The present disclosure provides a method for in-situ synthesizing tungsten carbide powder. In this method, cemented carbide scrap is used as an electrode and the molten salt electrolysis process is used to in-situ synthesize tungsten carbide powder, where a bidirectional pulse is used in the molten salt electrolysis process. In the method provided by the present disclosure, by using the bidirectional pulse and using the cemented carbide scrap as electrode in the molten salt medium, when the tungsten carbide scrap is oxidized, tungsten is dissolved in ionic form, deposited after the direction of current changes, and reacted with the carbon anode sludge in situ to generate tungsten carbide powder. In the present disclosure, the carbon anode sludge is treated appropriately, the recycled product can be used in upmarket application, there is no need to apply complicated processes to process the tungsten powder into tungsten carbide, and the tungsten carbide nanopowder with high-performance can be recycled and prepared in a short process.

A system and method for treating flue gas of a boiler based on solar energy are provided, wherein a heat pump is connected with a heat collector via first and second valves, a carbon dioxide electrolysis chamber is connected with a flue gas pretreatment chamber and a power distribution control module for electrolyzing and reducing carbon dioxide, a gas phase separation chamber is connected with a gas phase outlet to separate a mixture, and discharge the separated gas phase products; a Fischer-Tropsch reaction chamber is connected with the gas phase separation chamber to pass the separated carbon monoxide and hydrogen into a flowing reaction cell, a liquid phase product separation chamber is connected with a liquid phase outlet to separate the liquid phase hydrocarbon fuel products, and separate and supplement electrolyte; an electrolyte cooling circulation chamber is connected with the liquid phase product separation chamber.

Systems for producing iron may include (a) a reactor configured to receive iron ore and a reducing gas, and from these produce iron; and (b) a carbon dioxide reduction electrolyzer configured to produce at least carbon monoxide and/or a hydrocarbon. Such systems may be configured to transport carbon dioxide produced by the reactor and/or produced by combustion of a gas generated by the reactor to a cathode side of the carbon dioxide reduction electrolyzer. Such systems may be further configured to transport at least a portion of the carbon monoxide and/or hydrocarbon produced by the carbon dioxide reduction electrolyzer to the reactor, where the carbon monoxide and/or hydrocarbon serves as at least a part of the reducing gas.

Systems for producing iron may include (a) a reactor configured to receive iron ore and a reducing gas, and from these produce iron; and (b) a carbon dioxide reduction electrolyzer configured to produce at least carbon monoxide and/or a hydrocarbon. Such systems may be configured to transport carbon dioxide produced by the reactor and/or produced by combustion of a gas generated by the reactor to a cathode side of the carbon dioxide reduction electrolyzer. Such systems may be further configured to transport at least a portion of the carbon monoxide and/or hydrocarbon produced by the carbon dioxide reduction electrolyzer to the reactor, where the carbon monoxide and/or hydrocarbon serves as at least a part of the reducing gas.

An electrochemical system and process are provided to convert an amount of chalcopyrite (CuFeS.sub.2) to a product including copper ions. In an electrochemical reactor, a potential is applied across an anode and a cathode to convert the chalcopyrite to an intermediate, chalcocite (Cu.sub.2S). The anode is covered to prevent contact with the intermediate, thus limiting subsequent conversion of the intermediate to covellite (CuS) in favor of conversion to a material more suited to chemical oxidation, cuprite (Cu.sub.2O). For example, the anode can be covered with one or more layers of filter paper. Upon application of an oxidizing agent, the cuprite is oxidized to produce a product including copper ions. The cathode and covered anode allow for efficient and inexpensive processing. The cost of this technique is comparable to industry standards, and moreover, has a much smaller environmental footprint than heat-based copper extraction.

An electrochemical system and process are provided to convert an amount of chalcopyrite (CuFeS.sub.2) to a product including copper ions. In an electrochemical reactor, a potential is applied across an anode and a cathode to convert the chalcopyrite to an intermediate, chalcocite (Cu.sub.2S). The anode is covered to prevent contact with the intermediate, thus limiting subsequent conversion of the intermediate to covellite (CuS) in favor of conversion to a material more suited to chemical oxidation, cuprite (Cu.sub.2O). For example, the anode can be covered with one or more layers of filter paper. Upon application of an oxidizing agent, the cuprite is oxidized to produce a product including copper ions. The cathode and covered anode allow for efficient and inexpensive processing. The cost of this technique is comparable to industry standards, and moreover, has a much smaller environmental footprint than heat-based copper extraction.

Three-dimensional (3D) hollow nanosphere electrocatalysts that convert CO.sub.2 into formate with high current density and Faradaic efficiency (FE). The SnO.sub.2 nanospheres were constructed from small, interconnected SnO.sub.2 nanocrystals. The size of the constituent SnO.sub.2 nanocrystals was controlled between 2-10 nm by varying the calcination temperature and observed a clear correlation between nanocrystal size and formate production. In situ Raman and time-dependent X-ray diffraction measurements confirmed that SnO.sub.2 nanocrystals were reduced to metallic Sn and resisted microparticle agglomeration during CO.sub.2 reduction. The nanosphere catalysts outperformed comparably sized, non-structured SnO.sub.2 nanoparticles and commercially-available SnO.sub.2 with a heterogeneous size distribution.

Three-dimensional (3D) hollow nanosphere electrocatalysts that convert CO.sub.2 into formate with high current density and Faradaic efficiency (FE). The SnO.sub.2 nanospheres were constructed from small, interconnected SnO.sub.2 nanocrystals. The size of the constituent SnO.sub.2 nanocrystals was controlled between 2-10 nm by varying the calcination temperature and observed a clear correlation between nanocrystal size and formate production. In situ Raman and time-dependent X-ray diffraction measurements confirmed that SnO.sub.2 nanocrystals were reduced to metallic Sn and resisted microparticle agglomeration during CO.sub.2 reduction. The nanosphere catalysts outperformed comparably sized, non-structured SnO.sub.2 nanoparticles and commercially-available SnO.sub.2 with a heterogeneous size distribution.

Embodiments relate to systems and methods for gas delivery for personal medical consumption having safety features. A hydrogen or oxygen gas delivery system herein can include electrolytic cores performing electrolysis-based reactions, and obtain free hydrogen (H2) gas for collection and delivery to a user. In aspects, the electrolytic core(s) can be scaled to produce a sufficient amount of hydrogen (H2) or oxygen (O2) gas so that the user can ingest that gas directly, without a need for storage. The system can be portable, and configured with a delivery tube for transmitting hydrogen or oxygen gas to a user. While safety risks are generally minimal, the system can be configured with sensors to detect fault conditions or hazards such as combustion or overpressure, which can only be caused by deliberate user action to expose gaseous products to flame or spark, and even then would not be likely to trigger violent combustion.

There is disclosed a process for synthesis of a C2-8 alkane comprising: (a) providing an electrolyte formulation comprising from about 3N to about 6N C2-C5 carboxylic acid and from about 2 M to about 4 M alkali C2-C5 carboxylate, wherein the C2-C5 carboxylate and carboxylic acid have the same carbon alkyl length into a pressure vessel having an electrode cell or stack; (b) adding electrical current to the electrode cell or stack; (c) pressurizing the pressure vessel; and (d) recovering a gas stream from the pressure vessel comprising a C2-8 alkane, CO.sub.2 and H.sub.2. Preferably, the carboxylic acid is acetic acid and the alkane is ethane.