Tag Archives: university
Ethanol: Logic Of Circular Biofuel Trade Comes Into Question
http://www.ft.com/cms/s/0/e4baefbe-b0d6-11e2-9f24-00144feabdc0.html#ixzz2TSTQBQ4m By Greg Meyer Despite having the world’s biggest ethanol industry, the US imported 9.6m barrels of the biofuel from Brazil last year. Brazil, the ethanol pioneer, imported 2m barrels from the US. The US and Brazil, the giants of the market, together produce 87 per cent of the world’s output, according to analysts FO Licht. The US product is largely distilled from corn, while Brazil makes ethanol from its sugar cane crop. For the engine of a car, the two vintages are virtually identical. Yet in the eyes of the law they are quite distinct. This helps explain why the US and Brazil are shipping one another ethanol at great expense rather than simply using it at home. Washington is weaning its domestic ethanol industry off subsidies. In 2011 a tax credit for ethanol blenders expired, as did a corresponding import tariff. But the industry still has the support of a government mandate requiring domestic ethanol consumption to grow each year. The mandate is indirectly helping to drive imports from Brazil. The mandate, known as the renewable fuel standard, is split between volumes for traditional corn-based ethanol and “advanced biofuels” whose production releases less greenhouse gas impacts than ploughing fields for grain. Corn ethanol has the biggest share, but the advanced biofuel requirement is growing more rapidly. US production of advanced biofuels has not matched government expectations. To meet the mandate, fuel companies are allowed to import sugar cane ethanol, mainly from Brazil. The US Environmental Protection Agency estimates about 15.9m barrels of sugar ethanol imports will be needed this year. “As the mandate grows, ethanol imports rise accordingly,” say economists at the University of Missouri’s Food and Agricultural Policy Research Institute. Another US policy encouraging Brazil to export ethanol is set by California. The state, known for standard-setting vehicular pollution controls, welcomes the use of sugar cane ethanol to satisfy its low carbon fuel standard programme. In the reverse direction, US ethanol exports to Brazil are well below a peak of 9.4m barrels reached in 2011 when the South American country suffered poor sugar harvests. The Brazilian ethanol industry has also been hurt by domestic government policies that have kept petrol prices artificially low to fight inflation. This year, Brasilia raised the required ethanol blending rate to 25 per cent from 20 per cent of motor fuel in a bid to help the domestic biofuel industry. But imports from the US are expected to continue nonetheless. The US corn-based ethanol industry has more capacity than needed for a domestic fuel market where demand is weak and most fuel companies refuse to blend more than 10 per cent ethanol with petrol. Brazilian imports arriving under the advanced biofuels mandate further add to supplies. So a portion of the relatively cheap, unwanted corn ethanol barrels flows back to Brazil. The Energy Information Administration, in a note last year, called it a “complex environment” where blenders and ethanol producers “not only have to produce enough corn ethanol to meet the overall renewable fuels mandate, but … must also import significant volumes of sugar cane ethanol to meet the advanced biofuel mandate, all in the face of demand constraints”. The American and Brazilian ethanol industries are squaring off as regulators consider how to apportion this year’s US ethanol mandate. The Renewable Fuels Association, the main US corn-based ethanol lobby, argues the EPA should lower the advanced biofuels mandate to insure against unreliable supplies from Brazil. Furthermore, tight corn stocks and slowing output suggest the US may not be able to export as much ethanol as in years past, the association says. The circular trade between the companies is “economically absurd”, the RFA added. Unica, the Brazilian sugar cane industry group, contends that the US should uphold its advanced biofuel targets, which would support ethanol imports from Brazil. “The fact that there is two-way trade in ethanol between the US and Brazil demonstrates both the complexity and success of government intervention into fuel markets,” Unica wrote to the EPA in April. There is nonetheless an irony in the fact that biofuels promoted to reduce greenhouse gases are being ferried between the US and Brazil in ships belching petroleum exhaust. As the EPA notes: “This two-way trade of ethanol engenders additional transport-related emissions.” Continue reading
Biomass: When Could Torrefaction Be Commercially Viable?
10 May 2013 Andrew Mourant The pros and cons of the roasting process – torrefaction – for biomass crops is now under scrutiny as never before by university research teams around the UK, as Andrew Mourant reports… WHAT DOES the next decade hold for exploiting biomass as a commercially viable energy crop? And is there a business future for pre-roasting crops such as willow and poplar so these can be used effectively alongside coal in power stations? The idea has been around for almost 40 years but has yet to take off commercially. Many unanswered questions still surround the science and economics, but the energy world is striving to close that knowledge gap. The roasting process – torrefaction – is now under scrutiny as never before by university research teams around the UK, and is a significant part of the Supergen Bioenergy hub project. This, a five-year programme, has just started gathering momentum having attracted a £3.5mn grant from the Energy and Physical Science Research Council (EPSRC) . Supergen, based at the University of Manchester, intends uniting the best brains of industry and academia. It’s looking far beyond the process of torrefaction, adopting a “whole systems” approach – from crop production to its use in power stations. It’s also examining social and economic impacts besides the science. The problems created by untreated biomass at power stations are well-documented. The material is burned alongside coal which is crushed to powder in huge mills before being blown into the burners. But while coal is easily ground, most biomass is springy and fibrous. This limits the amount that can be processed and used in co-firing. Some power stations have invested heavily in separate mills for cutting biomass so they can use more of it. Torrefaction, however, has the potential to make a huge difference to their operations. After biomass is roasted in an airless environment at about 280°C, moisture, along with some gases and volatile substances, is lost. What’s left is transformed into a harder fuel that’s easier to crush, move and store. It also has a longer shelf life. Shrouded in secrecy Much of the new research is a work in progress, one in which industry collaborators are reluctant to discuss their involvement. Drax , for example, working alongside the University of Leeds, was reluctant to answer detailed questions from Renewable Energy Focus, with a spokeswoman saying only: ‘a lot of what we do in this area is confidential’. Drax provides ‘some guidance on the direction which research takes… through sharing feedback on our findings… we provide a link to the real world of business and engineering,’ a spokeswoman said. But she declined to say if there had been significant discoveries about which crops work best for torrefaction; or if Drax has learned from commercially advanced operations such as Topell in Holland – the Netherlands leads the world in the business application of this type of torrefaction technology. Eon, another partner with Leeds University, was also unforthcoming about its role. What is known is that the university’s work is wide-ranging. It’s considering, for instance, whether or not torrefied biomass could be at risk of spontaneous combustion; also its potential explosiveness when roasted and ready for use. Environmental impact Meanwhile environmental impacts are being examined at Bath University by researcher Dr Paul Adams. “We’ve done a lot of work on the use of resources and energy,” he said. “You often find there’s a lot of ‘embodied’ energy in creating biomass, for instance using inorganic fertilisers on the crop feedstock. Producing these is quite energy-intensive. “There are hundreds of crops that can be used for torrefaction. But another approach is to use industrial bi-product from forestry sawmills or furniture manufacturers that would otherwise go into landfill, decompose aerobically and release methane. Its global warming potential is 25 times higher than that of CO2. “Our assessment looks at the whole system of where biomass feedstock is coming from – from cradle to grave. We’re not just interested in carbon, but for instance, water, which is used not only in crop cultivation but the industrial process. Another aspect to consider is the use of metal in creating a torrefaction plant.” Other scientists are examining what torrefaction means for CO2 emissions, among them Dr William Hall at Coventry University. “We’ve been looking at the burning temperature and time the process takes,” he says. “It’s been theoretical: we’ve used hardwood and softwood in applying the model. We found that the CO2 emissions are linked to the conditions – there’s quite a narrow window of temperature. If you stray outside that window, you can increase emissions rather than reducing them.” Dr Hall has published detailed findings in the Journal of the Energy Institute. His work took two approaches. The first was to look at use the latent heat of hot syngas for torrefaction (syngas is a mix of carbon monoxide, carbon dioxide and hydrogen produced from gasifying a carbon-containing fuel). “But that’s only possible when the gasification plant and torrefaction plant are on the same site,” says Dr Hall. “So we also considered what happens when you use the heat from volatile torrefaction products that have been combusted.” In terms of reducing CO2, Dr Hall concludes that the ideal torrefaction temperature is 280°C for hardwood and 300°C for softwood where syngas heat was used to heat pre-dried woodchips. When torrefaction volatiles provided the heat source, the optimum temperature dropped to 240°C and 260°C for hardwood and softwood respectively. “The downside to torrefaction is that mass is lost and therefore the energy yield is never 100%,” says Dr Hall. “There are many uncertainties remaining about the process.” So, although torrefied products have a greater energy density than other biomass and less energy is needed to grind it up in power stations, the power industry must decide whether that overall energy loss is worth the effort and expense. Explosive risks? The focus at Leeds is about building up a knowledge base of how fuels behave; the dusts; the explosive risks, says research team leader Professor Jenny Jones. “We’re looking to see if torrefied fuels can be stored outside – whether they’re at risk of self-heating spontaneous combustion,” she says. “At the moment power stations have to invest in underground storage for biomass. It’s a big capital investment. As torrefied biomass has been heat-treated, you’ve removed a lot of the material that moulds will attack and cause it to spontaneously ignite.” Dr Daniel Nowakowski, who’s based at Aston University and has studied torrefaction for over two years, agrees. “Removing moisture and some volatiles makes it less sensitive to degradation and also hydrophobic (water repellent),” he said. “It’s good for storage and handling – there are major cost-savings.” Dr Nowakowski and his team used a small experimental reactor to torrefy various crops including beech, willow and switch grass. Trials were conducted at temperatures ranging from 225–300°C, with torrefying times ranging from 30 minutes to two hours. Meantime, Professor Gordon Adams is leading the Leeds University study into explosiveness. One problem, he says, is finding sufficient torrefied material with which to experiment. “While Jenny Jones’s group is making small quantities, one test we do is in a metre cube explosion vessel and you need kilos for that,” he said. “We’d been working 18 months before we got one of the manufacturers to deliver 20kgs. Several companies are making it – it will be big business one day.” However, such is the commercial sensitivity, and with negotiations between suppliers and power companies underway, Professor Adams was unwilling to name the producer. The explosiveness test for torrefied biomass uses a pulverised material whisked up with air in an upright pyrex Hartmann tube. “In terms of how little you need to react with air, the indication is that biomass is very reactive compared with coal,” says Professor Adams. “There have been a number of biomass plant explosions. Burning torrefied biomass is do-able but it will release volatility sooner.” The dust clouds created by biomass tipped into storage silos presents a hazard against which the industry has always to be on guard. The dangers were underlined by a fire at a Npower biomass plant in Tilbury, Essex, in February that prevented it exporting power to the grid for four months. While Npower claimed the fire was caused by a “number of relatively minor events that, taken in isolation would not have escalated”, smouldering dust from wood pellets ignited by drafts of air were widely speculated to have been the cause. Npower says it has since improved safety measures at the site. Still some way to go Developing a biomass supply chain and infrastructure for industrial scale torrefaction ‘could probably take a decade to get into place’, says Professor Adams. It raises big logistical questions – transporting the bulky crop with its significant water content is cumbersome and costly. However pellet plants are now being built; and the pellets, which are dried during the process, are easier and cheaper to ship than raw biomass. In business terms, working out just where to build a torrefaction plant will be crucial. That’s a question Professor Adams, for one, still struggles to answer. “Do you place it at source (near the feedstock crop) or near the power station?” he wonders. “The size of a big-coal fired station is such that you would need a torrefaction plant of its own. No one knows what the economics will be.” Continue reading
Cleaner Energy, Warmer Climate?
Tue, 05/07/2013 – 12:00am Massachusetts Institute of Technology The growing global demand for energy, combined with a need to reduce emissions and lessen the effects of climate change, has increased focus on cleaner energy sources. But what unintended consequences could these cleaner sources have on the changing climate? Researchers at MIT now have some answers to that question, using biofuels as a test case. Their study, recently released in Geophysical Research Letters , found that land-use changes caused by a major ramp-up in biofuel crops — enough to meet about 10 percent of the world’s energy needs — could make some regions even warmer. “Because all actions have consequences, it’s important to consider that even well-intentioned actions can have unintended negative consequences,” says Willow Hallgren, the lead author of the study and a research associate at MIT’s Joint Program on the Science and Policy of Global Change. “It’s easy to look at a new, cleaner energy source, see how it will directly improve the climate, and stop there without ever considering all the ramifications. But when attempting to mitigate climate change, there’s more to consider than simply substituting out fossil fuels for a cleaner source of energy.” Hallgren and her colleagues explored some of those consequences in considering two scenarios: one where more forests are cleared to grow biofuel crops, and one where forests are maintained and cropland productivity is intensified through the use of fertilizers and irrigation. In both cases, the researchers found that at a global scale, greenhouse-gas emissions increase — in the form of more carbon dioxide when CO2-absorbing forests are cut, and in the form of more nitrous oxide from fertilizers when land use is intensified. But this global warming is counterbalanced when the additional cropland reflects more sunlight, causing some cooling. Additionally, an increase in biofuels would replace some fossil fuel-based energy sources, further countering the warming. While the effects of large-scale expansion of biofuels seem to cancel each other out globally, the study does point to significant regional impacts — in some cases, far from where the biofuel crops are grown. In the tropics, for example, clearing of rainforests would likely dry the climate and cause warming, with the Amazon Basin and central Africa potentially warming by 1.5 degrees Celsius. This tropical warming is made worse with more deforestation, which also causes a release of carbon dioxide, further contributing to the warming of the planet. Meanwhile, Arctic regions might generally experience cooling caused by an increase in reflectivity from deforestation. “Emphasizing changes not only globally, but also regionally, is vitally important when considering the impacts of future energy sources,” Hallgren says. “We’ve found the greatest impacts occur at a regional level.” From these results, the researchers found that land-use policies that permit more extensive deforestation would have a larger impact on regional emissions and temperatures. Policies that protect forests would likely provide more tolerable future environmental conditions, especially in the tropics. David McGuire, a professor of ecology at the University of Alaska at Fairbanks, says these findings are important for those trying to implement mitigation policies. “Hallgren et al. caution that society needs to further consider how biofuels policies influence ecosystem services to society, as understanding the full dimension of these effects should be taken into consideration before deciding on policies that lead to the implementation of biofuels programs,” McGuire says. He adds that he finds Hallgren’s incorporation of reflectivity and energy feedbacks unique among studies on the climate impacts of biofuels. Beyond the climate While Hallgren focuses specifically on the climate implications of expanded use of biofuels, she admits there are many other possible consequences — such as impacts on food supplies and prices. A group of her colleagues explored the economic side of biofuel expansion as part of a study released last year in Environmental Science & Technology — a paper that was recognized as that journal’s Best Policy Analysis Paper of 2012. The team, led by Joint Program on Global Change co-director John Reilly, modeled feedbacks among the atmosphere, ecosystems and the global economy. They found that the combination of a carbon tax, incentives for reforestation and the addition of biofuels could nearly stabilize the climate by the end of the century; increased biofuels production alone could cut fossil-fuel use in half by 2100. But just as Hallgren found trade-offs when she dug deeper, so did Reilly and his team of researchers. “The environmental change avoided by reducing greenhouse-gas emissions is substantial and actually means less land used for crops,” Reilly says. This leads to substantial rises in food and forestry prices, he says, with food prices possibly rising by more than 80 percent. Hallgren says, “There is clearly no one simple cause and effect when it comes to our climate. The impacts we see — both to the environment and the economy — from adding a large supply of biofuels to our energy system illustrate why it is so important to consider all factors so that we’ll know what we’re heading into before making a change.” Continue reading
