## 3.3 Chemical conversion techniques

Definition

Chemical processes (e.g., hydrolysis, transesterification, hydrogenation, oxidation, pulping) are processes where chemical changes in the substrate occurs.

Example 1: Biodiesel production

Biodiesel refers to a vegetable oil - or animal fat-based diesel fuel consisting of long-chain alkyl (methyl, ethyl, or propyl) esters. Biodiesel is typically made by chemically reacting lipids (e.g., vegetable oil animal fat with an alcohol producing fatty acid esters). The triglyceride (oil or fat) is chemically changed as shown in the reaction equation.

The chemical process is shown in the videos below.

https://www.youtube.com/watch?v=ieuW8GUdTSM

https://www.youtube.com/watch?v=KtUWDzAsR-w

Biodiesel is meant to be used in standard diesel engines and is thus distinct from the vegetable and waste oils used to fuel converted diesel engines. Biodiesel can be used alone, or blended with petro diesel in any proportions. Blends of 20% biodiesel and lower can be used in diesel equipment with no, or only minor modifications.

The leading biodiesel producers worldwide in 2017 are US, Brazil and Germany with 6, 4.3 and 3.5 billion litres, respectively. The Netherlands produced 0.4 billion litres.