Introduction

Innovative treatment of the syngas produced by the pyrolytic process, or mixtures of biological gas, to obtain liquid methane with high calorific value, gaseous hydrogen, liquid carbon monoxide and carbon dioxide in a high degree of purity to be used in food sectors with high added value. Process and a plant that allow the production of methane, carbon monoxide, hydrogen and carbon dioxide, avoiding high costs and consumption and that do not cause serious damage to the environment. A further object is to obtain pure carbon dioxide from biogas and / or syngas at acceptable costs, to be used in the food sector (beverages, modified atmosphere packaging, etc.); this is possible because the separation process is based on two state transitions: frost (gas – solid) and sublimation (solid – gas). The process determines a drastic reduction of environmental impact since, by recovering CO2, carbon monoxide and hydrogen, it determines a reduction of the industrial processes currently used for the production of these gases.

Technical features

Furthermore, the process determines an optimization of production, as it would recover:

• CO2 with reduction of the industrial processes currently used for the production of this gas;
• Gaseous hydrogen that can be used to power fuel cells or internal combustion engines, as well as in the chemical industry which currently adopts production systems with a high environmental impact based on the cracking of petrochemical fractions;
• Liquid carbon monoxide with reduction of the discharges of this gas into the atmosphere.

These and other objectives are achieved by a process for treating a gas mixture consisting mainly of methane and carbon dioxide, where the process comprises the following steps: i) purification of the gas mixture; ii) cooling the purified gas mixture to obtain carbon dioxide in the solid state; iii) fractional separation of solid carbon dioxide, liquid carbon monoxide and gaseous hydrogen from methane, where the aforementioned phases occur substantially at atmospheric pressure; iv) sublimation of solid carbon dioxide.

Possible Applications

• Syngas industrial processes of pyrolysis and gasification, many of which are already clearly interested;
• Companies that use pure CO2 for food supply.

Advantages

• Currently patented cryogenic systems and scientific research results do not include applications on syngas. Considering the technical-scientific evolution that these systems are having, the invention proposed on the specific mixture of gas could greatly increase its commercialization and find application in the purification of other gaseous mixtures to obtain biofuels.