Systems and methods for processing waste to generate energy and green hydrogen

Abstract

Systems and methods for generating green hydrogen from raw materials (e.g., biological waste) are investigated. The raw materials are at least partially dehydrated to produce a dry intermediate and recovered water. The dry intermediate is thermally decomposed to produce synthesis gas and char. The recovered water is electrolyzed to produce oxygen and green hydrogen.

Claims

[Claim 1] A method for generating green hydrogen and purified water, The process involves at least partially dehydrating the raw materials to produce a dried intermediate and recovered water, Using a dehumidifier, (a) Receiving moist, high-temperature air from the drying of the raw materials, and (b) generating a dry, high-temperature airflow from the moist, high-temperature air, wherein the dry, high-temperature airflow is used to dry the raw material. To do, The method involves condensing water from the aforementioned humid, high-temperature air using a condenser, wherein the condensed water is purified water. The process involves thermally decomposing the aforementioned dry intermediate to produce synthesis gas and char, wherein the thermal decomposition step is carried out within a temperature range and residence time that decomposes compounds of perfluoroalkyl substances and polyfluoroalkyl substances (PFAS), the temperature range being 871°C to 982°C (1600°F to 1800°F), and the residence time being 10 to 20 minutes. The recovered water is electrolyzed to produce oxygen and green hydrogen, Methods that include... [Claim 2] The method according to claim 1, wherein the raw materials include biological waste. [Claim 3] The method according to claim 2, wherein the biological waste comprises at least one of urban wastewater and landfill leachate. [Claim 4] The method according to claim 1, wherein the raw material contains 60% to 85% moisture. [Claim 5] The method according to claim 1, wherein the dried intermediate contains 15% to 25% moisture. [Claim 6] The method according to claim 1, further comprising supplying at least a portion of the oxygen to a container containing the raw materials. [Claim 7] The method according to claim 1, further comprising generating electricity using at least a portion of the synthesis gas. [Claim 8] The method according to claim 7, further comprising burning the synthesis gas to generate an exhaust flow and using a turbine that works in cooperation with a generator to generate electricity from the exhaust flow. [Claim 9] The method according to claim 8, further comprising using the heat from the exhaust flow as a heat source for dehydrating the raw material. [Claim 10] The method according to claim 7, further comprising burning the synthesis gas using a dry low-emission (DLE) combustor. [Claim 11] The method according to claim 1, further comprising electrolyzing the recovered water using electricity derived from the combustion of the synthesis gas. [Claim 12] The method according to claim 11, further comprising using at least electricity not derived from the combustion of the synthesis gas to assist in the electrolysis of the recovered water. [Claim 13] A system that generates green hydrogen from biological waste, A dryer configured to dry the biological waste using a dry, high-temperature airflow and to produce a moist, high-temperature airflow and dried biological waste, The dryer is further configured to generate a dry, high-temperature airflow and condensed water from the moist, high-temperature airflow. A condenser configured to condense water obtained from the aforementioned humid, high-temperature airflow, wherein the condensed water includes purified water. An electrolytic device configured to produce oxygen and green hydrogen by electrolyzing the condensed water, A pyrolysis apparatus configured to pyrolyze the aforementioned dried biological waste to produce synthesis gas and char, wherein the pyrolysis apparatus is configured to pyrolyze the aforementioned dried biological waste at 871°C to 982°C (1600°F to 1800°F), and the residence time is 10 to 20 minutes. A cogeneration facility configured to generate electricity using the aforementioned synthesis gas, A system equipped with these features. [Claim 14] The system according to claim 13, wherein the dryer includes a belt dryer configured to dry the biological waste to a moisture content of 15% to 25%. [Claim 15] The system according to claim 13, further comprising a storage tank having an aeration floor configured to mix a given amount of the biological waste with oxygen produced by the electrolytic device. [Claim 16] The system according to claim 13, further comprising a line for transferring waste heat from the pyrolysis apparatus to the dryer. [Claim 17] The system according to claim 13, wherein the cogeneration equipment comprises a dry low-emission (DLE) combustor configured to burn the synthesis gas. [Claim 18] The system according to claim 17, further comprising a turbine configured to receive combustion gas from the combustor, and a line for transferring waste heat from the turbine to the dryer.

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