Dipac Associates

Other

Enertech Environmental, Inc.

Sgc Advisors, LLC

Norman L Dickinson

Kevin M Bolin

Brian Dooley

Edward Overstreet

Robert G Murray

Michael K Klosky

In the processes for treating municipal sewage and storm water containing biosolids to discharge standards, biosolids, even after dewatering, contain typically about 80% water bound in the dead cells of the biosolids, which gives biosolids a negative heating value. It can be incinerated only at the expense of purchased fuel. Biosolids are heated to a temperature at which their cell structure is destroyed and, preferably, at which carbon dioxide is split off to lower the oxygen content of the biosolids. The resulting char is not hydrophilic, and it can be efficiently dewatered and/or dried and is a viable renewable fuel. This renewable fuel can be supplemented by also charging conventional biomass (yard and crop waste, etc.) in the same or in parallel facilities. Similarly, non-renewable hydrophilic fuels can be so processed in conjunction with the processing of biosolids to further augment the energy supply.

Slurry dewatering and conversion of biosolids to a renewable fuel

A process for enhancing the fuel form, raising the energy content, and lowering the level of impurities of low rank coals and/or carbonaceous wastes, like Municipal Solid Waste (MSW), Refuse Derived Fuel (RDF), and sewage sludge, by providing the low rank fuel, carbonaceous waste, or mixtures thereof as a slurry in water of processable viscosity. This feed slurry is heated under pressure, usually in the presence of an alkali, to a temperature at which a significant physical and molecular rearrangement occurs, characterized by the splitting off of a substantial proportion of the oxygen bound in the low rank coal or carbonaceous waste as carbon dioxide. At these conditions, solid particles in the feed slurry lose much of their fibrous and hydrophilic character, and are broken up into smaller particles of char, resulting in a slurry of dramatically improved rheology, i.e., capable of a much higher solids concentration (or energy density) at processable viscosity. Simultaneously, cation and anion impurities, like sodium, potassium, chlorine, sulfur, nitrogen, toxic metals, and others, are significantly reduced in the resulting product char slurry fuel.

Efficient utilization of chlorine and/or moisture-containing fuels and

Disclosed is a method and system for recovering energy from low-grade fuels such as industrial, municipal and agricultural waste, low-grade carbonaceous fuels such as lignite and similar solid fuels in which the fuel is comminuted into small particles and slurried in water. The alkali content of the slurry is adjusted to be at least about equal to the chemical equivalent of the halogen content of the slurry and, following pressurization of the slurry, it is heated sufficiently so that the substantial portion of chemically bound oxygen in the fuel separates therefrom as carbon dioxide, leaving a slurry including char particles and dissolved impurities such as halogen salts. The char particles are removed from the slurry and reslurried with just enough halogen-free water to provide the slurry with the needed viscosity to maximize the energy density thereof. The char particles are then reacted with air at a temperature below their ignition value to convert the fuel value of the low-grade fuel into thermal energy which is then further used, for example, to drive a turbine.

Efficient utilization of chlorine and moisture-containing fuels

A pressurized combustion of slurries of low-cost, unbeneficiated solid fuels in the presence of steam and alkali in which sulfur oxide emissions are inherently low, emissions of nitrogen oxides controlled by the injection of a scavenging agent and emissions of particulates prevented by condensing steam on and around them. The combustion has applications to steam boilers, combined cycles and gas turbines, including steam injected (STIG) and intercooled steam injected (ISTIG) versions. Turbine blade and nozzle erosion and deposits are avoided by the effective wet separation of ash particles before reheating and expansion.

Pressurized wet combustion at increased temperature

A fuels conversion which consumes energy and produces an aqueous waste is combined with a pressurized wet combustion which charges the waste, converting its combustible contaminants to energy returned to the conversion, concurrently purifying the waste for use or disposal. The heating value of the contaminants may be supplemented by an extraneous fuel, using the waste as slurrying medium, so that the combination is made energy self-sufficient. Transfer of heat may be by direct contact between hot combustion products and fuel being converted. Other processes which produce aqueous waste and consume energy may similarly be combined with the wet combustion.

Combination of fuels conversion and pressurized wet combustion

Liquid wastes and solid wastes, which can be put into slurry form, have combustible constituents burned from them at supercritical temperature and subcritical pressure, with respect to water, resulting in purified water and, with the more concentrated wastes, recovery of valuable energy. Pressure makes possible the recovery of latent heat so that the dry heating value of the waste is made available. Consequently, relatively dilute wastes can be 'incinerated' without the consumption of auxiliary fuel.

Pressurized wet combustion of wastes in the vapor phase

In a continuous pressurized process for the combustion, in the presence of steam and alkali, of solid fuels charged as aqueous slurries, the improvements comprising the elevation of inlet zone temperature in an entrained phase reactor by recirculating hot solid products to the zone, maintaining increased temperature and/or reduced steam partial pressure in the reactor and/or utilizing contaminated water from an associated fuels processing apparatus as a source of slurry and/or reactor temperature control water. An embodiment suitable for a coal-fired gas turbine locomotive is described and illustrated.

Pollution-free pressurized combustion utilizing a controlled

A fuel efficient combination of pressurized combustion and compressed air energy storage in which combustion air compressors have excess capacity which is utilized, during off-peak periods, to charge an underground storage cavern. Air withdrawn from the cavern during peak periods is utilized as combustion air, freeing the turbines which drove the air compressors during the off-peak period to power generators producing peak load electricity.

Combination of supercritical wet combustion and compressed air energy

A continuous process for the combustion of solid fuels under conditions such that flue gas is essentially free of particulates and oxides of sulfur and nitrogen. Fuel is charged as an aqueous slurry and additional water condensed from the flue gas may be recycled to the pressurized combustion zone. Combustion is promoted both by water vapor and alkali added with the fuel slurry, while the alkali serves also to neutralize and remove sulfur in completely oxidized, or sulfate, form. Heat of combustion raises the temperature of the reactants above the critical temperature of water, forming a hot fluid from which useful heat is transferred. Under the pressure of the system, heat recovery results in condensation of water, retaining and slurry product ash and providing recycle water, which helps to control reaction temperature as well as to promote the combustion.

Pollution-free low temperature slurry combustion process utilizing the

A continuous process for the combustion of solid fuels in a fluidized bed of solid particles under conditions such that flue gas is essentially free of dust and oxides of sulfur and nitrogen. Fuel is charged as an aqueous slurry and additional water condensed from the flue gas is recycled to the combustion zone. Combustion is promoted both by water vapor and alkali added with fuel slurry, while the alkali serves also to neutralize and remove sulfur in completely oxidized, or sulfate, form. Useful heat is recovered from the hot gases leaving the combustion zone and, in some cases, from the fluidized bed itself. Under the pressure of the system recovery of heat results in condensation of water which serves to scrub dust from the flue gas, slurry product ash and furnish recycle water, which controls reaction temperature as well as promoting the combustion.

Pollution-free pressurized fluidized bed combustion utilizing a high

A continuous process for the combustion of solid fuels in the presence of an aqueous liquid phase under conditions such that oxides of nitrogen are not formed and oxides of sulfur and particles of ash are effectively prevented from contaminating the gaseous products released to the atmosphere. Fuel is charged as a slurry in alkaline aqueous solution and contacted with combustion air so that the catalytic properties of both water and alkali operate to permit rapid and complete combustion at comparatively low temperatures. Temperatures in the adiabatic reactor are, however, permitted to exceed the critical temperature of the liquid phase. Under the conditions of the process, formation of nitrogen oxides is negligible, sulfur in the fuel goes to sulfur trioxide which dissolves completely in the alkaline liquid phase which also retains particles of ash and unburned fuel. The resulting flue gas is essentially free from objectionable pollutants. Heat is made available at a temperature high enough to generate and superheat steam.

Growing community of inventors

Monte Sereno, CA, United States of America

Norman L Dickinson