50 L CO is mixed with 10 L O2 to form CO2. The reaction goes to the maximum extent and the volumes are measured under identical conditions. What is the volume of each of the gases on completion of the reaction?
CO O2 CO2
(a) 40 0 20
(b) 30 0 20
(c) 30 5 15
(d) 0 10 15
Answers
Answer:
2.3.2 Oxy-combustion
Complete combustion of hydrocarbons (without impurities) in the presence of enough oxygen produces water vapor and carbon dioxide. Separation of water vapor from the gas stream is simple; condensation can provide the suitable separation. In precombustion technologies, combustion is made using pure oxygen (up to 97% purity); however, a small amount of nitrogen and argon remains. A big part of the exhaust gases is recycled in the boiler to maintain the usual temperature levels of pulverized coal (PC) without capture. This avoids full resizing of the boiler and its associated exchangers. The flow of uncycled CO2 still contains water vapor, impurities (particularly some NOx and SOx amounts that remain in the exhaust gas of scrubbing systems), and incondensable gases such as oxygen, nitrogen, and argon. The latter originates from the ASU (air separation unit) and parasite air entries due to the lack of a seal of the PC cycle (combustion chamber, deduster, gas-gas heater, etc.). The content of CO2 in these exhaust gases is about 75% (wet basis). The next step is to condense the water and purify the CO2 until it is 99% pure so that it can be transported in the supercritical state. A simple schematic of the oxy-combustion system is shown in Fig. 23.7 (Sadati et al., 2015; Kanniche et al., 2010).
