Biodiesel Quality Affected by Sulfur Content Originated by Different Feedstocks and a Database for the Same; Final rept. for Aug 06-07 Dec

摘要

According to EPA regulations, the deadline for compliance with stringent limitations on the sulfur content of highway diesel fuel was 2006. EPA regulations set the same ultra-low sulfur standard for biodiesel as well. Generally, biodiesel contains lower sulfur than fossil diesel. However, due to the divisibility of feedstock origins, the sulfur content in biodiesel may be higher than 15 ppm. Sufficient information regarding sulfur content in biodiesel would be critical to biodiesel producers, distributors, and consumers and beneficial as a guideline in compliance with federal policy of ultra-low sulfur transportation fuels. To answer the questions regarding how the sulfur content in the feedstocks affects the biodiesel quality, this research studied biodiesel quality as affected by the sulfur content of different feedstocks. Sulfur contents in feedstocks, seed meals, oils/fats, and biodiesel made from different feedstocks were investigated according to ASTM standards. Results showed that the sulfur content varied greatly from one source to another. The highest level of sulfur in seed and meal was found in rapeseed and mustard seeds. The expeller pressed oils have very little sulfur. The sulfur is further reduced when the oils are processed into biodiesel Results of 16 oil/fat samples showed an even more significant reduction after converting to biodiesel. Six of those oils/fats, however, had a sulfur level greater than 15 ppm. Although four fuels of biodiesel made from those oils met the sulfur specification, corn oil and tallow did not.