Exploratory coprocessing research. Quarterly report Number 10, December 1, 1990--February 28, 1991

The objectives of this project are to: (1) study the scope of hydrothermal pretreatment of coal on subsequent conversion, (2) identify and study the chemical or physical causes of this effect, and (3) attempt to elucidate the chemistry responsible for any coal-resid synergisms. This project is divided into three tasks. This quarter the authors concentrated on Tasks 1 and 2 as described below. Task 1: scope of hydrothermal pretreatment. The report contains a preprint submitted to the upcoming ACS meeting in Atlanta describing efforts to evaluate the aqueous pretreatment effect. The results showed that the aqueous pretreatment techniques at 350 C were most effective for the Wyodak coal, with the lignite showing a slight benefit, and the Illinois {number_sign}6 coal showing essentially no benefit. Task 2: chemistry of pretreatment. This quarter the authors investigated the chemistry of pretreatment using labeled water. In particular, catechol that was treated with and without kaolin and H{sub 2}{sup 18}O and was found to have labeled oxygen incorporation. They are aware of no precedents for such a reaction, and suspect that the exchange comes about from an intermediate step where the catechol dimerizes and can lose water in a reversible step. They further suspect that the role of kaolin for the polymerization reaction is to absorb or remove the water in some way so that the reaction is no longer reversible. However, the presence of water reverses the effect. Clays are well known to promote dehydration reactions, so such an explanation is reasonable