Development of the HYGAS Process for Converting Coal to Synthetic Pipeline Gas
Authors: Lee B.S. 
Published: December 2007

A process for converting coal to synthetic pipeline-quality gas is in the final stage of development. A large pilot plant with a daily capacity of 80 tons of coal feed and 1.5 MMcf of gas product is now in operation. Three methods of generating hydrogen from coal char are being developed and will be tested with the HYGAS process, with the goal of establishing commercial operation by 1980.

Introduction

The development of the HYGAS process at the Institute of Gas Technology (IGT) has been a continuous effort since 1946. The need for pipeline-quality gas from coal to supplement pipeline-quality gas from coal to supplement a projected shortage of natural gas was long forecast by IGT and others as being inevitable in the face of a continuing 5 to 6 percent annual increase in demand for natural gas. Despite this, even recently researchers had to defend the need for coal gasification. However, in the last 2 years, the projected shortage etched an indelible mark on the consciousness of both the public and private sectors when the annual discovery rate of gas fell far short of our past additions to reserves. The "energy crunch" for natural gas is now being realized by all - so much so that the development of coal gasification processes no longer needs justification, but only processes no longer needs justification, but only immediate commercialization.

Unfortunately, an industry for converting pipeline gas from coal cannot be established at will. To comprehend the sheer magnitude of such an industry we must realize that just to supply by coal gasification the incremental annual demand of about 1 Tcf/year would require an investment of about $2 billion and the development of more than 1 billion tons of coal deposit for an annual production of 50 million tons of coal. With these factors in mind, we shall discuss the status of HYGAS process development.

Chronology

Work on the HYGAS process began in 1946 and continued under the sole sponsorship of the American Gas Association (AGA) until 1964. During this period much work was done on the fundamentals of reaction kinetics, process yields, and the incorporation of several key process innovations. Experiments went from bench-scale batch studies to small continuous units at high temperatures and pressures that could handle throughputs of about 10 pressures that could handle throughputs of about 10 lb of coal feed per hour. In 1964 the U.S. Dept. of the Interior, of Office of Coal Research (OCR), joined AGA as co-sponsors in a 3-year program that ended with a preliminary design for a large HYGAS pilot plant. During this period, effort was pilot plant. During this period, effort was concentrated on the testing of different types of coal from the U.S. and on defining suitable operating conditions for each type of coal. Most of the work was done in units having, a throughput up to 100 lb of coal feed per hour. In 1967 the contract with OCR was amended to cover the engineering, construction, and operation of the HYGAS pilot plant. Out of this phase of the program will come the necessary scale-up phase of the program will come the necessary scale-up data for a demonstration plant. During, the construction phase, OCR provided the bulk of the funding. In 1971, phase, OCR provided the bulk of the funding. In 1971, the federal government and the gas industry started a joint program, administered by OCR and AGA, to accelerate the development of coal gasification through the demonstration plant stage. Funding is two-thirds by government and one-third by industry.

Process Features Process Features There are two key features in the HYGAS process that should be clearly understood.

JPT

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