(90d) The Non-Catalytic Decomposition of Lignin into Chemical and Fuel Intermediates

In this presentation we will present the results of a study performed to explore the non-catalytic decomposition of lignin into chemical intermediates.

Motivation . . .

Lignin is one of the most abundant biopolymers. On average, 24 wt% of a plant’s structure is composed of lignin. Lignin is produced as a low value by-product from wood pulping processes as well as from ligno-cellulosic biofuel facilities, such as those producing ethanol. Most produced lignin is burnt to recover its energy content. The quest to decompose lignin into fragments that could serve as the building blocks for useful fuel and chemical components has been an active area of research for many years. These efforts have primarily focused on catalytic pyrolytic or biochemical decomposition strategies. However, a commercially feasible approach has been elusive.

Presentation Contents – a Novel Approach to Lignin Decomposition

This presentation will describe a novel, high temperature, high pressure continuous reaction scheme designed and built to study lignin decomposition. A dilute slurry of lignin entrained in a basic water solution was pressurized to near super-critical conditions and heated to its decomposition temperature in a continuous tubular reactor. The reactor outlet stream was cooled against room temperature water and the four resulting phases (gas, polar liquid, non-polar liquid, and solid) were collected and analyzed with a variety of methods. When these initial results are compared to recently published catalytic decomposition results, this novel approach appears to be attractive. A combination of low residence time with appropriate reaction temperature and pressure result in the cleavage of ether bonds and the production of phenolic hydroxyl groups and various organic acids (e.g. vanillic and homovanillic acid) while minimizing the formation of char.