Ultrasonics Improve Biodiesel Process Efficiency
Hielscher ultrasonic mixing reactors improve your biodiesel production process. Ultrasonication produces higher transesterification conversion yields in less time. Ultrasonic mixing increases production capacity and reduces methanol and catalyst usage.
Efficient Biodiesel Processing
Today, making biodiesel is not just about making a renewable fuel. Biodiesel producers must produce a high-quality biodiesel with consistent characteristics, regardless of feedstock quality variations. “In the current environment, only the least-cost producers are able to produce fuel at positive margin.” (Bill Babler of First Capitol Risk Management).
Hielscher ultrasonic mixing technology offers you the best biodiesel processing efficiency when building a new biodiesel plant or when upgrading existing plants. Hielscher ultrasonic devices are tested and proven in worldwide installations to increase biodiesel yield and lower operational costs. This includes small 1 million-gallon-per-year entrepreneurs as well as 45 million-gallon-per-year industrial biodiesel plants.
Making biodiesel from oil, methanol (or ethanol) and a catalyst, is a simple chemical process called transesterification. However, the reaction kinetics of this process are problematic. The conventional transesterification of the triglycerides to fatty methyl esters (FAME) and glycerin is slow and not complete. During the conversion process not all fatty acid chains are turned into alkyl esters (biodiesel). This reduces your biodiesel yield and quality, significantly!
The use of conventional mechanical agitation systems results in a long conversion time and in an inferior biodiesel yield.
Oil and methanol are immiscible. For the chemical biodiesel reaction to occur, you need to form a methanol-in-oil emulsion. This requires ultrasonic emulsification equipment rather than conventional mechanical mixers or stirrers. Ultrasonic cavitational mixing is the most advanced means to form fine-size emulsions at large flow rates. Smaller methanol droplets make better biodiesel, increase reaction speed and require less excess methanol.
There is a direct link between methanol droplet size and biodiesel yield as well as conversion speed. This makes Hielscher ultrasonic reactors the most productive technology in the biodiesel industry. Ultrasonic mixing reactors produce more high quality biodiesel, faster.
The diagram below shows the volume percentage of separated glycerin. After two seconds sonication in a Hielscher ultrasonic reactor, you get more glycerin faster. For every single glycerin molecule you produce, you make three biodiesel molecules. This improves your process capacity and biodiesel production yield.
The installation of Hielscher ultrasonic reactors into your biodiesel process line reduces your operational costs, too. You can install Hielscher ultrasonic reactors in small biodiesel batch systems and in large continuous biodiesel plants. We will be glad to assist you with the best installation setup or with retrofitting ultrasonic reactors to your existing biodiesel process.
Excess methanol does not react during the biodiesel conversion process. An excess of methanol is added to boost the chemical reaction kinetics. The excess methanol has to be recovered after the biodiesel reaction process. Methanol recovery is very expensive, because it requires much heat and vacuum. Therefore, all excess methanol increases your processing costs. In many biodiesel plants, the excess methanol recovery system is the most expensive process step.
The use of Hielscher ultrasonic reactors reduces the required excess methanol by up to 50%. A stoichiometric ratio of 1:4 or 1:4.5 (oil : methanol) is sufficient for most feedstocks, when using Hielscher ultrasonic mixing.
Many small and mid-size biodiesel producers reduce their costs by switching to poorer quality feedstocks, such as animal fats, used cooking oils or waste vegetable oils. The ultrasonic process intensification improves the conversion results for any feedstock. This makes is easier to produce ASTM 6751 or EN 14212 compliant biodiesel from high FFA oil or high viscosity fat or grease.
Catalyst material costs represent a marginal fraction of the biodiesel production costs only. As with the excess methanol, the true costs result from recovery and inferior glycerin quality. Ultrasonic mixing in the biodiesel production process improves the methanol-in-oil emulsification and generates more and smaller methanol droplets. This leads to a better droplet size distribution and to a more efficient catalyst usage. In addition to that, the ultrasonic cavitation improves the chemical mass-transfer. As a consequence, you can save up to 50% catalyst when compared with shear mixers or stirrers.
Glycerin is a byproduct of biodiesel production. A higher conversion rate and a lower excess methanol usage lead to a much faster chemical conversion and to a sharper and faster separation of the glycerin. For the reasons described above, the glycerin contains less catalyst and less mono-glycerides. This reduces the glycerin refining costs.
- The Use of Ultrasonic Reactors in a Small Scale Continuous Biodiesel Process – Graham Towerton (2007)
- Biodiesel from Algae using Ultrasonication
- Sonocatalysis – Ultrasonically assisted catalysis
- Influence of Mass Transfer on the Production of Biodiesel
- Biodiesel Production Technology
- Biodiesel Analytical Methods
- ‘Foolproof’ Way to Make Biodiesel
- Technical Biodiesel Databases
- Biodiesel Emissions Database
- American Society of Agricultural and Biological Engineers
- Wikipedia: Biodiesel
Biodiesel is a green fuel. To be green, the energy required for growing, harvesting and processing biodiesel must be lower than the energy contained in the biodiesel. The installation of Hielscher ultrasonic mixing lowers the overall energy required for producing biodiesel. Hielscher ultrasonic devices have an outstanding energy efficiency in the conversion of electricity to ultrasonic mixing in the liquid. To produce 1000 gallon of biodiesel, Hielscher ultrasonic devices use approximately 7 kWh of electricity, only. This is much less than the energy consumption of shear mixers or hydro-dynamic mixers. This reduces the annual electricity bill of your biodiesel plant.
In general, the ultrasonically assisted biodiesel transesterification can run at lower process temperatures. This reduces the required heating energy.