A process to recover energy, reduce pollution potential, and add value to organic waste such as animal manure is described. The process involves the anaerobic digestion of feedstocks, such as animal manure, at low to high temperatures in batch, semi-continuous or continuous reactors. The process makes use of existing handling and storage equipment at the farm and requires minimal supervision and skill by the operator. The system is not affected by high concentrations of volatile acids and ammonia or nitrogen. The productivity of the anaerobic digester system, in terms of methane a gas production and quality, is exceptionally high. The anaerobic digester requires only a singe reaction vessel. Consequently, the process is low cost and does not interfere with regular farm operations.

Anaerobic digester system

A process to recover energy, reduce polluction potential, and add value to organic waster such as animal manure is described. The process involves the anaerobic digestion of feedstocks, such as animal manure, at low to high temperatures in batch, semi-continous or continuous reactors. The process makes use of existing handling and storage equipment at the farm and requires minimal supervision and skill by the operator. The system is not affected by high concentrations of volatile acids and ammonia or nitrogen. The productivity of the anaerobic digester system, in terms of methane gas production and quality, is exceptionally high. The anaerobic digester employs plural pressurizable anaerobic digesters connected in parallel. Consequently, the process is scaleable, low cost and does not interfere with regular farm operations.

Integrated anaerobic digester system

The invention is an improved controlled natural purification system for an advanced wastewater treatment and protein conversion and recovery. The system provides for treating municipal wastewater and associated organic industrial discharges anaerobically and aerobically. The system consists of such treatments in a tank complex where the waste organics are reduced to inorganic forms available for microalgae culture in tanks uniquely designed for rapid growth. The system includes a recovery mechanism to recover the algae for food purposes. Utilizing organic wastewater as the renewable resource, the system has the potential to develop from a wastewater treatment process that removes excess nutrients, producing reusable water and a commercially valuable algal by-product, to large scale algae farming cost-effectively producing millions of tons per year of sterile, stable, high protein algal foodstuff.

Controlled natural purification system for advanced wastewater treatment and protein conversion and recovery

Methane gas produced according to an anaerobic digestion of organic wastes is introduced into digested separated water which is alkalized by a photo-culture of algae, whereby impurity carbon dioxide gas is removed by absorption. Accordingly, methane of high concentration is recovered and at the same time, by-product algae is recycled as feedstock, and thereby improving the yield of methane.

Anaerobic digestion process

Integrated waste treatment and fertilizer and feed supplement production methods to be implemented at organic waste source sites, at remote treatment sites, or partially at the organic waste source site and at a remote location, whether in small or large scale operations. The methods are suitable for retrofitting existing organic waste sources and for treating the organic waste generated by a single source or by a plurality of sources. These methods provide: Reduction or elimination of emissions of acrid and greenhouse gases; effluents that meet discharge standards and that can be used in wetland and irrigation projects; organic based, granular, slow release NPK fertilizer of standard composition and size that can be supplemented with micronutrients and soil amendment materials and whose composition can be adjusted to meet demands and needs of specific markets; methane-rich biogas recovery for its subsequent use for heating, for power generation or for catalytic and synthetic processes, and feed supplement including feed supplement for cattle. The methods comprise steps for thoroughly separating suspended and dissolved materials, preventing gas emissions and capturing gases, and minimizing waste disposal. Fertilizer base is produced by mixing waste with at least one of a phosphate precipitating agent, a base, a flocculant, and optionally with an ammonia retaining agent and a densifier, subsequently separating and drying the precipitate. Pathogen-free, odor-free and dust-free fertilizer is obtained by temperature controlled incineration.

Methods for producing fertilizers and feed supplements from agricultural and industrial wastes

Conventional anaerobic digestion, as practiced in municipal waste treatment plants, is modified to yield high-quality methane gas. Upwards of 98 percent methane is produced rather than the normal 60 to 70 percent methane (diluted with carbon dioxide). The process, wherein digestion is conducted under several atmospheres of pressure, involves the application of Henry's Law. Digesting sludge is used as a scrubbing agent. According to one system a recirculation loop features pressure release and degassing of carbon dioxide. Degassed sludge is then pumped, under pressure, back into a digestion tank. The recirculation rate is designed to maintain sludge in the digester in an unsaturated state with regard to carbon dioxide solubility. This keeps the carbon dioxide from precipitating out of the sludge within the digestion tank and results in high purity methane production. Another system accomplishes similar results by periodically depressurizing the digestion tanks to allow carbon dioxide to escape. This configuration requires no recirculation for degassification.

High quality methane gas through modified anaerobic digestion

Interruption of algal-bacterial symbiosis by high-intensity light permits increased algae production.

Unbalanced culture method of algae production

The present invention relates to the manufacture of high calorific fuel gas through a process of anaerobic digestion involving retention of a slurry of organic material, maintained at a predetermined volume-to-interface (V/I) ratio and for a desired liquid retention time, pH and temperature to produce substantial amounts of methane gas while minimizing the production of carbon dioxide gas. When operating in the preferred range of volume-to-interface (V/I) relationships, the faster molecular diffusion rate of methane from the slurry as compared with carbon dioxide gas allows virtually all of the methane to be collected from the slurry while a considerably smaller amount of carbon dioxide gas is collected. Instead, the bulk of the carbon dioxide remains in the spent slurry which is transferred as sludge to a loop for carbon dioxide stripping. Liquid retention is controlled by a recirculation-stripping loop. Stripping of the carbon dioxide from the sludge in this loop is greatly improved by adjustment of pH with acid.

Jay E. Ort

Papers

High quality methane gas through modified anaerobic digestion

Unbalanced culture method of algae production

Anaerobic digestion process