咨询公司埃森哲(Accenture)在研究报告《生物燃料的转变期》(Biofuel's Time of Transition)中指出，第一代乙醇和生物柴油已经在全球燃料市场上占据了一席之地，但监管不明、消费者的负面看法、供应链及风险管理工具方面的投资需求等问题影响了生物燃料的发展。

　　该报告作者、埃森哲能源产业研究部门驻伦敦高级管理人员梅利莎•斯达克(Melissa Stark)说，需要多方面的通力合作才能使生物燃料技术切实可行。

　　这是埃森哲在生物燃料方面进行的第二次深度研究，他们发现生物燃料产业所面临的发展时期困难比去年发布第一份报告时预计的要严重。斯达克说，虽然使生物燃料成为全球性产业的大部分要素都已经具备，但是这些要素还需要进一步发展完善。

　　她发现世界各地有关生物燃料应用的法规五花八门，其内容很大程度上取决于法规制定者对农业支持、能源安全和气候变化的重视程度。

　　斯达克强调，在美国，能源安全是推动乙醇成为燃料结构一部分的背后力量，不过随着人们日渐意识到玉米作为燃料原料的低能效及其对环境的影响，监管者和消费者都变得更为慎重。

　　斯达克说，政府在这个问题上的明确态度对生物燃料产业至关重要。她发现联邦和各州监管机构不再强制要求使用乙醇，而是转向鼓励使用清洁燃料、将以环保方法生产的乙醇和生物柴油加入到燃料结构中来。

　　随着第二代和第三代生物燃料的发展，这一趋势会更加引人瞩目。第二代生物燃料包括用农作物废料生产的燃料，第三代燃料包括藻类生物柴油和通过合成生物学制造的产品。

　　斯达克说，美国有太多的第一代乙醇，我们需要支持第二代、第三代生物燃料。她还说，用玉米生产乙醇的制造商自己也在投资研究更多地利用作物废料的方法，以抵消碳排放;它们能共存一段时间，然后会向着更多地使用废料而不是粮食的方向发展。

　　但埃森哲的研究报告指出，生物燃料产业面临的最大挑战来自于供应链、基础设施和金融市场。

　　生物燃料业仍面临着一个“先有鸡还是先有蛋”的大难题：由于没有足够的乙醇加油站，所以汽车厂商不会生产更多使用85%乙醇(E85)的汽车;而同时，又因为路上没有足够多的汽车需要乙醇，所以零售商不会建更多的乙醇加油站。

　　该报告指出，截至4月份，美国大约有1,557座E85加油站，大部分位于中西部地区，距离一个乙醇供应地较近。美国全国乙醇汽车联盟(National Ethanol Vehicle Coalition)的执行董事菲尔•兰姆伯特(Phil Lampert)说，如果在每个驾车者密集区5英里以内设置一座E85加油站，那么全国总计需要2万座加油站。

　　埃森哲在报告中引述的数据显示，据伊利诺伊州官员根据本州改造64个加油站的费用作出的估计，将现有设备改造为E85加油机的成本为每台3,500美元;新增一台E85加油机的成本为7,000美元。

　　石油公司需要作出决定，在混合、储存和分销生物燃料的基础设施上投入资金，而且还要确保各类生产商的供应，其中包括很多小企业。

　　调整供应链、加入生物燃料需要大规模投资，但如果监管机构不能明确表示将不断支持市场的增长，整合了生物燃料业务后的石油公司也不愿意生产生物燃料。

　　斯达克说，现在的问题是要兑现对供应链的投资，并且努力找到一种风险管理方法，这两个问题都需要克服许多重大障碍才能解决。

　　研究报告指出，面向乙醇和生物柴油的金融市场刚刚起步，还没有足够的流动性让生产商和消费者在整个市场或全球范围进行交易，或是通过期货和期权对风险加以管理。

　　眼下，科技进步为乙醇和生物柴油在全球燃料结构中的地位提供了支持。该报告称，农作物产量已经显著提高，为利用玉米等粮食作物生产燃料提供了支持;同时用作物废料和柳枝稷等纤维素材料生产的第二代生物燃料将会从第一代生物燃料所引发的基础设施建设中获益。

　　First-generation ethanol and biodiesel have carved a space in the global fuel market, but their growth is dogged by unclear regulation, adverse consumer perception and the need for investment in the supply chain and risk-management tools, says consulting firm Accenture in a report.

　　'There are a lot of pieces that need to come together to make it feasible,' said Melissa Stark, a London-based senior executive in Accenture's energy-industry group and author of the study, 'Biofuel's Time of Transition.'

　　In the firm's second in-depth study of biofuels, Accenture found that the industry's growing pains are bigger than the analysts expected last year when they published the first study. While most of the elements to make biofuels a global industry are in place, they need to evolve, Ms. Stark said.

　　She found a patchwork of regulations determining the use of biofuels across the world, with rules depending on how much weight lawmakers give to agricultural support, energy security and climate change.

　　In the U.S., energy security is behind the push for the inclusion of ethanol in the fuel mix, but a greater awareness of corn's poor energy efficiency as a fuel feedstock and its impact on the environment has made regulators and consumers wary, Ms. Stark noted.

　　Government clarity on the issue is crucial for the industry, said Ms. Stark, who sees state and federal regulations moving away from mandating the use of ethanol to encouraging cleaner fuels, with sustainably produced ethanol and biodiesel in the mix.

　　That will come more to the fore as the industry makes advances in second-generation biofuels, such as from crop waste, and third-generation fuels, including algae biodiesel and products created through synthetic biology.

　　'For the U.S., there's so much first-generation ethanol, we need to create support for second- and third-generation,' said Ms. Stark. Producers of corn-based ethanol are themselves investing in ways to use more crop waste to offset emissions, she added. 'They can live together in tandem for a while, and move towards using more of the waste than the food,' she said.

　　But the biggest challenges for the industry lie in the supply chain, infrastructure and financial markets, according to the Accenture report.

　　The biofuel industry still faces a powerful hurdle in the chicken-and-egg conundrum of there not being enough ethanol pumps for auto makers to make more cars that run on 85% ethanol, or E85, while there aren't enough cars on the road demanding ethanol for retailers to install the pumps.

　　As of April, the U.S. had approximately 1,557 outlets for E85 -- mostly in the Midwest, close to a supply of ethanol, according to the study. To install an E85 outlet within five miles of the majority of drivers would require a total of 20,000 sites, according to Phil Lampert, executive director of the National Ethanol Vehicle Coalition.

　　The estimated cost to put in an E85 pump ranges from $3,500 for a conversion, according to Illinois officials' estimate based on the state's conversion of 64 sites, to $7,000 for a new pump, which Accenture cited in its report.

　　Oil companies are faced with decisions to invest in the infrastructure to blend, store and distribute biofuels, and with securing supply from a diverse pool of producers that include many small companies.

　　Altering the supply chain to integrate biofuels requires large investments, but the integrated oil companies are reluctant to make them without a clear signal from regulators that the growth of the market will continue to be supported.

　　'Now, it's about monetizing these investments in the supply chain, and trying to find a risk-management solution -- these are the two things that will take a lot of heavy lifting to get through,' said Ms. Stark.

　　Financial markets for ethanol and biodiesel are in their infancy, with not enough liquidity for producers and consumers to trade across markets and across the globe, or to manage risk through futures and options, the report says.

　　For the moment, technological advances are supporting ethanol and biodiesel's place in the global fuel mix. Agricultural yields have improved greatly to support the diversion of food crops such as corn into fuel, the report says, and second-generation biofuels made from cellulosic material such as crop waste and switchgrass will benefit from the infrastructure buildup sparked by the first-generation.