Methods and systems for removing contaminants, such as water and/or carbon dioxide, from a gas stream, such as a natural gas stream or a flue gas stream. One or more solid-tolerant heat exchangers are employed to chill the gas stream to a temperature at which the contaminants solidify. The solidified contaminants may then be separated and removed from the gas stream. In one or more aspects, the one or more solid-tolerant heat exchangers may include a scraped heat exchanger.

A process for treating effluent streams in a renewable transportation fuel production process is described. One or more of the sour water stream and an acid gas stream are treated directly in thermal oxidation section. The process allows the elimination or size reduction of a sour water stripper unit, waste water treatment plant, and sulfur recovery unit.

A system for recovering natural gas liquid from a source, comprising: a heat exchanger for cooling wellstream fluid directed therethrough; a first separator for receiving the fluid from the heat exchanger for separating liquid and gas; in a first configuration, the gas from the first separator being directed to a turbo-expander for reducing the temperature and pressure of the gas to form a cold fluid; the cold fluid being directed to a second separator for separating liquid and gas; gas from the second separator being directed to the heat exchanger where it flows therethrough for cooling the wellstream fluid; wherein if the turbo-expander is not operating, the first configuration may be a changed to a second configuration to bypass the turbo-expander and direct the gas from the second separator to a Joule-Thomson valve to form the cold fluid.

The processes disclosed herein are environmentally friendly technologies to produce biocarbon products with low water intensity as well as low carbon intensity. Some variations provide a low-water-intensity process for producing a biocarbon product, comprising: providing a starting feedstock comprising biomass and water; drying the starting feedstock to generate a dried feedstock and a first vapor; pyrolyzing the dried feedstock to generate hot solids and a second vapor; condensing the first vapor to generate a first condensed liquid having a first pH from about 1 to about 7; condensing the second vapor to generate a second condensed liquid having a second pH from about 1 to about 7; forming acid water comprising the first condensed liquid, the second condensed liquid, or a mixture thereof; washing and cooling the hot solids using the acid water, to generate washed, cooled solids; and recovering the washed, cooled solids as a low-water-intensity biocarbon product.

A method is provided for reprocessing a petroleum-based waste oil feedstock into diesel fuel. The method includes forming a treated feedstock by (a) filtering the feedstock, thereby removing solids and metals from the feedstock, and (b) dehydrating the feedstock; vaporizing the treated feedstock to produce an oil vapor; passing the oil vapor through at least one catalyst bed and subsequently through a cooler, thereby converting the oil vapor to a hydrocarbon liquid product with a diesel product boiling point range; and removing contaminants from the hydrocarbon liquid product, wherein the contaminants are selected from the group consisting of particulates and color precursors.

A distillation apparatus for use in microwave-assisted pyrolysis includes a microwave, a pyrolysis reactor, a microwave-absorbent bed, and a condenser. The pyrolysis reactor is located within the microwave and configured to receive a liquid input stream and to output a vapor. The microwave-absorbent bed is located within the pyrolysis reactor that converts microwave energy provided by the microwave to thermal energy to initiate pyrolysis within the pyrolysis reactor, wherein the pyrolysis reactor provides a vapor output. The condenser is configured to receive the vapor output of the pyrolysis reactor and to cool and condense the vapor into a recoverable product.

Solvent consumption in supercritical ethanol, propanol or butanol treatment of either refined pre-extracted lignin or comparatively impure lignin-rich solid residual from hydrothermally pretreated lignocellulosic biomass can be minimized by conducting the reaction at very high loading of lignin to solvent. Comparatively impure, crude lignin-rich solid residual can be directly converted by supercritical alcohol treatment to significantly diesel-soluble lignin oil without requirement for pre-extraction or pre-solubilisation of lignin or for added reaction promoters such as catalysts, hydrogen donor co-solvents, acids, based or H2 gas. O:C ratio of product oil can readily be obtained using crude lignin residual in such a process at levels 0.20 or lower.

Systems and methods of producing a solid fuel composition are disclosed. In particular, systems and methods for producing a solid fuel composition by heating and mixing a solid waste mixture to a maximum temperature sufficient to melt the mixed plastics within the solid waste mixture is disclosed.

A subsea fluid processing system which receives a wellstream flow. The subsea fluid processing system includes a pressure control device which regulates a pressure of the wellstream flow, a gas-liquid separator unit which receives the wellstream flow downstream of the pressure control device and which provides a liquid stream and a gas stream, a first membrane separator which receives the gas stream and which provides a retentate stream and a permeate stream, a compressor which receives the permeate stream and which provides a compressed permeate stream, and a discharge cooler which receives the compressed permeate stream and which provides a cooled compressed permeate stream for injection into a subsurface reservoir. A density of the cooled compressed permeate stream is higher than a density of the compressed permeate stream.

Various illustrative embodiments of a system and process for recovering high-quality biomethane and carbon dioxide product streams from biogas sources and utilizing or sequestering the product streams are provided. The system and process synergistically yield a biomethane product which meets gas pipeline quality specifications and a carbon dioxide product of a quality and form that allows for its transport and sequestration or utilization and reduction in greenhouse gas emissions. The system and process result in improved access to gas pipelines for products, an improvement in the carbon intensity rating of the methane fuel, and improvements in generation of credits related to reductions in emissions of greenhouse gases.