Fouling of an MMA process is reduced by strategically removing an aqueous slip stream.

A catalyst and corresponding methods of using a catalyst are provided that can be beneficial for conversion of paraffins into a product stream enriched in aromatics and/or methane while reducing or minimizing the content of ethane in the product stream. Such catalysts and methods can be useful, for example, for processing a raw gas, associated gas, tail gas, natural gas, or other type of methane-containing feed stream to convert C.sub.2+ hydrocarbons in the stream to heavier hydrocarbons and methane while reducing or minimizing content of ethane in the products from the conversion reaction. Such conversion can be useful for upgrading a methane-containing feed stream to have an energy content that is suitable for pipeline transport under one or more specifications for transport of natural gas. The catalyst and corresponding method can also be beneficial when used as a second stage catalyst in a configuration involving multiple conversion stages.

Provided is a methanol plant that can obtain fresh water from sea water by using, in a seawater desalination device, the exhaust heat discharged in a step for producing methanol from natural gas. The methanol plant is provided with: a heat exchanger (4) that recovers into a thermal medium (for example, seawater) the exhaust heat discharged from a step for producing methanol from a feed stock (for example, natural gas); and a seawater desalinization device (6) that obtains freshwater from seawater using the exhaust heat recovered by means of the thermal medium.

Plant for the synthesis of melamine starting from urea, wherein the stream of offgas containing NH3 and CO2 produced by the synthesis of melamine is converted into urea in a dedicated urea plant.

The present invention provides an improved process for removing heat from an exothermic reaction. In particular, the present invention provides a process wherein heat can be removed from multiple reaction trains using a common coolant system.

A method and an apparatus for preparing an alpha-olefin. The method includes supplying a feed stream including a gaseous ethylene monomer to a monomer dissolution device to dissolve the feed stream in a solvent and form a liquid ethylene monomer, and supplying a feed stream including the liquid ethylene monomer as a discharge stream to a reactor, thereby removing heat of dissolution of the gaseous ethylene monomer outside of the reactor, and decreasing an amount of a refrigerant used in an alpha-olefin production process to improve economic feasibility.

Digestion of cellulosic biomass solids may be complicated by release of lignin therefrom. Methods and systems for processing a reaction product containing lignin-derived products, such as phenolics, can comprise hydrotreating the reaction product to convert the lignin-derived products to desired higher molecular weight compounds. The methods can further include separating the higher molecular weight compounds from unconverted products, such as unconverted phenolics, and recycling the unconverted phenolics for use as at least a portion of the digestion solvent and for further conversion to desired higher molecular weight compounds with additional hydrotreatment.

According to the present invention, there is provided a polysilicon production apparatus including: a horizontal reaction tube having an inlet port through which gaseous raw materials including reactant gases and a reducing gas are supplied, an outlet port through which residual gases exit, a reaction surface with which the gaseous raw materials come into contact, and bottom openings through which molten polysilicon produced by the reactions of the gaseous raw materials is discharged; and first heating means adapted to heat the reaction surface of the horizontal reaction tube. The horizontal reaction tube includes reaction regions consisting of first reaction regions where polysilicon is deposited and second reaction regions where reaction by-products are converted to the reactant gases. The first reaction regions are connected in series with the second reaction regions. Also provided is a polysilicon production method using the polysilicon production apparatus.

Process and plant for producing hydrocarbon products from a feedstock originating from a renewable source, where a hydrogen-rich stream and on off-gas stream comprising hydrocarbons is formed. A portion of the hydrogen-rich stream is used as a recycle gas stream in a hydroprocessing stage for the production of said hydrocarbon products, and another portion may be used for hydrogen production, while the off-gas stream is treated to remove its H.sub.2S content and used as a recycle gas stream in the hydrogen producing unit, from which the hydrogen produced i.e. make-up hydrogen, is used in the hydroprocessing stage. The invention enables minimizing natural gas consumption in the hydrogen producing unit as well as steam reformer size.

A radio frequency (RF) hydrocarbon resource upgrading device may include a first hydrocarbon resource upgrading path that may include a plurality of first RF power applicator stages coupled in series. Each first RF power stage is configured to apply RF power to upgrade a hydrocarbon resource passing therethrough. The RF hydrocarbon resource upgrading device may also include a second hydrocarbon resource upgrading path that may include at least one second RF power applicator stage coupled in parallel with at least one of the first RF power applicator stages. The second RF power applicator stage is configured to apply RF power to upgrade the hydrocarbon resource passing therethrough.