The discovery of abundant natural gas resources has greatly increased the study of using methane as a feedstock to produce transportation fuels. Biogas (primarily containing methane and CO2), which is generated from waste biomass via anaerobic digestion or landfills, is regarded as a renewable source of methane, and has the potential to achieve sustainable production of transportation fuels. Since biogas also contains a significant amount of impurities (e.g., H2S, NH3, and siloxane), a cleaning procedure is generally required prior to conversion to transportation fuels. Physical approaches, mainly compression and liquefaction, have been commercially applied to upgrade biogas to bio-compressed natural gas (CNG) and liquefied biogas (LBG). For chemical approaches, catalytic reforming is the dominant method for converting methane to syngas, followed by Fischer–Tropsch synthesis (FTS) or fermentation of syngas to a variety of alcohols (e.g., methanol, ethanol, and butanol) and liquid hydrocarbon fuels (e.g., gasoline, diesel, and jet fuels). High purity hydrogen, a clean fuel, can also be produced via reforming. Methanol can be produced by direct oxidation of methane, while interest in the biological conversion of methane to methanol has grown recently due to its mild operating conditions, high conversion efficiency, and potential for using raw biogas. The derived methanol can be further converted to gasoline via a methanol to gasoline (MTG) process. This paper provides a comprehensive review of major research progress on technologies for converting biogas/methane into transportation fuels, and discusses the principles, kinetics, operating conditions, and performance of each technology. Efficient direct conversion of biogas into ethanol and higher alcohol fuels (e.g. butanol), which is envisaged to be the focus of research pursuits in the near future, is also discussed, with emphasis on the development of methane-utilizing microbes through genetic engineering.

Progress and perspectives in converting biogas to transportation fuels

Low sulfur gasoline of relatively high octane number is produced from a cracked, sulfur-containing olefinic naphthas by hydrodesulfurization followed by treatment over an acidic catalyst comprising an intermediate pore size zeolite such as zeolite ZSM-5 in combination with molybdenum. The use of the molybdenum in combination with the zeolite has been found to give improved catalytic activity coupled with lower coking, longer catalyst life and other advantages.

Gasoline upgrading process

Medium-load power generating plant with an integrated coal gasification plant, with a gas-turbine power generating plant part connected to the coal gasification plant, with a steam generating plant part connected to the raw-gas heat exchanger installation of the coal gasification plant, and with a methanol synthesis plant. The methanol synthesis plant has parallel-connected modules and is connected to the gas-turbine power generating plant part via a central purified gas distribution system which includes a purified gas continuous-flow interim storage plant connected parallel to the pure gas supply line and is connected on the gas side to the raw-gas heat exchanger installation.

Medium-load power-generating plant with integrated coal gasification plant

Low sulfur gasoline is produced from an olefinic, cracked, sulfur-containing naphtha by treatment over an acidic catalyst, preferably an intermediate pore size zeolite such as ZSM-5 to crack low octane paraffins and olefins under relatively mild conditions, with limited aromatization of olefins and naphthenes. This is followed by hydrodesulfurization over a hydrotreating catalyst such as CoMo on alumina. The initial treatment over the acidic catalyst removes the olefins which would otherwise be saturated in the hydrodesulfurization, consuming hydrogen and lowering product octane, and converts them to compounds which make a positive contribution to octane. Overall liquid yield is high, typically at least 90 % or higher. Product aromatics are typically increased by no more than 25 wt.% relative to the feed and may be lower than the feed.

Hydrocarbon upgrading process

The present invention relates to a process for catalytically converting a feedstock comprising an oxygenate to olefins utilizing a heat exchange device to transfer heat from at least a portion of an effluent of an oxygenate conversion reactor to the feedstock to cause at least a portion of the feedstock to vaporize.

Process for converting oxygenates to olefins with direct product quenching for heat recovery

A methanol-to-gasoline conversion process in which the conversion is conducted in a number of reactors which are fed directly by the charge, preferably in equal proportions. A diluent gas, preferably recycled light hydrocarbons separated from the product, is passed in sequence through each of the beds to carry away the heat of reaction. In this way, a high effective recycle ratio is maintained in each bed although the actual recycle ratio for the entire system is low.

Conversion of methanol to gasoline

There is provided a fluid catalytic cracking (FCC) process in which olefinic light gas produced in the FCC reactor unit (2), is separated from the FCC unit effluent (8). The separated light gas is then upgraded in a catalytic reactor (40) to increase gasoline production. By-product light parafinic gas (56) from reactor unit (40) is recycled to the FCC reactor as a lift gas (18).

Integrated catalytic cracking process with light olefin upgrading

A process for oligomerizing C2 to C10 olefins obtained by catalytic cracking of heavy crude oil is disclosed. The olefins are oligomerized in the presence of added hydrogen over a shape selective zeolite to gasoline and distillate products. Feed pretreatment, to remove basic nitrogen compounds present in light olefin stream in refinery, with water wash or a guard bed is practiced improves catalyst life.

Process for upgrading light olefinic streams

A process is disclosed for increasing the octane number of an FCC unit gasoline pool by upgrading selected gasoline boiling-range streams. FCC gasoline is mixed with the feed to a light olefin upgrading reactor. Upgraded gasoline is then fractionated in an existing FCC gas plant.

Upgrading of cracking gasoline

A catalytic conversion process for reacting lower aliphatic C 1 -C 4 oxygenates, such as methanol, to produce gasoline boiling range hydrocarbons. Improved cycle average gasoline yield is sustained without a substantial reduction in cycle average gasoline octane number by selectively programming the conversion reactor inlet temperature during a process cycle.

Sergei Yurchak

Papers

Conversion of methanol to gasoline

Integrated catalytic cracking process with light olefin upgrading

Process for upgrading light olefinic streams

Upgrading of cracking gasoline

Conversion of oxygenates to gasoline at variable inlet temperature