US 5,104,419 AGranted

Solid waste refining and conversion to methanol

OwnerHarald F. Funkinventor

Life of this patent

Estimating the term…

Loading patent…

Abstract

A process for converting solid waste into a synthesis suitable for producing liquid fuel, comprising (a) partially oxidizing and combusting solid waste material in a closed combustion zone at a temperature of 800.degree.-1000.degree. C. and at a pressure below ambient to produce combustion gases by introducing into the combustion zone a gaseous oxidant comprising oxygen having a purity of at least 95% by volume and carbon dioxide in an oxygen to carbon dioxide ratio, by volume, of about 50:50, (b) conducting the combustion gases, oxygen and carbon dioxide through the solid waste material; (c) withdrawing a producer gas comprising the combustion gases and any unreacted oxygen and carbon dioxide; (d) removing particulate matter from the producer gas; (e) separating carbon dioxide from the producer gas and recycling a portion of the separated carbon dioxide to the combustion zone; (f) separating the less volatile, condensable components of the carbon dioxide-free producer gas, from the more volatile, non-condensable synthesis gas components thereof, and (g) compressing the producer gas at some time prior to the completion step (e). In a preferred embodiment, the more volatile components and at least a portion of the separated carbon dioxide from step (e) are admixed and the resulting admixed gas mixture is reacted to form methanol. Preferably, the less volatile components are converted by chemical reaction to hydrogen and the hydrogen is recycled into admixture with the producer gas at some time prior to the commencement of step (e).

Claims38

Dependent claims

A process for converting solid waste into a synthesis gas suitable for producing liquid fuel, which minimizes or eliminates adverse environmental effects resulting from the discharge of gaseous materials to the atmosphere, comprising the steps of:

(a) partially oxidizing and combusting solid waste material in a closed combustion zone at a temperature in the range 800.degree.-1000.degree. C. and at a pressure below ambient by introducing into said combustion zone a gaseous oxidant comprising oxygen having a purity of at least 95% by volume and carbon dioxide, said oxidant having an oxygen to carbon dioxide ration, by volume, in the range 60:40 to 40:60 for producing combustion gases;
(b) conducting said combustion gases, oxygen and carbon dioxide through and in intimate contact with said solid waste material;
(c) withdrawing from said closed combustion zone a producer gas comprising said combustion gases and any unreacted oxygen and carbon dioxide;
(d) removing particulate matter from said producer gas;
(e) separating carbon dioxide from said producer gas and recycling at least a portion of said separated carbon dioxide to said combustion zone for providing the carbon dioxide introduced into said zone;
(f) separating the less volatile, condensable components of said carbon dioxide-free producer gas, comprising methane and higher hydrocarbons, from the more volatile, non-condensable synthesis gas components thereof, comprising carbon monoxide and hydrogen;
and
(g) compressing said producer gas at some time prior to the commencement of step (e) wherein said less volatile components are separated from said more volatile components by cooling said carbon dioxide-free gases wherein said carbon dioxide gas is cooled by contacting said gas with relatively large surface area to volume ratio solids which are cooler than said gas, whereby said gas cools by transferring heat to said solids, said gas being sufficiently cooled by contact with said solids that the less volatile components of said gas condense or sublime on said solids.

5 more elements

(a) partially oxidizing and combusting solid waste material in a closed combustion zone at a temperature in the range 800.degree.-1000.degree. C. and at a pressure below ambient by introducing into said combustion zone a gaseous oxidant comprising oxygen having a purity of at least 95% by volume and carbon dioxide, said oxidant having an oxygen to carbon dioxide ration, by volume, in the range 60:40 to 40:60 for producing combustion gases;
(b) conducting said combustion gases, oxygen and carbon dioxide through and in intimate contact with said solid waste material;
(c) withdrawing from said closed combustion zone a producer gas comprising said combustion gases and any unreacted oxygen and carbon dioxide;
(d) removing particulate matter from said producer gas;
(e) separating carbon dioxide from said producer gas and recycling at least a portion of said separated carbon dioxide to said combustion zone for providing the carbon dioxide introduced into said zone;
(f) separating the less volatile, condensable components of said carbon dioxide-free producer gas, comprising methane and higher hydrocarbons, from the more volatile, non-condensable synthesis gas components thereof, comprising carbon monoxide and hydrogen;
and
(g) compressing said producer gas at some time prior to the commencement of step (e) wherein said less volatile components are separated from said more volatile components by cooling said carbon dioxide-free gases wherein said carbon dioxide gas is cooled by contacting said gas with relatively large surface area to volume ratio solids which are cooler than said gas, whereby said gas cools by transferring heat to said solids, said solids defining a packed tower through which compressed carbon dioxide-free gas is passed for separation into condensable and non-condensable components, said gas is sufficiently cooled by contact with said solids that the less volatile components of said gas condense or sublime on said solids, and said condensed or sublimed, less volatile components are recovered by partially evacuating said tower for revaporizing said components.

5 more elements

Dependencies are inferred from the claim text.