**5. Sourcing of UCO for production of FAME**

The global population and consumption of vegetable oils have a direct relationship. The increase in population has triggered the consumption of vegetable oil that gives rise to massive volumes of UCO. The largest percentage of these vegetable oils is used in households, restaurants, and fast-food outlets for cooking and frying. **Table 5** shows the estimated amount of UCO collected by some countries. Canada is reported to generate between 0.120 and 0.135 million tons of UCO per year [42, 69], while the United States of America produced 0.6 million tons of yellow grease in 2011. The United Kingdom and the European Union countries generate ∼0.7 million tons to 1.0 million tons and 0.2 million tons of UCO per year, respectively [45, 70].

*A Comparative Evaluation of Biodiesel and Used Cooking Oil as Feedstock for HDRD… DOI: http://dx.doi.org/10.5772/intechopen.104393*


#### **Table 5.**

*Annual collection of UCOs in some countries.*

In South Africa 0.6 million tons of UCO are collected per year, while more than an estimated 0.2 million tons of UCO is produced but not collected from households, bakeries, takeaway outlets, and restaurants per year [44, 70], which contributes to soil and water contamination, sewage blockages, and damage to aquatic life [71]. China, Malaysia, and Japan generated 0.6 million tons, 0.5 million tons, and 0.6 million tons of UCO, respectively, annually. It is reported that more than 60% UCO generated globally is indiscriminately disposed of [24].

UCO is produced when vegetable oils sourced from palm, soybean, sunflower, cottonseed, olive, palm kernel, and rapeseed or animal fats like butter, fish oil, and tallow, are used for cooking or frying food [72]. With feedstock accounting for between 80% and 85% of the production cost of biodiesel, the use of UCO can result in a substantial reduction in production costs, thereby significantly reducing the cost of biodiesel fuel. This makes biodiesel more viable as a feedstock for green diesel production as a substitute fuel for internal combustion engines, particularly unmodified CI engines. The focus of this research work has been on the conversion of biodiesel product into HDRD via the hydrogenation technique.
