A process for recovering valuables from vent gas in polyolefin production is disclosed. The process includes a compression cooling separation step, a heavy hydrocarbon separation step, a light hydrocarbon separation step, a N.sub.2 purification step, and a turbo expansion step in sequence. The N.sub.2 purification step comprises a membrane separation procedure. The light hydrocarbon separation step comprises at least one gas-liquid separation procedure. A first gas, which is obtained by the gas-liquid separation procedure and is heated through heat exchange with multiple streams in the light hydrocarbon separation step, enters the heavy hydrocarbon separation step and is further heated; the heated first gas then enters the N.sub.2 purification step; a first generated gas, which is obtained by the membrane separation procedure of the N.sub.2 purification step, enters the heavy hydrocarbon separation step and the light hydrocarbon separation step in sequence, and is cooled through heat exchange with multiple streams in the heavy hydrocarbon separation step and the light hydrocarbon separation step; and then the cooled first generated gas enters the turbo expansion step. The energy consumption of a compressor can be greatly reduced. An external cooling medium with a temperature lower than an ambient temperature is not needed. The purity and recovery of N.sub.2 and hydrocarbons can be improved, which can facilitate reduction of energy consumption of a whole system, an investment, and a material consumption.

This invention relates to a vacuum air gap membrane distillation system for desalination purposes. More particularly, this invention relates to a membrane distillation system with multiple cells in which the system's flux is increased due to the temperature and pressure differential within the system. The configuration of the vacuum air gap membrane distillation system allows for latent heat within the system to be recycled effectively reducing the energy consumption of the system.

The present disclosure relates to a hybrid AD-DCMD desalination system, where two subsystems, such as AD and DCMD, are integrated synergistically to maximize freshwater production. The waste heat released from an AD condenser is used to drive the DCMD subsystem in a first configuration of the hybrid AD-DCMD system, while another configuration relies on the heat released due to an exothermic adsorption process in an adsorption bed. The DCMD subsystem is included to exploit the waste heat of the AD subsystem to enhance performance. In both these configurations, seawater is used to release the heat from the AD subsystem, which is then fed into the DCMD subsystem. The hybrid AD-DCMD system configurations demonstrate improved performance in terms of GOR, specific daily water production (SDWP), and freshwater cost reduction.

An air intake system for directing intake air to an internal combustion engine of a machine is disclosed. The air intake system may comprise an air compressor configured to increase a pressure of the intake air, and a membrane unit downstream of the air compressor and having a membrane with selectivity for siloxanes. The membrane may have a first side and a second side, and the first side may be exposed to a higher pressure than the second side when the air compressor is operating. The membrane may be configured to separate the intake air into a permeate that traverses the membrane from the first side to the second side, and a retenate that remains on the first side. The permeate may have a higher siloxane content than the retenate. The retenate may be directed to the internal combustion engine for combustion.