Prince of Songkla University (PSU) in Thailand was granted a petty patent for a biodiesel test process using only a microwave oven as the main equipment, making it economical in terms of money and time (only 15 minutes for the result to come out).

The simple method will be made public, free of charge to interested people, communities and small-scale producers.

Assoc. Prof. Chakrit Thong-urai, Director of R&D Center for Alternative Energy from Palm Oil and Oil Crops, said that the process was called “A glyceride estimation testing process using microwave-assisted transesterification”. This is to remake a small amount of biodiesel in a short time using a domestic microwave oven as a test device.

Generally, there are various glyceride testing methods used to test the quality of biodiesel. However, the PSU method is an easy, fast and cheap. Previously, small-scale and medium-scale biodiesel producers usually tested the oil quality by looking at it and feeling it to see its clarity. These producers can also send it to the Petroleum Authority of Thailand or to Prince of Songkla University to be tested using a more complicated method but the expenses are high: 6,000 baht (US$185) for a test that takes 15 days. With the new PSU method, it takes only about 15 minutes and at a cost of only around 5 baht (US$0.15) for chemicals used in the process.

This test process is conducted by adding methanol solution and a catalyst to the biodiesel and then heating it in a microwave oven. The test is done in a funnel with measuring scales on it. If there is glyceride in the oil, its quality is not good because not all the mixture has been changed to biodiesel. This process takes not more than 15 minutes. However, the mixture, the heat and the time used for the test have to be precise and therefore consultation with an expert in the field is necessary, PSU says.

When beginning to use this process, a problem may occur because microwave ovens have different wattages and give out different levels of heat. The heating time and heat intensity have to be adjusted.