M. M. Lobnitz’s scientific contributions

A process design is discussed which produces consumer grade unleaded gasoline from high sulfur, agglomerating coal. The major advantage of this gasoline synthesis route over other coal conversion approaches is that only barely detectable amounts of polynuclear aromatic compounds are present in either the process or product streams, substantially reducing the potential threat to the health and safety of workers and local communities. Another advantage is that most of the feedstock is converted to gasoline; a single, readily marketable commodity. One notable environmental innovation is an acid gas removal unit capable of removing carbon dioxide and hydrogen sulfide while minimizing release of carbon monoxide and volatile organic compounds. Another innovation is a rail-based solid waste handling system that automatically differentiates between three differnt solid byproduct trains utilizing the same transport corridor, thus eliminating potential disposal errors as it diminishes the land area disturbed during transport activities. Because this process involves only three major conversion steps, product yields are high and waste product types are fewer in number, minimizing areas requiring implementation of pollution control and simplifying disposal system design and operation.

Plant designs, performance data, cost estimates and bus-bar power costs were developed for four configurations of small-scale cogeneration plants using lignite as fuel. The configurations evaluated consisted of lignite gasification combined with phosphoric acid fuel cells, lignite gasification with a combustion turbine generator, a direct-fired atmospheric fluidized bed boiler plant, and a direct-fired conventional boiler plant. The plants were sized on the basis of the same lignite feed of 740 TPD and production of 100,000 lbs per hr of process steam for industrial use. Results in terms of net electrical power output and bus-bar power costs in constant 1983 dollars were: for the gasification/fuel cell plant, 32.5MW and $0.068 kWh; for the gasification/combustion turbine plant, 20.1MW and$0.081 per kWh; for the fluidized bed boiler plant, 20.6MW and $0.074 per kWh; and for the conventional direct-fired boiler plant, 21.2MW and$0.066 per kWh.

This paper examines the fate of non-criteria pollutants in five basic coal conversion processes: low Btu gasification, gasification with oxygen, high Btu gasification, indirect liquefaction, and direct liquefaction. Based on each pollutant's physical and chemical properties, the fate of each pollutant is traced, through each process step and relative quantities of final pollutant loads are compared both with respect to other coal conversion processes and to conventional coal combustion. Tradeoffs in the two approaches to non-criteria pollutant control are evaluated with regard to relative ambient concentrations, the mode of release and location of maximum impact.

An analysis was made of unique technical issues to be considered in siting solar-thermal energy systems in small communities. Four systems are described: central receiver, parabolic trough, parabolic dish, hemispherical bowl. The difference between central receiver systems and distributed receiver systems are indicated with reference to current applications. Finally, a technical siting comparison is made of the four systems defined, including overall efficiency, end use, land requirements, failure rates, safety considerations, energy backup systems and capital costs.