Science & Tech

What is ethanol blending?

The practice of blending (mixing) of petrol with ethanol is what is referred to as ethanol blending. If the blending is mandatory it means it is obligatory, or required by authorities through invocation of an act of Law.

The question that may then arise is; so what is ethanol? In its simplest form ethanol, which is also referred to as ethyl alcohol, grain alcohol or ETOH, is a liquid made from the fermentation of distilled simple sugars. Ethanol has varied uses, but here we will only concentrate on it as a biofuel (renewable form of energy).

Fuel ethanol, or bioethanol is produced from such crops as corn (maize), wheat, sugarcane, potatoes, cassava, and other agricultural feedstocks. Major global ethanol producers are Brazil (top producer), which uses sugarcane, and the United States of America, where most of the corn crop is dedicated to ethanol production.

Because pure fuel ethanol has chemical properties similar to those of other grain alcohols, it has to be denatured or made unfit for human consumption. The most common denaturant (agent for denaturation) is petrol, hence, blending of ethanol and petrol is a requirement in making ethanol inconsumable where it is to be used as a fuel.

Insights into global mandatory blending trends

Ethanol blending is not a new thing, neither is it unique to Zimbabwe. Over 60 countries have embraced ethanol blending. Ethanol has been blended with petrol since the 1930s in varying percentages worldwide with Brazil leading in mandatory blending anhydrous (having little or no water) ethanol between 1976 and 2019 with percentages varying between 10 and 27 (E10 and E27).

The first production car to run entirely on ethanol (E100) was the Fiat 147, manufactured in Brazil in 1978. The letter ‘E’ means ethanol, and the corresponding number denotes ethanol content in ethanol-petrol blend. Hydrous ethanol (E100) is widely used in Brazil, as authorities advocate use of renewable and clean energy sources.

Harnessing its natural resources, Brazil established a strong agricultural sector making it the world’s top producer of ethanol, which has also helped the country in developing its manufacturing industry. Due to limited quantities to meet local and export demand, the mandatory blending in Brazil is at E25.

India is also one of the countries advocating use of biofuels like ethanol so as to reduce reliance on oil imports. India’s mandatory blending fluctuates between 2 percent and 3 percent, and the country’s target is 10 percent ethanol blending by 2022, and 20 percent by 2030 depending on availability of ethanol. As is the case in Brazil ethanol blending with petrol in India is hamstrung by availability of ethanol due to unavailability of water resources to meet ethanol fuel and food crops demand.

According to data compiled by the Indian Sugar Manufacturers Association (ISMA) there is a requirement of 31,36-lakh kilolitres of ethanol in the 21 States where the Ethanol Blending Programme (EBP) is being implemented. However, there has been a supply commitment of only 17,63-lakh kilolitres of ethanol for the period between December 2017 and November 2018.

In the United States of America; the world’s second largest producer of ethanol after Brazil, there are three categories of ethanol-petrol blends; E10, E15, and E85. According to Energy Information Administration (EIA) of the 142,86 billion gallons (a gallon is equal to 3,79 litres) of petrol consumed in the US in 2018, about 14,138 billion gallons were fuel ethanol, translating to 10 percent of total volume.

In China, mandatory ethanol blending with petrol is 10 percent; and in Japan ethanol blending, though considered as favourable, due to the country’s renewable energy policy, is affected by availability since the Japanese are wary of competition between fuel crops and food crops, which has the effect of pushing prices up.

ALSO ON ZIMVOICE:  ZERA reduces petrol blending levels

Japan, however, imports fuel ethanol from Brazil, and the US. Available ethanol-petrol blends in Japan are E3 and E10. In Thailand mandatory blending is 20 percent (E20).

Which vehicles are ethanol blend compliant?

Researches have revealed that all petrol engines manufactured since 1986 can run on ethanol blends of up to E10. Since the 1990s, there was a shift to flex-fuel vehicles (FFVs), with more than 100 models being available. FFVs manufactured in 2001 and newer can use any ethanol-petrol blends up to E85, or even E100.

Many vehicles today, therefore, have been designed with fuel ethanol in mind, because ethanol blends are dominant fuels sold in Europe, South America and the bulk of Asian countries. Because of its higher octane rating as compared to petrol, fuel ethanol is commonly used in high performance vehicles such as race cars, with superior ethanol blends of E85 and E100 preferred because they significantly increase the power of the vehicle.

However, since flex-fuel vehicles are identical to unleaded petrol only vehicles, it may not be easy to tell whether one is driving an FFV or not. But knowing the model year may be crucial in telling whether one’s vehicle is compliant with higher levels of ethanol-petrol blending or not. For vehicles manufactured from 2008, or 2006 for General Motors, most manufacturers have resorted to using yellow fuel caps, yellow rings, and labels on fuel doors to denote flex-fuel vehicles.

Advantages of ethanol blending

For a country like Zimbabwe ethanol blending may be the way to go, considering the abundance of arable land, water bodies and favourable climatic conditions. There are over 10 000 water bodies in Zimbabwe, which if fully utilised will go a long way in ascertaining adequate bioethanol for the domestic market and reduce the country’s foreign currency commitments on fuel imports.

Ngee Ann Polytechnic of Singapore listed quite a number of advantages of using ethanol-petrol blends, most of which centre on the environmental friendliness of fuel ethanol as a clean and renewable energy source. Depending on percentage blends, ethanol blended fuels can reduce greenhouse gas emissions by as much as 37,1 percent for E85 and E100.

Bioethanol can also reduce high-octane additives, and spills are easily biodegraded or diluted to non-toxic concentrations. Besides environmental considerations, ethanol blending can help in boosting agriculture, creating employment down the value chain, fosters energy security and economic freedom through the shift from foreign-produced oil to domestically produced energy sources.

In Zimbabwe, three players are licensed to produce ethanol; Green Fuel, which invested heavily in Chisumbanje and Middle Sabi, Triangle and a yet to be named licensee.

In an interview with The Herald in February last year, Conrad Rautenbach, said Green Fuel has a capacity to produce 120 million litres of ethanol per year; and employs over 3 000 Zimbabweans, and is expecting to employ a further 500. He also said that the company had, at inception in 2009, committed to develop 10 percent of total land under sugarcane to the community, at a cost of $11 million.

Recently, the ethanol producer rolled out a community empowerment programme, which saw 350 households getting 0,5ha plots under irrigation in villages around Chipinge South constituency, where the company operates.

Ethanol processing plants also produce electricity as a by-product which can be fed onto the national grid, for example, Green Fuel generates 18 Mega Watts of power as a by-product, and at peak 50MW will be generated.

Disadvantages of ethanol blending

Where availability of arable land is an issue, there may be concern on biodiversity as natural habitats are destroyed. This also plays into the food versus fuel debate where lucrative prices are offered for fuel ethanol, thus attracting farmers and pushing prices of food crops up. If there are more players, prices may be competitive, but if monopolies are allowed, prices will go up.

ALSO ON ZIMVOICE:  ZERA reduces petrol blending levels

In Zimbabwe, Green Fuel produces ethanol from sugarcane as its major product, whereas Triangle produces sugar as a key product, and ethanol from molasses. In this instance prices are not likely to be uniform, because both companies will rely on the profitability of their key product. One hinges on a fuel crop and the other on a food crop, and prices will always fluctuate, either pushing ethanol up or sugar prices up. If Green Fuel were to produce sugar there will be competition on both ends, which will make prices of both products competitive.

For benefits to be accrued the price of ethanol should remain low as compared to prevailing prices of unleaded petrol, thus, saving foreign currency for the country which will be used in other sectors. Thus, there should be transparency in pricing structures, with both large-scale and small-scale producers partnering for the come good, where win-win outcomes are achieved.

Ethanol may be a clean energy source, but this cannot be said of its production. Large amounts of carbon dioxide are released during production, and other greenhouse gases (GHB) also fill the air in equal amounts to internal-combustion engines (Ngee Ann Polytechnic, Singapore). The use of phosphorous and nitrogen in the production of ethanol has a negative effect on the environment.

Motorists are usually worried about immediate cost imperatives ahead of long term benefits, as such there is need to give a few pointers. Petrol has higher energy content as compared to bioethanol, which means bioethanol is not as efficient as petrol. Burning a litre of ethanol produces 34 percent less energy than burning the same amount of petrol, meaning ethanol’s energy is 70 percent that of petrol.

In terms of fuel economy, therefore, one’s mileage performance is reduced by 3 percent as compared to unleaded petrol for E10 blends, and around 6 percent for E20. For E85 vehicles fuel economy is at 25,56 percent lower than unleaded petrol, and for E100 fuel economy can be up to 30 percent lower.

However, fuel economy can be addressed if prices of ethanol-petrol blends are comparatively lower than unleaded petrol, and where other imperatives like availability, forex issues and energy security are factored in. Because ethanol has a higher octane rating, engine efficiency can be improved by raising compression ratio.

Other factors to consider are that ethanol is hydroscopic; it absorbs water vapour from the atmosphere, which dilutes its fuel value, and may cause phase separation in blends, causing engine stalls. For this reason, fuel ethanol containers must be kept tightly sealed. Electric fuel pumps may also be affected due to increase in internal wear and undesirable spark generation. Gauging indicators may give erroneous fuel quantity indications due to compatibility complications.

The way to go

Notwithstanding the negatives, which can easily be worked on anyway, the benefits of ethanol blending are many, and Zimbabwe can reap the rewards of geographical location, which favours ethanol production. However, highlighting grey spots will go a long way in accruing both short and long term benefits, and drawing in citizens, so that they embrace the use of ethanol blends from an informed point of view.

It is this that makes our Vision 2030 a reality thorough unity of purpose. With Zimbabweans consuming about 2 million litres of fuel per day, there is need to put measures in place to ascertain that adequate volumes are produced to meet the E20 threshold or higher.

Communities should also benefit from activities around ethanol production in their localities.


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