John W. Flock

Catalysis of the Rochow Direct Process

Abstract The synthesis of dimethyldichlorosilane by the “Direct Process” is at the heart of the silicone industry. The Direct Process has been the object of intensive research and development over the past 40 years, yet there are aspects of the reaction that remain in an elementary state of understanding. The goal of this work was the discovery of previously unknown variables, including trace elements, which affect product distribution and rate. Fluidized and stirred bed reactors were used. Trace quantities of tin were found to affect the Direct Process profoundly, and the effects of tin and zinc were synergistic. A catalyst system consisting of copper, zinc, and tin was discovered which yielded 90% dimethyldichlorosilane with nearly complete silicon utilization. This is a major improvement over the best previously reported performance.

Nuclear process heat—application to coal gasification

Abstract The high temperature gas cooled reactor has achieved peak coolant temperatures from 775 to 950°C, depending on the core design. These temperatures are sufficiently high to consider the HTR as a source of heat for several large industrial processes. In this article the application is to a coal gasification process which produces a mixture of carbon monoxide and hydrogen as the key product. The gasifier system itself is coupled to the HTR via a catalyzed fluidized bed coal gasifier operating at 700°C and producing methane. The feed to this gasifier is a mixture of carbon monoxide, hydrogen and steam with the stoichiometry chosen to effect an overall athermal reaction so that no heat is directly transferred into the gasifier. Its hydrogen supply is generated by steam reforming the methane produced using the direct HTR heat. This indirect system has advantages in terms of its final product, indirect heat transfer and ultimately in the savings of approximately 40% of the coal which would otherwise have been assumed in an all-coal process producing the same final product.

Nuclear Process heat—application to fuels and chemical production

Abstract Synthesis gas, a mixture of CO and H 2 , produced from coal and a HTR nuclear source can be an economic feedstock for synthetic fuel and chemicals production. Such chemicals as hydrogen, ammonia, methanol, steel, can be readily produced from synthesis gas and other raw feedstocks by standard chemical engineering practice. Direct coal liquefaction is accomplished by adding H 2 to a pressurized coal slurry or solution. The use of the HTR to provide both the synthesis gas (using its high temperature capability) and steam or electricity for chemical process application (using its steam bottoming cycle capability) gives substantial conservation advantages in the use of coal compared to the non-nuclear equivalent processes. The desirability of efficiently using both the high and low temperature sources of the HTR requires a coupling between two or more chemical processes and the HTR (in a ‘Chemplex’) if a match is to be made between the high temperature and steam cycles of the HTR and the needs of the chemical processes.