Taking our foot off the gas with biofuels
24 Aug 2020
Stepped up environmental KPIs and increasing fuel demand are key drivers in the biofuels sector, which is evolving as regions jockey to ensure feedstock markets for their growers. GEA technologies ensure processors get the most out of these precious resources, including next-generation feedstocks for advanced biofuel production.
According to the OECD-FAO Agricultural Outlook from 2019, future demand for biofuels will be shaped even more strongly by national and regional policies, as countries pursue their own strategies for moving away from fossil fuels while ensuring growers have markets for their feedstock commodities. The U.S. and the EU rank high in biofuel production, however, major future growth in this sector is expected to be driven from countries outside these regions.
We sat down with Barbara Harten, Application Manager, Renewables, andEckard Maedebach, Product Manager Distillation, both of GEA, to talk about this evolving industry and how GEA is supporting processors with efficient mechanical and thermal solutions.
What are biofuels and what are they made from?
BH:Biofuels are made in part or completely from plant-based material or animal fats. The fact that these “feedstocks” are regenerative, means they are generally categorized as renewable resources. Most biofuels are blended as a percentage into fossil fuel-based gasoline or diesel (fuel) to accommodate existing engines. Conventional or first-generation biofuels are made from fresh or edible feedstocks, including oils and fats, and have been in use for more than 30 years. Second-generation, or advanced biofuels are made from non-edible feedstocks, including animal fats, used cooking oils and sugar-containing waste; here the goal is to minimize the use of feedstocks that can be utilized in human nutrition.
Common biofuels include:
- bioethanol
- biodiesel
- biogas
- biobutanol
Bioethanol, which depends on the fermentation of plant-based sugars and starches, is a gasoline substitute. According to the OECD-FAO Agricultural Outlook from 2019, about 60 percent of bioethanol is produced from corn, 25 percent from sugar cane, 7 percent from molasses, 4 percent from wheat, and the remainder from other grains, cassava or sugar beets. Conversely, roughly 77 percent of biodiesel, a diesel substitute which relies on a chemical reaction between lipids (plant or animal) and alcohol, is based on vegetable oils: 30 percent soybean oil, 25 percent palm oil, 18 percent rapeseed (canola) oil, and about 22 percent from waste cooking oils.
Biogas is produced via the fermentation of organic matter in the absence of oxygen, known as anaerobic digestion. Paper, wood, some plastics, dried foliage, manure and municipal waste are all examples of potential organic matter used in this process. Biogas burns easily and without generating much pollution and can be used to produce green electricity. If compressed, it can be used to power vehicles as well. Biobutanol can be directly used as a substitute for gasoline without any alterations. It is derived from the fermentation of bacteria and algae; high production costs however remain a barrier to its more widespread use.
In addition to coming from renewable resources, what other benefits do biofuels have over fossil fuels?
EM:Biofuels emit less CO2 if a low production CO2 footprint is maintained from well to wheel and have energy densities close to fossil fuels. And depending on type, biofuels contain fewer or even no sulfur compounds. Because biofuels are made from renewable materials, they are often counted in targets for reducing GHG emissions and therefore subsidized more readily, contributing to their intensive use in the transport industry and growing use in the aviation and maritime industries. Biodiesel, considered a clean-burning diesel replacement, can be used as a blend in diesel engines without modification; with engine modifications, biodiesel can be used at 100 percent. Bioethanol as dehydrated ethanol (99.8 percent vol.) can be mixed as a percentage without engine modifications, normally up to 10 or 15 percent, whereas bioethanol as anhydrous alcohol (95-96 percent vol.) can substitute a percentage of 0-85 percent gasoline in flex-fuel engines, which are common in Brazil.
BH: As they grow, of course, plant-based feedstocks absorb carbon dioxide from the atmosphere. Another factor to consider are the byproducts or co-products that are created from biofuel production. For example, biodiesel production results in glycerol or glycerin, which can be used in fertilizers and in animal feed – and with further purification in food, pharmaceuticals and cosmetics. If based on rapeseed (canola), the biodiesel process produces rapeseed meal; and when soybeans are used, soybean meal is created; both contain high-quality minerals and protein and are therefore added to livestock, poultry and fish feed.
EM:Similarly, ethanol production based on corn and cereals creates tons of stillage, which can be used in animal feed, preferably as dried distiller’s grains with solubles (DDGS). Alternatively, the biomass can be used as a renewable fuel source, producing electrical power and heat for this process, or for conversion into biomethane for use as fuel.
Manufacturers and consumer alike are looking for ways to move away from mineral oil-based glycerine. Biodiesel production meets this demand, creating green glycerine as a co-product, which is then used to create the kinds of home and personal care products people demand today.” – Barbara Harten, Application Manager, Renewables, GEA
– Barbara Harten, Application Manager, Renewables, GEA
GEA has long-standing credentials when it comes to biofuel production and processing. What solutions does GEA offer producers in this industry?
EM: In terms of bioethanol production , GEA offers key technologies and solutions covering all key aspects of the core process, including: raw material milling and mashing, liquefaction, saccharification, fermentation, distillation, dehydration, as well as decanters , dryers and evaporators for separating and drying the DDGS, plus condensate recycle/polishing concepts for minimizing waste streams and saving process water. GEA competence has gone into the building of major bioethanol plants around the world, some reaching capacities of up to 500,000 liters per day in one train. Our solutions optimize energy consumption by reusing the thermal energy involved or making use of patented heat pump principles with mechanical vapor recompression.
BH:Ourbiodieselcapabilities include the conversion of oils and fats to biodiesel as well as pre-treatment to purify crude feedstocks. GEA also has solutions for soap splitting via separation, methanol recovery and water evaporation to isolate the glycerol for resale or reuse in plants.
GEA Separator RSE and RSI for degumming, neutralization and dewaxing of vegetable and animal oils and fats to ensure the production of high-grade oil for biodiesel production, including advanced biofuels like HVO.
Our pre-treatment process lines, which include our world-renowned GEA RSE and RSI Separators, support chemical and physical refining processes by:
- eliminating waxes, making biodiesel more stable at cold temps
- removing impurities to improve glycerin quality
- removing gums that cause fouling in the thermal glycerin process
- removing free fatty acids, reducing amount of matter organic non-glycerin
- eliminating phosphates in the wastewater, reducing disposal costs
The GEA decanter for stillage decantation in bioethanol production ensures a high percentage of dry matter (up to 35 percent), reducing drying costs while minimizing fouling. Stillage, when combined with yeast and then dried, creates DDGS, a co-product rich in protein which can be used in animal feed.
GEA holds a patent for the alcohol neutralization process used during pre-treatment prior to the biodiesel process. And we have another pending, which will reduce monoglycerides and the consumption of catalysts (<0.30 percent-wt. catalyst savings) in biodiesel production, reducing processing costs. Our portfolio and experience in both biodiesel and bioethanol production means we’re able to manage the installation of complete process lines for customers, liaising with third parties as required to ensureefficient and on-time commissioning.
There’s a lot of debate about food-grade feedstocks contributing to land-use changes and diverting resources from feeding a growing global population. How far is the industry in developing advanced biofuels and to what extent is GEA supporting in this area?
BH:The discussion is ongoing, and of course you need to consider the entire value chain, including inputs, when it comes to growing biofuels feedstocks, as well as transport, processing, etc. In terms of developing advanced biofuels from waste (human or animal) and plant dry matter, this has been scaled up successfully in several markets. In Finland, for example, which is a country with no gas or oil resources, wood-based products and forest biomass are used to produce sustainable advanced biofuels. The total energy share of advanced biofuels in road transport should reach 10 percent there by 2030. Likewise, they are using these advanced fuels to produce more sustainable plastics and adhesives which improves the environmental footprint of their packaging and construction materials.
At GEA we’ve seen an upswing in customers, particularly in the EU and the U.S., producing “renewable diesel” or HVOmade from animal fat and used cooking oil. HVO was introduced in 2005, when it was made exclusively from palm oil. Today, there is more focus on making HVO from feedstocks of relatively low quality, which then qualifies it as an advanced biofuel. Free of aromatics, oxygen and sulfur, HVO has high cetane numbers, resulting in reduced NOx emission, better storage stability and better cold flow properties, making it suitable for nearly all diesel engines.
HVO can be used as a pure fuel in fleet operations (e.g., city buses, mine vehicles) and is also approved for blending in aviation fuel. Having a commercial market to reuse these oils, includingindustrial and post-consumer, slaughterhouse and poultry fat, for example,is also beneficial as it means less ends up as pollution in our waters and networks, where it is also more difficult and expensive to manage.For processors, another major benefit of HVO is that it does not require any major modifications of existing refinery facilities.
GEA separators are highly sought after for the pretreatment of HVOs which is often necessary for metal reduction to reduce and/or prevent catalyst inactivation. We’re currently testing animal fats in these areas; the capabilities of these oils and fats; and looking at their efficiency for several global customers.
As a renewable fuel, biodiesel has a greatly reduced environmental footprint when compared to conventional diesel. Low sulfur content and the fact that it produces less particulate matter, has higher lubricity and is biodegradable, makes it a better option for the environment.” – Barbara Harten, Application Manager, Renewables, GEA
– Barbara Harten, Application Manager, Renewables, GEA
Will electric vehicles (EV) affect the production of biofuels?
EM:The uptake of EVs picked up tremendously in 2019; that said, they achieved only around 2 percent of the global transport mix. Because the size and capacity of EV batteries remains a stumbling block for heavy-duty, long-haul road vehicles, including refrigerated trucks, as well as marine vessels and airplanes, biofuel usage is increasing in these sectors, with more markets looking to use recycled biomass-rich materials.While keeping the cost of biofuels competitive with fossil fuels remains important, at least in the mid-term, markets with clear targets to reduce emissions will either continue or begin to subsidize producers until the industry reaches critical tipping points in supply and demand.
