2014年4月13日日曜日

Integrated gasification combined cycle

Integrated gasification combined cycle

http://en.wikipedia.org/wiki/Integrated_gasification_combined_cycle

An integrated gasification combined cycle (IGCC) is a technology that uses a gasifier to turn coal and other carbon based fuels into gas—synthesis gas (syngas). It then removes impurities from the syngas before it is combusted. Some of these pollutants, such as sulfur, can be turned into re-usable byproducts. This results in lower emissions of sulfur dioxide, particulates, and mercury. With additional process equipment, the carbon in the syngas can be shifted to hydrogen via the water-gas shift reaction, resulting in nearly carbon free fuel. The resulting carbon dioxide from the shift reaction can be compressed and stored. Excess heat from the primary combustion and syngas fired generation is then passed to a steam cycle, similar to a combined cycle gas turbine. This results in improved efficiency compared to conventional pulverized coal.

Significance

Coal can be found in abundance in America and many other countries and its price has remained relatively constant in recent years. Consequently it is used for about 50 percent of U.S. electricity needs.[1] Thus the lower emissions that IGCC technology allows may be important in the future as emission regulations tighten due to growing concern for the impacts of pollutants on the environment and the globe.[1]
This technology is being utilized in a project under construction, located in Kemper, Mississippi. The Kemper Project is using lignite coal to produce energy for Mississippians.

Operations
Below is a schematic flow diagram of an IGCC plant:

Block diagram of IGCC power plant, which utilizes the HRSG

The gasification process can produce syngas from a wide variety of carbon-containing feedstocks, such as high-sulfur coal, heavy petroleum residues and biomass.
The plant is called integrated because (1) the syngas produced in the gasification section is used as fuel for the gas turbine in the combined cycle, and (2) steam produced by the syngas coolers in the gasification section is used by the steam turbine in the combined cycle. In this example the syngas produced is used as fuel in a gas turbine which produces electrical power. In a normal combined cycle, so-called "waste heat" from the gas turbine exhaust is used in a Heat Recovery Steam Generator (HRSG) to make steam for the steam turbine cycle. An IGCC plant improves the overall process efficiency by adding the higher-temperature steam produced by the gasification process to the steam turbine cycle. This steam is then used in steam turbines to produce additional electrical power.

Installations

The DOE Clean Coal Demonstration Project helped construct 3 IGCC plants: Wabash River Power Station in West Terre Haute, Indiana, Polk Power Station in Tampa, Florida (online 1996), and Pinon Pine in Reno, Nevada. In the Reno demonstration project, researchers found that then-current IGCC technology would not work more than 300 feet (100m) above sea level.[2] The DOE report in reference 3 however makes no mention of any altitude effect, and most of the problems were associated with the solid waste extraction system. The Wabash River and Polk Power stations are currently operating, following resolution of demonstration start-up problems, but the Piñon Pine project encountered significant problems and was abandoned.

The first generation of IGCC plants polluted less than contemporary coal-based technology, but also polluted water; for example, the Wabash River Plant was out of compliance with its water permit during 1998–2001[3] because it emitted arsenic, selenium and cyanide. The Wabash River Generating Station is now wholly owned and operated by the Wabash River Power Association.
IGCC is now touted as capture ready and could potentially capture and store carbon dioxide.[4] (See FutureGen)Poland's Kędzierzyn will soon host a Zero-Emission Power & Chemical Plant that combines coal gasification technology with Carbon Capture & Storage (CCS). This installation had been planned, but there has been no information about it since 2009. Other operating IGCC plants in existence around the world are the Alexander (formerly Buggenum) in the Netherlands, Puertollano in Spain, and JGC in Japan.

There are several advantages and disadvantages when compared to conventional post combustion carbon capture and various variations and these are fully discussed at reference 6.[5]


Cost and reliability
The main problem for IGCC is its high capital cost, upwards of $3,593/kW.[6] Official US government figures give more optimistic estimates[7] of $1,491/kW installed capacity (2005 dollars) v. $1,290 for a conventional clean coal facility, but in light of current applications, these cost estimates have been demonstrated to be incorrect.[citation needed]
Outdated per megawatt-hour cost of an IGCC plant vs a pulverized coal plant coming online in 2010 would be $56 vs $52, and it is claimed that IGCC becomes even more attractive when you include the costs of carbon capture and sequestration, IGCC becoming $79 per megawatt-hour vs. $95 per megawatt-hour for pulverized coal.[8] Recent testimony in regulatory proceedings show the cost of IGCC to be twice that predicted by Goddell, from $96 to 104/MWhr.[9][10] That's before addition of carbon capture and sequestration (sequestration has been a mature technology at both Weyburn in Canada (for enhanced oil recovery) and Sleipner in the North Sea at a commercial scale for the past ten years)—capture at a 90% rate is expected to have a $30/MWh additional cost.[11]
Wabash River was down repeatedly for long stretches due to gasifier problems. The gasifier problems have not been remedied—subsequent projects, such as Excelsior's Mesaba Project, have a third gasifier and train built in. However, the past year has seen Wabash River running reliably, with availability comparable to or better than other technologies.
The Polk County IGCC has design problems. First, the project was initially shut down because of corrosion in the slurry pipeline that fed slurried coal from the rail cars into the gasifier. A new coating for the pipe was developed. Second, the thermocoupler was replaced in less than two years; an indication that the gasifier had problems with a variety of feedstocks; from bituminous to sub-bituminous coal. The gasifier was designed to also handle lower rank lignites. Third, unplanned down time on the gasifier because of refractory liner problems, and those problems were expensive to repair. The gasifier was originally designed in Italy to be half the size of what was built at Polk. Newer ceramic materials may assist in improving gasifier performance and longevity. Understanding the operating problems of the current IGCC plant is necessary to improve the design for the IGCC plant of the future. (Polk IGCC Power Plant, http://www.clean-energy.us/projects/polk_florida.html.) Keim, K., 2009, IGCC A Project on Sustainability Management Systmes for Plant Re-Design and Re-Image. This is an unpublished paper from Harvard University)
General Electric is currently designing an IGCC model plant that should introduce greater reliability. GE's model features advanced turbines optimized for the coal syngas. Eastman's industrial gasification plant in Kingsport, TN uses a GE Energy solid-fed gasifier. Eastman, a fortune 500 company, built the facility in 1983 without any state or federal subsidies and turns a profit.[12][13]

There are several refinery-based IGCC plants in Europe that have demonstrated good availability (90-95%) after initial shakedown periods. Several factors help this performance:

1.None of these facilities use advanced technology (F type) gas turbines.
2.All refinery-based plants use refinery residues, rather than coal, as the feedstock. This eliminates coal handling and coal preparation equipment and its problems. Also, there is a much lower level of ash produced in the gasifier, which reduces cleanup and downtime in its gas cooling and cleaning stages.
3.These non-utility plants have recognized the need to treat the gasification system as an up-front chemical processing plant, and have reorganized their operating staff accordingly.

Another IGCC success story has been the 250 MW Buggenum plant in The Netherlands. It also has good availability. This coal-based IGCC plant currently uses about 30% biomass as a supplemental feedstock. The owner, NUON, is paid an incentive fee by the government to use the biomass. NUON has constructed a 1,311 MW IGCC plant in the Netherlands, comprising three 437 MW STEG units. The Nuon Magnum IGCC power plant was commissioned in 2011, and was officially opened in June 2013. Mitsubishi Heavy Industries has been awarded to construct the power plant.[14] Following a deal with environmental organizations, NUON has been prohibited from using the Magnum plant to burn coal and biomass, until 2020. Because of high gas prices in the Netherlands, two of the three units are currently offline, whilst the third unit sees only low usage levels. The relatively low 59% efficiency of the Magnum plant means that more efficient CCGT plants (such as the Hemweg 9 plant) are preferred to provide (backup) power.
A new generation of IGCC-based coal-fired power plants has been proposed, although none is yet under construction. Projects are being developed by AEP, Duke Energy, and Southern Company in the US, and in Europe by ZAK/PKE, Centrica (UK), E.ON and RWE (both Germany) and NUON (Netherlands). In Minnesota, the state's Dept. of Commerce analysis found IGCC to have the highest cost, with an emissions profile not significantly better than pulverized coal. In Delaware, the Delmarva and state consultant analysis had essentially the same results.
The high cost of IGCC is the biggest obstacle to its integration in the power market; however, most energy executives recognize that carbon regulation is coming soon. Bills requiring carbon reduction are being proposed again both the House and the Senate, and with the Democratic majority it seems likely that with the next President there will be a greater push for carbon regulation. The Supreme Court decision requiring the EPA to regulate carbon (Commonwealth of Massachusetts et al. v. Environmental Protection Agency et al.)[15] also speaks to the likelihood of future carbon regulations coming sooner, rather than later. With carbon capture, the cost of electricity from an IGCC plant would increase approximately 30%. For a natural gas CC, the increase is approximately 33%. For a pulverized coal plant, the increase is approximately 68%. This potential for less expensive carbon capture makes IGCC an attractive choice for keeping low cost coal an available fuel source in a carbon constrained world.
In Japan, electric power companies, in conjunction with Mitsubishi Heavy Industries has been operating a 200 t/d IGCC pilot plant since the early '90s. In September 2007, they started up a 250 MW demo plant in Nakoso. It runs on air-blown (not oxygen) dry feed coal only. It burns PRB coal with an unburned carbon content ratio of <0.1% and no detected leaching of trace elements. It employs not only F type turbines but G type as well. (see gasification.org link below)
Next generation IGCC plants with CO2 capture technology will be expected to have higher thermal efficiency and to hold the cost down because of simplified systems compared to conventional IGCC. The main feature is that instead of using oxygen and nitrogen to gasify coal, they use oxygen and CO2. The main advantage is that it is possible to improve the performance of cold gas efficiency and to reduce the unburned carbon (char).
With a 1300 °C class gas turbine it is possible to achieve 42% net thermal efficiency, rising to 45% with a 1500 °C class gas turbine, with CO2 capture. In case of conventional IGCC systems, it is only possible to achieve just over 30% efficiency with a 1300 degree gas turbine.[citation needed]
The CO2 extracted from gas turbine exhaust gas is utilized in this system. Using a closed gas turbine system capable of capturing the CO2 by direct compression and liquefication obviates the need for a separation and capture system.[16]


IGCC Emission Controversy
In 2007, the New York State Attorney General's office demanded full disclosure of "financial risks from greenhouse gases" to the shareholders of electric power companies proposing the development of IGCC coal-fired power plants. "Any one of the several new or likely regulatory initiatives for CO2 emissions from power plants - including state carbon controls, EPA's regulations under the Clean Air Act, or the enactment of federal global warming legislation - would add a significant cost to carbon-intensive coal generation";[17] U.S. Senator Hillary Clinton from New York has proposed that this full risk disclosure be required of all publicly traded power companies nationwide.[18] This honest disclosure has begun to reduce investor interest in all types of existing-technology coal-fired power plant development, including IGCC.
Senator Harry Reid (Majority Leader of the 2007/2008 U.S. Senate) told the 2007 Clean Energy Summit that he will do everything he can to stop construction of proposed new IGCC coal-fired electric power plants in Nevada. Reid wants Nevada utility companies to invest in solar energy, wind energy and geothermal energy instead of coal technologies. Reid stated that global warming is a reality, and just one proposed coal-fired plant would contribute to it by burning seven million tons of coal a year. The long-term healthcare costs would be far too high, he claimed (no source attributed). "I'm going to do everything I can to stop these plants.", he said. "There is no clean coal technology. There is cleaner coal technology, but there is no clean coal technology."[19]

One of the most efficient ways to treat the H2S gas from an IGCC plant is by converting it into sulphuric acid in a wet gas sulphuric acid process wsa process However, the majority of the H2S treating plants utilize the modified Claus process, as the sulphur market infrastructure and the transportation costs of sulphuric acid versus sulphur are in favour of sulphur production.


See also
 

Relative cost of electricity generated by different sources
Environmental impact of the coal industry

External links
Hunstown: Ireland's most efficient power plant @ Siemens Power Generation website
Natural Gas Combined-cycle Gas Turbine Power Plants Northwest Power Planning Council, New Resource Characterization for the Fifth Power Plan, August 2002
Combined cycle solar power

This page was last modified on 22 January 2014

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IGCC(石炭ガス化複合発電)

http://www.mhi.co.jp/products/category/integrated_coal_gasfication_combined_cycle.html

石炭ガス化複合発電(IGCC:Integrated coal Gasification Combined Cycle)システムは、石炭をガス化し、ガスタービンコンバインドサイクル発電(GTCC)と組み合わせることで、従来型石炭焚き火力に比べて発電効率が20%(相対値)と飛躍的に向上する次世代の火力発電システムです。

三菱重工業のIGCCは、空気吹き二段噴流床ガス化炉、乾式燃料供給システムにガス精製設備、ガスタービンを組み合わせた石炭利用高効率発電プラントです。
三菱IGCCは、発電用として送電端効率が高い空気吹きガス化技術を世界で初めて成功した純国産技術に基づくもので、簡素化、合理化を図り、経済性および信頼性を大幅に向上しています。
従来の超臨界圧微粉炭火力に比べ効率が10〜20%向上し、同率のCO2削減が可能となります。 また、脱硫性能が微粉炭火力に優れるだけでなく、灰をスラグ化するため灰容積が約半分以下となり、灰捨て場面積が少なく、かつ非溶出性なので取り扱いが容易となるなど、環境面でも優れた性能を発揮します。

三菱IGCCプラント 鳥瞰図


三菱 IGCCシステム構成



三菱 IGCCシステムの熱効率

(注)本図に示す性能(出力・効率)は、燃料・サイトなど各種条件によって変る可能性があります。


製品について





IGCCガス精製装置
IGCCガス精製装置では、ガス化炉からの生成ガス中に含まれる硫黄化合物・窒素化合物などを取り除きます。
生成ガスを冷却・洗浄し、吸収液にて硫黄化合物を吸収する湿式ガス精製方式を採用しています。
ガス化炉生成ガス中の硫黄化合物の組成は、H2S(硫化水素)、COS(硫化カルボニル)が主形態であるため、アミン溶液での吸収を可能とするよう、COS変換器における触媒反応によってCOSをH2Sに変換します。その後、生成ガスをアミン水溶液にくぐらせ、H2Sを吸収します。

ガス精製プロセスの役割
 
1)精製ガス条件
TOS(H2S+COS):<50ppm⇒環境対策
NH3:<10ppm⇒環境対策(NOx対策)
アルカリ金属(Na、K)、微量成分(Cl、F、Zn、Pb、V、Hg、Se、B、Ca、etc)⇒GT用燃料規格、アミン劣化対策
 
2) 熱回収による発電効率の低下防止⇒GT入口ガス温度の上昇、蒸気使用量の最小化
ガス精製プロセスの特長

COS触媒の開発⇒再加熱不要
再加熱不要⇒高熱効率
熱交換器少⇒コスト削減・シンプルなプロセス
長寿命のCOS触媒⇒メンテナンス回数少
ガス精製プロセス概要

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火力発電のコストは下げられる、石炭で高効率な設備が商用運転へ

http://www.itmedia.co.jp/smartjapan/articles/1212/06/news080.html

2012年12月06日 15時15分 更新

原子力よりもコストが高いとされている火力発電だが、新しい技術でコストの低下とCO2排出量の低減を図る取り組みが着実に進んでいる。燃料費が圧倒的に安い石炭を使った高効率な発電設備が福島県内で実証を完了して、2013年4月から商用運転を開始することが決まった。

[石田雅也,スマートジャパン]

福島県いわき市で2007年から実証実験が続けられていた「IGCC(石炭ガス化複合発電)」の実用化にメドがつき、発電能力25万kWの設備が2013年4月から商用運転に移行する(図1)。火力発電事業を運営する卸供給事業者の「常磐共同火力」が実証設備を受け継いで商用化することになった。

IGCCは価格が安い石炭を使って高効率な発電を可能にする方式で、火力発電のコストを大幅に引き下げることができるため注目を集めている。東京電力によれば、火力発電で1kWhの電力を作るのに必要な燃料費は石油が最も高くて15.95円で、次にガスが10.67円、そして石炭は4.39円である。
現在の火力発電で最も多く使われているガスと比べて石炭のコストは4割程度で済む。

図1 IGCC(石炭ガス化複合発電)の実証設備。出典:クリーンコールパワー研究所

このところ電力会社が火力発電による燃料費の増加を理由に電気料金を値上げする動きが相次いでいるが、コストが安く済む石炭による火力発電を増やせば、燃料費の問題は解消できる。

コンバインドサイクル発電で効率向上
これまで石炭を使った火力発電には大きな問題点があった。ガスや石油と比べて発電効率が低く、CO2の排出量が多いために、環境に対する悪影響が指摘されてきた。この問題を解決する新しい発電方式がIGCCである。
IGCC(Integrated coal Gasification Combined Cycle)は2つの技術を組み合わせて発電効率を向上させる。石炭を「ガス化」してから発電する技術に加えて、火力発電の最新技術である「コンバインドサイクル発電」を併用する。

図2 石炭を使った火力発電の効率向上。出典:クリーンコールパワー研究所

従来の石炭による火力発電では、ボイラーで石炭を燃焼して蒸気を発生させて、発電用の蒸気タービンを回していた。この方法では熱エネルギーを電気エネルギーに変換する効率は40%以下にとどまる。
IGCCでは最初に石炭をガス化して、まずガスを燃焼した熱でガスタービンを回して発電する。さらに燃焼した後の高温の排熱で蒸気を発生させて2回目の発電を可能にする。この2段階の発電方式は、天然ガスを使った最新の火力発電設備でも使われているコンバインドサイクルと呼ばれるもので、発電効率を大幅に向上させることができる有望な技術だ。

コンバインドサイクル発電はガスタービン内の温度が高いほど発電効率も高くなる特性がある。現在のIGCCの実証設備はガスタービンの温度を1200度で運転させて、発電効率を42.9%まで改善した。さらに商用運転の段階では1400~1500度に高める予定で、発電効率は48~50%まで向上する見込みだ(図2)。

古い火力発電設備をIGCCで刷新へ
いわき市のIGCCは国の補助金を受けたプロジェクトで、9つの電力会社とJ-POWERの共同出資による「クリーンコールパワー研究所」が約5年間にわたって長期耐久運転試験などを続けてきた。IGCCの実証設備は東京電力と東北電力が設立した常磐共同火力の勿来発電所(図3)の敷地内に建設されており、2013年4月からの商用運転は常磐共同火力が実施する。

図3 勿来(なこそ)発電所。出典:常磐共同火力

勿来発電所では石炭を主体に4基の火力発電設備が運転中で、合計162万5000kWの発電能力がある。このうち2基は運転開始から40年以上が経過している。火力発電設備の耐用年数は通常40年程度とされていることから、今後はIGCCによる新しい発電設備へ順次移行していくことが予想される。
 全国の電力会社は石炭のほかに石油を燃料に使った古い火力発電設備を数多く稼働させている。こうした発電設備を高効率なIGCCへ転換させれば、燃料費を大幅に削減することができ、同時にCO2排出量を抑制することもできる。原子力発電に頼らずに安定した電力を低コストで供給する体制を構築することは決して不可能ではない。

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石炭ガス化複合発電

http://ja.wikipedia.org/wiki/%E7%9F%B3%E7%82%AD%E3%82%AC%E3%82%B9%E5%8C%96%E8%A4%87%E5%90%88%E7%99%BA%E9%9B%BB

石炭ガス化複合発電(せきたんガスかふくごうはつでん)(Integrated coal Gasification Combined Cycle, IGCC)とは、石炭をガス化して利用する発電方式。
コンバインドサイクル発電(ガスタービンと蒸気タービンを組み合わせ発電する方法)を使うことで、従来の石炭火力発電より高い熱効率で発電することが出来る。具体的には、1,400℃~1,500℃級IGCC商用機の場合、従来の超臨界圧石炭火力発電(SC)や超々臨界圧石炭火力発電(USC)等の石炭(微粉炭)火力発電よりも高く、将来の先進超々臨界圧石炭火力発電(A-USC)と同等の、送電端で低位発熱量基準48~50%程度の熱効率での発電が可能となる。これにより従来の石炭火力より20%少ない(石油火力とほぼ同等)CO2排出量で石炭発電が可能となり、LNGコンバインドサイクル発電と同等のSOxNOx・煤塵排出量で発電が可能となる。また従来の石炭火力発電では使うことが出来なかった低品位炭が利用できるため、燃料費のコスト削減や燃料調達先の多様化によるエネルギーセキュリティの向上が期待できる[1]
日本では、経済産業省の支援の下で電力会社9社等の11法人が中心となって共同で開発に取り組んできた。1986年度(昭和61年度)から1996年度(平成8年度)までにパイロットプラント試験、1997年度(平成9年度)から2001年度(平成13年度)までに要素研究や設計研究を行い、2001年度から2012年度(平成24年度)までに株式会社クリーンコールパワー研究所が、常磐共同火力株式会社勿来発電所構内において、将来の商用機の二分の一の規模で発電効率・燃焼温度・発電量が少ない、42%・1,200℃・25万kW級の実証機の実証試験に取り組んだ(運転試験は2007年度から)[2]。この開発で大きな役割を果たしたのが三菱重工業で、結果として三菱重工は世界で始めて空気吹き・酸素吹き双方の石炭ガス化技術の開発に成功した企業になった[3]
2013年4月1日から、クリーンコールパワー研究所を吸収合併した常磐共同火力株式会社が、実証機を転用した勿来発電所10号機の商用運転を開始した[4]


最終更新 2013年4月16日

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【205】 素直な電気とエネルギー政策へ ... 石炭火力の時代 / 武田 邦彦



公開日: 2012/03/24
中部大学教授・武田邦彦さんのブログ音声をご紹介します
( ご本人のご厚意により、引用が認められています )

武田邦彦さんのサイト ( http://takedanet.com )

・ 素直な電気とエネルギー政策へ・・・石炭火力の時代
2012/03/25 の記事 ( http://takedanet.com/2012/03/post_8b1... )

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IGCC  



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[ScienceNews2013]CO2排出ゼロに挑む 石炭ガス化技術開発



公開日: 2013/10/23
一次エネルギーとしての石炭は、二酸化炭素の排出が多いという欠点がありながらも、世­界的な需要はむしろ増加傾向にあります。日本ではこれまでも環境負荷の少ない石炭火力­発電の技術開発が行なわれてきました。
高効率な石炭火力発電技術に加え、さらにそこから発生するCO2そのものも分離・回収­する技術を融合させた革新的な石炭火力発電、それが多目的石炭ガス製造技術"EAGL­E(イーグル)"です。
新エネルギー・産業技術総合開発機構(NEDO)と電源開発株式会社若松研究所などが­推進するEAGLEプロジェクトを取材しました。

JSTサイエンスニュース:http://sc-smn.jst.go.jp/top/index/news

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世界で進む石炭シフト 1of2



公開日: 2013/06/01
説明はありません。

世界で進む石炭シフト 2of2



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磯子火力発電所



アップロード日: 2011/03/06
いつぞやの撮影がTVに出ました。私は黒子してました(^^;)。
 
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ニッポンの火力発電がスゴイ!石炭・LNG発電の最新技術【1/2】  


アップロード日: 2012/01/29
説明はありません。

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ニッポンの火力発電がスゴイ!石炭・LNG発電の最新技術【2/2】



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福島に最新鋭の石炭火力発電設備を2基建設!【鳥越俊太郎】ニュースの職人 82



公開日: 2013/12/14
東京電力と三菱重工業、三菱商事など三菱グループ3社は共同で、
福島県内に最新鋭の石炭火力発電設備を2基建設する。
合計出力は100万キロワット規模。
総投資額は3千億円で、政府も補助金拠出を検討する。
2020年にも運転を始める。
老朽火力から切り替えて燃料費を抑える。
同時に建設工事などで雇用を創出し、
原子力発電所事故で被害を受けた地域の復興を後押しする。
鳥越さんが最新鋭の石炭火力発電について解説!

鳥越俊太郎「ニュースの職人」チャンネル。より
http://www.shuntorigoe.com/index.html/

画像:http://podcast.kiqtas.jp/torigoe/
画像:http://onand.under.jp/ 

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