Abstract: Processes, systems, and associated control methodologies are disclosed that control the flow of biogas during the biogas cleanup process to create a more consistent flow of biogas through the digester, while also optimizing the output and efficiency of the overall renewable natural gas facility. In representative embodiments, a biogas buffer storage system may be used during the cleanup process to control the pressure and flow rate of biogas. The biogas buffer storage system may monitor and control the biogas flow rate to either bring down or increase the digester pressure, thereby maintaining a normalized biogas flow rate.

Abstract: Processes, systems, and associated control methodologies are disclosed that control the flow of biogas during the biogas cleanup process to create a more consistent flow of biogas through the digester, while also optimizing the output and efficiency of the overall renewable natural gas facility. In representative embodiments, a biogas buffer storage system may be used during the cleanup process to control the pressure and flow rate of biogas. The biogas buffer storage system may monitor and control the biogas flow rate to either bring down or increase the digester pressure, thereby maintaining a normalized biogas flow rate.

Abstract: In processes and systems utilizing a compressor to fill a vessel with gas, for example, in the filling of the fuel tank of a vehicle that operates on compressed natural gas (CNG), a number of advantages are realized by establishing independent control over the flow rate of gas discharged from the compressor, such as on the basis of the compressor discharge pressure, utilizing feedback from one or more gas pressure sensors. In representative embodiments, a detected or actual measured compressor discharge pressure can serve as a process variable, in a feedback control loop for regulating the output of the compressor.

Abstract: In processes and systems utilizing a compressor to fill a vessel with gas, for example, in the filling of the fuel tank of a vehicle that operates on compressed natural gas (CNG), a number of advantages are realized by establishing independent control over the flow rate of gas discharged from the compressor, such as on the basis of the compressor discharge pressure, utilizing feedback from one or more gas pressure sensors. In representative embodiments, a detected or actual measured compressor discharge pressure can serve as a process variable, in a feedback control loop for regulating the output of the compressor.

Abstract: Processes and systems are described, which provide important advantages in filling gas storage vessels, such as gas cylinders for the transport of compressed natural gas (CNG). For example, the flow of gas from the fill station may be terminated safely, using an auto-fill shut-off mechanism, without the risk of exceeding vessel pressure ratings and overall reduced risk of operator error. The automatic termination of flow can occur at a preselected pressure that may, for example, be set at a fixed value, or may otherwise be adjusted based on the local temperature at the time of the fill.