Gaseous carbon compounds can be converted to carbon neutral or negative products using biological processes to metabolise the gaseous carbon compounds or use thermochemical processes to convert gaseous carbon compounds to syngas followed by thermochemical or biological processes to produce products. The gaseous carbon compounds include a mixture of CO2 and CH4 from either a single source, or two or more different sources. Separate biological processes are incorporated to process different gaseous carbon compounds. A gaseous carbon compound produced as a by-product of one biological process can be used as at least part of the feedstock for another process. A renewable energy system can be provided to power equipment. A control system can be used to control flow of gaseous carbon compounds and reactants entering the entire carbon processing systems to provide mass balanced quantities of gaseous carbon compounds and reactants in each processing system and/or between processing systems.

A system for removing undesirable compounds from contaminated air includes a biofilter having an alkaline material introduction system and a fuzzy-logic based controller. A contaminant, such as hydrogen sulfide, is removed from contaminated air by passing the contaminated air through the biofilter.

The present invention provides a process of cultivating microalgae and a joint method of same jointed with denitration. During the microalgae cultivation, EM bacteria is added into the microalgae suspension. In the nutrient stream for cultivating microalgae, at least one of the nitrogen source, phosphorus source and carbon source is provided in the form of a nutrient salt. During the cultivation, the pH of the microalgae suspension is adjusted with nitric acid and/or nitrous acid. The joint method includes (1) a step of cultivating microalgae; (2) a separation step of separating a microalgae suspension obtained from step (1) into a wet microalgae (microalgae biomass) and a residual cultivation solution; and (3) a NOx absorbing/immobilizing step of denitrating an industrial waste gas with the residual cultivation solution obtained from step (2). The nutrient stream absorbed with NOx obtained from step (3) is used to provide nitrogen source to the microalgae cultivation of step (1).

The invention relates to a method of reducing carbon dioxide and metal-containing dust and, more particularly, to a method of simultaneously reducing carbon dioxide and metal-containing dust by passing an off-gas, which contains carbon dioxide or carbon dioxide and metal-containing dust, through a reactor in which a sulfur-oxidizing microorganism is grown using carbon dioxide as a carbon source to produce sulfuric acid, and producing metal sulfates (MeSO.sub.4) by reaction of the produced sulfur acid with metal components present in the off-gas.

Culture systems and methods of using same. The systems include a housing defining an inner space. The inner space includes a headspace and at least a portion of a reservoir. A surface for immobilizing cells is moveable between the headspace and the reservoir. The systems can be used for coculturing methanotrophs and phototrophs for processing biogas and wastewater, particularly from anaerobic digesters.

Provided are products of manufacture and methods for the removal of gaseous methane and carbon dioxide, for example, for the removal of environmental or atmospheric or anthropogenically produced gaseous methane and carbon dioxide. Products of manufacture as provided herein comprise living emission abolish filters (LEAFs) for the removal of methane and carbon dioxide, where the “living” component of the “emission abolish filter”, or biofilter, comprises a methane-capturing bioagent, optionally comprising halophilic methanotroph bacterium. Products of manufacture as provided herein are manufactured as arrays, sheets, microfibers and/or microbeads comprising immobilized living, active methane-capturing bioagents, optionally comprising halophilic methanotroph bacterium. In alternative embodiments, the methane-capturing bioagents are enclosed or immobilized in or onto a crystal gel matrix or a nanoshell. Products of manufacture as provided herein can replace gas flares, flare stacks or a gas combustion devices, or are used with a methane scrubbing system.

A biological desulfurization processing system is provided. The biological desulfurization processing system includes a desulfurization reaction tank and a culture tank of desulfurization bacteria. The culture tank of desulfurization bacteria is used for cultivating desulfurization bacteria and is connected to the desulfurization reaction tank. The desulfurization reaction tank includes a desulfurization reaction zone. The desulfurization reaction zone includes at least one desulfurization layer and at least one supporting layer, and the desulfurization layer and the supporting layer are stacked in a staggered manner. A biological desulfurization processing method is also provided.

Biodegradation media placed in, around, and/or above a methane source reduces the quantum of methane and other alkane gases such as ethane, propane, and butane released into the atmosphere under diverse and fluctuating environmental conditions over a sustainable and/or extended duration. Non-biodegradable material configured for methane biodegradation possesses enhanced drainage of precipitation, improved gas transmission and gas exchange, moisture retention, and a nutrient sustainability.

The present invention relates to a method of reducing carbon dioxide and air pollutants, and more particularly to a method of simultaneously reducing emissions of carbon dioxide and air pollutants, in which an off-gas containing carbon dioxide, SOx, and NOx is passed through a sulfur-oxidizing microorganism reactor, thereby converting carbon dioxide present in the off-gas into biomass, SOx into sulfate ions, and NOx into amino-N.

The invention present provides a method (and suitable apparatus) to convert biomass to ethanol, comprising gasifying the biomass to produce raw syngas; feeding the raw syngas to an acid-gas removal unit to remove at least some CO.sub.2 and produce a conditioned syngas stream; feeding the conditioned syngas stream to a fermentor to biologically convert the syngas to ethanol; capturing a tail gas from an exit of the fermentor, wherein the tail gas comprises at least CO.sub.2 and unconverted CO or H.sub.2; and recycling a first portion of the tail gas to the fermentor and/or a second portion of the tail gas to the acid-gas removal unit. This invention allows for increased syngas conversion to ethanol, improved process efficiency, and better overall biorefinery economics for conversion of biomass to ethanol.