Next Generation Biofuel Crops

Next Generation Biofuel Crops

Using recycled cooking oil for fuel has yet to become a widespread commercial success, nor is their enough fryer oil out there to fuel even a fraction of the vehicles in this country. But in theory, almost any plant material can be converted to biofuel, including waste products like sawdust and corn stalks (currently ethanol is made mainly from corn kernels, not stalks). Researchers are working on biofuels made from species that grow prolifically on marginal land and require little or no irrigation or fertilizer. Some are even looking to harvest invasive species as feedstock for biofuel plants.

Unfortunately, a variety of practical and technological hurdles have prevented large-scale production of these environmentally-friendly biofuels thus far. But as the science continues to advance, these challenges are likely to be overcome. Here are a few of the most promising biofuels currently under development.

Hemp

Hemp fiber has a long history of use, and the seeds are not only nutritional, but have a remarkably high oil content. Hemp, essentially a weed, thrives on poor land and requires minimal inputs, yet produces nearly four times as much oil per acre as soybeans, which is currently the only crop grown on a large scale for biodiesel in the U.S. The biggest challenge to using hemp as a biofuel is that so little of it is grown. Some countries, such as France and Canada, produce it on a limited scale, but in the U.S. “industrial” hemp has been illegal for farmers to grow since the 1930s—even though it does not contain enough THC to get anyone high.

Switchgrass

While corn-based ethanol contains scarcely as much energy as is required to produce it, fuel made from switchgrass, a native prairie plant found in the Great Plains region, contains more than 5 times as much energy than it takes to grow it and refine it into ethanol. Rather than tilling up native prairie to plant corn, switchgrass-based biofuel could encourage replanting of the prairie. The problem is that “cellulosic” biofuel technology, which is needed to convert grasses and woody plant materials to ethanol, has not progressed as rapidly as the technology used to convert grain to fuel. It exists, but it’s not quite cost-effective yet. Still, several million gallons of cellulosic biofuel are now produced annually in the U.S., and it seems that it’s only a matter of time before we have the technology for switchgrass to replace corn as a feedstock for ethanol.

Carrizo Cane

Hundreds of thousands of acres in the southern U.S., from Florida to California, are infested with an exotic plant known as carrizo cane, or giant reed. This relative of bamboo grows 20 to 30 feet tall in a year’s time, producing more biomass per acre than almost any other plant on earth. It has been touted as an even better candidate for cellulosic ethanol production than switchgrass, and is already being used on a commercial scale in Europe, where it is a native species, for that purpose. It’s invasive tendencies provide little incentive to plant it elsewhere, however. There has been some effort to harvest the carrizo cane already growing in the U.S., which is found primarily along riverbanks and in wetlands, where it chokes out native plants. This approach sounds like a win-win, but has proved logistically infeasible thus far.

Jatropha

This tropical shrub is poisonous to people and livestock, but the seeds are 40 percent oil, which was historically used as lamp oil. Starting in mid-2000s, tens of thousands of acres of jatropha were planted for biofuel, mostly in India and Africa. The plant was known to thrive on marginal land, but rich soil and irrigation are needed for maximum oil production. Researchers are continuing to breed improved varieties, however, and several African countries continue to invest in it, envisioning this scrappy shrub as a key to their future fuel supply.

Algae

Algae produces up to 200 times more oil per acre than soy. These fast-growing aquatic organisms can be grown in salt water, municipal wastewater lagoons, or in shallow manmade basins in the desert where no other crops can survive. The U.S. Department of Energy, along with several of the world’s largest oil companies, have poured hundreds of millions of dollars into scaling up algae fuel production. A decade ago, industry promoters promised algae fuel would be as cheap as petroleum fuel by now— and that it would be widely available in gas stations. But quirks of the plant have made large-scale production cost-prohibitive, and many algae fuel start-ups have gone under in recent years. Others are still pursuing the dream. This summer, Exxon Mobil reported a technological breakthrough that promises to finally make algae fuel cost-effective—it does, however, involve genetically engineered strain of algae.

New reaction offers sustainable route to biodiesel

A new chemical reaction that converts waste glycerol from biodiesel production into methanol – a necessary reagent in biodiesel production – has been discovered unexpectedly by UK researchers. The work, which is still at a preliminary stage, could theoretically allow biodiesel to be produced entirely from renewable resources, cutting the need for fossil fuel based methanol.

In the transesterification process of biodiesel production, the carbon chain of a molecule of vegetable oil is broken into three. At each break, a hydrogen atom from methanol is substituted for the link to the adjacent carbon atom. The production of biodiesel, however, leads to the formation of large quantities of crude glycerol – around 10% of the mass of biodiesel created – but is generally uneconomical to refine. Researchers are seeking ways to convert this waste product into something useful, and some efforts have focused on the dehydration reaction to acrolein – used as a herbicide and polymer precursor. This reaction is usually acid-catalyzed, but researchers at Cardiff University considered that it could also be base-catalyzed and investigated this using magnesium oxide. Much to their surprise, they found that the main product was not acrolein but methanol.

                        The proposed mechanism for methanol formation from glycerol

As a result of these experiments, which included isotopic labelling of reactants, the researchers determined that the glycerol was being reduced back to methanol by carbon–carbon bond scission and reduction using water as a hydrogen source. They hypothesize that the reaction can take place by either of two mechanisms: the first begins with double dehydration to acrolein and the second proceeds via the ethylene glycol radical and hydroxyethanal. Further investigations showed that cerium dioxide was a more effective catalyst than magnesium oxide, achieving complete conversion with methanol selectivity of 60%. The work is still at an early stage but the researchers have closed the sustainability loop for the transesterification process of biodiesel.

The use of fuel additives to improve biodiesel quality characteristics

Modern fuel additives are very important both for improving fuel properties, as well as to increase engine longevity and improve technical characteristics. Effective characteristics of the engine also depend on the engine design, the materials and production technology of its components.

On the other hand, even the engines are being constantly improved during operation of a great number of extraneous factors such fuel, oil, coolant; various sealing elements reduce their economy. Engine parts and elements wear and rub themselves during chemical and thermal processes. Although the intervals between the vehicle services are becoming longer because of improved technologies, the engine still remains one of the key elements for service. So the lengthening of the engine durability is the main object of interest for users as well as for manufacturing or service organizations. For this reason the view that the application of additives in improving fuel properties is a way to solve a number of issues related to the motor operating characteristics improvement is becoming stronger.

In the recent year’s multifunctional additives which act systemically improving lubrication, cleaning, burning, corrosion and other properties are becoming more popular. These accessories appeal to consumers as they improve some fuel properties and have multiple effects. They accelerate the combustion in the cylinder of the engine as make fuel burn more smoothly.

Τhe biodiesel physical properties can be uplifted by using different additives including metal based additives, antioxidants and oxygenated additives, cold flow improver etc. into biodiesel to solve the problem of cold flow properties for their large number of usage in diesel engines. Some additives were used to improve the performance and reduce exhaust emissions from diesel engines.

The range of benefits accruing from fuel additives is very significant and includes:

- Protection of fuel tanks, pipe lines and other from massively expensive corrosion.

- Protection of fuel system equipment in the diesel engine from catastrophic premature wear.

- Reduced pumping costs and energy use in long-distance fuel pipelines.

- Reduced refinery processing needed to meet fuel cetane and specifications.

- Cold flow improvement in middle distillates, maximizing use of bio fuel.

- Stability improvement to prolong storage life of fuels throughout the operating theatre.

- Fuel saving from optimized vehicle performance and economy.

- Emission reduction from fuel system cleanliness and combustion optimization.

Biodiesel is non-explosive, nontoxic, non-flammable and biodegradable fuel which provides reduction of many detrimental exhaust emissions. It has no SO_X emission, particulate and soot and it can be reduced polycyclic aromatic hydrocarbons emissions.

However there are some disadvantages associated with the use of biodiesel fuels.

Some biodiesel fuel increases NO_X emission, which have rigorous environmental regulations and relatively poor low temperature flow properties compared to conventional diesel. Another demerit is the oxidation stability of biodiesel because of containing the double bond molecules in the free fatty acid. Fuels containing bio-components present special challenge in use, for which a range of additives provide valuable benefits. Aspect includes:

- Reduce oxidation stability.

- Potential for increased injector deposit formation.

- Corrosion in long term storage.

- Adverse effect on cold flow characteristics.

- Increased microbial contamination.

It is considered that fuel physical properties (density, viscosity and cooking area) do not change. However, their influence on engine performance and durability requires further studies.

The quality of biodiesel can be bettered by improving the technological processes, production, careful selection and processing of raw materials. However, their properties can also be improved by use of special additives which affect each characteristic or the entire set of them. Consequently, the composition of biodiesel and the use of additives directly affect such properties as viscosity, density, behavior at low temperatures, Volatility, and the cetane number. Popularity of complex (multifunctional) additives which act systemically improving lubrication, cleaning, burning, corrosion and other properties have been growing recently. Their influence on the properties of biodiesel and engine efficiency and durability requires further studies.

The advantage of biodiesel manufacturing by heterogeneous base catalyst

The manufacturing of biodiesel by heterogeneous catalysis has major economic benefits compared to the traditional homogeneous catalysis.

The main reason is the suppression of operations generating large amounts of waste water (except during feedstock pretreatment), namely the catalyst removal by acid/base neutralisations, washing of FAME and glycerol, as well as at methanol recovery by distillation of aqueous solutions.

There is no salt waste, and catalyst consumption drops dramatically.

In the homogeneous process the glycerol has maximum 85% purity after expensive separations, while the heterogeneous process delivers glycerol that is >98% pure, a valuable product.

In addition, the continuous operation is intrinsically more efficient than batchwise. Heterogeneous catalysis may be applied both to low and to high FFA oils. In the last case a preliminary esterification with methanol is necessary, which can be performed by employing solid acid catalyst, as e ion-exchange resins.

The small amounts of water  formed can be removed simply by adsorption. Higher FFA lipids, as animal fat and industrial greases, can be treated in a reactive distillation device.

EU biofuels blending economics turn towards ethanol from biodiesel

Increasing outright FAME 0 prices over the course of April and ethanol prices holding below Eur500/cu m have resulted in European blending interest turning from biodiesel to ethanol.

At the beginning of the year, biodiesel was highly favored over ethanol. Over the first quarter, the price of T2 ethanol averaged $288.24/cu m over Eurobob gasoline. By Thursday 28^th April evening, though, this premium had fallen to $172.98/cu m as Eurobob gasoline (The Argus Eurobob oxy assessment is used as a benchmark price in gasoline transactions throughout northwest Europe. Eurobob is an unfinished gasoline and the European swaps market shifted to price against this ethanol-ready blendstock in January 2010) increased substantially more than ethanol day-on-day.

In January and February, blenders were reducing their incorporation rates of ethanol as much as possible, in an attempt to wait out the higher premiums in the hope that ethanol prices would fall and gasoline would increase.

RED FAME 0 outright prices had been generally on a firming trajectory for the most of April, on the back bullishness in vegoils complex, which kept feedstock prices at strong levels.

Outright prices on RED FAME 0 averaged at around $766/mt during Q1 and $857/mt for April, whereas the comparable T2 ethanol prices were at $718/mt and $668/mt respectively. RED FAME 0 was last assessed at $863/mt Thursday, whilst T2 ethanol stood at around $688/mt.

Eurobob gasoline barges were assessed at $489.75/mt on Thursday at a discount of $10/mt to the front-month swap, up from $479.75/mt Wednesday, when the discount to the front-month swap was $5.75/mt.

Although the energy content of biodiesel is relatively higher than that of ethanol, the divergent price movements between the two biofuels has shifted blending economics in favor of ethanol.

"The logic is that people start using more cars as of now, and blenders should blend more ethanol given better blending economics," one source said, adding that the sustained premium of ethanol over Eurobob was "not good, but better. It would make sense to blend more now."

European gasoline demand is expected to strengthen on the back of the US summer driving season, which typically represents a seasonal peak of demand for the road fuel, and absorbs European arbitrage barrels.

The May USAC-UKC arbitrage swap -- which tracks the differential between US RBOB and Northwest European Eurobob forward values -- widened on Thursday leading to more support for the arbitrage from the Northwest Europe to the US Atlantic Coast. The swap rallied to break the 16 cents/gal mark, as a function of the more rapid fall in European cracks at a time of global oversupply, and an overall rebalancing of European values to open arbitrage outlets.

"It is getting heated as arb goes wider," said a trading source.

Improved price differentials between the two regions may be a catalyst for the opening of the spot market arbitrage.

Decarbonization of the EU transportation policy will only be successful if it places the right incentives for the production of advanced alternative fuels

According to a recent article in the Financial Times, the company responsible for waste water treatment in London spends 1 million pounds a month on fatberg removal. Fatbergs have been defined as “large conglomerations of fat, oil and grease” which accumulate in the sewer systems under our cities and eventually clog them.

Waste management companies throughout the EU have been increasingly reporting constant encounters with fatbergs over the past few years. Most of these companies are public or semi-public entities.

An extrapolation of the London figures gives a good indication of the amount of public money being spent in clearing fatbergs from urban sewers: dozens, if not hundreds of millions wasted every year.

Projected increases of urban population and changing eating patterns indicate that fatbergs are to become larger and more abundant.

For many years collectors of waste cooking oil, widely known as used cooking oil (UCO), have been providing a public service by ensuring the separate removal of used cooking oil from restaurants.

Private and public initiatives, mostly at municipal level, have been promoting collection of used cooking oil from households. Their work should be recognized and promoted by the public authorities.

The motto of the new EU paradigm the “Circular Economy” states that “waste is a resource”. Rightfully so. Used cooking oil is no exception, quite on the contrary, as it is the feedstock of one of the greenest existing alternative fuels, known as Used Cooking Oil Methyl Ester, or UCOME.

This alternative fuel has greenhouse gas savings of up to 90% when compared to fossil fuel. Being a waste, it does not compete with food or feed and produces no indirect land use change (ILUC) emissions. As such it is to be considered as a second generation or advanced biofuel.

The EU’s Energy and Climate energy Policy is at a crossroads following the COP 21 Agreement reached in Paris last December. In order to achieve its objectives (limiting global warming to well below 2°C and pursuing efforts to limit the temperature increase to 1.5°C) the EU will have to use all available sustainable tools to effectively reduce the carbon footprint of the EU economy.

Used cooking oil collection and its use for the production of alternative fuels necessarily have to play a role in this process.

The European Commission estimates that the EU transport sector produces nearly a fourth of the EU greenhouse gas savings emissions.

In order to tackle these figures, the Energy Union Strategy foresees a number of key legislative or policy instruments to be adopted within the next year, namely a Communication on the Decarbonization of the EU transport Sector, a Renewable Energy Directive for 2030, a Directive on the sustainability of bioenergy and a Communication on Waste to Energy.

This integrated approach to decarbonization of the EU transportation policy will only be successful if it places the right incentives for the production of second generation, advanced alternative fuels.

In this context, a specific recognition of used cooking oil-based biodiesel as a highly sustainable alternative fuel in the Communication on Decarbonizing the Transport Sector coupled with the introduction of right incentives for the production of used-cooking oil biodiesel in the upcoming Renewable Energy Directive for 2030, and the endorsement of used cooking oil collection practices in the Communication on Waste to Energy appear as the most suitable measures to reduce greenhouse gas emissions while liberating millions of euros currently being spent on waste management, literally eaten by the fatbergs silently growing beneath our feet.

Ways to reduce the high viscosity of Vegetable Oils

Different ways have been considered to reduce the high viscosity of vegetable oils:

1. Dilution of 25 parts of vegetable oil with 75 parts of diesel fuel.

2. Microemulsions with short chain alcohols such as ethanol or methanol.

3. Transesterification with ethanol or methanol, which produces biodiesel.

4. Pyrolysis and catalytic cracking, which produces alkanes, cycloalkanes, alkenes,

and alkylbenzenes.

1. Dilution of oils with solvents and microemulsions of vegetable oils lowers the viscosity, some engine performance problems, such as injector coking and more carbon deposits, etc. To dilute vegetable oils the addition of 4% ethanol increases the brake thermal efficiency, brake torque, and brake power, while decreasing brake specific fuel consumption. Since the boiling point of ethanol is less than those of vegetable oils the development of the combustion process may be assisted through unburned blend spray. The viscosity of oil can be lowered by blending with pure ethanol. 25 parts vegetable oil and 75 parts diesel have been blended as diesel fuel. This mixture is not suitable for long-term use in a direct injection engine.

2. Another way to reduce of the high viscosity of vegetable oils, microemulsions with immiscible liquids such as methanol, ethanol, and ionic or non-ionic amphiphiles. Short engine performances of both ionic and non-ionic microemulsions of ethanol in soybean oil were nearly as good as that of No. 2 diesel fuel.. All microemulsions with butanol, hexanol, and octanol met the maximum viscosity requirement for No. 2 diesel fuel. The 2-octanol is an effective amphiphile in the micellar solubilization of methanol in triolein and soybean oil. Lower viscosities and better spray patterns (more even) could be achieved with an increase of butanol. All microemulsions with butanol, hexanol, and octanol meet the maximum viscosity requirement for No. 2 diesel. The 2-octanol is an effective amphiphile in the micellar solubilization of methanol in triolein and soybean oil. Methanol is often used due to its economic advantage over ethanol.

3. Among all these alternatives, transesterification seems to be the best choice, as the physical characteristics of fatty acid esters (biodiesel) are very close to those of diesel fuel, and the process is relatively simple. In the esterification of an acid, an alcohol acts as a nucleophilic reagent; in hydrolysis of an ester, an alcohol is displaced by a nucleophilic reagent. Transesterified vegetable oils have proven to be a viable alternative diesel engine fuel with characteristics similar to those of diesel fuel. The transesterification reaction proceeds with a catalyst or any unused catalyst by using primary or secondary monohydric aliphatic alcohols having 1–8 carbon atoms as follows. Transesterification is catalyzed by a base (usually alkoxide ion) or acid (H2SO4 or dry HCl). The transesterification is an equilibrium reaction. To shift the equilibrium to the right, it is necessary to use a large excess of the alcohol or else to remove one of the products from the reaction mixture. Furthermore, the methyl or ethyl esters of fatty acids can be burned directly in unmodified diesel engines, with very low deposit formation. Although short-term tests using neat vegetable oil show promising results, longer tests lead to injector coking, more engine deposits, ring sticking, and thickening of the engine lubricant. These experiences lead to the use of modified vegetable oil as a fuel. Technical properties of biodiesel, such as the physical and chemical characteristics of methyl esters related are close to, such as physical and chemical characteristics of methyl esters related to its performance in compression ignition engines are close to petroleum diesel fuel. Compared with transesterification, the pyrolysis process has more advantages. The liquid fuel produced from pyrolysis has similar chemical components to conventional petroleum diesel fuel.

4. Pyrolysis utilizes biomass to produce a product that is used both as an energy source and a feedstock for chemical production. Compared with transesterification, the pyrolysis process has more advantages. The liquid fuel produced from pyrolysis has similar chemical components to conventional petroleum diesel fuel. Vegetable oils can be converted to a maximum of liquid and gaseous hydrocarbons by pyrolysis, decarboxylation, deoxygenation, and catalytic cracking processes.