1. The Field of the Invention
The present invention relates to upflow anaerobic reactors that are designed for biodegradation of biodegradable matter and production of biogas therefrom. In particular, the present invention relates to apparatuses and methods for preventing clogging of the effluent line of an upflow anaerobic reactor.
2. The Relevant Technology
A bioreactor is a device that uses bacteria to promote biodegradation or “digestion” of organic waste materials into simple organics and gaseous biogas products. Biogas is typically a mixture of methane, carbon dioxide, hydrogen sulfide, and other volatile organic compounds. If produced in sufficient quantities, the methane gas can be used as a fuel.
A bioreactor can also be used to treat and detoxify organic waste matter and wastewater. Wastewater treatment has always been important, particularly in agricultural production and food processing, which produces wastewater containing high concentrations of organic matter.
Anaerobic digestion is one traditional method of treating wastewater containing high concentrations of organic matter. Anaerobic digestion removes large quantities of organic matter from the waste material and produces biogas as a useful byproduct. Anaerobic digestion is particularly suitable for wastewater containing high concentrations of organics, such as wastewater generated through agricultural production and processing.
Many attempts have been made to decompose organic waste using closed vessels. One type of closed vessel reactor that has shown high decomposition rates is the upflow anaerobic sludge blanket reactor. In this reactor, waste material is introduced into the bottom of the reactor and forced up through the vessel where it passes through a blanket of bacteria, which decompose the organic material and produces biogas that can be collected and used as a fuel.
To achieve high decomposition rates in an upflow bioreactor, the bacterial culture should be well established. Once the bacterial culture is well established, the upflow bioreactor can be operated continuously and a high rate of digestion can be maintained for an extended period of time (e.g., months or even years).