31  5,744,650  32  When  carbon  monoxide  is  of  negative  order,  in  order  to  have  an  intrinsically  stable  system,  a  disturbance  in  the  temperature  must  produce  a  smaller  percentage  increase  in  reaction  rate  than  the  percentage  increase  in  ~T  of  the  system.  As  used  herein.  "inlet  coolant  temperature"  refers  to  the  temperature  of  the  coolant  prior  to  entering  any  heat  transfer  means.  e.g  ..  internal  coils,  external  jackets.  shell  and  Design  of  the  heat  removal  equipment  is  an  important  aspect  of  controlling  the  reaction  partial  pressures  in  this  invention  where  the  process  is  operated  in  inverse  or  nega› tive  order  in  carbon  monoxide.  The  temperature  difference  between  the  reaction  product  fluid  temperature  and  the  inlet  coolant  temperature  should  be  small  to  provide  the  neces› sary  control.  The  lower  the  temperature  difference  the  better  It  is  normally  desirable  to  increase  the  temperature  dif› ference  between  the  reaction  temperature  and  the  reactor  cooling  means,  e.g.,  coolant.  so  that  the  equipment  size  can  be  minimized.  Some  have  disclosed  running  at  reactor  temperatures  hot  enough  to  generate  useful  steam  from  the  exothermic  heat  of  reaction.  A  typical  non-aqueous  triph› enylphosphine  system  will  have  a  temperature  difference  of  approximately  30°  C.  between  the  reaction  and  the  coolant.  If  instead  of  a  5°  C.  ~T  between  reaction  product  fluid  and  reaction  zone  coolant.  e.g.,  heat  exchanger.  the  ~T  was  20°  C ..  a  1  °  C.  increase  in  reactor  temperature  will  give  a  new  temperature  difference  between  reaction  product  fluid  and  reaction  zone  coolant.  e.g..  heat  exchanger.  of  21  °  C’.  Whereas  the  reaction  rate  increased  by  10%,  there  was  only  a  5%  (i.e.  ‰o)  increase  in  the  heat  removal  capability.  Since  more  heat  is  being  generated  than  is  being  removed.  the  reactor  would  continue  to  wann  until  some  action  is  taken  to  increase  the  heat  transfer  from  the  system  or  until  the  reactant(s)  were  exhausted.  As  an  illustration,  assume  a  reaction  is  only  dependent  on  reaction  temperature.  If  for  some  reason  the  reactor  tem› perature  increases  by  1  °  C  .•  the  reaction  rate  will  increase  by  approximately  10%  which  will  in  turn  generate  10%  more  heat.  If  nothing  is  changed  with  the  reaction  zone  cooler.  the  heat  removed  will  depend  on  the  new  AT  of  the  system.  If  the  original  AT  was  5°  C.,  the  new  AT  will  be  6°  C..  a  20%  (i.e.  $^{1}$/s)  increase  in  heat  removed  which  tends  to  drive  the  system  back  to  the  original  set  of  steady  conditions.  Higher  carbon  monoxide  partial  pressures  provide  desired  benefits  $_{in }$organopolyphosphite  modified  metal  catalysts  in  that  olefin  efficiency  losses  due  to  hydrogenation  may  be  reduced  and  the  dissociation  of  an  inhibiting  organomono› phosphite  from  the  catalyst  is  favored.  The  dissociated  or  uncoordinated  inhibiting  organomonophosphite  is  more  readily  hydrolyzed  and  the  hydrolysis  fragments  can  be  scrubbed  from  the  solution  as  disclosed  herein.  Higher  carbon  monoxide  partial  pressures  give  both  a  higher  lined  out  activity  and  lower  efficiency  losses  to  alkanes  since  the  higher  carbon  monoxide  partial  pressure  makes  it  a  more  effective  competitor  for  a  metal,  e.g.,  rhodium,  alkyl.  If  carbon  monoxide  reacts  with  the  metal.  e.g.,  rhodium.  alkyl,  the  acyl  precursor  of  the  aldehyde  is  obtained;  if  hydrogen  reacts  with  the  metal,  e.g  .•  rhodium.  alkyl.  the  corresponding  alkane  is  obtained.  However.  as  indicated  above.  operating  at  the  higher  carbon  monoxide  partial  pressures  where  hydroformylation  is  of  a  negative  order  significantly  com› plicates  control  of  partial  pressures.  35  wherein  U  is  a  heat  transfer  coefficient  dependent  on  the  conditions  on  both  the  process  and  coolant  sides  of  the  equipment.  A  is  the  surface  area  available  for  heat  transfer,  and  ~Tis  the  appropriate  temperature  difference  between  the  reaction  product  fluid  temperature  and  inlet  coolant  tem› perature.  At  steady  state,  The  cycling  may  be  initiated  when  operating  under  con› ditions  were  the  rate  $_{of }$hydroformylation  is  inverse  order  in  carbon  monoxide.  These  conditions  are  not  normally  encountered  with  conventional  triphenylphosphine- modified  metal  catalysts  since  the  region  where  carbon  monoxide  is  of  negative  rate  order  is  also  a  region  which  gives  lower  isomer  ratios  and  increased  catalyst  deactiva› tion.  $_{Conventional }$triphenylphosphine-modified  metal  cata› lysts  typically  operate  under  conditions  where  increasing  carbon  monoxide  partial  pressure  increases  reaction  rate  and  conversely  decreasing  carbon  monoxide  partial  pressure  decreases  rate.  Removal  of  heat  from  a  system  is  described  by  the  following  equation:  Most  chemical  reactions  are  affected  by  temperature.  and  by  some  or  all  of  the  reactant  concentrations.  If  a  catalyst  is  used.  its  concentration  also  will  affect  the  reaction  rate.  In  most  circumstances  it  is  desirable  to  control  the  conditions  in  the  reactor  at  some  steady  state.  Changes  in  conditions  may  cause  undesirable  changes  in  selectivity.  catalyst  per- formance  or  other  operational  difficulties.  Temperature  has  an  exponential  effect  on  $_{the }$hydroformylation  reaction  rate.  A  change  in  reaction  temperature  of  10°  C.  typically  doubles  the  rate  of  reaction.  If  the  reaction  rate  increases,  the  heat  generated  increases,  and  the  extra  heat  must  be  removed  to  keep  the  temperature  from  continuing  to  increase.  Continuous  stirred  tank  reactors  used  for  exothermic  reactions  must  have  some  means  of  removing  the  heat  of  reaction  from  the  reactor.  The  cooling  can  be  accomplished  in  a  number  of  ways.  putting  a  cooling  jacket  around  the  reactor,  installing  cooling  coils  in  the  reactor.  or  pumping  the  reactor  solution  through  an  external  heat  exchanger.  In  all  cases  the  driving  force  for  the  heat  removal  is  the  tempera› ture  difference  between  the  reaction  product  fluid  and  the  reactor  zone  coolant.  the  control  will  be.  For  hydroformylation  in  regions  where  the  reaction  is  of  a  negative  order  in  carbon  monoxide.  the  difference  should  be  below  25°  C.  and  more  preferably  below  20°  C.  Temperature  difference  below  15  °  C.  may  be  achieved  using  heat  transfer  means  such  as  evaporative  cooling.  enhanced  heat  transfer  or  larger  equipment.  Hydroforrnylation  reaction  rate  may  cycle  during  continu› ous  operation  in  a  continuous  stirred  tank  reactor  as  may  carbon  monoxide  partial  pressure.  hydrogen  partial  pressure.  total  reaction  pressure,  hydroformylation  reaction  rate  and/  or  temperature  if  one  $_{is }$hydroformylating  under  conditions  where  the  reaction  is  of  negative  or  inverse  order  in  carbon  monoxide.  Cycling  conditions  disrupt  steady  operation  of  the  unit.  U  niforrn  partial  pressures  and  temperature  are  desired.  As  used  herein.  "cycling"  refers  to  frequent  periodic  and  extreme  changes  in  process  parameters,  e.g  .•  reaction  rate.  reaction  temperature.  total  reaction  pressure.  carbon  monoxide  partial  pressure,  hydrogen  partial  pressure  and  total  reaction  pressure.  during  $_{the }$hydroformylation  process.  carbon  monoxide  in  order  to  dissociate  inlubiting  complex  and/or  prevent  or  lessen  coordination  of  the  organomono› phosphite  ligand  with  $_{the }$metal-organopolyphosphite  ligand  complex  catalyst  and  facilitate  its  hydrolysis,  then  the  hydroforrnylation  is  operated  in  a  reaction  region  where  control  of  carbon  monoxide  partial  pressure.  hydrogen  par› tial  pressure.  total  reaction  pressure.  hydroformylation  reac› tion  rate  and/or  temperature  is  more  difficult.  Heat  Removed=UMT  Heat  Removed=Heat  Generated  by  the  reaction. 