chem sulphur recovery

decrease temp

lcp - system partially counteract imposed change, increasing temp, favouring exo fwd rx, shift right until equilibrium re-established, increase yield but slow both rr.

increase temp

lcp - system partially counteract imposed change, decreasing temp, favouring endo reverse rx, shift left until equilibrium re-established, decrease yield but increase both rr.

increase pressure

lcp - system partially counteract imposed change, decreasing pressure, favouring fwd rx, shift right until equilibrium re-established, increase yield, both rr

decrease pressure

lcp - system partially counteract imposed change, increasing pressure, favouring reverse rx, shift left until equilibrium re-established, decrease yield, both rr

increase partial pressure of 2H2S(g) + SO2(g)

lcp - system partially counteract imposed change, decreasing partial pressure, favouring fwd rx, shift right until equilibrium re-established, increase yield

lcp

if an equilibrium system is subjected to change, the system will re-establish equilibrium to partially counteract the imposed change

decrease partial pressure of 2H2O(g)

lcp - system partially counteract imposed change, increasing partial pressure, favouring fwd rx, shift right until equilibrium re-established, increase yield

increase pressure

lcp - system partially counteract imposed change, decreasing pressure, favouring fwd rx, shift right until equilibrium re-established, increase yield, both rr

temp conditions for step 2 and why.

300-400°C. high temperature increase both rr, make more in less time. however, higher temp decreases yield as fwd rx is exo and equilibrium will shift left to counteract this change. higher temp increase energy cost, introduce inherent safety risks, increasing cost to maintain temperature. therefore, a compromise is made for the temperature and moderate temperature is used

pressure conditions for step 2 and why

179 kPa. high pressure increase both rr. lcp - system will act to partially reduce pressure of system by shifting right with less moles, increasing yield. therefore use high pressure to maximise efficiency & rate. however infinitely high pressure not used due to cost to maintain pressure and inherent safety risk introduced. 

add catalyst

catalyst increases rr by lowering ea through alternate rx pathway and is not consumed in rx, doesn’t affect position of equilibrium. Thus lower temp (ie lower ea) can be used to achieve faster rate, decreasing energy costs and safety risks, also increase yield