Techtrend

Biofuel jatropha falls from wonder-crop pedestal

(Reuters) – Jatropha, a biofuel-producing plant once touted as a wonder-crop, is turning out to be much less dependable than first thought, both environmentalists and industry players say.

Some biofuel producers found themselves agreeing with many of the criticisms detailed in a report launched by campaign group Friends of the Earth this week — “Jatropha: money doesn’t grow on trees.”

Jatropha has been widely heralded as a wonder plant whose cultivation on non-arable land in Africa, Asia and Latin America would provide biodiesel and jobs in poor countries without using farmland needed to feed growing numbers of local people.

“The plant can withstand dry conditions, low nutrient levels and exposed conditions,” according to the website of the Netherlands-based Jatropha Investment Fund. “Many desert areas and land which is not currently cultivated will be very suitable for the establishment of plantations.”

But some biofuels producers have found the plant less robust than first thought.

“Jatropha is not the miracle crop that many people think it is,” said Dominic Fava, business development manager of British biofuels firm D1 Oils, which processes jatropha grown in Asia and Africa.

Other company managers say that while the plant needs no irrigation, high yields depend on good soil and chemical additives.

“The idea that jatropha can be grown on marginal land is a red herring,” Harry Stourton, Business Development Director of UK-based Sun Biofuels, which cultivates jatropha in Mozambique and Tanzania, told Reuters.

“It does grow on marginal land, but if you use marginal land you’ll get marginal yields,” he said.

Sun Biofuels estimates its Mozambique plantation, once it matures in two years, may yield two tonnes of oil per hectare of jatropha, and notes it is grown with fertilizers and pesticides on the fertile land of former tobacco fields.

“It is perhaps inappropriate to be offering guaranteed returns at such a stage of domestication, when we’ve still got a lot to learn about this crop,” said Fava.

The report was launched amid a heated debate in the European Union about biofuels, which critics charge are competing for land with food crops and creating unwanted side-effects around the globe.

“It’s good that developers agree jatropha is no wonder-crop. But it means they’ll grow on fertile land,” said Christine Pohl, author of the report.

“We think such land should be used for food production, particularly in light of growing populations and in light of global food insecurity,” she said.

(Reporting by Juliane von Reppert-Bismarck; editing by Tim Pearce)

Original article available here: http://www.reuters.com/article/idUSTRE70K4VU20110121

마쯔다의 최근 친환경자동차 전략
“친환경차의 핵심은 디젤엔진의 개선”

마쯔다의 환경 전략과 핵심이 되는 환경 기술의 전모가 밝혀졌다. 도요타 자동차, 혼다, 닛산 자동차가 하이브리드 자동차와 전기 자동차 등 차세대 자동차 개발에 힘을 돌 리는 동안, 마쯔다가 어떤 환경 전략을 취하는가는 회사의 향후 위상과 생존에 큰 영향을 준다. 마쯔다가 개 발한 환경 기술은 배기량 1.3L 휘발유 엔진으로 연료 1L 당 주행 거리 30km라는 하이브리드 자동차 수준의 연비를 실현하는 것이다.

“SKYACTIV – G”라고 불리는 이 첨단 가솔린 엔진의 등장으로, 만약 마쯔다가 나중에 이 엔진을 사용하여 하이브리드 자동차를 만든다면, 도요타 와 혼다의 하이브리드 차량의 연비를 간단히 뛰어넘게 된다. 또한 마쯔다는 “SKYACTIV – D”라고 불리는 깨끗하고 연비가 좋은 차세대 디젤 엔진도 개발 중이며, 2012년경에 일본, 미국, 유럽에서 시판하는 자동차에 실용화할 예정이다.

높은 연비 성능을 자랑하면서, 요소 SCR (선택적 촉매 환원)과 NOx (질소 산화물) 흡착 촉매와 같은 고가의 NOx 후처리 장치를 장착하지 않고 엄격한 배기 가스 규제를 충족시키는 엔진이다. 가솔린과 디젤의 두 SKYACTIV 엔진 기술은 향후 마즈다 엔진의 기반이 될 것이다.

가솔린 엔진의 기술 개발은 배기 가스 규제에 대한 대응하는 역사라 고 할 수 있다. 시작은 1970년대 미국 캘리포니아에서 큰 문제가 된 대기 오염이었다. 급속하게 증가하는 자동차의 배기가스가 문제시되고, 미국은 세계 최초의 배기가스 규제 “마스키 법률”을 제정했다. 일본에서도 규제가 시작되었고 도시 대기 오염 문제에 자동차 회사는 진지하게 대응하였다.

◆ 유럽이 선택한 엔진 개선
그래도 선진국의 배기가스 규제는 해를 거듭할수록 어려워지고 갔 다. 1990년대 들어 논의된 지구 온난화 문제에 대한 대응에 바로 착수하는 여유는 자동차 제조 업체에게 없 었다.

까다로운 배기가스 저감 요구가 계속되고 그것에 대응하기 위하여 자 동차는 필사적이었다. 여기서 우리가 알아야 할 것은 인체에 유해한 NOx 등의 배기가스 저감과 인체에 무해하지 만 온실 효과가 있는 CO2 배출 감소는 일반적으로 절충된다는 것이다. 연비를 높이려면 NOx가 나오기 쉬워 진다. 가솔린 엔진으로 효율적으로 일을 할 수 있는 범위는 매우 좁다. 이러한 기본적인 제약에서 클린화와 연비 향상의 균형을 어떻게 극복하는가 하는 문제는 자동차 제조 업체를 혼란스럽게 했다.
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이때, 상황을 변화시킨 것은 도요타였다. 교토의정서가 채택된 1997 년 세계 최초의 하이브리드 자동차, 초대 “프리우스”를 발매했다. 혼다도 2000년 초 “인사이트”를 개발하 여, 가솔린 엔진을 전기 모터와 하이브리드화하여 클린화와 연비 향상을 동시에 충족하였다. 가솔린 엔진이 싫어하는 낮은 에너지를 모터가 보완하여 낮은 에너지의 연비 악화를 극복했 던 것이다.

유럽에서는 1990년대 중반부터 후반에 걸쳐 지구 온난화 문제에 대 한 의식이 높아졌다. 이에 따라 승용차에서도 배기가스 저감을 위해 연비 성능을 우선하는 경향이 강해지고, 가솔 린 차보다 연비가 뛰어난 디젤차가 보급되기 시작했다. 디젤차는 배기가스가 약점으로 되어 왔지만, 커먼레일 등 디젤엔진의 배기가스 억제 기술을 개발하여 디젤도 배기 가스 규제에 대응할 수 있게 되었다. 하지만, 유럽에서 도 배기가스 규제 강화 움직임이 없어진 것이 아니다. 최근에는 유럽 업체들도 디젤 청정화 추구에 대한 부담 을 무시할 수 없게 되었다. 폭스바겐(VW)은 청정화하기 쉬운 가솔린 엔진을 중심으로 연비 대책을 마련하였다.

그래서 태어난 것이 “다운 사이징 + 과급기”라는 새로운 가솔린 엔진 이다.
디젤의 비율이 높은 고급차 메이커 BMW와 다임러도, 배기가스 정화 및 연비 향상을 모두 추구하는 가솔린 엔진의 개선에 착수했다. 자연 흡기의 린번(희박 연소) 엔진 개발이 다. 양사는 환경 전략 중 하나로 하이브리드화 추진을 내걸고 있지만, 그 경우에도 가솔린 엔진의 기본 성능 향상 연구를 지속해 오고 있다.

◆ 후처리가 필요 없는 저가 디젤 엔진 개발
마쯔다는 새로운 가솔린 엔진뿐만 아니라 새로운 청정 디젤도 발표했 다. 이것은 대형 차량의 환경 성능 향상을 염두에 둔 것이다. 마쯔다가 발표한 새로운 청정 디젤 “SKYACTIV – D”의 개요는 배기량이 2.2L에서 최대 토크 400Nm이라는 큰 토크를 발휘한다. 세계 의 배기가스 규제는 디젤이 쉽게 달성할 수 없는 수준으로 높아지고 있다. 그래서 유럽 메이커는 현 재 고가의 후처리(요소 SCR이나 백금 촉매)를 추가하여 규제를 만족시키고 있다.

그런데, 마쓰다의 새로운 청정 디젤은 PM(입자상 물질) 감소를 위한 DPF 이외의 후처리가 불필요하다고 말한다. 마쯔다는 기존의 디젤 엔진의 연소 방식을 수정하여 가장 효 율이 높은 상사점에서 연료를 분사하는 시스템을 고안하고 있다. 따라서 분사 압력을 새로운 가솔 린 “SKYACTIV – G”의 무려 10배나 되는 2000기압까지 증가시켰다. 또한 압축 비율은 기존 의 “16”에서 “14”로, 가솔린 엔진과 대조적으로 세계에서 가장 낮은 압축률을 실 현했다.

디젤은 공기만을 압축하여 고온이 된 순간에 연료를 분사하여 자기 착화하는 연소 방식이다. 휘발유는 공기와 쉽게 섞이지만, 점화 어려운 성질을 이용하여 혼합기를 압축한다. 그 리고 플러그에 불을 켠다. 한편, 디젤을 사용하는 경우에는 공기와 섞여 어렵지만, 아주 타기 쉬운 성질을 가 지고 있기 때문에 유해 물질이 발생할 수 있다. 그리고, 플러그가 없는 디젤엔진의 압축 비율을 14까지 낮 추는 저온 시동 시 연소가 불안정하게 된다. 그래서, 가변 버블 타이밍을 사용하여 배기가스의 열을 실린더 로 복원하여 연소를 안정시켰다. EU 모드의 CO2 배출이 105g/km(6 단 MT). 즉, 연료 1L 당 약 25km의 연 비가 된다. 일본 미국 유럽에서 2012 년에 실용화되는 “SKYACTIV – D”는 지금까지 디 젤보다 낮은 비용으로 게다가 높은 효율을 실현했다.

마쓰다 SKY 전략은 결코 하이브리드를 부정하는 것이 아니다. 마쯔다 가 이상적이라고 생각하는 것은 효율적인 엔진, 작은 배터리와 모터의 조합이다. 2010년 3월, 도요타에서 마쯔 다가 하이브리드 기술의 라이선스 공여를 받는 것으로 양사는 합의하였다. 마쯔다에서 볼 때, 도요타와 의 제휴는 이상적인 하이브리드 자동차 구상을 실현하기 위한 것이다. 마쯔다는 하이브리드 차량을 개발하 기 전에 먼저 전통적인 내연 기관을 제대로 발전시키는 것을 우선한 것이다.

NDSL 기술동향, 2010/11/19

Original article available here: http://www.cleandiesel.co.kr/infor/tech_read.asp?id=15&pageNo=1&searchpart=&search=&mykeyword

Antonov gears up for China – and EVs

In the VW mule testing, the TX6 has proved capable of matching the fuel efficiency of a standard Golf 1.6 FSI equipped with an Aisin 6-speed automatic.

A 3-speed for EVs

While the TX6 is focusing Antonov’s development and production teams, a major R&D program concerns a 3-speed automatic gearbox for EVs. Antonov has built one for Jaguar in partnership with MIRA as part of the U.K. government’s Technology Strategy Board-funded “Limo-Green” project.

“We decided that for real efficiency an EV should have a 1st gear for launching and a 3rd for cruising, while the car would spend perhaps 95% of its running time in 2nd,” explained Roberts. “A 3-speed parallel-shaft gearbox with mainly commercial off-the-shelf (COTS) components maximizes motor efficiency. A single speed is not sufficient and a 2-speed provides a ratio step that feels like shifting from 1st to 4th in an IC car.

“It is virtually impossible to refine the shift and there is danger of gearbox damage,” he claimed.

Roberts noted that in the early days of the auto industry, large engines and small transmissions were common. Now, he said, “we are seeing small engines (or electric motors) and large (with more ratios) transmissions. We will see a downsizing policy for electric motors just as we are seeing it for IC engines today, and we will see efficiency improved by the use of multispeed transmissions.

“We can easily add four more speeds to our EV transmission,” he asserted.

For example, to use a 900-N·m (664-lb·ft) motor with a single-speed transmission would involve approximately “1200 A running round a vehicle” – an industrial level. But by using a three-speed transmission, 400 N·m (295 lb·ft) would be sufficient and bring the system down to 400-500 A, which he noted would be far more acceptable.

Roberts sees the 3-speed EV as suitable initially for larger vehicles in the U.S. and not city cars. But with the growing trend toward EV solutions, and with China always likely to want more and better technology, it could be that Antonov’s TX6 might eventually pave the way for the company’s multispeed EV transmission range, with applications in a wide span of vehicles.
Stuart Birch

Original article available here: http://www.sae.org/mags/AEI/9198

The electric car fetish
by Kurt Cobb
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Not too long ago a dinner guest at a party I attended told me that my concern about the peaking of global oil production was misplaced. Didn’t I know that the electric car was already on its way? That a lot of smart people were involved in making it a reality before too long? That the main problem of charging on long trips had already been solved with battery switching stations that could now be deployed?

I registered my skepticism that the electric car would ever become a widespread phenomenon. I cited resource constraints for key metals needed for batteries and the length of time needed to turn over the existing car fleet–around 17 years in the United States, for example. That assumes, of course, that the necessary infrastructure to produce such a fleet is already in place, which it isn’t and won’t be for some time, if ever.

If the peak in oil production is close by, then that alone would doom the widespread adoption of an electric car fleet since global society could soon be dealing with an immediate oil crisis that wouldn’t wait on the slow cycles of new technology adoption. (Some people believe we are already dealing with that crisis and that it began with the 2008 oil price spike which saw crude oil futures vault to $147.)

One can easily cite all the obvious impediments that constrain the widespread adoption of private electric automobiles: the lack of charging infrastructure; the poor performance of electric vehicles for range and acceleration compared to gasoline- and diesel-powered vehicles; consumer skepticism about electric vehicles; and the creaking existing electrical infrastructure which would probably need serious expansion to accommodate a worldwide fleet of private electric automobiles. Perhaps all of these problems could be overcome if the world had decades to work on them. But it is doubtful that we have that kind of time.

In addition, there are three issues which rarely get a hearing. First, in the United States, for example, transportation produced 33 percent of all carbon dioxide emissions in 2008. (I was unable to find comparable figures for the world.) If the entire automobile and truck fleet were to be electrified, the amount of carbon dioxide emissions would decline, but not by as much as one might expect.

The problem is that as of 2006 (the latest year for which global figures are available) 66 percent of the world’s electricity is generated by conventional fossil-fuel powered plants, according the U.S. Energy Information Administration. The number is 71 percent for the United States, the country with about one quarter of all motor vehicles in the world–about 256 million out of approximately 1 billion.

That means that simply replacing the current gasoline- and diesel-powered vehicle fleet with one running on electricity will not even come close to reducing carbon dioxide emissions from that source by the 80 percent that scientists say is vital to preventing catastrophic climate change. We’ll simply be substituting cars powered by gasoline and diesel with ones powered indirectly by coal and natural gas.

Of course, we could greatly increase our deployment of renewable energy sources such as wind and solar to accommodate the need for new greenhouse gas-free electricity generation, couldn’t we? There are three problems with this view. First, both sources are intermittent, so we will have to maintain a substantial baseload generating capacity using fossil fuels to ensure adequate electricity production when the wind fails and the sun isn’t shining.

Second, the scale of deployment would almost be unimaginable. The energy density of windmills and solar panels is at least an order of magnitude lower than that of fossil fuels. The square miles of photovoltaics and the number of windmills needed to generate electricity for an automobile and light truck fleet would imply an enormous footprint for these sources of power. Third, the time to scale up such solutions to the necessary level might be decades. This is the so-called rate-of-conversion problem. It actually takes time to implement alternative energy and infrastructure solutions. The key question is: How much time do we have? The answer appears to be: Not very much!

Let’s assume for the moment that climate change can be ignored–a big and dangerous assumption, I know! The next question we must ask then is: Is there enough fossil fuel and nuclear power to run an electric car infrastructure? Several developments should give us pause. First, a recent study suggests that coal production from existing coal fields may peak in 2011. That’s not a misprint. Second, even though claims for vast supplies from new shale gas fields are being bandied about, there is reason for caution about natural gas supplies as well. Shale gas reserves are actually much more limited than widely believed; they are costly to produce; and, their extraction will likely be hampered by concerns about water pollution. Recently, the governor of New York ordered a moratorium on shale gas drilling until concerns about groundwater safety could be evaluated. Similar actions from other states seem likely as concerns about water supplies mount, and legislatures pause to think through stricter regulations that will mean slower exploitation of this resource.

As for nuclear power providing the additional electrical capacity we would require, one need only review the history of the civilian nuclear power industry to realize that there is little chance of this happening. The regulatory hurdles to rapid expansion are very large. The amount of uranium left to power the current fleet of uranium-fueled reactors is in doubt. And, the lead times to build nuclear generating plants are measured in decades, not years. Nuclear-generated electricity will likely do no more than maintain its share of electricity production in the decades ahead as plants beyond their service life are decommissioned.

So, what can we do about transportation? The quickest way to reduce liquid fuel consumption and thus carbon dioxide emissions in transportation would be to implement ride-sharing programs based on successful pilot programs around the world. This would mean allowing people to use their private cars as essentially part-time cabs. The advantage is that it reduces traffic, fuel consumption and greenhouse gas emissions NOW–not at some unspecified date in the future. The technical issues have already been worked out. It is the cultural ones which are the sticking points.

Second, we should in my view electrify public transportation to the extent possible. This would protect this part of our transportation infrastructure from sudden fuel shocks. And, it should be possible to do this with only a fraction of the outlays needed to make private electric cars available. In addition, public transportation should be vastly expanded with an eye toward new ways of configuring public transport that require significantly less energy, meet consumer expectations more readily, and can be cheaply and modularly constructed.

If the public had been able to foresee that the private automobile would lead to the despoilation of huge swaths of prime farmland to build roads and highways; the emptying out of many of America’s and the world’s cities into suburban sprawl; high blood levels of lead in children (from leaded gasoline which is now outlawed); a sedentary lifestyle that would contribute to an obesity epidemic that reaches down into children younger than 10; a nightmarish number of people killed and maimed on roadways each year; air pollution that regularly threatens human health; climate change through the production of greenhouse gases; and dependence on a fuel supply–petroleum–that has led to several wars and which regularly undergoes huge price swings; if they had known all that, would the public have agreed to allow the private automobile to become the dominant form of transportation in the so-called developed world?

It’s time to let go of the car culture so we can rid ourselves of its myriad ill effects. And, it is time to let go of the electric car fetish that is merely an extension of that ruinous car culture.

Original article available here: http://energybulletin.net/stories/2011-01-02/ellectric-car-fetish

A new study on global coal supplies suggests a worldwide peak in production from existing fields in 2011.

Claims that the world has 200 to 400 years of coal left at current rates of consumption have blinded policymakers and the public. The claims are based on two questionable notions: 1) That official coal reserve estimates are accurate and 2) that the world will experience no growth in the rate of consumption of coal over the period cited.

In a new study published in the international journal Energy researchers Tadeusz W. Patzek and Gregory D. Croft suggest that actual historical coal production is a better indicator of the future trend of worldwide coal output than stated reserves which are notoriously unreliable. They note, for example, that the state of Illinois, despite its rank as second in reserves in the United States, has seen its production decline by half over the last 20 years. In the meantime Illinois’ estimated recoverable reserves have actually increased from 32 billion tons to 34 billion tons between 1987 and 2006.

They mention the work of David Rutledge at the California Institute of Technology who has detailed the sharp downward revisions in the official reserve estimates in recent decades and who believes ultimate production will fall far short of the current reserve estimates. The trajectory for reserves, Rutledge shows, has largely been down as planners include constraints both technical and practical such as coal in seams too thin to mine economically or the presence of a large city over a shallow coalfield. Rutledge also applies Hubbert Linearization to the production data to obtain a truly startling picture of ultimate future recoveries: 50 percent less than current forecasts.

As for the second assumption, the idea that coal demand would stay the same even as the population and the world economy presumably grow is an absurd notion without any historical basis. So even if stated reserves are correct, exponentially rising rates of production would quickly whittle the supply down to perhaps 75 years with a peak coming much sooner than that.

But the authors believe such a path of growth is out of the question because of the near term production peak they expect in coal and oil as well. They calculate a peak in worldwide coal production from existing coalfields in 2011. They argue that nearly all of the world’s major coalfields have been known for a long time, and that only one major field has been discovered in the last 50 years. They recognize major untapped sources in Alaska and Siberia, but believe that the difficulties and long lead times involved in developing them will mean that the date of peak production will not be affected. Rather these areas might lessen somewhat the pace of decline. Perhaps the most shocking projection in the report is that coal production from existing coalfields is expected to fall by 50 percent over the next 40 years.

The authors also conclude that money would be better spent on increasing the efficiency of coal-fired electrical generating plants rather than on carbon capture and sequestration technology. Sequestration technology assumes long-lived coal reserves, the burning of which would contribute greatly to global climate change. But since the authors believe no such long-lived reserves exist, society would be better off managing the decline in available coal through greater efficiency in electrical generation so as to provide adequate power supplies. They suggest that existing coal-fired power stations upgrade to supercritical steam turbines which would lift efficiency from about 35 percent to 50 percent. This greater efficiency would also tend to reduce the rate of emissions of greenhouse gases.

The authors also believe a cap and trade greenhouse gas emissions regime will be ineffectual if the cap is set at the current high level of emissions. Declining availability of both coal and oil will cause emissions to fall without any technological innovation, and thus a high cap would tend to accomplish little or no additional reduction.

If Patzek and Croft are right, it would be a rare bit of good news for those concerned about climate change. But their findings would also be extremely bad news for a global society dependent of coal for 27 percent of its energy needs and which is headed for a peak in oil as well.

Original article available here: http://www.scitizen.com/future-energies/global-coal-supplies-it-might-be-worse-than-anyone-thinks_a-14-3558.html