One of the most raucous debates in the alternative energy field is the value of ethanol derived from corn. Does this biofuel provide a valuable means to extend petroleum fuel supplies, as its supporters contend? Or is it a boondoggle, as its critics claim, that consumes as much oil—on a Btu basis—as it replaces?

The latest answer is: It depends. That's the conclusion of a new study of the energy balance of ethanol production conducted by mechanical engineers at the Massachusetts Institute of Technology in Cambridge. Changing just a few of the assumptions regarding the energy inputs can make the difference between ethanol being seen as a fuel source or a fuel sink.

Engineering graduate student Tiffany Groode, working under the supervision of mechanical engineering professor John Heywood, analyzed the energy consumption and greenhouse gas emissions necessary at each step in making and using ethanol. Unlike previous efforts at determining the ethanol energy balance, Groode incorporated uncertainty in the values of the energy inputs, weighing each value with its probability for a given variable. Groode then computed the energy balance thousands of times, using values selected randomly according to their weighted likelihood.

Groode's findings explain why many widely publicized studies have produced contradictory results: The ratio of energy in to energy out is so close to one that selecting the boundaries of the problem can affect the outcome. For example, a 2003 analysis that concluded ethanol was a net energy loser counted the energy necessary to manufacture farm equipment as an energy input.

Groode also analyzed other raw materials for ethanol production. New technology has made the cellulose from corn stalks and husks, called stover, or from fast-growing switchgrass a viable feedstock for ethanol production. According to Groode's analysis, both have far lower energy inputs than grain for ethanol production. Whether we could grow enough of it to create a large-scale fuel source still remains to be seen.

Massachusetts Institute of Technology researchers say they've successfully grown stem cells on a three-dimensional scaffold of nanoscale protein fragments that acts more like a living body than other cell culture systems.

Shuguang Zhang, associate director of MIT's Center for Biomedical Engineering in Cambridge, and his graduate student coauthor hope that their scaffold will one day replace the ubiquitous Petri dish for growing cells.

"The time has come to move on from two-dimensional dishes to culture systems that better represent the natural context of cells in tissues and organs," Zhang said.

He coauthored a paper on the scaffolds, which appeared in December in PLoS ONE, a journal from the Public Library of Science in San Francisco. Graduate student Fabrizio Gelain was the coauthor.

Zhang and Gelain coaxed tiny fragments of amino acids, called self-assembling peptides, to organize themselves into useful structures. In this way, they created a designer scaffold from a network of protein nanofibers, each 5,000 times thinner than a human hair.

The researchers were then able to grow a healthy colony of adult mouse stem cells on the scaffold without the drawbacks of the Petri dish or the glass slide, Zhang said.

In the body, a cell's normal environment is a complex network of tiny fibers, gaps, and pores through which oxygen, hormones, and nutrients are delivered and waste products filtered away. Cells move within their natural environments in response to chemical signals or other stimuli, Zhang said, and scaffolding mirrors that environment more appropriately.

"Synthetic biopolymer microfiber scaffolds have been studied for more than 30 years to mimic a living 3-D microenvironment, but concerns exist about their degradation products and chemicals," Zhang said.

Some synthetic polymer biomaterials are simply too big to be used as scaffolds, he added. Getting cells to grow on them is like forcing spiders to build webs on skyscraper girders. The MIT nanofiber scaffold, about 1,000th the size of existing systems, is much closer in scale to the matrices that living cells manufacture themselves, Zhang said.

In addition to helping researchers get a more accurate picture of how cells grow and behave in the body, the new synthetic structure can provide a conducive microenvironment for tissue cell cultures and tissues used in regenerative medicine, such as skin grafts or neurons to replace brain cells lost to injury or disease, he added.

The scaffold itself can be transplanted directly into the body with no ill effects, he said.

A Swiss company and a California firm have announced a new 10-year research and development partnership to study enzymes for biofuel production. Their research will focus on the discovery and development of enzymes to convert cellulosic biomass economically to mixed sugars—a key step in producing biofuel from non-food parts of crops.

The new agreement allows San Diego-based Diversa Corp. to independently develop and commercialize fermentation-based enzyme combinations from a proprietary platform. Syngenta, based in Basel, Switzerland, will have exclusive access to enzymes from Diversa's platform to express in plants for enhanced cost-effective production.

The companies said that converting biomass to biofuels requires breakthrough developments in three areas: chemical preparation of the cellulosic biomass, conversion of pretreated cellulosic biomass to fermentable sugars by combinations of enzymes, and the development of novel micro-organisms to ferment the sugars to ethanol or other fuels. According to the companies, development of cost-effective enzyme systems can bring significant improvement to the economics of manufacturing biofuels.

Under terms of the new agreement, which replaces an earlier accord, Syngenta will pay Diversa $16 million of guaranteed research funding in the first two years. Diversa is eligible to receive certain milestone and royalty payments aligned with product development success.

Syngenta is an agribusiness committed to sustainable agriculture through innovative research and technology. The company is a leader in crop protection, employing more than 19,000 people in over 90 countries.

Since 1994, Diversa has pioneered the development of high-performance specialty enzymes. The company customizes enzymes for manufacturers within the alternative fuel, industrial, and health and nutrition markets.

A major energy supplier in California has begun to draw power from a new wind farm. Pacific Gas and Electric Co., which serves about 15 million people in central and northern California, has begun receiving renewable power from the Buena Vista Energy LLC Wind Project, located in the Altamont pass area of Contra Costa County in California.

PG&E's second newly constructed renewable project to come online under California's Renewable Portfolio Standard Program, Buena Vista will provide more than 38 MW of wind power to California's electricity customers.

"The Buena Vista partnership is ideal in that it provides our customers with an additional source of clean, renewable energy under California's Renewable Portfolio Standard and addresses avian issues in the Altamont area," said Fong Wan, PG&E's vice president of energy procurement. "The use of modern technology wind turbines reduces the number of turbines previously used to generate power, increases the production of renewable power, and is expected to lead to lower avian mortalities."

PG&E has a long history of developing, generating, and purchasing renewable power. The utility currently supplies more than 13 percent of its energy from renewable resources that qualify under California's RPS Program. In addition, more than 50 percent of the electricity that PG&E delivers to its customers comes from generating resources that emit no carbon dioxide, the primary contributor to global warming.

In an effort to make the Black Hawk global, Sikorsky Aircraft Corp. of Stratford, Conn., has agreed to acquire aircraft maker PZL Mielec from the Polish government. Sikorsky Aircraft is a subsidiary of United Technologies Corp. of Hartford, Conn.

PZL Mielec will form the foundation of Sikorsky's European operations.

Under the agreement, Sikorsky will acquire a 100 percent stake in the company, which is based in the city of Mielec.

PZL Mielec is Poland's largest fixed wing aircraft manufacturer with approximately 1,500 employees. The company is wholly owned by the Industrial Development Agency (known by the Polish acronym ARP), which is a government holding company under the Ministry of Treasury.
In 2006 Sikorsky announced plans to develop an International Black Hawk helicopter variant for global customers that would be manufactured using a global supply chain.

Upon completion of this acquisition, Sikorsky plans to aggressively modernize the factory and tooling at PZL Mielec to support International Black Hawk production and continue the current capability for aircraft design, manufacture, flight test, and delivery.

Sikorsky's parent company, UTC, through its subsidiaries, currently employs more than 7,000 people in Poland in the aerospace and building systems industries.

Sikorsky is a world leader in helicopter design, manufacturing, and service.

The Spanish Army has awarded Army General Dynamics Santa Barbara Sistemas of Madrid a $424.5 million contract for the supply of Long Range Spike Missile Systems.

General Dynamics Santa Barbara Sistemas, the prime contractor, has an agreement with the Israeli company Rafael for the manufacture of the systems. Approximately 60 percent of the program work will be completed in Spain, where General Dynamics Santa Barbara Sistemas will manufacture system components and perform final assembly and testing.

The Spike-LR is a lightweight, shoulder-launched multipurpose missile system with a range up to 4,000 meters. The contract calls for the manufacture of 260 launchers and 2,600 missiles, plus integrated logistics support. Work under the contract is expected to be completed by 2014.

General Dynamics Santa Barbara Sistemas, which employs 2,000 people in nine facilities in Spain, is the Spanish Army's main supplier of land combat vehicles, and artillery systems and ammunition.

General Dynamics Santa Barbara Sistemas is one of four companies that make up General Dynamics European Land Combat Systems, a business unit of General Dynamics.

General Dynamics, based in Falls Church, Va., employs approximately 81,100 people worldwide.

ASME will sponsor three biotechnial conferences in June. The ASME Bioprocess Technology Seminars and Exhibits will be held June 4–6, at the Radisson-Dublin St. Helens Hotel in Dublin, Ireland. Frontiers in Biomedical Devices 2007 is set for June 7–8, at the Hyatt Regency Irvine in Irvine, Calif. The 2007 Summer Bioengineering Conference will take place June 20–24, at the Keystone Resort and Conference Center in Keystone, Colo.

Dana Corp. of Toledo, Ohio, and a subsidiary, Dana Canada, have completed the sale of their trailer axle manufacturing assets to Hendrickson USA, a subsidiary of The Boler Co. of Itasca, Ill. The price was $31 million.

TGC Industries Inc. of Plano, Texas, plans to acquire six new vibrator vehicles for delivery in the first quarter of 2007 and two new shot-hole drill rigs for delivery in the second quarter. Currently, TGC has 42 vibrator vehicles and nine shot-hole drill rigs operating as energy sources.

IMS Software of Haverhill, Mass., has released IMSverify 2007 for numerically controlled machine simulation and collision detection.

Actify Inc. of San Francisco has released DesignShare 2.0 for enterprise collaboration based on Microsoft's SharePoint platform, which allows users to track, collaborate on, and manage product information including 2-D and 3-D data. The update includes changes to the user interface.

Watlow Electric Manufacturing Co. has opened a factory in Shanghai to produce tubular heaters for customers in China.

Parker Hannifin Corp. of Cleveland has acquired Cabett Subsea, a Houston designer and manufacturer of fluid handling systems and services used in deepwater oil and gas exploration and production. The company produces steel tube hydraulic and electro-hydraulic umbilicals.

home | features | breaking news | marketplace | departments | about ME back issues | ASME | site search

© 2007 by The American Society of Mechanical Engineers