Membrane operational modes

Based on operational models, membrane can be devided into two type:

1. Dead-end: The fluid flows at right angle to the membrane

-Deposited particles form “Cake Layer”
-Suitable for more concentrated Suspension

-Need more frequent cleaning

2. Cross-flow: The fluid runs parallel to the membrane

-High shear force near the membrane surface
-Minimize cake formation
-Recycle feed stream
-Require more energy
-Stable flux

Membrane separation for biorefinery

1. Detoxification

Nanofiltration (NF) and Reverse Osmosis (RO) membranes can be use to concentrate sugar and remove toxic compounds such as acetic acids, and sugar degraded products in the hydrolyzate.

2. Downstream processing and purification
Microfiltration (MF) can be used to remove particls (proteins etc) from fermented broth.

3. Desalination
ElectroDialysis (ED) can be used to remove inorganic salts

Membrane Process

The number of downstreaming steps for biobased chemical production strongly influences the quality and the price of the product. The total production costs are determined mainly by the downstreaming rather than by production of the product using fermentation.

After fermentation, a pretreatment of the fermentation broth is required to separate biomass, proteins, and cells. The multivalent salts also need to be removed for purification. he separation of inorganic salts and proteins/cells presents a special problem with the production of valuable substances from renewable raw materials. Therefore, the methods used for downstream processing will play a very important role.

Membrane Process is essentially a separation process based on molecular properties. The advanteges of membrane process include:

• It reduces the number of unit processes in treatment systems


• Potential for process automation and plant compactness


• Much smaller foot print than the conventional plants of the same capacity


• Easy scale-up, expansion and retrofication


• Less or no chemical use and provides highest quality water


• No formation of secondary chemical by-products


• Less sludge production


• Water reuse and recycling

Ceretainly, the disadvantges exist, includng membrane fouling, low membrane life time, low selectivity, and high capital and operating cost.

Based on the driving forces, the following processes are defined as:

Pressure driven membrane processes
Microfiltration (MF)

-Simple screening mechanism
Pore size 0.01 μm - 10 μm
DP » 0.01 to 0.5 MPa
-Low pressure process
-Most effectively remove particles and microorganisms (bacteria)
-High flux
-Colloids/Macromole ---> theoretically pass through the membrane

Ultrafiltration (UF)

-Screening and Adsorption
Pore size 1 - 100 nm
DP 0.1 to 1 MPa
-Membrane is classified in terms of Molecular Weight-Cut off (MWCO) : 1000 - 100,000
-Two layers: a thin (0.1 to 0.5 µm), skin layer and a porous substructure support layer
-Separation of macromolecules
-Only surface deposition: no internal pore plugging; so, relatively easy to remove, irreversible

Nanofiltration (NF)

- NF Removes molecules in the 0.001 micron range
DP 0.5 to 6 MPa
MWCO: 0.2 to 200
-NF is essentially a lower-pressure version of reverse osmosis
-NF performance characteristics between reverse osmosis and ultrafiltration

Reverse Osmosis (RO)
-Membrane: similar to UF, thin active layer; porous support layer

-Operating Pressure: 1.0 - 10 MPa

-RO has the separation range of 0.0001 to 0.001mm

Electrical driven membrane processes
-Electrodialysis (ED)

Concentration driven membrane processes
-Dialysis
-Osmosis

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Based on Modules, membrane module refers to the device which houses the membrane element:

• Tubular membrane module

- Membrane is cast inside the support tube
- Tubular membranes have a diameter of 5 - 15 mm
- High SS tolerance
- Flow is usually inside out
-Mainly MF and UF
- Low packing density, high prices per module

• Hollow fibre membrane module

- Consists of a bundle of hundreds and thousands of hallow fiber
- Entire assembly is inserted into a pressure vessel
- Feed can be applied inside of the fiber (inside-out flow) outside (outside-in flow)
- Highest packing density of all.
- Hollow fiber is used mainly for NF and RO

•Spiral wound membrane module

- Flexible permeate spacer is provided between two flat sheet membranes
- Membrane: sealed three side and open side is attached to perforated pipe
- Flow is in a spiral pattern.
- Membrane envelop is spirally wound along with a feed spacer
- Filtrate is collected within the envelop and piped out
- Packing density:high
- RO and NF

• Plate and frame

--------------------------------------------------
Membrane Fouling: Deposition or accumulation of solids on the membrane.

Fouling causes resistance to flow through the membrane and eventual decline in overall flux.
Three major mechanisms of resistance flow:
-Pore narrowing
-Pore plugging
-Gel/cake formation due to concentration polarization

Separation processes

Separation processes based on the molecular properties are summarixed as follows:

Microbial pretreatment of piomass

Biological pretreatment of wood chips has attract great attention and research activities to reduce the mechanical pulping refining energy. The same principle and idea can be applied to biomass pretreatment for lignocellulosic ethanol production.

A review of the literature suggests that fungal pretreatment could potentially lower the severity requirements of acid, temperature and time. These reductions in severity are also expected to result in less biomass degradation and consequently lower inhibitor concentrations compared to conventional thermochemical pretreatment. Furthermore, potential advantages of fungal pretreatment of agricultural residues, such as corn stover, are suggested by its effectiveness
in improving the cellulose digestibility of many types of forage fiber and agricultural wastes.

The bottleneck for cellulosic bioethanol commercilization

When talking about the bottleneck of cellulosic bioethanol commercialization, the 1st pop-up issues may be the technology of pretreatment, the efficiency of enzymatic hydrolysis, C5 microorganisms, etc. Another factor may be too much politics in this area. Too much talk, less action; too many talkers, not many real workers.....

Hydrothermal treatment of biomass using phosphorous acid as an additive

Instead of using as a solvent, phosphorous acid can be also used as a catalyst for biomass pretreatment.

Based on the study in Japan, the yield of monosaccharide obtained from the rice straw using hydrothermal treatment was low. but when 50 mM phosphoric acid solution was used to hydrothermal system, most of xylan in rice straw was successfully hydrolyzed to xylose and some amount of glucan was also converted into glucose at 160 °C for 15 min. The maximum xylose and glucose yields were 54.1 and 15.0 % at this condition, respectively.

The remained cellulose residue after hydrothermal treatment with phosphoric acid at 160 °C for 15 min was easily saccharified to glucose by enzymatic hydrolysis. After the enzymatic saccharification, the glucose yield was 81.6 %.

After neutralization of hydrolysate with NaOH, the salt formed is sodium phosphate. This salt used as nutrient by microorganisms.

Phosphoric acid pretreatment of biomass

It has been noticed that concentrated phosphoric acid is an ideal cellulose solvent. The advantages of phosphoric acid pretreatment of biomass includes:

• cellulose dissolution by phosphoric acid occurs at low temperatures
• phosphoric acid can dissolve cellulose in the presence of water
• the regenerated cellulose remains in an amorphous form suitable for hydrolysis
• the residual phosphorous acid has no inhibitory effects on the sequential
  hydrolysis and fermentation.

But what about the cost?

Complete Fermentation of Xylose and Methylglucuronoxylose

Complete Fermentation of Xylose and Methylglucuronoxylose Derived from Methylglucuronoxylan by Enterobacter asburiae Strain JDR-1

Changhao Bi, John D. Rice, and James F. Preston*
Department of Microbiology and Cell Science, University of Florida, Gainesville, Florida 32611

Abstract:

Acid pretreatment is commonly used to release pentoses from the hemicellulose fraction of cellulosic biomass for bioconversion. The predominant pentose in the hemicellulose fraction of hardwoods and crop residues is xylose in the polysaccharide methylglucuronoxylan, in which as many as one in six of the β-1,4-linked xylopyranose residues is substituted with -1,2-linked 4-O-methylglucuronopyranose. Resistance of the -1,2-methylglucuronosyl linkages to acid hydrolysis results in release of the aldobiuronate 4-O-methylglucuronoxylose, which is not fermented by bacterial biocatalysts currently used for bioconversion of hemicellulose. Enterobacter asburiae strain JDR-1, isolated from colonized hardwood (sweetgum), efficiently ferments both methylglucuronoxylose and xylose, producing predominantly ethanol and acetate. 13C-nuclear magnetic resonance studies defined the Embden-Meyerhof pathway for metabolism of glucose and the pentose phosphate pathway for xylose metabolism. Rates of substrate utilization, product formation, and molar growth yields indicated methylglucuronoxylose is transported into the cell and hydrolyzed to release methanol, xylose, and hexauronate. Enterobacter asburiae strain JDR-1 is the first microorganism described that ferments methylglucuronoxylose generated along with xylose during the acid-mediated saccharification of hemicellulose. Genetic definition of the methylglucuronoxylose utilization pathway may allow metabolic engineering of established gram-negative bacterial biocatalysts for complete bioconversion of acid hydrolysates of methylglucuronoxylan. Alternatively, Enterobacter asburiae strain JDR-1 may be engineered for the efficient conversion of acid hydrolysates of hemicellulose to biofuels and chemical feedstocks.

Continuous cultivation process

Continuous cultivation process has been developed to answer the need of rapid ethanol production for fuels and chemical in the near future.

Batch cultivation is rarely applied for dilute-acid hydrolyzate cultivation since the cells is exposed directly to the high concentration level of inhibitors. This problem is commonly overcome by applying fed-batch cultivation where the concentrations of inhibitors in the media are controlled by regulation of the feeding. The continuous mode of cultivation has generally been of interest to minimize the total time of fermentation and increase the volumetric production rate of ethanol as well as decrease the investment cost. Because the bioreactor is fed continuously, it would be possible to avoid sudden inhibition to the yeast. Therefore, continuous cultivation mode is a suitable alternative for large-scale ethanol production.

Cell immobilization

Cell immobilization is defined as “the physical confinement or localization of intact cells to a certain region of space with preservation of some desired catalytic activity”.

The advantages of cell immobilization include-

• enhancement of fermentation productivity;
• feasibility of continuous processing;
• cell stability;
• lower costs of recovery and recycling in downstream processing.
  

The techniques can be divided into four major categories based on the physical mechanisms:

• attachment or adsorption on solid carrier;
• entrapment within a porous matrix;
• self-aggregation by flocculation (natural) or with cross-linking agent (artificially induced);
• and cell containment behind a barrier.
  

Cell entrapment is a simple and useful method to provide a simulation of high-density cells used in small-scale bioreactors where a cell recirculation method with e.g. filter and continuous centrifuge is rather difficult. But there is a need for using the cell entrapment method in industry due to additional cost of immobilization material.

Self-aggregation of cells leading to formation of a flock and easy sinking is very useful for cell recirculation, and thus performs cell retaining. Yeast has a natural flocculation capability which is usually employed in the brewing industry. The flocculation of yeast is a reversible, asexual and calcium-dependent process. Lectin-like proteins, so-called flocculins, which stick out of the cell walls of flocculation cells, selectively bind mannose residues present in the cell walls of adjacent yeast cells. Calcium ions in the medium are needed in order to activate the flocculins. Once the yeast forms flocks, the separation of cells from broth can easily be carried out by sedimentation; thus cell recirculation is performed without any force-driven separation, i.e. filtration and centrifugation.

By-products of dilute-acid hydrolysis of lignocellulosic biomass

Dilute-acid hydrolysis is still a cheap and fast process to obtain sugar from lignocellulosic materials. However, a significant drawback of dilute-acid hydrolysis is the generation of several by-products during the process.

Organic acids

A large number of aliphatic acids are present in dilute-acid hydrolyzates originated from wood extractives, lignin degradation and sugar degradation.

• Acetic acid: a major acid constituent in hydrolyzates and is mainly produced from degradation of the acetyl group in the polysaccharides
• Levulinic acid and formic acid are products of sugar degradation
• Several kinds of fatty acids such as hexadecanoic, 9,12-octadecadienoic, oleic and octadecanoic that most likely are unmodified wood extractives, in addition to short-chain and branched aliphatic acids such as 2-methyl-2-hydroxybutanoic acid, methyl propanedionic acid and methyl botanedioic acid. These last acids are not important in terms of concentration, and thus result insignificant effects to the yeast.

The undissociated acids are harmful to the cells and inhibit cell growth. They are liposoluble and thus can diffuse across the plasma membrane into cytosol and may dissociate intracellularly. In order to maintain intracellular pH, protons must be transported across the membrane by the action of plasma membrane ATPase. This results in an increase of ATP consumption, and thereby causes lower biomass yield. In anaerobic conditions, ATP generation is achieved by the ethanol production pathway, resulting in higher ethanol yield at the expense of biomass formation. However, above critical extracellular concentration of undissociated acid, the diffusion rate of undissociated acid can exceed the transport capacity of the plasma membrane ATPase, and intracellular acidification occurs. It is found that the limit of extracellular pH at different acetic acid concentrations which allow yeast to grow. It was found that growth was possible at a pH not less than of 4.7 in cultivation containing 10 g/L acetic acid. Therefore, acetic acid is innocuous if it exists in low concentration or the cultivation is carried out at a pH higher than the extracellular pH limit.

Phenolic compounds

There are a number of phenolic compounds recognized in lignocellulosic hydrolyzates, including

• 3-methoxy-4-hydroxybenzaldehyde
• 4-hydroxyacetophenone
• vanillin
• syringaldehyde
• acetovanilone
• ferulic acid
• vanillic acid
• 4- hydroxybenzoic acid

These compounds are mainly liberated from lignin degradation in addition to aromatic wood extractives. The phenol aldehydes and phenol ketones were found as the worst inhibitors. Moreover, it was also shown the low molecular weight phenolic compounds are more toxic.

Phenolic compounds are considered to be important inhibitors due to their inhibitory effect in fermentation of lignocellulosic hydrolyzates. These compounds partition biological membranes and cause loss of integrity, hence disturb their ability to serve as selective barriers and enzyme matrices. The inhibition mechanism of phenolic compounds has not been elucidated yet.

Studies in inhibitory action of phenolic compounds have been carried out using higher concentrations than are actually present in the hydrolyzates. The water solubility of phenolic compounds is limited and depends on the composition of the liquid, which is different in hydrolyzates and the defined medium; therefore it is possible that the concentration at which the microorganism suffered has been lower. In addition, S. cerevisiae assimilates vanillin, hydroxybenzaldehyde, and syringaldehyde during fermentation, while growth has been reported on cathecol, recorcinol.

Furan compounds

Furfural and 5-hydroxymethyl furfural (HMF) have been found as further hydrolysis products of pentoses and hexoses respectively. Pentoses form furfural in high yield; but if the furfural is not removed as formed, it partially condenses into high-molecular-weight materials. By an analogous process, hexoses yield HMF which, on continued heating, yields levulinic acid and formic acid. Furfural has been reported to be a strong inhibitor for S. cerevisiae. The furfural concentration above 1 g/L was found to decrease significantly the CO2 evolution rate, the cell multiplication and the total viable cell number in the early phase of fermentation. During anaerobic fermentation, reduction of furfural to furfuryl alcohol occurs with high yields, while furoic acid is produced from oxidation of furfural during aerobic cultivation. In both cases, NADH-dependent alcohol dehydrogenase (ADH) is believed to be responsible for furfural conversion in yeasts.

HMF is chemically related to furfural and thus has similar inhibitory effects as furfural, except that it has a lower conversion rate which might be due to lower membrane permeability. It is also discovered that an addition of 4 g/L of HMF decreased the CO2 evolution rate (32%), ethanol production rate (40%), and specific growth rate (70%). However, these inhibitory effects were less than those caused by the same amount of furfural, and thus HMF cannot be considered as acutely toxic as furfural for growth and fermentation of S. cerevisiae.

The conversion rate of furfural is much faster than the conversion rate of HMF. Furthermore, HMF is converted to 5-hydroxymethyl furfuryl alcohol with a similar mechanism as it was shown in the case of furfural conversion.

Another potential barrier to biofuel commercialization

Based on Brent Erickson, the executive vice president of BIO’s Industrial & Environmental Section, a cellulosic biorefinery that produces both advanced biofuels and biobased products could create as many as 2,200 new jobs and increase economic activity by more than $1 billion.

This is a good news!

However, this will not become true until a real biorefinery plant nearly take off. Before that, a series of barriers need to be overcome. In addtion to the technical, engineering, financial, and market issue, a key factor to be easily overlooked is the technical resources. We are not lack of people but we are lack of technical professionals who have been well trained with solid and sound fundemental understanding of the technology.

When biofuels become a hot spot, it seems that thousands of biofuel specialists are available in the market overnight.

However, it is not difficult to find that quite a lot of them are not real experts. Unfortunately, they are in the position to provide advices, suggestions to the government, company managers or make decision by themselves. As a result, some key technology development or technology commercilization is delayed; some companies go to wrong direction; some companies have to be closed due to the bad decision..... Just like a diagnosis for a patient from a "fake" doctor, the patient treatment was delayed, or wrong description was given to the patient. What a result can we expect from this?

As a result, the time has been wasted; the money has been wasted, the opportunities has passed; and a lot of related people got hurt, i.e. human resources was also wasted.

It is so-called 'a busines can both succeed and fail because of human resources!'

Lignin solvents may work better for biomass treatment

Lignin is the big barrier for pretreatment and enzyme hydrolysis of lignocellulosic biomass. The idea to use ionic liquids is to decrystallize of the cellulose to make it more digestible for enzymes.

If we can use lignin solvent like dioxine to break down lignin linkages, it may significantly increase the enyzme digestability and reduce enzyme loadings during enzyme hydrolysis.

The misundstanding of lime treatment for detoxification of lignocellulosics hydrolyzate

Traditionally, lime treatment was used to remove phenolic compounds in pulping acid sulfite pulping spent liquor because of the formation precipitate calcium lignosulfonate.Unfortunately, this method was also proposed today to be used widely to remove other by-products such as acetic acid, furfural, and HMF in the hydrolyzate, which is not right from fundamental aspect. These by-products can be removed due to the lime trap from lime treatment, which also traps sugars and leads to 20-35% sugar loss.

Two science research progress on biofuel plants

These two progress means more than the research itself. It will significantly impact the lignocellulosic biomass biofuel production process, equipment, and cost.

1. Modified Plants May Yield More Biofuel.

2. Modified Lignin Has Potential Benefits For Ethanol, Paper And Feed.

The challenge of IL pretreatment of biomass

The challenge of IL pretreatment of biomass:

1. Moisture of biomass. Some level of water will reduce the efficiency and rate of decrystallization of cellulose, what is the tolerance of water level of biomass for IL function?

2. Particle size reduction. Lignocellulosics is the complex of lignin, cellulose, and hemicelluloses and is more difficult to degrade than cellulose due to strong interactions between lignin and glucose. So, particle size reduction is needed before IL pretreatment

3. IL recovery. After treatment, water is usually added to extract IL out. The question is whether we can extract 100% of the IL used out of the sugar solution by simple extraction. The IL lost in the sugar will cause 1) the cost increase of IL usage 2) the potential toxicity on microorganism during fermentation because IL is salt

4. Separation of sugar and IL. Since some ILs is miscible with water, sugar will dissolve in ILs. The separation of sugar will become a cost and technological issue.

5. The issue of hemicelluloses and lignin. How to handle these two compounds?

Efficiency and cost consideration for detoxification of lignocellulosics hydrolyzate

The hydrolyzate of lignocellulocis need to be detoxified before fermentation. However, there must be a consideration of the efficiency and cost when a method is selected.

Biological and membrane are very effective but not cost-effective for bioethanol production;
Lime treatment is effective and cheap but the sugar loss and by-product (gypsum) handling is another cost and environmental issue.

I like the idea of stripping combined with activated charcoal treatment, which works well with good cost advantage. The charcoal can be easily re-activated and reuse.

A list of Biodiesel Kits and Production Equipment suppliers

Websites:

1. http://journeytoforever.org/biofuel_supply.html
2. http://www.biodieselnow.com/blogs/methods/archive/2007/01/27/the-basics-of-biodiesel-production-101.aspx
3. http://www.biodieselpictures.com/

Suppliers:

1. Alvan Blanch is a British manufacturing and project engineering company with a global outlook, specializing in the design, production and supply of quality machines and integrated systems for the primary and secondary processing of agricultural produce and waste materials.

2. Arbor Biofuels Company LLC, is an Ann Arbor based start-up company. We manufacture methyl ester (biodiesel) from the collected vegetable oil waste of our area. We also specialize in the fabrication Biodiesel Purification equipment, particularly in the area of ion exchange columns or dry wash towers.

3. Anyang General International Co., Ltd (AGICO) is specially in design and manufacture of complete oil plants and equipments, importing and exporting various mechanical products and engaging in external economic and technical cooperation.

4. ARBODS Ltd supplies fuel/energy saver means/equipments and a complete range of biodiesel processing equipments, reactors, plants. From simple compact processing kits to full-scale commercial plants with equipment, personnel and training provided as required.

5. BDC Systems is a private company with many years experience in grain drying, cleaning, storage and handling equipment, also milling and mixing.

6. Bio100Supply ,located in Georgia, U.S.A. provides all of the lab ware, pumps, safety equipment and chemicals that are necessary for making homemade biodiesel or creating a SVO conversion kit for your car.

7. BioMac, supply a complete range of biodiesel processing equipment at an affordable cost. BMC provides a complete range of biodiesel processors and support system from compact units to full-scale industrial plants, tailored to customers’ needs.

8. Bio Development, LLC provides quality products to consumers searching for a way to produce alternative fuels in order to create a cleaner, safer environment.

9. Biodiesel 123. Biodiesel123 is made up of a team intent on manufacturing the safe and efficient biodiesel processors available.

10. Biodiesel Experts International, The premier source for Biodiesel process equipment, engineering, sales and support.

11. Bio-Diesel International, a company in Austria provides solutions for the industrial use of renewable resources.

12. Biodiesel Logic Inc is based on the vision that small to medium scale biodiesel production is not only logical but profitable. Also that small to medium scale packaged processing equipment can be improved by applying industrial engineering criteria that has not been normally available to the small biodiesel producer.

13. Orbitek Biodiesel Production Equipment specializes in Biodiesel Producers, Biodiesel Productions, Biodiesel Production Systems, Biodiesel Technology and Renewable Fuels.

14. Biodiesel Solutions manufactures the BiodieselMaster® line of continuous-flow automated processors at its 30,000 sq. ft. factory in Sparks, NV. It is an engineering company dedicated to supporting small-scale biodieselers in every aspect of making their own fuel. This company also supplies materials to biodiesel cottage industries and biodiesel plants.

15. Biodiesel-technologies's proprietary process offers advantages and cost efficiencies over its competitors for technology, production, and facilities in this emerging industry.

16. Biodiesel Technologies International, LTD (Biodiesel Gear) -Located in Illinois, this company produces cost effective biodiesel p equipment and and all of the accessories that you wil lneed to create your own homemade brew. They also supply individual parts such as hoses and pumps to home brewers who are attempting to design a one of a kind biodiesel processor.

17. Biodiesel Warehouse is focused on providing a practical online resource for the small to medium capacity (5 to 1 million gallons per year) home brewer, coop, farm or business. We believe in using high quality materials, and only sell processors which utilize steel plumbing and steel reaction vessels.

18. Biofuels, an Argentina company that provides pressurized steel units designed for individual or coop use. They will process both virgin or waste vegetable oil, and are fully self-contained.

19. Cavitation Technology Inc., is an engineering and manufacturing company, specializing in the production of the biodiesel equipment with its signature product.

20. Crown Iron Works Company's biodiesel production equipment is designed for continuous operation for maximum efficiency and safety. The process is a two stage transesterification reaction followed by ester washing, drying and alcohol recovery. Excess methanol is recovered from all product streams to virtually eliminate discharge to air and water and allow its reuse in the process.

21. DirectIndustry is the permanent virtual exhibition, connecting manufacturers and buyers in 5 languages, around the world. With 4 million visitors a month sourcing from over 48,000 industrial products, it is the biggest industrial exhibition online.

22. Ascension Industries, Inc. - Durco Industrial Filtration Division provides their state-of-the-art Biodiesel Dry Washing & Filtration Systems in the US,Europe, and Asia.

23. Doctor Diesel, Located in California, this company specializes in producing small-scale biodiesel making equipment and parts for the hobbyist or serious home brewer. It is also a good site to get advice on making your own biodiesel.

24. UkrBudMash Ltd., a company in Ukraine to provide BioDieselMatchTM continous stream biodiesel production systems.

25. Energea, a company in Austria with CTER technology "Continuous Trans Esterification Reactor" that opens a new chapter in biodiesel production: With up to 50% lower costs of investment and practically 100% yield. Turn-key installations, built in container sized modules, provide for considerably less space requirement.

26. EuroFuelTech manufactures all of the biodiesel equipment needed to produce quality fuel, whether you want to make 2,000 litres per day or 400,000 litres per day.

27. Evolution Biodiesel,LLC provides biodiesel processors.

28. EZBiodiesel is a company providing a full range of solutions to your biodiesel processor needs. It is ready to run processors from 20-800+ gallons, & Do It Yourself Kits available as well as parts & accessories and also has a vast amount of Free information about biodiesel.

29. Fertile Fuels is a Colorado based research and fuel production company focused on rural and urban Biodiesel production.

30. GHP-Biodiesel, a company in Germany provides small scale biodiesel equipment plus logistic support. Renting of equipment.

31. Green Fuels provides small and medium scale biodiesel equipment in Europe.

32. Green Grid Solutions, a Canadian company provides Biodiesel manufacturing supplies.

33. Greenline Industries is a proven provider of innovative technologies for the production of biodiesel fuel. It manufactures award-winning biodiesel production equipment and provide engineering and consulting services for the construction and management of biodiesel facilities.

34. GreenShift develops and commercializes clean technologies that facilitate the efficient use of natural resources.

35. Goat Industries, a company in UK to provide biodiesel equipment, 'veggie boost'er, conversion kits etc.

36. Home BioDiesel offers a quality product for the conversion of vegetable oils into diesel fuel.

37. Homebiodieselkits provides complete biodiesel kits assembled and ready to produce biodiesel fuel the same day. Including a superior fuel filtering system and solid one piece steel frame.

38. IBG Monforts Oekotec can certainly rightfully claim to be an expert in the oil seed processing industry.

39. Imerjent LLC, a start-up technology firm, launched in January 2007 to bring an innovative, highly automated biodiesel production system to market. The firm will specialize in manufacturing cost-effective, medium-scale modular systems.

40. JatroDiesel is a Biodiesel Production Equipment provider and Biodiesel producer.

41. KEE CHEUNG CO, located in China, is biology diesel-oil equipment factory, with strong technology strength, involved in biodiesel research, product, biodiesel equipment manufacture.

42. Kemia Gmbh Manufactures Biodiesel Production Equipment And Waste Oil Recycling Equipment. Containerized Units, Quick Delivery, Quick Installation.

43. Lurgi provides proprietary technologies and exclusively licensed technologies in the areas gas-to-petrochemical products via synthetic gas or methanol and synthetic fuels, gas generation and treatment, petrochemical intermediate and end products, biofuels as well as food and oleochemicals.

44. National Tank Outlet is your source for plastic storage tanks.

45. Nova Biosource Fuels, Inc. is a Leading Edge Provider of Biodiesel using its Proprietary Patented Process Technology. Nova currently has over 230 million gallons of Biodiesel in various stages of construction or in operation.

46. NAZCO distributes renewable alternative fuels; bulk vegetable oils and biodiesel production equipment for a cleaner world.

47. Olympia Green Fuels LLC, located in Washington, this company sells a modular kit for making biodiesel at home. These kits produce biodiesel from both fresh and waste vegetable oil. These processors will convert both fresh and waste vegetable oil into a washed and polished biodiesel fuel that is capable of meeting the quality standards of the ASTM.

48. Pacific Biodiesel, Inc. manages biodiesel plants in Hawaii, Oregon and Texas and creates truly sustainable, community-based biodiesel production facilities that incorporate feedstock usage, fuel processing and product distribution within localized geographic areas in order to maximize the economic and environmental benefits and minimize energy consumption.

49. PESCO-BEAM Bio-diesel Systems are the most complete systems on the market today.

50. Planet Biodiesel, located in Colorado this company supplies the information and products you need to make your own biodiesel fuel.

51. Renewable Energy Group (REG) leads the nation in biodiesel production and marketing.

52. SE-Energy specializes in offering a single-source solution for 40mm-320mm gal/yr biodiesel plants.

53. Special Technologies, located in Ukraine and provides modern technologies and equipment for biodiesel production.

54. SunBio Systems (SB) is focused on the small to mid sized biodiesel equipment market. SBS biodiesel machines range from the university grade research and development system to truck fleet and rural area systems, to mid sized plants that produce 50 million gallons per year.

55. Utah Biodiesel Supply carries a large selection of Biodiesel home brewing supplies, equipment, literature, soap, bumper stickers, decals, and more.

56. Wintek Corporation has methanol recovery systems for Biodiesel and glycerin to meet ASTM standards. Custom design in carbon or stainless steel for capacities of 5-150GPM.

57. YiXing HuaDing Food Machinery Co,.Ltd, a company in China and is able to provide design, manufacturing, fixing, debugging of 10 t/d-600t/d oil refining production line and main equipments, including disc centrifuge, bleaching tower, deodorization tower.

New Opportunities from ionic liquids in biorefinery

3rd Generation Biomass Conversion Technologies can be developed by using ionic liquid pretreatment of the lignocellulosic biomass. The recalcitrance of biomass due to crystallinity and lignin sheathing of biomass will be overcome leading to enhanced yields. The enzymatic hydrolysis of cellulose pretreated with ionic liquids will be faster and more efficient.

Ionic liquids:Green Solvents

"Ionic liquids (ILs)" are the liquids composed entirely of ions that are fluid around or below 100°C.

In 2005, one of my former colleagues synthesized chemicals in the lab using ionic liquids, which represents the trends of green chemistry because many of the solvents of yesterday’s industry are now recognized and regulated as harmful.

In 2006, another of my former colleagues have done a research on ionic liquids.delignification biomass. Recently we can quite a lot of research activities and reports have been focusing on the treatment of lignocellulosic biomass in the ionic liquids for biorefinery. And a patent has been issued to such a technology.

Yesterday, our VP asked us to evaluate the commercialization of ionic liquid pretreatment of lignocellulosic biomass.

I am surprised at the fast pace of the "green wave" of ionic liquid toward us!

Why are ionic liquids attracting so much attention? Because they

• have low or near zero vapor pressure because they are salts and can reduce volatile organic compounds emission. Yes, ionic liquids are the candidate to replace volatile organic solvent replacement!
• have the ability to design specific physical and chemical properties (Tunable properties) and allow to designer solvents. This is the most useful property of ILs. The range of physical and chemical properties available with ILs is considerably wider than those of commonly used organic solvents. Thus, an appropriate “Task Specific Ionic Liquid (TSIL)” can be designed with the precise physical and chemical properties desired by the end user.
• have low melting point, enabling them to be liquids at or below room temperature. e.g.
  1-ethyl, 3-methyl imidazolium benzoate for example has a melting point of -61°C.
• have different water miscibility.Some are water miscible and some are not. This property can be switched ON and OFF according to the process requirements by modifying the cation structure of a ionic liquid or by changing its anion. The anion chosen plays a prominent role in IL water miscibility. [PF6]-, [(CF3SO2)2N]- for example are generally water immiscible anions, and [CH3COO]-, [CF3COO]-, [NO3]-, Br-, I-, and Cl- are generally water miscible anions.
• have large liquid range and thermal stability, which makes them useful for reactions that need to be maintained at either low-high or both low and high temperatures. For example, 1- ethyl, 3-methyl imidazolium bis(trifloromethylsulfonyl) imide has a liquid range of 471 degrees, with a melting point -15°C and a decomposition temperature a 455°C. This property makes ILs useful for reactions that need to be maintained at either low-high or both low and high temperatures.
• have high air and water stability
• have high ionic conductivity and a large electrochemical window
• are recyclable

So, ILs CAN DO WHAT TRADITIONAL SOLVENTS CAN NOT DO!

It has been known that pretreatment of lignocellulosic materials using ionic liquids is more environment-friendly than conventional pretreatment methods because the ionic liquids can be recovered and reused. Moreover, by fractionating lignocellulose with ionic liquids it is possible to extract cellulose cleanly.

Unfortunately there is probably still a long way about its commercialization as green solvents, specifically as a media for biomass pretreatment because of the high price of ionic liquids, the cost IL recovery process, and the understanding of physico-chemical mechanisms during biomass pretreatment.

Cost, cost, a "energy barrier" for technology commercilization!

Microbial World to Power Fuel Cells with Waste

According to the Nikkei Report, Sapporo Breweries Ltd. has developed bacterial degradation technology to turn food processing plant waste into hydrogen for fuel cells. Sapporo is testing its technology at a Hiroshima bread bakery, where unused dough is decomposed by microorganisms to generate hydrogen. "The system can generate 25,000 liters of hydrogen from 125 kg of dough, which otherwise would be thrown away. Combining this setup with a system for manufacturing would provide enough energy to meet the daily needs of five average households."

The article also reports the Kajima Corporation is developing a microbial fuel cell that generates electricity using a feedstock of sewage sludge.The Kajima fuel cell uses electrodes coated with microorganisms typically found in waste water and rice paddies. "These microbes release hydrogen as they metabolize the sludge, and this hydrogen reacts with oxygen to generate electricity." A prototype of the fuel cell can reportedly generate 130 watts of electricity per cubic meter."

(Cited from Industrial Biotech Innovation Report.)

A New Process for Continuous Production of Succinic Acid

A new efficient integrated membrane bioreactor-monopolar electrodialysis process was developed for succinate production at high yield (1.35 mol/mol), high titer (83 g/L) and high volumetric productivity (10.4 g/L.h) . The combination of these three parameters shows that this system could be economically viable for the development of a biological route to succinic acid production.

Oxidation of Glycerol

Glycerol can be oxidized to produce fine and specialty chemicals. Traditionally, oxidation can be conducted by mineral acids, enzymatic, or electron-chemical processes but selective catalytic oxidation turns to be productive, cheaper, and environmental friendly.

Oxidation products are useful as intermediates. e.g. glyceric acid is an intermediate for medicine manufacture; dihydroxyactone is a self-tanning agent in cosmostics; tartronic acid is an chelating agent; hydroxypyruvic acid is used for fruit maturation and intermediate for amino acids;Mesoxalic acid has potential application in organic syntheses.

Most of recent studies focus on heterogeneous catalysts such as supported platinum or palladium, and gold etc while some on homogeneous catalyst such as TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl).

The oxidation ususlly use air or oxygen as an oxidant at mild temperature (20-80 C) in the liquid pahse. The pH has an important impact on catalyst performance, product coversion rate and selectivity.

Purification of Crude Glycerol

The glycerol obtained from transesterification is separated from biodiesel by gravity. The concentration of this type of glycerol is ~50% (wt),which is so-called raw glycerol and contains the contaminants such as alcohol, soap, base catalyst, salts, and untreated organic materials.

Crude glycerol can be obtained through the following purification of raw glycerol:

1. Acidification of the soaps with HCl and separation of formed free acids by gravity
2. Neutralization with caustic soda
3. Evaporation for methanol recovery and water removal. The methanol recovered can be reused for biodiesel production. The the crude glycerol with 80-85% (wt.) can be obtained.

Crude glycerol purification:

1. Crude glycerol can be purified by vacuum distillation to a purity of 99.5% (wt).
2. Crude glycerol with diluted salt can be refined with ion-exchange
3. Crude glycerol with high salt content can be purified with ion exchange chromatography and thin film distillation.

Hydrogen from Biomass

Different process routes of hydrogen-production from biomass can be broadly classified as follows:

1. Thermochemical gasification coupled with water gas shift. Maximum conversion can be achieved. But significant gas conditioning is required and removal of tars is important.

2. Fast pyrolysis followed by reforming of carbohydrate fractions of bio-oil. It produces bio-oil which is the basis of several processes for development of fuels, chemicals and materials.But therr are chances of catalyst deactivation.

3. Direct solar gasification. Good hydrogen yield but requires effective collector plates

4. Miscellaneous novel gasification process.

5. Biomass-derived syn-gas conversion.

6. Supercritical conversion of biomass.Can process sewage sludge, which is difficult to gasify. Require a selection of supercritical medium

7. Microbial conversion of biomass.Waste water can also be treated simultaneously. Also
generates some useful secondary metabolites. Selection of suitable microorganisms is needed.