Biodiesel

Oil and Fats in the Marketplace

I have only been able to make a limited update to this section. In fairness to readers I have indicated where figures have not been changed from 2011 because I do not have new information

The major biofuels in present use are bioethanol added to petrol (gasoline) and biodiesel added to petrodiesel. Bioethanol is produced from sugar cane in Brazil or from corn (maize) in the USA, with these two countries the major producers of bioethanol. Total production is growing but this is not a fat-based commodity and will not be considered further here.

Biodiesel is generally the methyl esters of natural triacylglycerols. These can replace petrodiesel completely, but more commonly the two components are blended at levels up to 10% or beyond of biodiesel for use in combustion engines.

Data about biodiesel can be discussed at three levels:

  • Government mandate. Many countries have laid down mandates (targets) for the introduction of blends of biodiesel. For example, the targets in EU27 were 2.5% of total transport fuel requiring 5 million tonnes of biodiesel in 2005, 5.75% requiring 11 million tonnes of biodiesel in 2010, and 10% requiring 20 million tonnes of biodiesel in 2020. These targets are not likely to be achieved but considerable progress has been made, particularly in Germany. Many other countries are declaring mandated levels and others are increasing existing mandates. These generally represent aspirations rather than achievements, but they continue to exert upward pressure on biodiesel production and consumption.

  • Plant capacity. Many companies have seen biodiesel production as a profitable investment. However, economic aspects have always been a difficulty. Biodiesel is only profitable when it is subsidised, usually by a reduction in fuel tax. Subsidies can be given but they can also be withdrawn or reduced, making for uncertainty. As biodiesel production grows these fuel tax reductions represent a loss in national revenues which have to be made up elsewhere in the tax system. The most costly part of biodiesel production is the cost of feedstock and particularly where this is a traditional vegetable oil, costs have risen in the recent past (see web page on Prices of Commodity Oils) with the result that many biodiesel plants are being underused or not used at all, awaiting a cheaper feedstock. Capacity levels are considered to be around three times production levels.

  • Production. Except through expensive business reports it is not easy to find up-to-date information on production levels. According to the European Biodiesel Board [www.ebb-eu.org/stats.php] in 2011 EU production (8.61 million tonnes), largely from rapeseed oil, was mainly in Germany and France (Table 1). In 2012 production capacity was 23.5 million tonnes. This large gap between production levels and capacity is behind the concern in Europe about imported biodiesel. Production of biodiesel in USA is reported by the EIA for 2010, 2011, and 2012 as 343, 967, and 969 million gallons (US). These volumes equate to 1.1, 3.2, and 3.2 million tonnes during these three years. Production of biodiesel is also increasing in Argentina and Brazil.

Feedstocks for biodiesel production can be categorised as conventional vegetable oils, fats of animal origin, and other (mainly nonfood) sources. The vegetable oils used for biodiesel are mainly rapeseed oil in Europe, soybean oil in USA, Argentina and Brazil, palm oil in Malaysia and Indonesia, and coconut oil in the Philippines. Sales will be related to the relative cost of petrodiesel and biodiesel. In most developed countries biodiesel is subsidised and in many developing countries diesel is itself a subsidised product, which complicates the position further. A significant factor has been the high and volatile cost of both the fossil fuel from which diesel is distilled and the vegetable oils from which most biodiesel is made (see web page on Prices of Commodity Oils). Cheaper biodiesel feedstock includes waste fat from frying operations in fast food shops and from industrial frying processes, animal fat below the premium grades accepted for food purposes, food from animals unfit for human consumption, and poultry fat.

The Jatrophus curcas plant is a nonfood crop often grown as a hedge to keep animals out of fields. Some varieties are toxic, some are not. This plant is being grown in India and in Africa and elsewhere as a potential source of vegetable oil that can be used as biodiesel. Work remains to be done to find the best varieties of this plant and the agricultural conditions which will supply the best yields. The first samples of jatropha oil are now available but they are still too small to affect the overall picture. In two or three years it is expected to become more significant though these achievements generally take longer than the optimistic forecasts. Other minor oils are being investigated in several countries. Of particular significance are crops that can be grown with only modest inputs on poor land that is either too salty or too dry. There have been recent reports on the cultivation ofPongamia sp., Pistacia chinensis,Cornus wilsoniana, Xanthoceras sorbifolia, poppy seed, mustard, camelina and others in various countries as sources of oil that could be used for biofuel. These are serious studies but it will be several years before they have any significant effect on supplies of biodiesel. 

Another potential feedstock is algal oil. Algae are microscopic plants able to fix carbon dioxide as carbohydrate using light as a source of energy. Under appropriate conditions the carbohydrate can be converted to lipid in situ (see the web page on Biosynthesis of algal oils). The carbon dioxide may be atmospheric but efficiency is increased with an enriched source such as those obtained from flue gases or from brewing processes. The photosynthetic system only operates during periods of daylight and is reversed during hours of darkness. It can be carried out in open ponds on land not otherwise suitable for agricultural production at yields in excess of those attained with conventional plants. Finally, lipid has to be extracted from the biomass. Despite concerns expressed by some about the viability of producing algal biofuel a large amount of money and of skilled effort is being devoted to this issue, particularly in the US. Algal lipids are already used as a source of higher-cost materials such as bioactive fatty acids (arachidonic, EPA, and DHA) and those used in personal care products.

There are two major current concerns:

  • Can we produce enough oil and fat from whatever source to meet these fuel demands while at the same time providing sufficient for food purposes for a population that is growing in size at about 0.8 million each year and, especially in the developing world, has a growing income to spend on meat and lipid? Demand also rises with increasing urbanisation.

  • How green is the biodiesel option when all factors including change of land use are taken into account?

The following Tables contain information about biodiesel taken from a range of sources. Figures in Table 4 are taken from Highlights of “OECD-FAO Agricultural Outlook 2010-2019” (88 pages) which can be downloaded. It is reported that much of the foreseen 18% expansion in oilseeds between 2010/11 and 2019/20 will be concentrated in Brazil, EU, and Argentina. Vegetable oil production is expected to rise by almost 30% by 2019 within which palm oil production is predicted to reach 70 million tonnes. The share of vegetable oil consumption used in biodiesel production is expected to rise from 9 to 15%. This will continue to be mainly in Europe. By 2019 Argentina (3.0 million tonnes) will be the major-biodiesel exporting country, with lower levels from Malaysia (0.6 million tonnes) and Colombia (0.4 million tonnes).

Table 1

Table 2

Table 3

Table 4

 

 

Readers may be interested in the article "Historical Perspectives on Vegetable Oil-Based Diesel Fuels" by Gerhard Knothe on this site.

Updated March 2013