While growing biofuels feedstocks on farms is becoming a commonplace, actually making biofuels on the farm is fairly rare. Two Pacific Northwest efforts to develop advanced technologies for farm-scale production illustrate significant potential to produce fuels from local feedstocks for local use.
In Corvallis, Oregon a start-up company is working to commercialize a biodiesel microreactor that could serve a small community’s fuel demands with a device that would fit on a bench in a shed. Near Spokane a nonprofit group is developing a farm-scale operation to process agricultural residues into energy products.
The biodiesel device is based on a microchannel technology developed by Goran Jovanovic of Oregon State University and announced in 2006. Contrasted with conventional biodiesel production, which involves mixing vegetable oils with alcohols and solvents for a process that takes 12-24 hours, microchannel technology generates a product nearly instantaneously by forcing oil and alcohol down channels smaller than a human hair. The basic microchannel unit is about half the size of a credit card, and units can be combined to scale to feedstock availability.
“By stacking many of these microreactors in parallel, a device the size of a small suitcase could produce enough biodiesel to power several farms, or produce hundreds of thousands of gallons a year,” Jovanovic notes.
The technology has now been licensed for commercial development by MTEK Energy Solutions, which is working with OSU and the Oregon Nanoscience and Microtechnologies Institute (ONAMI) to develop a commercial prototype. Company President Jeff Canin projects completion sometime in early 2008. The company plans to market the microreactors rather than produce fuel itself. Expectations are that fuel will be produced at costs competitive with larger plants. Since feedstock represents around 80 percent of the cost of biodiesel, and equipment only part of the remaining 20 percent, this is credible.
The major advantage of the microreactor is deployability, Canin says. That could enable on-site processing of low-value wastes such as fish oil in processing plants. It would also allow biodiesel production to start with limited cultivation of new oil crops such as jatropha, seen as a great opportunity for developing nations to grow oils on degraded, drought-ridden lands. The company views developing nations with both limited local feedstocks and markets as a major market for its technology. .
The agricultural residues project is being developed by Farm Power, a nonprofit dedicated to promoting farm-scale bioenergy production. The group is partnered with USDA Agricultural Research Service. In a federal bioenergy research complex heavily focused on large-scale technologies, ARS is a welcome oasis for distributed, community-based bioenergy development. The outfit is looking at potential feedstocks ranging from hog manure in North Carolina to cotton seed oil in Georgia to crop residues in the Northwest.
ARS has done some first-order studies looking at biofuels potential of Northwest residues. But, notes Gary Banowetz of ARS, the challenge is that these feedstocks have low energy density and a certain amount must be left on the soil to preserve fertility. Taking these constraints into account, it would require 167,000 acres worth of residues to supply one plant making 10 million gallons of ethanol yearly. So ARS is interested in smaller-scale technologies that are less hungry.
The Farm Power project at Rockport, Washington a few miles south of Spokane fits the bill. It employs technology developed at ARS Western Research Institute which uses heat to convert biomass into energy gas. The project aims to make this a commercially replicable technology while assessing the agronomic and economic practicalities of using residues. The gasifier will be fed with residues from Kentucky bluegrass seed. This is a significant crop in the area, and farmers who can no longer burn fields due to air pollution restrictions need to find new ways to dispose of the residue.
“Within five miles there are 5,000 acres of Kentucky bluegrass,” notes project manager Jack Zimmer. “That’s plenty of straw to keep this thing going. When we have this unit done, it can feed itself from a 2,000-acre farm.”
“Huge projects are fine,” Zimmer adds. “But there are lots of biomass materials that can be used to produce energy that are readily available and do not have to be moved long distances. If you are not having to haul feedstock from 20-40 miles away, it becomes more viable. That’s the philosophy of the farm-scale machine.”
Farm Power plans to place the gasifier on line in fall 2007, process around 2,400 pounds of biomass per day and use the gas to run an electrical generator. Inland Power has agreed to take the surplus. By fall of 2008 the group will report on the results. A second stage of the project is envisioned in which the gas is chemically converted to biofuels. At an estimated 60 gallons per biomass ton, the technology could fuel the farm and its neighbors.
Both of these projects underscore how biofuels production at the farm and community scale generates many benefits in terms of environmental and economic sustainability.
Community benefits – Corporate ownership of biofuels plants by large agribusiness corporations has raised criticism about who is gaining most of the benefits from this growing industry. While biofuels plants at any scale generate local economic benefits, local ownership keeps more of the money circulating closer to home. Farm-scale technologies open more local ownership opportunities because upfront capital costs are lower. In developing nations, where concerns over whether small farmers will actually benefit from bioenergy are greatest, farm-scale technologies could be hugely important.
Use of residues – Employing materials that now pose waste disposal problems is one way to increase biofuels production without competing with existing crops and markets. But collecting enough residues to support a large-scale plant demands a substantial supply. A 50-million-gallon-per-year cellulosic ethanol plant will require around two billion pounds of biomass annually, and material cannot economically be transported more than 50 miles. Plants will likely require a fairly consistent material. So residues that exist in smaller quantities may not find a use in large-scale operations, but could readily feed farm-scale technologies. The proximity of farm fields to production has another crucial advantage – Byproducts of production containing soil nutrients can be quickly sent back to the land to maintain fertility. Farm Power will do this with gasifier ash.
Crop establishment – As ethanol production shifts from its current sugar and starch feedstocks to cellulose, new crops of perennial grasses and fast-growing trees will have to be established. Oilseed crops will also have to be established in places such as the Northwest that want to feed biodiesel production with regional feedstocks. In either case, immediately ramping up new crops to supply large scale plants is challenging. Farm-scale technologies are inherently more scaleable. They can start on a smaller crop base.
Transportation – Shipping biofuels feedstocks represents a major share of the energy employed in making biofuels, and thus is a global warming pollution contributor. So shortening the distances improves the energy and pollution-reduction performance of biofuels. Replacing imported fuels with local production also cuts transportation demands.
Unlike the current petroleum-based system, biofuels will not grow in a “one size fits all” fashion. A diversity of feedstocks and markets will characterize the growth of biofuels, and this will include small local feedstock streams that supply community fuel demands. Economies of scale will favor larger-scale operations in many cases, but specific local feedstock opportunities, especially from residues, combined with lower transportation costs and markets, will give farm-scale production an edge if technologies are developed to maximize its natural advantages. That is why work being done by outfits like OSU, ONAMI, MTEK, Farm Power and ARS is vitally important to realize the farm-scale opportunity.
Patrick Mazza is Climate Solutions Research Director. This is part of a series of articles on Growing Sustainable Biofuels available at www.harvestcleanenergy.org.