confused

[marek.podyma]

we said the gas is at 09*101325 Pa but the gas only exerts a pressure of 4m*9.81*1.04 = 40.8Pa in the tank. could someone explain (maybe i'm confusing gauge Pressure with the combined pressure)

[Lei Chen]

gas is not liquid. It is related by PV=nRT. there will be certain amount of residue gas in the top which maintain the pressure at 0.9atm. If more gas is being produced. the pressure will increase, then the blower will operated and blow out the extra gas. So ideally, smaller the header space the fast the start up for gas production.

[LEIcl_nn2006]

City will be divided into 4 equal sections. SSO will be collected from each section on a weekly basis at different day of the week. All SSO collects on one day must be processed during the 8 hour of working hour. Treated SSO will be collected in buffer tank first.

There will be 2 injections per day for buffer tank to digester, 1 hour to complete each injection. Through, Biogas reinjection will be every 15 min and biogas will be produced constantly,  however there they are assume to by synchronized with the feed injection for simplicity. 10% of the heat carry by water is used to maintain digester at 35^oC.

Constant gas flow from gas tank is assumed. Fertilizer loading must be able to fill 34 m3 tanker trucks (largest tanker truck) in 2 hour.  Therefore, 17000kg/hour

Constant gas flow Assume.  Constant electricity produces.  W-2 is only running 10 hour /day (hours pasteurization tank will be operated.  W-4 is the by-pass water steam when W-1, W-2, W-3 don’t operate.

I have not fully incorporate the heat exchanger system into the PFD and the process

For more information see Updated PFD document and Heat exchanger in P&ID file.