skip to primary navigationskip to content
 

Biodiesel

Pilot plantBiodiesel is a sustainable, cleaner burning alternative fuel to crude-oil derived diesel. Researchers at the Department of Chemical Engineering, Cambridge University have developed a continuous pilot process, consisting of a reactor and various downstream separation steps, to produce biodiesel of a saleable quality. The process uses the novel Oscillatory Flow Reactor [OFR], an intensified plug flow reactor ideally suited to relatively long, two-phase reactions, such as the biodiesel reaction.

Operation of the new 30 litre/hour pilot plant started in October 2004 and following a number of minor modifications, an experimental programme has now started. The first objective is to look at the effect of residence time on conversion and product quality whilst at the same time investigating the performance of the separation/purification train. The feedstock for all the initial trials has been new commercial cooking oil, largely rapeseed oil.

The initial work has been carried out at a reactor temperature of 60oC and a pressure of 1 barg. The methanol ratio has been the literature standard of 0.2 litres per litre of feed oil with a catalyst concentration equivalent (as sodium methoxide) to 3g of NaOH per litre of oil.

The number of runs to date has been dictated largely by the time needed to carry out the analysis, a typical one day run produces about 30 samples which can take over a week to analyse in full.

Results so far are encouraging with conversions (as measured by the remaining tri-glyceride content) of almost 99% with residence times of 30 minutes and 99.5% at 40 minutes. Separation/purification has also worked well with methanol contents below 0.5% and flash points greater than 150oC. Final glycerol content has generally been below 0.02%. The density is 880 kg/m3 and the viscosity at 40oC is 4.2 mPas. The product is thus very close to meeting EU Specification EN14241.

The photo shows the biodiesel rig in operation, 19 November 2004, with Bob Skelton.

RSS Feed Latest news

Scientific heirloom awarded to Dr Owens

Mar 13, 2019

Dr Róisín Owens recognised at the Engineering & Physical Sciences Suffrage Science Awards at the Royal Society on International Women’s Day 2019.

International Women's Day celebration at CEB

Mar 11, 2019

Department members rallied around to celebrate International Women's Day with a specially designed cake.

Andrew Fellowship awarded to Dr Zheng

Mar 06, 2019

Dr Qingyuan Zheng awarded the Andrew Fellowship by the IChemE

View all news

Upcoming events

Machine learning and AI in (bio)chemical engineering

Jul 08, 2019

Department of Chemical Engineering and Biotechnology, Philippa Fawcett Drive, Cambridge, CB3 0AS

Stokes200 Symposium

Sep 15, 2019

Pembroke College, Cambridge

VPF8 Viscoplastic Fluids: from Theory to Application 2019

Sep 16, 2019

Jesus College, Cambridge

Upcoming events