪺㫀㫋㫐 㩷㩷㩷㪊㪍䋬 㪊㪇 㪇㪢 㪮䋨㪪 㫋㪼㪸㫄 㩷㫋㫌 㫉㪹 㫀㫅㪼㩷㩷㩷㩷㩷㩷㩷㪉㪏䋬 㪊 㪇㪇 㪢 㪮 䋩䋨㪞 㪸㫊㩷㫋㫌㫉㪹 㫀㫅 㪼㩷㩷㩷㩷㩷㩷㩷㩷㩷㩷㩷㩷㩷㩷㩷㩷㩷㪏 䋬 㪇㪇 㪇㪢 㪮 䋩㪞 㪸㫊㩷㩷㪽㫃㫆㫎㪮 㪸 㫋㪼㫉㩷㩷㪽㫃㫆㫎㪚 㫆 㫆 㫃㫀㫅㪾㩷㫎 㪸㫋㪼 㫉㩷㪽㫃㫆 㫎㪚 㫆㫅 㪻 㪼 㫅㫊㪸 㫋㪼㩷㫋㪸㫅 㫂㪚 㫀㫋㫐㩷㩷㪾㪸㫊

Fig. 6

Power generation flow diagram of the Kougasaki incineration facilityS
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Fig. 7 Super power generation system (SPGS)At present, one of three refuse incineration facilities in Kitakyushu City is under reconstruction to
introduce gasification melting furnace (the Moji incineration facility shown in Fig. 8). The power
generation efficiency of this facility is 20%, and it is 10% higher than HIF or conventional ones. In
order to achieve higher power generation efficiency, we expect to use this new facility instead oflow efficiency facility in HIF.

- 205 -

6

Utilization of sewage sludge in Kitakyushu City of JapanG a s ific a t io n M e lt in g F u r n a c e
W
W aa ss tt ee

CC oo kk ee (( 55 %% oo ff w
w aa ss tt ee ))S
S tt ee aa mm
LL iimm ee ss tt oo nn ee (( 44 %% oo ff w
w aa ss tt ee ))TT uu rr bb ii nn ee,, CC OH
H 22 OO 55 00 %%O 11 55 %%CC O
O 22 11 55 %% ,, CC H
H 44 ++ ,,H
H 22 22 00 %%G
G aa ss ii ff ii cc aa tt ii oo nn
33 00 00 㷄㷄~~
11 00 00 00 㷄㷄M
M ee ll tt ii nn gg
11 88 00 00 㷄
㷄

1 1 0 0 㷄CC oo mm bb uu ss tt ii bb ll ee
gg aa ssM
% oo ff w
w aa ss tt ee ))M ee lltt iinn gg A
A ss hh (( 11 00 %M
% oo ff w
w aa ss tt ee ))M ee lltt iinn gg M
M ee tt aa ll (( 33 %B
B oo ii ll ee rr

Fig. 8 Gasification melting furnace power generation at new Moji incineration facility(4) Cement materialization system
The system of cement materialization of DS in Kitakyushu city has following features.
䊶㩷 Because we directly supply the DS into a cement manufacturing process, everything can beeffectively utilized as cement materials. Thus, it does not waste any DS. Moreover, theorganic matter included is used as substitution of calcinations fuel.
䊶 Since the DS is thrown in a kiln at a temperature of 1,500 degrees C, it is decomposedcompletely. Thus, no odour emission occurs.
䊶㩷 Cement materialization business in a scale of 40,000t DS per year is at the national maximum
level.
䊶㩷 Since one of the private sector’s cement factories is adjacent to Kougaki WWTP, the cost forsludge transportation is low.
Since the limited number of cement companies accepts our sludge, there is no competition incontract. Therefore, we do not have space to quickly response to needs of the present times such as
converting to new systems, although the CMS mentioned above has advantages. This is our subject.
Measures of sludge treatment in the future(1) Subjects on future DS treatment in Kitakyushu city
The following are subjects on DS treatment in Kitakyushu city in coming years.
Correspondence to social situation changes like global warming prevention etc.
From now on, the use of the renewable energy that does not rely on fossil fuel will be further
advanced at a worldwide level as promoted by "Kyoto Protocol". Focusing on the sewage sludge,
the organic matter in the sludge is assumed to be biomass 100 percent renewable energy. So now
we are facing an important transitional period from waste to the valuable thing regarding sewage
sludge. Based on this realization, we should take the most appropriate measures for next-generation
method for the sewage sludge treatment in Kitakyushu city.
Regarding the reduction of sludge processing expense.

- 206 -

Utilization of sewage sludge in Kitakyushu City of Japan7

For further utilization of sewage sludge as useful resources, we want to select and introduce
methods that cost us the least.
Agreement limit for cement materialization
Present agreement term with the private sector for the materialization is going to expire in 2009.
Although it is possible to continue the agreement, we might have to concern about unfavourable
sludge acceptance price.
The sludge drier’s standard life to 2009
The Hiagari sludge drier was built in 1999 and has been operating for 7 years. The standard life thecentral government defines is ten years, so the sludge drier will reach the maturity date in three
years. If we continuously use the facility after the standard life passes, we must make overall
judgment for the maintenance and repairs.
(2) Direction and note in the future sludge treatment
Sewage sludge treatment adviser committee
This city set up "Sewage sludge treatment adviser committee" in August, 2005 by the specialists
who belong to universities and a laboratory in the country based on the subjects mentioned above to
make use of the sewage sludge as a valuable resource, and to examine a suitable processing method
for this city from the viewpoint of reducing the environmental burden of the city. We will do theoverall evaluation from the views on an economy, energy consumption, and an environmental
aspect, etc. by the end of this fiscal year, and bring the investigation results.
Sludge fuelization
There are several methods of sludge fuelization. Adopting new method, duration of practical use,energy consumption efficiency, global warming prevention as well as economies should be
evaluated. So-called dryness, dry granulation and carbonization methods have been practically used
inside and outside the country, though some subjects still remain unsolved in other methods. Mostof sludge fuelizing methods consume some kind of fuel through a dry process and the carbonization
process, etc. in order to create a new fuel. In other words, the fuel used is converted to the biomass
fuel. Supposed we do most efficient processing, energy yield by the conversion is 1.5 times energyof the fuel consumption. We should select the processing method and scale considering thesethings.
Sludge Fuelization verification test
At the Kitaminato WWTP, sludge fuelizing field test has been started since this march. This test
employs the Dry Granulation Method. In this method, exhaust gas that comes from the burning offuel is directly brown against the dry dram with paddles. This method is expected to have high dry
efficiency and possible to obtain dry grain in ball with nearly 8 % moisture which has about
17Mj/kg in lower calorific value. So this grain could be an alternative energy source of coal whichis consumed at power plants. We will continue this verification test until next march and make acomprehensive assessment on technical reliability, financial aspect, and heat balance and so on.
(This test is carried out by Japan Sewage Works Agency and Nippon Steel Corporation.)
Overhaul of dewatered sludge treatment system- 207 -

8

Utilization of sewage sludge in Kitakyushu City of Japan

During the overhaul of the sludge dryer, sludge is treated in the cement facility. The cost fortreatment is included in the present contract. The cement factory has the treatment capacity for thesludge and is always ready to receive the sludge. Considering the future, it will become an
important point to secure a way for overhaul. It is difficult to store DS temporally in the process ofthe sludge treatment because of the odour issue. Kitakyushu City has three refuse incineration
facilities, and each has capacity to stock 10 days or more volume of refuse in pit. In addition, total
incineration capacity makes one month overhaul of each facility alternately in a year. So
considering it, at least three ways might be required to secure the DS treatment in our city.
Bad odour control measures
As mentioned above, drier has two high and one low deodorizer at present. One of high deodorizers
was additionally introduced after the construction because people who live in the vicinity of theplant often complained about the bad odour from the drier. In spite of this improvement, even now
some complaint is reported from the neighbourhood. For the construction of fuelization facility inthe centre of highly populated cities, we need to think about how we can prevent possible odour
issue.
Conclusions
Kitakyushu City proclaimed “A grand design aiming at World Capital of Sustainable Development”
in 2004 in which we have 10 basic philosophies. Of those philosophies, reduction of environmental
burden, CO2 emission, water and air contamination and others, on our region and earth is included.
In adherence with the spirit of it, we consider introducing next generation’s sludge treatment
method from the following perspectives.
・Realizing “uniqueness of Kitakyushu city”
・Fuelizing biosolids sludge
・Emphasizing effective and efficient system in energy consumption and CO2 emission.
Kitakyushu city experienced severe environmental pollution in 1950s and 60s and finally overcame
it through citizen’s movement and cooperation between people, corporations and our government.
In this respect spread of sewerage in our city played an important role of the improvement of theenvironmental situations. Thorough sewage works, we will continue making contributions in apositive manner to resolving local and global environmental problems and fulfil our responsibility
as a world citizen in the future.

- 208 -

- 209 -Sea reclamation

Past
・sea reclamation（～1998）・sea dumping（～1999）London Treaty revision enacted in 1996

Sea dumping

Treatment of sewage sludge （Past）

Construction Bureau
Sewer Systems Administration Department

Utilization of sewage sludge
in Kitakyushu City of Japan

1977 78

79

80

81

82

83

84

85

86

87

88

89

90

91

92

93

94

95

96

97

98

99 2000 01

02

03

04

Sea dumping ⑤

Sludge incineration

Past
・sea reclamation（～1998）・sea dumping（～1999）

Cement materialization

present
・cement materialization（1997～）
・sludge incineration withrefuse（1999～）

Treatment of sewage sludge （Present）

Refuse In． ④

20,00010,000Cement ③

40,00020,000

Sea reclamation ②

60,00030,000Landfill ①

80,00040,0000100,000

50,0000120,000

60,000London Treaty revision enacted in 1996④㎥
140,000 ⑤

160,000

70,000t①

180,000

80,000200,000

90,000100,000

Transition of the amount of sewage
sludge and treatment～

110t/d

1,100℃

Rotary kiln

Preheater

Clinker Cooler

1,450℃- 210 -

5,100t/ year

facility

Cement10km

km

Distance

10km⇒ Cement Fa.
(Kanda)Sone WWTP⇒ Hiagari drier

Shinmachi WWTP

⇒ Hiagari drier

Hiagari WWTP

⇒ Hiagari I F (0.1km)⇒ Kougasaki I F(25km)

Hiagari dry facility

S t e a m f lo w

Kanda facility

W a t e r f lo w

G a s f lo w

S lu d g e f lo w

S te a m h e ad e r

158℃

6kg/cm2

D r ie d s lu d g e f e e d e r

S lu d g e d r y e rＰＰIn c in a la t io n
f a c ilit y

E a c h d e v ic e

D ir e c t ly b u r n n in g
fu rn a c e
D e o d o r iz e da ir p r e h e a t e r

F o r m m a k in g
m a c h in e

M ix in g d e v ic e

C o n stan tv o lu m e
fe e d e r

ＰS lu d g e p u m p t o m ix e r

C o n d e n s a teta n kD r y a ir
p re h e a te nＰ

C o n s ta n t fe e d e r（ h ig h m o is t u r e ）C o n s ta n t fe e d e r（ lo w m o is t u r e ）ＰS lu d g e c a k e

S lu d g e c a k e

T h e rm a ls to ra g e
d e o d o r iz a t io n
fu rn a c e

F o rm m a k e dcake hopper

The flow of sludge dryness facility at HW

In c in a la t io n
f a c ilit y

1km⇒ Cement Fa.
(Kurosaki)⇒ Hiagari drier

Kitaminato WWTP

Kougasaki WWTP

10km

Present state ofsludge treatment

Cement company

7,200t/year

8,200t/year

10.7Km

17.6t/daytreatment
25.1t/daySone

facility

5,800t/yaer

17.8t/day

9,600t/year

26.4t/day

Hiagari

19.0Kmtreatment

0.1Km

Shinmachi

9.5Km

22,900t/year

62.8t/dayDryertreatment

HiagariSludge10.9KmIncinalation with refuse

Dry Treatment

Cement Material

15.7ｔ/day

Kougasaki

24.7KmKurosaki facility

Cement company

1.2 Kmtreatment

Kougasaki

treatment

7,600t/year

33,700t/year

Kitaminato

20.8t/day

92.4t/day

Destination of dewatered sludge

SludgeCray, Lime

Cement Material Process

Stack

Dehumidifier- 211 -Steam
TurbineGas
Turbine

L.N.G.

270℃

28,300kw(23,000kw)

370℃

8,000kw

530℃

Steam 24kg/cm2

Stack

280℃ 90℃

Total Efficiency 26%

Super Electric Power Generation System in Kougasaki

Incinerator

Waste

40t/d

RefuseDrysludgePower generation flow diagram of theKougasaki incineration facility

600t/dRefuseincinaration

HopperDS dry facility

Hiagari Refuse incinaration facility

6,000kW

steam

steam

Form
makingmachineSteam dram

Steam drier
(75%
40%)

electricity

120t/dSteam turbine
generator

SludgeHiagari WWTP

Energy recycle system ofsludge incineration with refuse

Refuse genera tion
( 6,000kW )T otal in cin ar ated vo lum e
1 70,000 to n per ye ar

WWTP

Sale 2,0 00MW h

21 ,00 0MWh

In cin aration fac.

18 ,00 0MWh
( 7 ,00 0t-C O 2)
Total elect ric it y
41,000M Wh

G
G aass

8 ,0 0 0
w
0 kkw

S
Ste
teaam
m

280℃

S uuppeerr
G e n e ra tio n
S yy s te m

28
8 ,3
, 3 0 0 kkww

2 3 ,,000
00
0 kkww

T o t a ll

3 6 ,3 0
00
0k w
w

370℃

H e a tt E xxcch
h aan g
ge

280℃

SSte
teaam
m TTuurb
r bin
inee

530℃

G
b in
G aass TTu
urrb
in ee

Tow n
G
G aa sInn c in e r a tto
or

E ffic ie n c y 2 6 ％Super power generation system

Non-b io so lids
(plastic andoth ers)

6,50 0t i ncluded

Dry slud ge

Biosolid s

Hiagari incineration facility’s fuel for
power and electricity distribution

- 212 -Steam

KogasakiM
M ee lt
ltin
in g
g
1
18
80
00
0℃
℃

G
G aa ss if
ific
ic aa ttio
io n
n
3
30
00
0℃
℃
~
~
1
10
00
00
0℃
℃

C
Co
om
mb
bu
u ss ttib
ib le
le
g
g aa ss

T u r b in e

B
Bo
o ile
ile rr

1100℃

H
H 22O
O 5
50
0%
% ,, C
CO
O 1
15
5%
%
C
CO
O 22 115
5%% ,, C
CH
H 44+
+ ,H
,H 22 220
0%%M
M ee lt
ltin
in gg A
A ssh
h ((1
10
0%
% oo ff w
w aa ssttee ))M
M ee lt
ltin
in gg MM eettaall ((33%% oo ff w
w aa ssttee ))W
W aa ss ttee

C
C oo kk ee ((55%% oo ff w
w aa ssttee ))S te a m
LL im
im ee ssttoo nn ee ((44%% oo ff w
w aassttee ))G a s if ic a t io n M e lt in g F u r n a c e

Gasification melting furnace power
generation at new Moji incineration
facilityNight Soil Office

Collection OfficeElectricity Sewerage Plant

Hot Spring

Electricity

Power Company

Utilization of Heat
+20,000,000yen+

Electricity

Incineration 22%

Steam

Heat Supply 1%+107,000,000yen

Power+1,163,000,000yen

Power company 71%

SewageTreatment7%

Power Generation 23,500kw（Hiagari 255℃、Kogasaki 370℃）

Steam Temperature 400℃

（Hiagari 20kg/cm2、Kogasaki 23kg/cm2）

Steam Pressure 40kg/cm2

High Efficiency (20%)
Generation

Steam turbine 84%

Incineration 15%

Ratio of steam consumption
in Kougasaki

- 213 -cost（million yen）

2002

215

incinaeration cost

（３６．１ th. t）

99

69

412

2003

233

93

65

456

38

inci. tans. cost

（４３．０ th. t）

382

inci.

（４１．２ th. t）

443

cement825 （８４．２ th. t）
31885

ce. material cost

（４１．２ th. t）

391

inci.

（４５．６ th. t）

494

cement（８６．８ th. t）※ Incineration cost raised in 2004 from 7,000 to 10,000 yen per ton）

drying cost

2001

175

314

（３０．２ th. t）

270（４５．０ th. t）

inci.

78

60

450

537

cementinci.

（４０．４ th. t）

463

cement87851 （８１．１ th. ｔ）（３８．３ th.t）Social changing

present
・cement materialization（1997～）
・sludge incineration
with refuse（1999～

global warming prevention

Biosolids use、New type of treatment（fuel alternative）

future483（３７．６ th. t）

337

inci.

（４４．９ th. t）

fiscal year

2005

168

120

48

449

cement820 （８２．５ th. t）
34

1999 Law concerning the Promotion of the Measures to Cope with
Global Warming
2000 Fundamental Law for Establishing a Sound Material-Cycle Society
2003 renewable portfolio standard
2004 “A grand design aiming at World Capital of Sustainable
Development” proclaimed
2005 Coming into effect of Kyoto Protocol

Global environment conservation

Past
・sea reclamation（～1998）・sea dumping（～1999）London Treaty revision enacted in 1996

329

inci.

（４４．４ th. t)

475

cementce. trans. cost

2004

172

106

51

444

31

804 （８２．７ th. t）

cement material cost supposed at 10,000
yen per ton

Transition of sewage sludge treatment

2000

178

100

0

56

36

404

59

733 （７０．６ th. ｔ）

200

300

400

500

600

700

800

900

Sewage sludge process cost transition■Sewage sludge treatment adviser
committee■Measures to be considered Drier Dry granulation
 High temperature carbonization
 Low temperature carbonization

Comparison of future sludge process
methods

environment like global warming
prevention
Reduction of sludge treatment costResponse to social changes on

Sludge Drier’s standard life（～2009 ）Agreement of cement material （～2009）

Subjects for dewatered sludge treatment

- 214 -





Odour
countermeasures to control bad odour
in urbanized plot----biological, activatedcarbon deodorizations and others

Overhaul
How to treat dewatered sludge during
overhaul of facilities

Note for decision of method

Sludge fuelization verification test (drygranulation method)

To adopt efficient system in energy
consumption and CO2 emission control
 To utilize sewage biosolid as a fuel
 To realize uniqueness of Kitakyushu cityObjectives

Moisture 8%, Reduction rate 1/5, 17Mj/kg

Produced sludge grain

- 215 -

Ａ－１

110

Ｂ－１

96

Ｂ－２

80

Ｂ－３

77

Ｃ－ １

115

PrerequisiteTransportation cost included
Overhaul term’s process cost included
Countermeasure cost against bad odour not included
There would be companies to be able to accept products created

0

50

100

150

200

Cost (Euro/ton)

Ｃ－ ２

110

Ｄ－ １

29

Mere result based on questionnaires
from makers and so unauthorized

Cost for future DS treatment in our city