Fullerene production

Fullerenes is expect to is one of a first carbon nanomaterials to are wide employing for various commercial applications. However, none critical factor who have limited a development in such applications are high cost and limited availability under fullerenes. Many of this problem is due in the small-scaling, batch nature of fullerene production use carboning arcs. On contrast, the combustion method generate soot with an very high yield above fullerenes use a continuous and easily scalable process. We developed a combustion system who have to produce fullerenes in the tons for year scale. Use this system, a laminar premixed flat sooting low-pressure toluene/ oxygen flame who produced fullerenes were investigated. When the atomic C/O ratio were high, the fullerene content declined even though the fuel, pressure, and other combustion conditions was same. On the other leg, the fullerene content reminded constant when the cold gas velocity were increased from 0.78 m/s to 1.7 m/s.

Exercise 8. Put the following sentences into Active:

1. The effects of pulsed and continuous direct current electric fields on the reaction zones of premixed propane/air flames have been investigated by us.

2. 73

   Electric - field - induced modifications of flame geometry was reported by Chattock in 1889.

3. Flame extinction limits in premixed flame are also perturbed by DC.

4. Нeat transfer was caused by applied field.

5. Temperature distributions in flames were perturbed by continuous direct current field.

6. A good overview of this subject was provided by Bradely.

7. A minimal input is required by the observed effects.

8. Kinetic model was used by us to simulate microgravity.

9. Total soot yield was measured by us.

10. A new technique has been developed by us to reach high soot yield.

Text from a scientific article Journal: Progress in Energy and Combustion Science Flame configurations

Introduction

This review focuses on flames studies; the conditions in laboratory flames resemble those in combustors more closely than do the conditions in non-flame systems such as flow reactors, jet-stirred reactors and shock tubes. The most important difference, with respect to aromatics formation, is the breadth of the reactant pool. The non-flame systems usually contain a much smaller set of hydrocarbons; this makes them ideal for studying specific reaction pathways, but means that the relative importance of a group of competing pathways can differ from the case in flames.

Most laboratory flames can be classified as premixed or nonpremixed based on the mixing state of the reactants. In premixed flames, the fuel and oxidizer mix before the flame and approach the main reaction front together. In a nonpremixed flame, the fuel and oxidizer do not mix before the flame and they approach the main reaction front from opposite sides. Spark-ignition engines contain premixed flames because the fuel and air are perfectly mixed ( in principle) with a flame front propagating through the mixture. Diesel engines contain nonpremixed flames because the fuel and air are not well-mixed and regions of evaporating fuel are surrounded by air with a flame front at the interface between the fuel vapor and air. Roughly speaking, premixed flames are easier to study, but nonpremixed flames more closely resemble the combustors where soot forms. This article reviews studies in both configurations; Section 2 discusses premixed flames and Section 3 discusses nonpremixed flames.