The rapidly increasing prices of petroleum fuels and potential shortages, have created a need for renewable fuels derived from organic waste products. The objective of this research project is to produce advanced multipurpose, continuous microwave biofuelslchemical reactors to utilise waste vegetable oils. The heat transfer efficiency of the reactor was studied using pure vegetable oils to establish the reactor design, operating temperatures and controls necessary to produce First Generation biodiesel by advanced microwave technology. Water modelling was used to scale up the reactors from 200 W to 1.2 kW and then subsequently to 2 kW. Once the initial continuous reactor was optimised, the work was repeated using various grades of waste cooking oils provided by Longma Clean Energy Ltd. In order to achieve the required conversion to give 96.5% methyl esters, these oils needed larger quantities of both catalyst and methanol to reduce the viscosity of the crude oil. The system was then modified to carry out microwave assisted methanol extraction of free fatty acids, with the addition of a decanter to allow continuous phase separation. This process produced no glycerol, was energy efficient and the free fatty acids that were removed, were recovered in the methanol distillation unit. In the future, the waste frictional heat from the diesel engine could be used to grow algae, the waste heat from the exhaust gases could be used to heat the distillation unit and the carbon dioxide could be biofixated by microalgae. An industrial prototype 1.2 kW microwave de-acidification unit has now been built at the Longma Clean Energy site at Hereford. There is a surplus of poor quality biodiesel glycerol that is currently regarded as a waste product. The novel continuous microwave unit which was developed from the biodiesel reactor has been used to acetyl ate the glycerol with acetone at below 50°C to produce acetals for use as fuel additives. An atmospheric/vacuum fractional distillation column will be required to recover the methanol or acetone and to distil the acetal from the unreacted glycerol, which is then recycled. The technology developed can utilise any waste cooking oils, acidic seed oils or fats as biofuels for combined heat and power generation or to convert them to biodiesel fuels. This research work is the basis of an integrated, green, low carbon, microwave based refinery. 2
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:582852 |
| Date | January 2012 |
| Creators | Bennett, Samuel |
| Publisher | Liverpool John Moores University |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
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