Biomass-oil Needs and Recommendations
Material on this page was originally posted on Jeremy's and Jason's user pages. We should probably delete the stuff on those pages and instead put links on them pointing here. Also, it's not clear what is paraphrasing of the report, and what is the original contributions of Jeremy and Jason (and others).
Original source: DOE report on research needs for further development of biomass-oil industry in the United States.
Biomass Oil Analysis: Research Needs and Recommendations
June 2004 NREL/TP-510-34796
Since there is a large existing infrastructure for obtaining biodiesel from vegetable oils in the US and Canada, the focus of the report was on how to scale it up to make it competitive with petrodiesel. This can be accomplished by utilizing current petrodiesel distillation technologies to distill the biomass oils, reducing the costs of oil extraction by improving technology, and finding industrial uses for byproducts such as glycerol and glycerine.
The section that was most relevant to our discussion has been reproduced in Closed-loop micro-organism production systems below.
US Department of Energy (DOE) Office of Energy Efficience and Renewable Energy (EERE) Office of the Biomass Program (OBP)
- Dramatically reduce, or even end, dependence of foreign oil;
- Spur the creation of a domestic bioindustry
- Establish commercial biorefinery technology by 2010
- Commercialize at least four biobased products
- The technology and infrastructure used to make biodiesel can also be used to make various biomass-oil products that can replace comparable products made from petroleum.
- Biomass-oil production results in a number of coproducts, most notably, glycerin and meals (e.g. corn meal). Investing in new applications for coproducts could make biomass-oil production more profitable, and thus more competitive with petroleum.
- Processing of biomass-oil feedstocks (canola, etc.) into biodiesel is already highly efficient. It thus is an area of low-priority for research.
- On the other hand, reducing the cost of feedstocks (such as by increasing their concentration of lipids or by decreasing the cost of sowing and harvesting them) is a worthwhile area for federal investment.
- The number-one area for improvement is in bio-distillation, or the conversion of biomass oils to hydrocarbons.
(Comments in italics not part of original report)
- Demonstrate and optimize commercial bio-distillate production (industrial partnership)
- Demonstrate and optimize CO2 oil extraction technology (program R&D and/or solicitation)
- Develop and optimized fixed base and acid-base esterification catalysts that reduce glycerine refining costs program R&D or soliciitation)
- Support industry development of coproducts from glycerol or glycerine (solicitation)
- Support industry development of industrial products from meals (solicitation)
- Increase oil supplies by developing closed-loop microorganisms production systems (program and solicitation)
Closed-loop micro-organism production systems
Yeasts, molds, fungi, and bacteria can be genetically optimized and used to produce oils in closed manufacturing systems using inexpensive biomass substrates such as crop residues, wood wastes, MSW biomass, ore even pyrolysis oils. The non-oil portions of these organisms can be recycled back into production systems, making them truly closed looped. These organisms offer a couple of key benefits compared to the previous EERE micro algae prgram--major land resources nad water resources are not required and the genetically modified organisms are not exposed to the open environment, wildlife, or accidental release. In addition, many of these organisms do not require sunlight for photosynthesis.
Since closed loop production of micro organisms resembles manufacturing rather than agriculture, it is one feedstock supply research role that might be best suited to DOE. Particularly since DOE has already invested research in some of these areas in the past and has significant body of knowledge to start from. Some inexpensive stage gate analysis and solicitations could be undertaken in the near term to collect information and assess possible pathways for closed loop production of microorganisms. This will lay a foundation for program elements when they become necessary. If these early analyses reveal major benefits (significant oil supplies at exceptionally low costs) then the priority of this program element can be raised and research accelerated.
|Yeasts||Fat Content %||Molds||Fat Content %|
|Candida lipolytica||36||Eutomophtora virulenta||26|
|Trichosporum cutaneum||45||Aspergillus flavus||28|
|Candida curvata||58||Pytium ultimum||49|
|Lipomycens lipferus||63||Fusarium bulbigenum||50|
|Endomyces vernalis||65||Aspergillus fischeri||53|
|Rhodotorula glutinis||71||Penicillium lilacinum||56|
Oil Content of Yeasts and Molds
There are a number of novel feedstocks that do not require land--yeasts, bacteria, fungi, and molds. Yeasts and molds can contain up to 70% lipids. Arthrobacter AK 19, a soil bacterium, can produce up to 78.3% of its cell dry matter as oil using short chain hydrocarbons (similar to what is found in pyrolysis oils) as substrates. The presence of lipases (fat splitting enzymes) results in various combinations of mono, di-, and triglycerides and free fatty acids in these oils. The oils contain mostly oleic and palmitic acids similar to other vegetable oils. Fat producing organisms are grown in a carbohydrate rich environment. The fat producing portion of their growth cycle is triggered by depriving them of nutrients, typically nitrogent-based nutrients. Until that point, nitrogen based fertilizer is rquired to promote population growth. Microorganisms are regarded as fat-producers if they contain ATP that enables themto quickly produce acetyl coenzyme A. Conversion rates usign glucose feedstocks will rarely exceed 25% (glucose to fat). The key to using microorganisms for oil production is to identify low cost feedstocks for the microorganisms and optimize their conversion efficiency (italics mine).
Most testing has used glucose and other expensive substrates, which limit economics. Other sugars and cellulosic feedstocks have not been explored in as much detail. Microorganisms utilizing biomass substrates available for $50/ton (2.5 cents/pound) may produce a pound of oil for as little as 10 cents per pound (feedstock cost only) if the entire biomass could be converted. More realistically, a microorganisms may only feed on select fractions of biomass substrates. However, if oil could be extracted without leaving poisonous residues (super critical CO2 extraction, for example), then the substrates could be inoculated again with different types of organisms better suited the remaining portions of the biomass. In a slightly different vein, the lignocellulosic wastes from biomass ethanol production may be suitable substrates for microorganism oil production, eliminating or reducing drying costs. Other food, paper, and animal processing waste streams may be suitable for this approach.
Most microorganisms have not been optimized for fat production, although the EERE invested significant resources in a micro algae program from 1977 through 1996. Micro algae production suffered from a number of failings. First and foremost, the micro algae was grown to produce fat and a byproduct animal feed. The higher the fraction of fat, the higher percentage fo total production costs allocated to the fat. Thus, it was not clear that fat production costs could be minimized through this system, but perhaps oil supplies could be expanded. Internal NREL reports projected that fat production costs from microalgae would be on par with the cost of producing soybean oil. Second, large amounts of land and water are required for these phtosynthesis dependent systems. Some researchers postulated that large tracts of the American Southwest Desert could be converted into raceway systems using underlying brackish water. The environmental impacts of these systems were never fully considered. These open-air systems wuld contain genetically modified micro algae; vunerable to infestation and crosses with wild algae, exposure to migratory bird populations and flash flood events. Last but not least, these systems would need to be located in close proximity to coal fired power plants for easy access to CO2 (to enhance growth) and other pollutants that could be used as nutrients. Insufficient flat land with cheap water (the West has very little "cheap" water), near power plants was readily accessible for these systems.
The concept of using molds, yeasts, fungi and bacteria offers some of the same challenges that micro algae systems posed (nutrients, costs, microorganisms, and system optimization), but do not require large amounts of water (using water recycling) or land. In fact, using genetically modified organisms in a self contained environment offers minimal public safety risks. The carbohydrate fraction of the organisms can even be recycled back into the system to prevent release and to provide key nutrients for growth. Because these organisms are easy to modify, a number of high value chemicals could be coproduced in these systems, hopefully producign enough profit to make future investments in these systems viable.
The research goal for these systems should not be to produce oil at the same cost as petroleum diesel or less (too heroic) but to produce oils at a cost less than the cost of producing soy oil. These opportunities should be explored in more detail.