A rotary kiln process for making calcium carbide

Abstract

A preliminary economic analysis has indicated that the making of acetylene, via a kiln calcium carbide process, can be cost competitive with ethylene if used to produce vinyl chloride monomer. The work presented here includes (1) the kinetics of carbide formation from reduction of lime, (2) the characterization of this carbide product, and (3) a process demonstration in a prototype bench-scale rotary kiln. From the study of the reduction chemistry, it was found that reduction rates of lime to carbide are fast, needing less than 30 min to achieve conversions of 50-80% (1740-1870 °C). An increase of carbon monoxide pressure in the surrounding atmosphere tends to inhibit the reaction.

Calcium Carbide: A Unique Reagent for Organic Synthesis and Nanotechnology

“…The production of calcium carbide by the carbothermal reduction of calcium oxide was first described in 1984 . The standard process was modified by using rotating furnaces, which provided partial heating by fuel combustion in a flow of oxygen . The reactor could also be completely heated, owing to the combustion of fuel in oxygen .…”

“…[63] The standard process was modified by using rotating furnaces, which providedp artial heating by fuel combustion in af low of oxygen. [64] The reactor could also be completelyh eated, owing to the combustion of fuel in oxygen. [65] The use of ad irect-current plasma-fluidized bed reactor allowed the temperaturea nd reactiont ime for the carbides ynthesis to be decreased.…”

Effect of potassium carbonate on catalytic synthesis of calcium carbide at moderate temperature

“…Previous studies [3,5] have shown that calcium carbide can be formed by heating the calcia-carbon mixture at 1973 K. In this study, carbothermal reduction was carried out at 1973 K using coke-lime mixtures with and without addition of potassium carbonate. XRD patterns of the raw material mixture and reduced samples are presented in Fig.…”

“…Calcium carbide is now produced by reacting lime and carbon in large electric furnace at about 2400 K. The energy consumption for a typical electric arc furnace is about 4 kWh/kg CaC 2 [1]. Several techniques, aiming at developing a more efficient process, have been studied for the production of calcium carbide using different furnace design through different heating mechanisms [2][3][4][5]. However, due to high energy cost and technical difficulties, neither of them has been applied in practice.…”

Calcium‐Based Sustainable Chemical Technologies for Total Carbon Recycling

“…As a result, it diminishes the costs of the product relative to the price of electrical energy. Minor changes in the protocol include optimization of various stages or modification of the reactor (e.g., introduction of a bench‐scale continuous rotary kiln reactor) . More profound changes involve an alternative source of energy.…”