Ethanol biofuel is one of the most common and widely used biofuels out there. It is one of the easiest ways to make your motoring more sustainable, as it can be put into a regular petrol engine – or, better still, a hybrid vehicle combining a petrol-powered internal combustion engine and an electric motor – and there’s no need to buy a new car. It might not be the greenest or most sustainable way to drive, as ethanol is never used in pure form in an engine, but it’s certainly a start.
Ethanol is more sustainable than fossil fuels because it is sourced from plants. This means that no new carbon and similar emissions will be added to the atmosphere, as any carbon released by using this biofuel (or UK Syntech‘s ASB as well)was in the atmosphere not that long ago. Moreover, some of the carbon taken up by the plants used for making ethanol doesn’t go into the ethanol and won’t be released into the atmosphere. Both ways, this means that less new carbon dioxide is being added to the atmosphere, and every little reduction adds up in the long term.
Biofuel Basics
Ethanol used as biofuel is produced similarly to wine and other alcoholic beverages – and you may have guessed already from the name that ethanol is a type of alcohol. The process of producing ethanol fuel is fermentation of the sugars and starches in plant material, followed by distillation and dehydration (removing the water) to produce a pure alcohol – a lot purer than what you’ll find in the local bottle shop and something you definitely shouldn’t drink.
The hardest part of the process is what happens before the fermentation step. Although all plant matter (known as biomass) includes starches and sugars, many plants have a hard, woody layer known as lignin, which has to be removed before fermentation. This means pretreatment is needed to remove this hard outer layer so the sugars can be fermented by beneficial microbes (starches can be transformed into sugars, but this makes the process longer).
Many methods are used for pretreating the biomass to produce the sugars that can be fermented and ultimately turned into ethanol biofuel. These include chemical methods, physical methods and bacterial methods. Each of these has advantages and disadvantages. Chemical methods are quick and don’t require high energy inputs, but they often use harsh chemicals that aren’t good for the environment afterwards. Physical methods that smash the biomass to break or remove the lignin coating don’t involve toxic chemicals but require a lot of energy. Bacterial methods don’t require as much energy and don’t involve toxic chemicals, but the process takes a lot longer. Good things take time, I guess!
Research into bioethanol and the process of making it is a hot topic for many scientists in many fields these days. The goal is to make the process more efficient and more sustainable. The experts are always looking for new pretreatment methods, feedstocks and new strains of bacteria that break down the plant materials. One of the challenges is that sometimes, a method that works well for one type of biomass doesn’t work well for another.
What Is Ethanol Fuel Made From?
To ensure something’s sustainable, you must ask where it comes from and what it’s made from. This is the case of ethanol. Some people question whether the use of biofuels causes problems with food supply, either because food crops are used as feedstocks for biofuel production rather than feeding people or animals or because they take away land, fertilizer and food resources needed for growing food. It’s a good question. However, things have changed since the early days, and ethanol fuel is more sustainable than you might think. Biologists and agronomists are always looking for plant crops with multiple purposes, such as food–feed–fuel crops (food is for humans; feed is for animals) or food–fibre–fuel crops. Now, that’s what sustainability is all about making full use of every part of the plant!
Here, we’ll take a look at some of the plant materials (biomass) used as feedstocks for producing ethanol biofuel.
Corn (Maize)
One of the earliest feedstocks used for making bioethanol fuel was corn – common sweetcorn or maize like you’d buy in the supermarket as popcorn or corn on the cob. Corn has a high amount of sugar (it’s used for the notorious high-fructose corn syrup that is thought to be responsible for many obesity problems), but the downside is that it is also a food crop. Although the world would probably be better off with less high-fructose corn syrup, corn is important for feeding animals (especially in the USA) and people (corn chips, anybody?). This has discouraged the use of corn as a feedstock.
However, if you’ve ever seen a photo of a cornfield, you’ll see that not all of the corn plant is edible by humans or animals. After the cobs have been harvested, the leftover bits are known as stover, and it’s also got a lot of sugars in it and has potential as a feedstock. This has turned corn into a dual-purpose or even triple-purpose crop, where people and animals eat the corn while the stover is used as a fuel feedstock.
Miscanthus
Miscanthus × giganteus, also known as elephant grass, is a plant you probably have never heard of. It’s a plant that grows very vigorously, spreads easily and doesn’t require pampering the way many common crop plants do (e.g., it doesn’t need pesticides or much fertilizer, if any). It also contains a high proportion of carbon – think of how much it will take from the atmosphere! This makes it very suitable for producing biofuels, and because it can grow on scrubby land, it doesn’t compete with food plants.
Miscanthus is a dream feedstock, as it grows with very little input in terms of water or fertiliser and grows in places you’d never dream of growing crops. It can also handle conditions other plants can’t handle – drought, salt stress, floods, heat and cold. It can grow 3–4 metres tall in one year – and then do it again the next year. It’s grown in many parts of the world, including the UK. The only challenge is related to harvesting and collecting the stuff – which is probably easier than the process used for extracting fossil fuels, so I don’t know what they’re fussing about.
Straw
Straw is what’s left over after a grain has been harvested. Common types of straw used as a feedstock are from wheat, barley and rice. Previously, straw was used as animal bedding, and even (in earlier days) for human bedding, but with the rise of the car, there was less call for straw in stables. A lot of straw was burned after the harvest. However, now that they’ve worked out how to use straw as a biofuel feedstock, it’s becoming a valuable resource again.
Sugarcane
The sugar you put in your coffee is the juice of the sugarcane plant. When sugar is harvested and milled, a lot of waste is generated – at least 30% of the plant is considered waste. This sugarcane waste is known as bagasse. Bagasse still contains a lot of cellulose material that can be used as a feedstock for ethanol. In fact, in Brazil, which has a massive sugarcane industry and is the second-largest producer of ethanol fuel, all fuel is at least a biofuel blend, and many vehicles in the Brazilian fleet use either a biofuel blend or pure ethanol – or both!
Wood
Wood is harder to turn into ethanol because it has a higher proportion of lignin – the woody stuff that makes wood… wood. However, researchers have found bacteria that will break it down so it can be used for making ethanol biofuels. This means that all the leftovers after a tree has been logged for timber can be used for producing fuel. It also means that some trees that grow vigorously, such as willow, can be grown as a feedstock on land that isn’t suitable for producing food.
HVO Fuel in the UK
Now, let’s have a natter about HVO Fuel, a rising star in the UK’s green motoring scene. HVO, which stands for Hydrotreated Vegetable Oil, is a renewable diesel made from waste fats and oils. It’s a bit like the cool cousin of traditional biodiesel. The beauty of HVO is that it’s made without the complex chemical processes that some biofuels go through. Plus, it’s got a lower carbon footprint, making it a top choice for those wanting to drive cleaner on our British roads. With the UK’s commitment to reducing carbon emissions, HVO Fuel is gaining traction and might just become a common name at our local petrol stations. So, next time you’re having a chinwag about sustainable fuels, don’t forget to mention HVO!
Ethanol Biofuel vs HVO Fuel: Understanding the Differences
Ethanol biofuel and HVO (Hydrotreated Vegetable Oil) fuel are distinct in their composition, production processes, and applications. Here’s a brief comparison:
Source and Composition:
- Ethanol Biofuel: An alcohol-based fuel derived primarily from fermented sugars and starches of plants, most commonly corn and sugarcane.
- HVO Fuel: A renewable diesel produced from waste fats, residues, and vegetable oils through hydro treatment.
Production Process:
- Ethanol Biofuel: Involves fermentation of sugars and starches, followed by distillation to produce ethanol.
- HVO Fuel: Entails treating vegetable oils and fats with hydrogen in the presence of a catalyst, removing oxygen from the molecules, and converting them into paraffinic hydrocarbons.
Applications:
- Ethanol Biofuel: Typically blended with gasoline (petrol) and used in petrol engines. Common blends include E10 (10% ethanol, 90% gasoline) and E85 (85% ethanol, 15% gasoline).
- HVO Fuel: Can be used as a direct replacement for conventional diesel in diesel engines without modifications.
Environmental Impact:
- Ethanol Biofuel: Reduces greenhouse gas emissions compared to gasoline, but cultivating crops for ethanol can have environmental impacts, such as land use changes and water consumption.
- HVO Fuel: Boasts a significantly lower carbon footprint than conventional diesel and some biofuels, often made from waste and residues. It also offers better storage stability and cold properties compared to traditional biodiesel.
Understanding these differences can help in making informed decisions about sustainable fuel choices.
Other Waste Products
Last but not least, all food waste products can be used to make ethanol. This ranges from other types of waste from agriculture and the food production industry (such as the grain left over after brewing beer) to kitchen scraps and food waste from the restaurant trade. This isn’t being used commercially half as much as it should be – at least not yet. The idea of turning what we throw away into something we can use as fuel excites me, and I hope that more will be done with this in the future. After all, local councils already collect rubbish, so how hard would it be to set up a system for collecting food waste for use as biofuel? Watch this space!…