Volume 3, Issue 6
Published: July 27, 2009
Oil extraction options
Oil mill technology is well established, with an increasing number of farmers considering seed oil expulsion for biofuel production, if the market becomes sufficiently lucrative. The majority of oil pressing is carried out by big players in the food oil and biofuel arena like Cargill, ADM, Bunge and others. Rapeseed oil initially contains about 40% oil and the biodiesel aim is to reduce residual oil in the cake to about 1%. The first stage pressing takes the cake to about 22% residual oil. The second step uses solvent extraction to take the cake down to 1% residual oil. There are three processes for oil extraction: cold press, hot press and pre-press. Cold presses are used for premium food-grade oils typically, and the seed is not heated before it enters the hopper. Cold pressed oil can also be used straight in modified diesel engines. Cold pressing is a simple process and the oil is suitable for making biodiesel. However, cold pressing leaves around 13% oil in the cake, so the cake is often re-pressed. The oil cake is then milled and bagged for used as animal feed. During hot pressing, the seed is heated before it enters the hopper, causing cell rupture, reducing the oil viscosity and increasing the capacity of the press and also the yield. In most presses, the seed is heated to about 100?C, doubling the throughput of the press. Hot pressed oil is fine for biodiesel production and processes more seed processed than single pass cold pressing. However, heating increases gum and phosphorus content, so the oil is unsuitable for culinary use, and also needs further treatment for use in engines, using solvent extraction. There is a wide range of cold and hot press oil expeller manufacturers. Leading suppliers include De Smet Rosedowns, La Mecanique Moderne, Machinenfabriek Reinartz, KEK and Karl Strahle, as well as Chinese (Anyang General, Goyum Screw Press), and Indian manufacturers, like Kanika. Though the price of Chinese and Indian presses may be significantly lower, experienced biofuel suppliers prefer to opt for the European options as they tend to more rugged, reliable and require less maintenance and potential downtime.
To read the article in full you have to be a subscriber...
Further Articles in this Issue:
In line with the trend initiated in 2007, 2008 saw a relatively low increase in EU biodiesel production, and a reduction in two major producing member states, Germany and Austria. With 7.7 million tonnes,... [Read more]
After much debate the EU has come to a conclusion and approved the anti-dumping and countervailing measures against US biofuels exports. The temporary fees imposed in March will be extended for five more... [Read more]
QAccording to the Renewable Energy Directive, what are the sustainability criteria for biofuels in the EU? A The sustainability criteria are laid down in Article 17 of Directive 2009/28/EC (published in... [Read more]
On 26 June, the US House of Representatives narrowly passed the American Clean Energy and Security Act of 2009 with 219 votes, which includes a national cap-and-trade programme aimed at reducing greenhouse... [Read more]
It has been a slow start in Africa. But community operations are gradually raising the profi le of renewable fuel, once tarnished by its link to food production, a sensitive issue in a continent that is... [Read more]
Nowhere in the world is the food-versusfuel debate more pertinent than in Africa. North of the equator the continent is seeing a wave of urbanisation raising the demand for fuel and due to today’s hiked... [Read more]
The ability to fly conveniently and efficiently between nations has been a catalyst for the global economy and has shrunk cultural barriers like no other transport sector. But this progress comes at a... [Read more]
Ethanol is produced and used in hydrous (wet) and anhydrous (dry) forms, the latter requiring an additional costly and energy consuming drying process. An opportunity therefore exists for both producers... [Read more]
Scientifi c research organisation TNO has just completed tests measuring the emissions and running capabilities of several low blend hydrous ethanol fuels. A representative modern car (a Ford Mondeo) was... [Read more]
The old adage tells us that sometimes before moving forward, you have to take a step back to appreciate what has come before. Camelina, which has gone under several aliases including false fl ax and gold... [Read more]
A crucial factor when moving biomass is the bulk density – weight is rarely a problem. Loose plant-based biomass has a low bulk density ranging from 50 to 130 kg/m3 depending on the plant species, particle... [Read more]
Technical maturity and commercial viability of algal biofuels is a much debated topic, with estimates ranging from three years to (multiple) decades. However, most people involved in this emerging technology... [Read more]
Oil mill technology is well established, with an increasing number of farmers considering seed oil expulsion for biofuel production, if the market becomes sufficiently lucrative. The majority of oil pressing... [Read more]