Described herein are processes and apparatus for the large-scale synthesis of boron nitride nanotubes (BNNTs) by induction-coupled plasma (ICP). A boron-containing feedstock may be heated by ICP in the presence of nitrogen gas at an elevated pressure, to form vaporized boron. The vaporized boron may be cooled to form boron droplets, such as nanodroplets. Cooling may take place using a condenser, for example. BNNTs may then form downstream and can be harvested.

Disclosed is a plant for the production of urea. The plant comprises conventional sections for synthesis and recovery, for evaporation and condensation, for urea finishing, and for dust scrubbing. According to the invention, an additional evaporation and condensation loop is introduced from and to the dust scrubbing section. This loop results in a more favorable energy consumption of the plant.

Disclosed is a plant for the production of urea. The plant comprises conventional sections for synthesis and recovery, for evaporation and condensation, for urea finishing, and for dust scrubbing. According to the invention, an additional evaporation and condensation loop is introduced from and to the dust scrubbing section. This loop results in a more favorable energy consumption of the plant.

The present invention relates to a device for isolating and cleaning contaminated components comprising a chamber, an entrance door through which components to be isolated and cleaned are introducible into the chamber, means configured to deliver washing solution into the chamber and onto the components to be cleaned, a drying system configured to dry the chamber as well as its content, wherein the device further comprises an exhaust filter system attached to the air exhaust of the chamber, the exhaust filter system comprising a pipe, at least one filter and a blower, the exhaust filter system being configured to be able to bring the chamber under a pressure lower than atmospheric pressure by means of the blower all the time the chamber is closed. The present invention also relates to a corresponding method for isolating and cleaning contaminated components with the aforementioned device.

A method for revamping a self-stripping urea plant comprising the installation of a new CO2-stripping synthesis section (6), wherein at least part of the aqueous urea solution (10) leaving said new section (6) is directed to the existing low pressure recovery section (4) of the self-stripping plant, by-passing the existing self-stripping high-pressure section (2) and medium pressure treatment section (3).

A method for revamping a self-stripping urea plant comprising the installation of a new CO2-stripping synthesis section (6), wherein at least part of the aqueous urea solution (10) leaving said new section (6) is directed to the existing low pressure recovery section (4) of the self-stripping plant, by-passing the existing self-stripping high-pressure section (2) and medium pressure treatment section (3).

Disclosed is a process for the integrated production of urea and melamine. A urea production zone produces a urea synthesis stream comprising urea, water and ammonium carbamate. This stream is subjected to processing, preferably involving stripping, so as to separate an aqueous urea stream from residual dissociated carbamate vapor comprising ammonia, carbon dioxide, and water. The urea is fed to a melamine synthesis zone and subjected to melamine forming conditions so as to form melamine and off-gas comprising carbon dioxide and ammonia. The dissociated carbamate vapor and the melamine off-gas are subjected to combined condensation so as to form a dilute melamine off-gas condensate.

The invention provides a method and a plant for producing urea ammonium nitrate (UAN). The method involves the use of a condensation section, optionally in combination with a medium pressure decomposition section, between the dissociation and neutralization sections. The invention further provides a method of modifying an existing UAN plant. The advantages of the process of the invention are that the emission of CO.sub.2 can be reduced, the plant capacity can be increased and the high capital expenditure needed for CO.sub.2 compression equipment is reduced.

The present invention provides a low pressure generating plasma reactor closed loop process, comprising: feeding a fresh feed gas flow and a fresh feed absorption liquid flow to a plasma reactor closed loop comprising a condenser, a liquid loop, a recycle gas loop, and a plasma generator; converting feed gas to reactive plasma products in the plasma generator; quenching and absorbing the reactive plasma products into an absorption liquid circulating in the liquid loop where the reactive plasma products react to form liquid reaction products, thereby generating low pressure in the closed loop; monitoring the composition and low pressure of the recycle gas loop and, if the pressure increases, adjusting the composition of the fresh feed gas flow and/or fresh feed absorption liquid flow to bring the composition of the feed gas towards stoichiometric ratio with the absorbed reactive plasma products; extracting circulating absorption liquid, containing the liquid reaction products, from the plasma reactor closed loop as a product flow. The present invention also provides a low pressure generating plasma reactor closed loop system, comprising a plasma generator, a condenser, a recycle gas loop, a liquid loop, and a pump.

Separation methods and systems for converting high concentrations of animal wastes and other nutrient-rich organic materials into nutrients and other useful products such as struvite and potassium struvite. Advantageously, the system and methods do not require the addition of external chemicals other than an acid and a base.