The present invention utilizes mechanical vapor compression and/or thermal vapor compression integrating compression loops across multiple process stages. A sequential network of compressors is utilized to increase the pressure and condensing temperature of the vapors within each process stage, as intra-vapor flow, and branching between process stages, as inter-vapor flow. Because the vapors available are shared among and between compressor stages, the number of compressors can be reduced, improving economics. Balancing vapor mass flow through incremental compressor stages which traverse multiple process stages by splitting vapors between compressor stages enables the overall vapor-compression system to be tailored to individual process energy requirements and to accommodate dynamic fluctuations in process conditions.

The present invention utilizes mechanical vapor compression and/or thermal vapor compression integrating compression loops across multiple process stages. A sequential network of compressors is utilized to increase the pressure and condensing temperature of the vapors within each process stage, as intra-vapor flow, and branching between process stages, as inter-vapor flow. Because the vapors available are shared among and between compressor stages, the number of compressors can be reduced, improving economics. Balancing vapor mass flow through incremental compressor stages which traverse multiple process stages by splitting vapors between compressor stages enables the overall vapor-compression system to be tailored to individual process energy requirements and to accommodate dynamic fluctuations in process conditions.

A process and system for monitoring and controlling the operation of a dehydrogenation reactor is provided. Samples of hydrocarbon streams are taken at sampling locations to be analyzed at a single gas chromatograph or other analytical equipment. Actions can be taken to modify the operation of the dehydrogenation reactor as necessary to maintain its operation within predetermined parameters. In particular, actions may be taken when a hydrocarbon stream exhibits an amount of cracking that is outside parameters. It is usually intended that actions will be taken on a gradual basis once or twice per day to reduce the cost of the process while still providing the necessary changes to operations.

A process and system for monitoring and controlling the operation of a dehydrogenation reactor is provided. Samples of hydrocarbon streams are taken at sampling locations to be analyzed at a single gas chromatograph or other analytical equipment. Actions can be taken to modify the operation of the dehydrogenation reactor as necessary to maintain its operation within predetermined parameters. In particular, actions may be taken when a hydrocarbon stream exhibits an amount of cracking that is outside parameters. It is usually intended that actions will be taken on a gradual basis once or twice per day to reduce the cost of the process while still providing the necessary changes to operations.

This disclosure provides systems and methods that utilize integrated mechanical vapor or thermal vapor compression to upgrade process vapors and condense them to recover the heat of condensation across multiple processes, wherein the total process energy is reduced. Existing processes that are unable to recover the heat of condensation in vapors are integrated with mechanical or thermal compressors that raise vapor pressures and temperatures sufficient to permit reuse. Integrating multiple processes permits vapor upgrading that can selectively optimize energy efficiency, environmental sustainability, process economics, or a prioritized blend of such goals. Mechanical or thermal vapor compression also alters the type of energy required in industrial processes, favoring electro-mechanical energy which can be supplied from low-carbon, renewable sources rather than combustion of carbonaceous fuels.

Methods of preparing unsaturated compounds or analogs through dehydrogenation of corresponding saturated compounds and/or hydrogenation of aromatic compounds are disclosed.

Methods of preparing unsaturated compounds or analogs through dehydrogenation of corresponding saturated compounds and/or hydrogenation of aromatic compounds are disclosed.

The present invention utilizes mechanical vapor compression and/or thermal vapor compression integrating compression loops across multiple process stages. A sequential network of compressors is utilized to increase the pressure and condensing temperature of the vapors within each process stage, as intra-vapor flow, and branching between process stages, as inter-vapor flow. Because the vapors available are shared among and between compressor stages, the number of compressors can be reduced, improving economics. Balancing vapor mass flow through incremental compressor stages which traverse multiple process stages by splitting vapors between compressor stages enables the overall vapor-compression system to be tailored to individual process energy requirements and to accommodate dynamic fluctuations in process conditions.

The present invention utilizes mechanical vapor compression and/or thermal vapor compression integrating compression loops across multiple process stages. A sequential network of compressors is utilized to increase the pressure and condensing temperature of the vapors within each process stage, as intra-vapor flow, and branching between process stages, as inter-vapor flow. Because the vapors available are shared among and between compressor stages, the number of compressors can be reduced, improving economics. Balancing vapor mass flow through incremental compressor stages which traverse multiple process stages by splitting vapors between compressor stages enables the overall vapor-compression system to be tailored to individual process energy requirements and to accommodate dynamic fluctuations in process conditions.

Provided are: a catalyst that is used in a reaction for producing hydrogen from an alkane without emitting CO.sub.2; a method of producing hydrogen without emitting CO.sub.2 by using the catalyst; and a method of producing ammonia using, as a reducing agent, hydrogen produced using the catalyst. The alkane dehydrogenation catalyst according to the present disclosure contains a graphene having at least one type of structure selected from an atomic vacancy structure, a singly hydrogenated vacancy structure, a doubly hydrogenated vacancy structure, a triply hydrogenated vacancy structure, and a nitrogen-substituted vacancy structure. The graphene preferably has from 2 to 200 of the structure approximately per 100 nm.sup.2 of the atomic film of the graphene. In addition, the hydrogen production method according to the present disclosure includes extracting hydrogen from an alkane by using the alkane dehydrogenation catalyst.