Ethanol Production | United Petroleum – 100% Australian Owned

Ethanol Production

United Petroleum and Dalby Bio-Refinery are proud to provide a renewable resource that replaces imported petroleum, improves the air that we breathe, provides a high value animal feed back into the food supply chain.

 

sorghum-full-bloom

Facts about Ethanol

  • Ethanol is a sustainable, renewable fuel while petroleum fuels are unsustainable, fixed and running out!
  • A very recent study found that the global warming impact of the modern ethanol plant is 40% lower than that of a petroleum plant.
  • Ethanol is an oxygenate that reduces petrol tailpipe carbon monoxide emissions by as much as 30% and tailpipe fine particular matter emissions by 50%.
  • Ethanol’s higher “octane” actually results in improved fuel consumption.
  • Ethanol delivers 67% more energy than in takes to produce it.
  • AUD115 million of capital expenditure went directly into Queensland companies for the construction of the DBRL plant.
  • For every 1,000kg (1 tonne) of sorghum consumed DBRL produces 900kg of WDGS and 90kg of syrup for beef and dairy feed lots.
Myth Fact
Ethanol will cause the cost of food to increase in Australia. Ethanol produced from sorghum and other grains consumes only the starch content of the grain. The energy and protein rich by-product goes back into the food chain as animal feed. From one tonne of sorghum, approximately 80% of the grain will be recycled as very high quality animal feed. In an annual sorghum crop of approximately 2,000,000 tonnes per annum in Australia, only 200,000 tonnes per annum (or 10%) will be diverted to ethanol with 160,000 tonnes of high quality feed going back into the food chain – a net loss of only 40,000 tonnes.  Sorghum not consumed in Australia is almost always exported to Japan.
Ethanol has a lower energy density and hence reduces vehicle fuel economy. Theoretically E10 fuel consumption is approximately 1-3% higher, however this is almost always offset by being 3cents per litre cheaper at the bowser than unleaded fuel. Further, the real world experience is that reduced fuel consumption is a non issue, in fact, the “increase in octane” results in improved fuel consumption.
Ethanol consumes more energy during production than it produces. Petroleum distillates have a negative energy balance. Petrol delivers 23% less energy than is required to produce it!  Ethanol on the other hand has a positive energy balance. On average, ethanol delivers 67% more energy than it takes to produce it (USDA).
Ethanol damages car engines. Contrary to popular belief, ethanol does not dissolve the metal in car engines. Some rubber components in pre-1986 cars may harden but all vehicles manufactured after 1986 are approved to use E10. Millions of flex fuel vehicles in the USA actually use E85 which is 85% ethanol and is up to 25cpl cheaper than unleaded petrol.
Ethanol production requires subsidies to remain viable. The ethanol industry receives virtually no subsidies compared to the billions of dollars of subsidies enjoyed by the petroleum industry. The ethanol industry does not currently pay excise, an incentive used worldwide to encourage development. In Australia the industry will start to pay excise on an energy basis from 2011; this is in line with all other transport fuels [Energy Grants (Cleaner Fuels) Act 2004].
Ethanol has a net positive carbon footprint. Actually, the carbon footprint of ethanol production is almost neutral; when DBRL captures carbon dioxide the footprint may become net negative. DBRL is currently conducting its own carbon Life Cycle Analysis.
Ethanol cannot replace petroleum fuels on a sustainable basis. The truth is that ethanol is “grown every year” in the field while petroleum fuels are fixed, finite and running out! And whilst agreeing ethanol cannot totally replace petroleum fuels, it and other renewable fuels can make a very significant contribution to dwindling and expensive world fuel supplies.
Ethanol from second generation feed-stocks is imminent. Second generation will not happen unless first generation lays down the building blocks and develops the market.

Wet distillers grainWet Distillers Grain

During the production of ethanol, yeast fermentation converts the starch component of the grain to ethanol and carbon dioxide. As a result the remaining nutritional components, protein, fat, fibre, vitamins and minerals are concentrated three-fold and are a valuable feed for livestock. The residue is centrifuged to separate the grain solids (wetcake) from the liquid solubles. The liquid solubles are further concentrated to produce “syrup” which can be mixed with the wetcake or sold “as is”. The wetcake or Wet Distiller Grain (WDG), typically has a moisture level of 68% and may be dried further to produce Dried Distillers Grain (DDG). Distillers grains is an excellent source of protein and energy.

The Process

DBRL employs innovative processes and stringent quality measure to ensure the highest grade ethanol is produced and will be the first ethanol plant of its type built in Australia to use dry grain (Sorghum) as its feedstock. Ethanol is produced by fermenting sugars sourced from grain. This in itself sounds rather simple, but in fact the process is very complex and strictly controlled under full Quality Control. The process begins by milling the feedstock – grinding the raw grain (Soghum) into a fine powder called meal. The meal is then mixed with water and an enzyme and heated to turn the starch in the meal into a liquid. The material (called the mash) is cooled and another enzyme is added, which converts the liquid starch into fermentable sugars. This is called saccharification. Once this process is complete, yeast is added and the mash is placed into a series of fermenters, which assist the yeast in converting the sugars into ethanol. This usually takes around 48 hours, and produces a mix of liquids and solids with an alcohol content of around 11-14 percent. This mix is then pumped from the fermentation tanks into a distillation system, which removes the alcohol from the water and the solids. This distillation gives us a liquid which is around 96 percent ethanol. The rest of the liquids and solids are called stillage, and are set aside. The 96 percent ethanol liquid is then dehydrated using a Molecular Sieve, removing virtually all the water. This gives us pure ethanol. At this stage, unleaded petrol is added to the ethanol to make it unsuitable for human consumption. This is called denaturing. After the denaturing, the ethanol is ready to be added to your vehicle as a fuel additive or alternative. The stillage steam is further processed into high protein animal feed called wet distillers grains and syrup.

Dalby refinement process

Steps in the Grain Ethanol Manufacturing Process

Milling
The sorghum, corn or wheat first passes through hammer mills, that grind it into a fine powder called meal.

Liquefaction
The meal is then mixed with water and alpha-amylase, goes through cookers, and starch is liquefied at higher temperatures. These high temperatures reduce bacteria levels in the mash.

Saccharification
The mash is then cooled and the secondary enzyme (gluco-amylase) added to convert the liquefied starch to fermentable sugars.

Fermentation
Yeast is added to ferment the sugars to ethanol in a batch fermentation process which lasts for up to 48 hours.

Distillation
The fermented mash, (11-14% alcohol), the non-fermentable solids from the grain, and the yeast cells are pumped to the distillation system where the alcohol is distilled off. The alcohol leaves at 96% stength, and the residue mash, exits as a co-product.

Dehydration
The alcohol then passes through a molecular sieve to remove the remaining water from the ethanol. The alcohol product at this stage is approximately 99.8% purity.

Denaturation
Ethanol that is used for fuel is then denatured with a small amount (2-5%) of petrol, to make it unfit for human consumption.

Co-Products
There are two main co-products created in the production of ethanol

  • Distiller’s grain
  • Syrup

At full capacity, the biorefinery is expected to produce more than 76 million litres of fuel ethanol each year, using in excess of 200,000 tonnes of sorghum. One of the most important components of the DBRL business is our specialised workforce. Staff are highly-skilled with a specialised knowledge of the manufacturing processes. DBRL is dedicated to an on-going education programme for staff giving good results in quality control, commitment and motivation.

Ethanol Specifications
Denatured Fuel Ethanol shall mean Ethanol that conforms to the ASTM D4806 Specification for Fuel Ethanol and the following table:

Denatured Fuel Ethanol

Parameter Method Specification
Strength (%v/v @ 15C) ASTM D5501 > 95.6
Moisture (% v/v ) ASTM E1064 < 1.0
Methanol (% Volume) ASTM D5501 < 0.1
Acidity (mg/l as Acetic Acid) ASTM D1613 56 max
PHe ASTM D6423 6.5-9.0
Non- volatile matter (mg/100ml) ASTM D1353 < 2.5
Inorganic chloride (mg/l) ASTM D512 B 32.0 max
Copper (mg/l) ASTM D1688 A 0.10 max
Sulfur (mg/l) ASTM D5453 30.00 max
Sulfate (mg/l) ASTM D7328 4.00 max
Denaturant (% volume) 1.0- 1.5

Undenatured Industrial Grade Ethanol

Parameter Method Specification
Strength (%v/v @ 20C) ASTM D4052 > 99.7
Appearance ASTM D2090 Clear liquid, free from any foreign matter
Acidity % Wt/Wt ASTM D1613 < 0.002
Moisture (% v/v ) ASTM E1064 < 0.42
Non-volatile matter (% Wt/Wt) ASTM D1351 < 0.002
Color (Pt/Co) ASTM D1209 10.0 max
Density @ 20C (Kg/m3) ASTM D4052 795.0 max
Miscibility with water Not Applicable Complete
Odor Not Applicable Characterisitc

Dalby Refinery

Dalby Bio-Refinery Ltd (DBRL) is Australia’s first grain-to-ethanol facility. First commissioned in 2008, DBRL is one of the largest consumers of sorghum in the Darling Downs region. The grain is converted into fuel-grade ethanol and a high value animal feed products called wet distillers grains (also known as wet cake) and syrup. DBRL produces 76 million litres of ethanol each year, which is shipped across the country and blended with petrol (10% ethanol and 90% ULP) to form a cleaner burning fuel for Australia’s consumers. The ethanol production process begins with the receipt of sorghum grain which is then ground into a fine powder. The powder is mixed with water and enzymes to begin the process of breaking down the starch into glucose molecules. Once the starch has been converted, yeast is introduced into the process. In an anaerobic environment, yeast ferment (i.e. metabolize) glucose into ethanol. The ethanol is then distilled from the fermentation broth, called beer, and is purified into nearly 100% pure ethanol. The final product is then denatured with 1.5% ULP and is then shipped to petrol blending stations. The remaining product once the ethanol has been distilled away is called stillage. The stillage is dehydrated down to a moisture content of approximately 32% which forms a high protein, high energy animal feed which is sold to nearby beef and dairy feedlots. DBRL converts nearly 200,000 metric tonnes of sorghum into 76 million litres and 180,000 tonnes of wet cake each annum, and employs approximately 50 people. United Petroleum purchased Dalby Bio-Refinery Ltd in October 2011.

Our Quality Fuels