A method for treating an offgas produced in the processing of a renewable feedstock, includes hydrotreating a renewable feedstock to produce an effluent having a hydrotreated liquid and a vapour phase. The effluent vapour phase contains hydrogen, carbon dioxide, hydrogen sulphide and carbon monoxide. The effluent is separated into a liquid stream and an offgas streams. The offgas stream, containing carbon dioxide and hydrogen sulphide is directed to abiological desulfurization unit where a majority of the hydrogen sulphide is converted to elemental sulphur and a CO2-rich gas stream is produced.

The invention relates to a process for aftertreatment of gas streams in which unwanted components are present in an amount that varies irregularly in a periodic manner or over time and/or in a varying concentration, by means of an absorption or gas scrubbing process. For this purpose, during the entry of the desorption peak into the gas scrubbing apparatus, the amount of scrubbing medium is increased proceeding from a normal value during a first phase and, after the end of the desorption peak, the amount of scrubbing medium is returned back to the normal value during a second phase, wherein the laden scrubbing media are collected in different intermediate vessels during the two phases, mixed and released as a mixture to a downstream scrubbing medium regeneration apparatus.

A process is provided for making a polymer comprising providing a mixture of at least one furandicarboxylic acid, at least one diol, and at least one C2-C3 dicarboxlic acid, ester derivatives of C2-C3 dicarboxylic acid, hydroxy fatty acid or ester derivative of a hydroxy fatty acid; adding a catalyst and processing said mixture at reaction conditions until a polymer product is produced. The polymer consists of random units based upon the starting materials that are used.

Provided are apparatus and systems for performing a swing adsorption process. This swing adsorption process may involve passing an input feed stream through two swing adsorption systems as a purge stream to remove contaminants, such as water, from the respective adsorbent bed units. The wet purge product stream is passed to a solvent based gas treating system, which forms a wet hydrocarbon rich stream and a wet acid gas stream. Then, the wet hydrocarbon rich stream and the wet acid gas stream are passed through one of the respective swing adsorption systems to remove some of the moisture from the respective wet streams.

Acid gas compounds are removed from a process gas such as, for example, syngas or natural gas, by flowing a feed gas into a desulfurization unit to remove a substantial fraction of sulfur compounds from the feed gas and flowing the resulting desulfurized gas into a CO.sub.2 removal unit to remove a substantial fraction of CO.sub.2 from the desulfurized gas.

The present invention relates generally to the field of emission control equipment for boilers, heaters, kilns, or other flue gas-, or combustion gas-, generating devices (e.g., those located at power plants, processing plants, etc.) and, in particular to a new and useful method and apparatus for: (i) reducing the levels of one or more gas phase selenium compounds and/or one or more other RCRA metals, or RCRA metal compounds (regardless of whether such other RCRA metals or RCRA metal compounds are in the gas phase or some other phase); (ii) capturing, sequestering and/or controlling one or more gas phase selenium compound and/or one or more other RCRA metals, or RCRA metal compounds (regardless of whether such other RCRA metals or RCRA metal compounds are in the gas phase or some other phase) in a flue gas stream and/or in one or more pieces of emission control technology; and/or (iii) capturing, sequestering and/or controlling one or more gas phase selenium compound and/or one or more other RCRA metals, or RCRA metal compounds (regardless of whether such other RCRA metals or RCRA metal compounds are in the gas phase or some other phase) in a flue gas stream prior to desulfurization and/or in one or more pieces of emission control technology prior to one or more desulfurization units.

Provided are apparatus and systems for performing a swing adsorption process. This swing adsorption process may involve passing an input feed stream through two swing adsorption systems as a purge stream to remove contaminants, such as water, from the respective adsorbent bed units. The wet purge product stream is passed to a solvent based gas treating system, which forms a wet hydrocarbon rich stream and a wet acid gas stream. Then, the wet hydrocarbon rich stream and the wet acid gas stream are passed through one of the respective swing adsorption systems to remove some of the moisture from the respective wet streams.

The invention provides a process to purify a gas stream by using an adsorbent bed and a secondary device to remove heavy hydrocarbons with a recycle stream then sent first to a vessel containing an amine solvent to remove acid gases including carbon dioxide and hydrogen sulfide and then in most embodiments of the invention sending the treated gas stream to a dehydration unit such as an adsorbent bed or to a triethylene glycol absorbent to remove water. The invention further provides improved integration of the process streams to allow for smaller amine solvent and dehydration units as compared to the prior art.

Acid gas compounds are removed from a process gas such as, for example, syngas or natural gas, by flowing a feed gas into a desulfurization unit to remove a substantial fraction of sulfur compounds from the feed gas and flowing the resulting desulfurized gas into a CO.sub.2 removal unit to remove a substantial fraction of CO.sub.2 from the desulfurized gas.

Systems and methods are provided for using a multi-stage capture process for capture of CO.sub.2 from air. A first or initial sorption process is used to sorb CO.sub.2 from air. After sorption from the air is complete, the desorption step of the initial stage is used to form a secondary CO.sub.2-containing stream that is passed into one or more additional sorption stages. This secondary CO.sub.2-containing stream can be at a concentration of roughly 1.0 vol % or more. Sorption of CO.sub.2 from the secondary CO.sub.2-containing stream is performed using a different contacting method, such as a contacting method that is higher efficiency. The second or later CO.sub.2 sorption stage can produce a CO.sub.2-containing output stream with a CO.sub.2 concentration of 80 vol % or more, or 90 vol % or more, or 95 vol % or more. This high purity output stream can then be sequestered and/or used for further processing.