TECHNICAL SERVICES BULLETIN, October 2001
(2 of 4)

PRODUCTION OF BIODIESEL FROM MULTIPLE FEEDSTOCKS AND PROPERTIES OF BIODIESELS AND BIODIESEL /DIESEL BLENDS
John A Kinast
Gas Technology Institute

Summary: Soy biodiesel is predominantly used in the United States, while canola biodiesel is dominant in Europe. The high price of biodiesel (over double the price of diesel) is in large part due to the high price of the feedstock. However, biodiesel can be made from other feedstocks, including beef tallow, pork lard, and yellow grease. This project sought to understand the impact of the different feedstocks be generating biodiesel from each feedstock though one series of tests to quantify the differences between them.

The production of methyl esters identified a number of conclusions.

• Biodiesel is easier to produce and cleaner with equivalent amounts of processing when starting with clean vegetable oil (e.g., soy and canola). The tallow, lard and yellow grease biodiesels need additional processing at the end of transesterification to achieve acceptable biodiesel properties, and would benefit from processing before transesterification to reduce or eliminate components that may interfere, as for the high free fatty acid yellow grease.
• Additional investigation should be considered that would focus on methods of economically handling free fatty acids and other components, at lease to reduce their interference, and ideally, contribute to the production of methyl esters.
• Adequate testing is required during and after the processing to know the state of the fuel. Without it, the producer cannot ensure that “fuel grade” methyl esters are produced, instead of “commercial grade”.

The properties testing of the biodiesels confirmed that the known advantages and disadvantages of soy and canola biodiesels are the same as the biodiesels based on the other feedstocks, and that the changes in properties expected from the feedstock variations occur.

• The test results show that there are problems in operating at lower temperatures (cloud point, cold filter plugging point, and pour point), and that the minimum temperatures at which biodiesels are usable increase as they move from vegetable to animal sources, due to the greater degree of saturation. Yellow grease, although originally vegetable oils, display intermediate temperatures. Additives to reduce cloud/plugging/pour point problems would help the adoption of biodiesels in areas with low ambient temperatures (much of the United States for the tallow and lard biodiesels).
• Viscosities show the same trends as temperatures, with the lard and tallow biodiesels higher than the soy and canola biodiesels. Because of the effect that high viscosities can have on injector spray performance, this property should be monitored in biodiesel production.
• The biodiesels have high boiling points, flash points, and extremely low vapor pressure, as well as an inability to smoke under the smoke point test. These results indicate a high level of safety for handling biodiesels.

The specifications used to identify methyl esters that are acceptable as biodiesel were reviewed in light of the properties testing. The biodeisel specifications do not need any additions from the test suite conducted in this project. The tests would contribute additional information about the composition and properties, but the tests in the specifications adequately identify whether the quality of the fuel is acceptable.

The biodiesel specification and the ASTM D 975 diesel specification can be partially applied to B20, with problems when limiting values differ significantly between the two.

Biodiesel is mixed with diesel to bring much of the beneficial characteristics to diesel equipment, while reducing the overall cost of the fuel. Because biodiesel is usually used blended, the focus was to determine the characteristics of biodiesels from different feedstocks in varying concentrations with diesel when tested on a consistent basis. It was expected that some properties would vary in a non-intuitive manner, e.g., not varying linearly with respect to blend fraction.

The results collected add data to concentration ranges that have previously been overlooked in the study of the potential of biodiesel blends. It also adds information concerning feedstocks that have been considered only superficially.

The properties tested were those that would most affect operation of diesels, and consisted of: viscosity, pour point, cloud point, cold filter plugging point, Cetane nuber, scuffing load BOCLE (lubricity), and oxidation stability. Cetane number did not exhibit any oxidation stability show a predominantly linear relation between biodiesel fraction and insolubles produced, moving toward the higher levels of the biodiesels. However, two biodiesels showed peaks with 35% biodiesel that were significantly higher than pure biodiesel.

Of particular interest for people considering use of biodiesels in other than B20 or pure applications is the shifts in temperature for various properties tested. The biodiesel blends exhibited a viscosity depression at low concentrations. Conversely, most biodiesels significantly increased pour point, cloud point, and cold filter plugging point at low concentrations (<10-20%), then proceeded more linearly above that. Care should be taken in handling and use due to the temperature increases that occurred for pour point, cloud point, and cold filter plugging point.

The effect on lubricity cited by advocated of biodiesel was verified by the test results. Significant lubricity increases occurs with concentrations at 3% or less of the biodiesels, seeming to confirm the concept that biodiesel additives can improve operation of diesels and temperature increases occur. In particular, further study may be warranted to improve the processing of the beef tallow and pork lard, with a goal of reducing cost while enhancing the characteristics of the methyl esters that improve lubricity.

FPRF Comments: This Report is a 50 page bound document. It will be provided to all full members of FPRF upon request and others of interest for a binding charge of $50.00.

EVALUATION OF MEAT AND BONE MEAL FED TO HYBRID STRIPED BASS
Dr. Paul Brown
Purdue University

Industry Summary

Introduction: If we want to eat fish in the future, we must grow them. Commercial harvest from the oceans of the world has not increased significantly since 1989 and is unlikely to exceed the 80 mmt currently harvested. According to the United Nations Food and Agriculture Organization, just to keep pace with population growth, we need to produce 40 mmt of new aquaculture production by 2035. If per capita consumption of fish and shellfish increases by 1% per year, than new production must be over 100 mmt in the same time period. In 1995, global swine production was 83 mmt and global chicken production was 46 mmt. Thus, it appears that significant new industries are poised for rapid growth in the 21st century. Increases in animal production of this magnitude increase demand for high-quality feedstuffs. Fish require comparatively high levels of crude protein in diets; thus, the protein feedstuffs are critical for realization of this new growth.

The hybrid striped bass is one of the new aquacultural production industries in the US and one of the most rapidly growing. Further, production is located across the country, not centered in any particular region. However, dietary formulations are not standardized and significant opportunities exist for evaluation of new feedstuffs and realizing incorporation into production diets. In this study, we will build upon our previous research with this new hybrid and continue development of diets specifically for the hybrid striped bass.

Detailed nutritional research with the hybrid striped bass began in the late 1980’s. To date, nutritional requirements for lysine, arginine, methionine, choline, and phosphorus have been quantified. Further, estimates of the remaining essential amino acids are available and have been found appropriate. Given several of the critical nutritional requirements for this hybrid, practical diets were developed for meaningful evaluations of protein feedstuffs in practical diets fed to this hybrid. To date, only soy products have been evaluated.

Objectives: Evaluate meat and bone meal in diets fed to hybrid striped bass by incorporating the ingredient in graded levels into a practical diet.

Summary: Mean consumption of diets containing meat and bone meal was higher than consumption of the control diet containing no meat and bone meal and weight gain was also higher in all treatments containing meat and bone meal compared to the control. Feed conversion ratio was lower in all but one treatment. Meat and bone meal exerted no significant effects on lipid accumulation in the body cavity or liver. Additionally, fillet composition was not affected by met and bone meal in the diet. Apparent crude protein digestibility and apparent phosphorus and amino acid availabilities were lower in fish fed the highest level of meat and bone meal (45% of diet) compared to fish fed all other diets, but there were no differences in nutrient availability in fish fed 15, 20, 25, 30, 35 or 40% of the diet as meat and bone meal can be used as the primary source of crude protein and essential amino acids in diets fed to hybrid striped bass. Using the highest level of incorporation, changes in dietary formulation could reduce feed prices by 20% if feed manufacturers used meat and bone meal.

Scientific Abstract: We fed juvenile hybrid striped bass one of eight diets to evaluate meat and bone meal as a source of crude protein and essential amino acids. Diets contained either 0, 15, 20, 25, 30, 35, 40 or 45% meat and bone meal substituted for an isonitrogenous amount of soybean meal and fish meal. All diets were fed for a seven week growth trial, which was followed by a 2-week digestibility trial. Mean consumption, weight gain and feed conversion ratio were not significantly affected by addition of meat and bone meal into diets. Intraperitoneal and liver lipid concentrations were not significantly affected by meat and bone meal. Fillet proximate composition was not significantly different among treatments. Apparent crude protein, phosphorus and amino acid availabilities were generally lower in fish fed the highest level of meat and bone meal, but those values were not significantly different in other dietary treatments. Based on these data, it appears meat and bone meal can be used as the primary source of crude protein and essential amino acids in practical growth diets for hybrid striped bass.

< previous   next >

BACK TO TECHNICAL SERVICES BULLETINS INDEX