(57s) Optimizing the Catalytic Cycle for the Dehydration of Biobased Glycerol to Economically Viable C3 Compounds

Glycerol is a byproduct of biodiesel and has a limited amount of uses in industry. However, numerous economically viable C3 compounds such as acrolein, acrylic acid, 1,2-propanediol, 1,3-propanediol, propionaldehyde and hydroxyacetone can be produced from glycerol. If the biodiesel industry continues to grow at current rates there will be a surplus of glycerol. A catalytic process has been developed for dehydrating glycerol, but recently published research shows that the catalyst life is unquestionably too short for a typical industrial process. The catalyst used for this process has such a short life because solid carbon builds up and coats the catalyst carrier particles. The catalyst is effective over short time spans but since the life is so short it is not practical for an industrial process. There are a number of things that can be tried to extend this life span. The reaction with the current catalyst is very fast and produces a large quantity of solid carbon. This is the major problem that needs to be addressed. One possible approach is to utilize a less active catalyst that meets the conversion and yield objectives without completely reducing the products to solid carbon. It is hypothesized that this will increase the useable life of the catalyst and increase efficiency and productivity of the process due to minimizing costly catalyst changes. In order to increase the total carbon utilization, steam and hot air will be supplied to the carbon build up on the catalyst in order to produce syngas. If this is successful the syngas can be used as an energy source for the process. The experiment uses a packed bed reactor to house the catalyst and measure kinetics of the catalytic reaction. Integral reactor analysis will be used. It is subject to temperature variation, in order to get valid data the process has to run until it reaches steady state. At steady state the measurements of concentrations are read at the inlet and exit and used to calculate the conversion rate, yield rate and selectivity. Currently the selectivity and yield rates are insufficient for a long time period. By changing and comparing one variable at a time the limiting stage will be determined. The limiting stage is hypothesized to be either diffusion of glycerol to the catalytic site or the diffusion of product out of the pore and away from the site. In order to determine if this is the problem the catalytic carrier will be crushed into a powder, this should have a dramatic impact on the selectivity of the process. This research will be profitable to the biodiesel manufacturing industry in order to improve over all carbon utilization of the process. Also, due to a recent tax-credit for biodiesel manufacturing if the cost of manufacturing this renewable energy source can be decreased, it will be possible to decrease the impact of energy the global climate by the use of fossil fuels. The results of this research will result of farther development of domestic resources. This research is an important and viable step in enabling the conversion of the abundant by-product glycerol to marketable C3 compounds.