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Biochemical Conversion

Biochemical conversion

Biochemical conversion primarily involves using microorganisms or enzymes to breakdown complex chemicals present in biomass into simpler sugars or alcohols. Biomass conversion to alcohols such as ethanol has attracted wide interest in the recent past. The corn to ethanol technology is mature and is commercial in the US.

 

Nevertheless, this technology has created some debate in the context that corn is still a primary food to many around the world. To circumvent this issue, significant strides have been made in the use of lingo-cellulosic biomass as a source for ethanol. In this method enzymes are used to breakdown cellulose to its monomers and subsequently subjected to fermentation under anaerobic conditions using
microorganisms. 

 

But now our commitment in Biomasse Power is to develop a new biofuel source from the 3th generation of biomass source production like the Microalgues..      

Fermentation

Fermentation

Fermentation is the process by which microorganisms such as yeast and bacteria convert organic molecules into other products. For biofuels the typical useful fermentation products are ethanol and butanol, both of which can be used as liquid transport fuels.

 

 

 

 

 

 

 

 

 

 

 

 

 

Microorganisms, yeasts and bacteria, can be used to ferment organic biomass into alcohols and other valuable solvents.  Fermentations occur in the absence of oxygen.  Yeasts can be used to produce ethanol.  Solventogenic clostridia are bacteria, which can be used to produce hydrogen gas, Acetone, Butanol and Ethanol, the so called ABE fermentation.   Butanol is the main product.   Yeasts are more tolerant to alcohol and therefore produce more than bacteria, however often the bacteria are capable of using a wider range of substrates.  Ethanol and butanol have several advantages over petrol and diesel as fuels.

 

Product uses

Each product can be used for a variety of applications: 

 

 

 

 

 

 

 

Acetone

Degreaser, paint thinner, glue dissolver, food additives, pharmaceutical & cosmetics industries.

Butanol

Fuel, polymer manufacture, pharmaceutical manufacture, extractant (hormones, antibiotics and vitamins), butanol is also used in paints, resins, dyes, brake fluid, degreaser & perfumes. Butanol has superior fuel qualities to ethanol 

Ethanol

Fuel, antiseptic, paints & perfumes

Hydrogen 

Power generation & coolant in power stations.

Usable Substrates

The substrates that can be used in this process are very extensive.  By-products, leftovers and wastes of agriculture (for example from harvesting, husks, shells and stalks, leaves etc.), forestry (for example sawdust and fibres), municipals and industry (for example black liquor, wastewater, sewage, glycerol, dairy waste, distillers’/ brewery grains, paper and cardboard).  

Advantages of ethanol and butanol

  • Can be produced sustainably and are renewable fuel sources

  • Adds oxygen to petrol/diesel blends – reducing greenhouse gas and unburned hydrocarbon emissions

  • Blend with petrol and diesel as a fuel extender

  • Higher octane rating than petrol/ diesel which increases engine performance

  • Lowers cetane rating (combustion efficiency) of diesel

Butanol versus ethanol

  • Not hygroscopic (does not pick up water)

  • Completely miscible with diesel (separation under cold and damp conditions is a problem with ethanol-diesel blends requiring emulsifier addition)

  • Low vapour pressure (easier and safer to handle) means less evaporation in comparison to ethanol, highly flammable vapours are a problem with ethanol

  • Blend with petrol to any per cent (ethanol limited to 85%)

  • No engine modifications required (less corrosive than ethanol) which means it can be added to any vehicle on the road. Indeed this was demonstrated by David Ramey who drove his unmodified Buick 10,000 miles across America on biobutanol

  • Can be handled & stored in current infrastructure for petrol

  • More similar properties to petrol and diesel therefore makes it easier to blend, it has a higher viscosity, reducing pump and injector leakage (observed with ethanol) which is important for fuel delivery in the vehicle

  • A longer hydrocarbon chain = more energy from its combustion compared to ethanol

 

Useful site links

Biofuel Research Centre

Celtic Renewables

Biogas and Anaerobic Digestion

Biogas production using anaerobic (oxygen free) digestion is a biological treatment process to reduce odor, produce energy and improve the storage and handling characteristics of manure.

Biogas Production

A biogas production system must be specially designed and requires regular attention by someone familiar with the needs and operation of the digester. Associated manure handling equipment and gas utilization components are also required. The digester does not remove significant nutrients and requires an environmentally responsible manure storage and handling system.

A well designed and operated digester will require modest daily attention and maintenance. The care and feeding of a digester is not unlike feeding a cow or a pig; it responds best to consistent feeding and the appropriate environmental (temperature and anaerobic- oxygen free) conditions. The earlier a problem in operation is identified the easier it is to fix and still maintain productivity.

Biogas Safety

Anaerobic digestion systems and associated manure storage and handling present many safety hazards. A good designer and responsible digester owner will learn about and be concerned with safety from the very beginning of any digester project. A qualified digester designer, builder or equipment supplier should have excellent knowledge about and be sensitive to the safety needs of workers and visitors around a biogas system.

Areas of concern will likely include:

  • Gas releases that are flammable, explosive or immediately toxic.

    • Hydrogen Sulfide gas, which can accumulate in the bottom of tanks and pump sumps, can kill almost instantaneously.

    • Carbon Monoxide gas can accumulate in engine and machine rooms from engine exhaust and poorly operating boilers.

    • Biogas can accumulate under roofs and ceilings in explosive mixtures.

  • Confined spaces that may be immediately hazardous to life and should only be entered using appropriate procedures and equipment.

  • Noise levels that require workers to wear hearing protection.

  • Liquid tanks and ponds that may result in drowning.

  • Pumps and other machinery that are entanglement hazards due to rotating shafts, pinch points and other moving parts.

  • Biogas and manure liquids that cause rapid corrosion or failure of electrical equipment, gas handling piping and building components.

  • Small children and unaware visitors who can wonder into areas of danger and become serious injured or drown.

  • Ladders, platforms and roofs without guards, cages or other fall prevention measures.

  • Dirty liquids and gases escaping under high pressure.

Biogas Safety-related Links

 

COPYRIGHT GREEN POWER  Biotech                      Last update May-01st-2019                                                      Powered by GPB

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