NOVELTY - The method comprises plasma gasifying a feed material comprising waste to produce gasifier gaseous product comprising synthesis gas and a gasifier non-gaseous product, biologically converting carbon monoxide in a fermentation feed gas to produce a fermentation product gas, utilizing the fermentation product gas comprising hydrogen as fuel, separating microorganisms from the extracted portion of suspension to produce a sludge comprising separated microorganisms and a biomass-reduced effluent, and recycling the biomass-reduced effluent to the deep shaft reactor.    USE - The method is useful for converting a waste to energy, where the waste is agricultural waste, forestry waste, biomass, municipal solid waste, auto shredder residue, yard waste, industrial waste, coal, bitumen and/or coke (claimed), coal fines, coal mine waste, forestry products corn stover, bagasse, switchgrass and miscanthus, petcoke, heavy sludge, refinery tar, wood chips, used plastics and/or tires, biosolids including manure, timber and wood waste, corncobs, cotton plants, rice straw and other agricultural residues, and non-biomass waste selected from auto shredder residue including paper, construction debris, furniture and auto fluff.    ADVANTAGE - The method is capable of economically and safely converting waste to energy with increased flexibility in operation in an eco-friendly manner, produces minimal amounts of environmentally-undesirable slag, air emissions and water emissions, and avoids the contamination of the reactor due to undesirable microorganisms.    DETAILED DESCRIPTION - The method comprises plasma gasifying a feed material comprising waste to produce gasifier gaseous product comprising synthesis gas and a gasifier non-gaseous product, biologically converting carbon monoxide in a fermentation feed gas to produce a fermentation product gas, utilizing the fermentation product gas comprising hydrogen as fuel, separating microorganisms from the extracted portion of suspension to produce a sludge comprising separated microorganisms and a biomass-reduced effluent, recycling the biomass-reduced effluent to the deep shaft reactor, gasifying the sludge to produce additional gasifier gaseous product, utilizing the extracted suspension to produce methane gas via fermentation, combining the biomass in the extracted suspension with suitable substrates and fermenting to produce butanol, ethanol and acetone, extracting heat from the gasifier gaseous product utilizing the extracted heat for preheating oxidant and generating steam, and removing particulate from the gasifier gaseous product. The gasification is performed at a gasification temperature and a gasification pressure, and comprises introducing oxidant and feed material into a plasma gasifier. The carbon monoxide is obtained from the gasifier gaseous product. The carbon monoxide is biologically converted by introducing a fermentation feed gas into a deep shaft reactor, saturating a fluid with carbon monoxide gas by contacting the fluid with fermentation feed gas comprising carbon monoxide in a retention chamber under pressure, introducing the saturated fluid into the riser of the deep shaft reactor such that the suspension within the deep shaft reactor circulates about the divider flowing with a first linear velocity up the riser, passing over the top of the divider, flowing with a second linear velocity down the downcomer, vacuum degasifying a product gas from the headspace by suspension circulating from the top of the divider down into the downcomer becomes carbon monoxide-depleted, maintaining a desired level of total dissolved solids within the deep shaft reactor by continuously, periodically or semi-continuously removing an extracted portion of suspension from a top portion of the deep shaft reactor, extracting a carbon monoxide-depleted portion of suspension from a lower portion of the downcomer, adjusting the pH of the suspension to a pH of greater than 9 such that carbon dioxide is converted to soluble bicarbonate, forming a mixture comprising the fluid and the fermentation feed gas and increasing the pressure of the mixture, measuring the concentration of carbon monoxide in the fermentation product gas, and adjusting the volume of fermentation feed gas introduced into the deep shaft reactor. The deep shaft reactor contains a suspension comprising a liquid nutrient medium lacking a carbon source and photoactivated microorganisms for carrying out a water-gas shift reaction, has a vertical depth and a shaft width, and comprises a downcomer, a riser separated by a divider, and a headspace above a normal operating suspension fill line. The first linear velocity is greater than the second linear velocity. The separation of microorganisms from the extracted portion of suspension comprises ultra-filtration, micro-filtration, centrifugation, decanting and/or clarification. The saturation of the fluid comprises the biomass-reduced effluent. The majority of the biological conversion is performed in the absence of light. The introduction of the carbon monoxide-saturated fluid into the riser of the deep shaft reactor comprises injecting carbon monoxide-saturated fluid to locations within the riser via high pressure pumps and injection nozzles or sprayers. The concentration of carbon monoxide in the fermentation feed gas is introduced into the deep shaft reactor. The level of total dissolved solid is present in the deep shaft reactor such that the concentration of carbon monoxide in the fermentation product gas is maintained below a desired value, which is zero. The concentration of carbon monoxide is adjusted in the fermentation feed gas by combining the fermentation product gas with the fermentation feed gas as diluent. The vertical depth of the deep shaft reactor is 50-600m. The gasification temperature is greater than 2200 degrees C. The gasification pressure is atmospheric pressure. The fermentation product gas is utilized by increasing the purity of the hydrogen in the fermentation product gas, combusting the fermentation product gas, and electrochemically converting the hydrogen to electricity.    DESCRIPTION OF DRAWING(S) - The figure shows a flow diagram of a method for converting a waste to energy.