Brown Grease Research Articles

A PILOT PLANT TO PRODUCE BIODIESEL FROM HIGH FREE FATTY ACID FEEDSTOCKS

Biodiesel is an alternative diesel fuel consisting of the alkyl monoesters of fatty acids from vegetable oils or animalfats. Currently, most biodiesel is made from soybean oil, methanol, and an alkaline catalyst. However, there are large amountsof fats and oils that are unsuitable for human consumption that could be converted to biodiesel at lower cost. The problemwith processing these waste oils is that they often contain large amounts of free fatty acids that cannot be converted to biodieselusing an alkaline catalyst. These free fatty acids react with the alkaline catalyst to produce soaps that inhibit the separationof the biodiesel, glycerin, and wash water. Previous research has developed a process for pretreating these high free fatty acidfeedstocks using acid catalysts, which do not form soaps. The objective of this study was to construct a pilot plant to producebiodiesel from a wide variety of feedstocks including those with high free fatty acids. A 190 L batch pilot plant has been builtthat can process high free fatty acid feedstocks using an acidcatalyzed pretreatment followed by an alkalinecatalyzedtransesterification. Case studies of pilot plantscale production of biodiesel from soybean oil, yellow grease with 9% free fattyacids, and brown grease with 40% free fatty acids are presented. The effect of varying the reaction parameters is discussed,and the separation and washing processes are described. Estimates of the fuel cost using different feedstocks are alsoprovided.

BIODIESEL PRODUCTION FROM OILS AND FATS WITH HIGH FREE FATTY ACIDS

Biodiesel is an alternative fuel for diesel engines consisting of the alkyl monoesters of fatty acids from vegetableoils or animal fats. Most of the biodiesel that is currently made uses soybean oil, methanol, and an alkaline catalyst. The highvalue of soybean oil as a food product makes production of a costeffective fuel very challenging. However, there are largeamounts of lowcost oils and fats such as restaurant waste and animal fats that could be converted to biodiesel. The problemwith processing these low cost oils and fats is that they often contain large amounts of free fatty acids (FFA) that cannot beconverted to biodiesel using an alkaline catalyst. In this study, a technique is described to reduce the free fatty acids contentof these feedstocks using an acidcatalyzed pretreatment to esterify the free fatty acids before transesterifying the triglycerideswith an alkaline catalyst to complete the reaction. Initial process development was performed with synthetic mixturescontaining 20% and 40% free fatty acids, prepared using palmitic acid. Process parameters such as the molar ratio of alcohol,type of alcohol, acid catalyst amount, reaction time, and free fatty acids level were investigated to determine the best strategyfor converting the free fatty acids to usable esters. The work showed that the acid level of the high free fatty acids feedstockscould be reduced to less than 1% with a 2step pretreatment reaction. The reaction mixture was allowed to settle betweensteps so that the watercontaining alcohol phase could be removed. The 2step pretreatment reaction was demonstrated withactual feedstocks, including yellow grease with 12% free fatty acids and brown grease with 33% free fatty acids. After reducingthe acid levels of these feedstocks to less than 1%, the transesterification reaction was completed with an alkaline catalystto produce fuelgrade biodiesel.

Dried Hermetia Illucens Larvae Meal as a Supplement for Swine

A digestion trial and a palatability trial were conducted to evaluate dried, ground soldier fly (Hermetia illucens) larvae as a dietary supplement for swine. After processing, the larvae, which were collected from cattle feces and urine slurry, contained 42% crude protein, 3 5% ether extract and 5% calcium. Two diets were formulated to contain 20% crude protein and 13% ether extract using either the larvae meal or soybean meal plus stabilized brown grease. These diets were fed to six barrow pigs in a triplicated 2 × 2 latin square design digestion trial. Apparent digestibilities of dry matter, nitrogen, ether extract, crude fiber, ash, NFE, calcium and phosphorus for the larvae meal diet were 77.5, 76.0, 83.5, 53.8, 45.2, 84.7, 38.9 and 23.0, respectively. Corresponding values for the soybean meal diet were 85.3, 77.2, 73.0, 49.2, 61.6, 91.3, 39.3 and 51.3, with values for dry matter, nitrogen, ash and NFE being greater (P<.05) than for the larvae meal diet. Nitrogen balance averaged 8.13 g per day for the larvae meal diet and 9.33 g per day for the soybean meal diet. When given a choice of three diets, pigs did not, as indicated by intake, discriminate against a diet containing larvae meal. Consumption of the larvae meal diet was greater (P<.05) than that of a soybean meal diet containing no added fat.

Influence of High Levels of Plant and Animal Fats in Calf Starters on Growth, Feed Consumption, and Palatability

Summary In a growth experiment with seven calves per starter, the addition of 10% brown grease, 10% hydrogenated cottonseed oil, or 5% of each to calf starters markedly reduced consumption and weight gain. The addition of 10% of each of the fats further reduced weight gains and starter consumption. The simple and partial correlations between starter consumption and weight gains were 0.84 and 0.85, which indicates that a major portion of the reduction in growth was associated with reduced starter intake. In a cafeteria study, each of nine calves significantly preferred the control starter. However, one calf demonstrated a similar decisive preference for the starter with 10% added brown grease. In another cafeteria study with 11 calves, 1% brown grease did not significantly affect palatability of a calf starter.

Taste Panel Evaluation of the Effect of Added Fat on the Flavor of Chicken Meat

ABSTRACT THE ready availability of fats for feeding purposes led many poultry nutritionists into the study of the utilization of high levels of fats in poultry rations with particular attention to feed efficiency and growth rates. The final criterion of a finished broiler, the flavor of the bird, was generally ignored in these experiments. Very few data have been reported on the effect of added dietary fat on the flavor of chicken meat. The few reports published were favorable to use of fat. Aitken et al. (1954) using 10 percent beef tallow in 22 or 25 percent protein diets reported that 10-week-old male broilers, as shown by a consumer’s preference test of 45 individuals, did not differ in flavor from the control birds. Siedler et al. (1955) fed the fatty acids of choice white grease as 3 percent of the diet, and choice white grease, yellow grease, brown grease, prime tallow, . . .

Protein and Energy Levels for Turkey Starting Diets

ABSTRACT THE relationship of protein to energy and fiber and its effect on the growth rate of chicks has been of interest for many years. Robertson et al. (1948) observes satisfactory growth of Leghorn chicks fed a diet containing 800 Calories of productive energy per pound. A similar energy level (850 Calories) was subsequently reported by Panda and Combs (1950) to be required by New Hampshire chicks for rapid growth. Stabilized white grease did not affect the growth of New Hampshire chicks when fed at levels of 2, 4, and 8% of the diet, even though Calories derived from fat were observed to be efficiently utilized at the 2 and 4% levels (Seidler and Schweigert, 1953). White, yellow and brown grease may efficiently be utilized by the chick when fed at the 3% level, whereas a reduction in caloric efficiency has been noted when the same substances were fed at the . . .