TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The gasification is optionally preceded by the process of pyrolysis of the residues of at least one renewable natural raw material in the absence of oxygen. The residues of at least one renewable natural raw material: are residues from agricultural crops, urban or industrial residues, or residues originating from fishing, animal breeding or mining activities, provided that they can be subjected to gasification; have a high content of components among sugars, starch, lignocellulosic components, oils, fats or other organic materials; and originate from sugarcane, corn or sorghum, such as sugarcane bagasse and straw, corn straw and cobs, and sorghum straw. The gasification reaction takes place at 700-1500 degrees C and pressures of 1-25 bar. The pyrolysis process takes place at 100-700 degrees C and pressures of 1-10 bar absolute. The transformation of the methanol into olefins takes place at 250-800 degrees C and pressure of 10-100kPa. The amount of produced olefins corresponds to a global carbon yield in relation to the methanol of 65-90% or more. The olefin is used a raw material source from a non-natural (fossil) origin, such as naphtha, natural gas, coal, recycled plastic and combustion gas from thermoelectrical power generation plants. The reduction of the carbon dioxide with: hydrogen takes place at 300-800 degrees C and at pressures 1-100 bar; and organic materials takes place at 550-1100 degrees C and pressures of 4-150 bar. The ethanol is dehydrated in order to obtain ethylene. The transformation of methanol step generates streams with characteristics similar to those of the natural gas, the liquefied petroleum gas and the gasoline, as additional by products. The fermentation step is used the yeast Saccharomyces cerevisiae. Preferred Process: The process is integrated with a method of processing of renewable natural agricultural raw material. The residue generated in the method of processing of renewable natural agricultural raw material is directed to the pyrolysis process or the gasification reaction. The processing method comprises the fermentation of the sugar or the starch, provided that the latter is previously hydrolyzed, in the renewable natural agricultural raw material, resulting in the production of ethanol and carbon dioxide. The must originated from the fermentation step is subjected to a process of distillation for the production of ethanol. The carbon dioxide generated in the fermentation is reduced to carbon monoxide by means of a reaction with hydrogen or with organic materials containing carbon, oxygen and hydrogen, generating a complementary amount of synthesis gas. The hydrogen originates from the water electrolysis reaction. The water generated as a by product in the production of olefins from methanol and in the process of dehydration of the ethanol can be used to extract the sugarcane juice, to adjust the concentration of the juice for fermentation or in the electrolysis of the water for generating hydrogen, which is useful to reduce the carbon dioxide, and for generating oxygen, which is employed in the gasification reaction. In the method, some streams of higher temperature generated in the process provide the necessary heat to reduce the residual humidity of the sugarcane bagasse and straw, the leaves, the culm and the cob of the corn plant, as well as of other biomasses with high moisture content, to the levels required for the gasification process, or to preheat the charge in the pyrolysis and gasification reactors, the charge of methanol and/or dimethyl ether or the charge of ethanol, fed into the dehydration reactors. The higher temperature streams comprise the streams leaving the gasification reactor and those leaving the step of formation of olefins from methanol. EXAMPLE - A sugarcane bagasse (70%) was burned in boilers at a pressure of 65 bar to supply the electrical and thermal energy required by the processes of crushing of the sugarcane. The sugarcane juice was subjected to a conventional process of filtration, washing of the filtercake and pH adjustment. The juice was then fed into fermentation vats in the form of batches fed in the presence of inoculated Saccharomyces cerevisiae. After distillation, the fermented must yielded hydrated ethanol (62.2 tons). The hydrated ethanol, were fed to the reactors 135 tons of steam required by the adiabatic process. The mixture of hydrated ethanol and steam was preheated in kilns using the heat present in the output stream from the gasifiers, in addition to the burning of the liquefied petroleum gas obtained as a by product from the formation of propylene. The excess bagasse and straw corresponded to a total 178 tons with 37% average moisture content. The two residues derived from the production of ethanol were initially subjected to partial drying in vessels. After drying, the mixture of bagasse and straw with 15% residual moisture content was heated to 150 degrees C in the absence of air. The pyrolysis vapors thus obtained were then fed to a gasification reactor together with a small amount of oxygen required to maintain at 1200 degrees C. The hot stream of synthesis gas generated at the outlet of the reactor was used to preheat part of the mixture of ethanol and steam fed in the dehydration reactors. The carbon dioxide formed in the gasification process was reduced to carbon monoxide with the addition of hydrogen into the reactor to give a methanol. The methanol was converted to dimethyl ether, and was fed to a reactor system, transform the carbon dioxide obtained in the fermentation into additional synthesis gas by means of a reduction reaction to give a propylene.